diff --git a/Gulpfile.ts b/Gulpfile.ts
index ebedfd43c23..d7e20a557fd 100644
--- a/Gulpfile.ts
+++ b/Gulpfile.ts
@@ -128,7 +128,8 @@ const es2016LibrarySourceMap = es2016LibrarySource.map(function(source) {
 
 const es2017LibrarySource = [
     "es2017.object.d.ts",
-    "es2017.sharedmemory.d.ts"
+    "es2017.sharedmemory.d.ts",
+    "es2017.string.d.ts",
 ];
 
 const es2017LibrarySourceMap = es2017LibrarySource.map(function(source) {
diff --git a/Jakefile.js b/Jakefile.js
index fc2b6359355..2e5d660c4f1 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -71,6 +71,7 @@ var compilerSources = [
     "transformers/destructuring.ts",
     "transformers/ts.ts",
     "transformers/jsx.ts",
+    "transformers/esnext.ts",
     "transformers/es2017.ts",
     "transformers/es2016.ts",
     "transformers/es2015.ts",
@@ -107,6 +108,7 @@ var servicesSources = [
     "transformers/destructuring.ts",
     "transformers/ts.ts",
     "transformers/jsx.ts",
+    "transformers/esnext.ts",
     "transformers/es2017.ts",
     "transformers/es2016.ts",
     "transformers/es2015.ts",
@@ -301,7 +303,8 @@ var es2016LibrarySourceMap = es2016LibrarySource.map(function (source) {
 
 var es2017LibrarySource = [
     "es2017.object.d.ts",
-    "es2017.sharedmemory.d.ts"
+    "es2017.sharedmemory.d.ts",
+    "es2017.string.d.ts",
 ];
 
 var es2017LibrarySourceMap = es2017LibrarySource.map(function (source) {
diff --git a/package.json b/package.json
index 3bf9dbcff7b..ed77c9bd35f 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
     "name": "typescript",
     "author": "Microsoft Corp.",
     "homepage": "http://typescriptlang.org/",
-    "version": "2.1.0",
+    "version": "2.2.0",
     "license": "Apache-2.0",
     "description": "TypeScript is a language for application scale JavaScript development",
     "keywords": [
diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 112a53e88ec..3e65b547d5b 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -1139,8 +1139,8 @@ namespace ts {
             }
             else if (node.kind === SyntaxKind.ArrayLiteralExpression) {
                 for (const e of (<ArrayLiteralExpression>node).elements) {
-                    if (e.kind === SyntaxKind.SpreadElementExpression) {
-                        bindAssignmentTargetFlow((<SpreadElementExpression>e).expression);
+                    if (e.kind === SyntaxKind.SpreadElement) {
+                        bindAssignmentTargetFlow((<SpreadElement>e).expression);
                     }
                     else {
                         bindDestructuringTargetFlow(e);
@@ -1155,6 +1155,9 @@ namespace ts {
                     else if (p.kind === SyntaxKind.ShorthandPropertyAssignment) {
                         bindAssignmentTargetFlow((<ShorthandPropertyAssignment>p).name);
                     }
+                    else if (p.kind === SyntaxKind.SpreadAssignment) {
+                        bindAssignmentTargetFlow((<SpreadAssignment>p).expression);
+                    }
                 }
             }
         }
@@ -1550,7 +1553,7 @@ namespace ts {
                 const seen = createMap<ElementKind>();
 
                 for (const prop of node.properties) {
-                    if (prop.name.kind !== SyntaxKind.Identifier) {
+                    if (prop.kind === SyntaxKind.SpreadAssignment || prop.name.kind !== SyntaxKind.Identifier) {
                         continue;
                     }
 
@@ -1916,6 +1919,9 @@ namespace ts {
                     return bindParameter(<ParameterDeclaration>node);
                 case SyntaxKind.VariableDeclaration:
                 case SyntaxKind.BindingElement:
+                    if ((node as BindingElement).dotDotDotToken && node.parent.kind === SyntaxKind.ObjectBindingPattern) {
+                        emitFlags |= NodeFlags.HasRestAttribute;
+                    }
                     return bindVariableDeclarationOrBindingElement(<VariableDeclaration | BindingElement>node);
                 case SyntaxKind.PropertyDeclaration:
                 case SyntaxKind.PropertySignature:
@@ -1929,8 +1935,21 @@ namespace ts {
                 case SyntaxKind.EnumMember:
                     return bindPropertyOrMethodOrAccessor(<Declaration>node, SymbolFlags.EnumMember, SymbolFlags.EnumMemberExcludes);
 
+                case SyntaxKind.SpreadAssignment:
                 case SyntaxKind.JsxSpreadAttribute:
-                    emitFlags |= NodeFlags.HasJsxSpreadAttributes;
+                    let root = container;
+                    let hasRest = false;
+                    while (root.parent) {
+                        if (root.kind === SyntaxKind.ObjectLiteralExpression &&
+                            root.parent.kind === SyntaxKind.BinaryExpression &&
+                            (root.parent as BinaryExpression).operatorToken.kind === SyntaxKind.EqualsToken &&
+                            (root.parent as BinaryExpression).left === root) {
+                            hasRest = true;
+                            break;
+                        }
+                        root = root.parent;
+                    }
+                    emitFlags |= hasRest ? NodeFlags.HasRestAttribute : NodeFlags.HasSpreadAttribute;
                     return;
 
                 case SyntaxKind.CallSignature:
@@ -2495,9 +2514,9 @@ namespace ts {
             transformFlags |= TransformFlags.AssertTypeScript;
         }
 
-        if (subtreeFlags & TransformFlags.ContainsSpreadElementExpression
+        if (subtreeFlags & TransformFlags.ContainsSpreadExpression
             || isSuperOrSuperProperty(expression, expressionKind)) {
-            // If the this node contains a SpreadElementExpression, or is a super call, then it is an ES6
+            // If the this node contains a SpreadExpression, or is a super call, then it is an ES6
             // node.
             transformFlags |= TransformFlags.AssertES2015;
         }
@@ -2526,7 +2545,7 @@ namespace ts {
         if (node.typeArguments) {
             transformFlags |= TransformFlags.AssertTypeScript;
         }
-        if (subtreeFlags & TransformFlags.ContainsSpreadElementExpression) {
+        if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
             // If the this node contains a SpreadElementExpression then it is an ES6
             // node.
             transformFlags |= TransformFlags.AssertES2015;
@@ -2541,10 +2560,13 @@ namespace ts {
         const operatorTokenKind = node.operatorToken.kind;
         const leftKind = node.left.kind;
 
-        if (operatorTokenKind === SyntaxKind.EqualsToken
-            && (leftKind === SyntaxKind.ObjectLiteralExpression
-                || leftKind === SyntaxKind.ArrayLiteralExpression)) {
-            // Destructuring assignments are ES6 syntax.
+        if (operatorTokenKind === SyntaxKind.EqualsToken && leftKind === SyntaxKind.ObjectLiteralExpression) {
+            // Destructuring object assignments with are ES2015 syntax
+            // and possibly ESNext if they contain rest
+            transformFlags |= TransformFlags.AssertESNext | TransformFlags.AssertES2015 | TransformFlags.AssertDestructuringAssignment;
+        }
+        else if (operatorTokenKind === SyntaxKind.EqualsToken && leftKind === SyntaxKind.ArrayLiteralExpression) {
+            // Destructuring assignments are ES2015 syntax.
             transformFlags |= TransformFlags.AssertES2015 | TransformFlags.AssertDestructuringAssignment;
         }
         else if (operatorTokenKind === SyntaxKind.AsteriskAsteriskToken
@@ -2578,6 +2600,11 @@ namespace ts {
             transformFlags |= TransformFlags.AssertTypeScript | TransformFlags.ContainsParameterPropertyAssignments;
         }
 
+        // parameters with object rest destructuring are ES Next syntax
+        if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+            transformFlags |= TransformFlags.AssertESNext;
+        }
+
         // If a parameter has an initializer, a binding pattern or a dotDotDot token, then
         // it is ES6 syntax and its container must emit default value assignments or parameter destructuring downlevel.
         if (subtreeFlags & TransformFlags.ContainsBindingPattern || initializer || dotDotDotToken) {
@@ -2811,6 +2838,11 @@ namespace ts {
                 transformFlags |= TransformFlags.AssertES2017;
             }
 
+            // function declarations with object rest destructuring are ES Next syntax
+            if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+                transformFlags |= TransformFlags.AssertESNext;
+            }
+
             // If a FunctionDeclaration's subtree has marked the container as needing to capture the
             // lexical this, or the function contains parameters with initializers, then this node is
             // ES6 syntax.
@@ -2848,6 +2880,12 @@ namespace ts {
             transformFlags |= TransformFlags.AssertES2017;
         }
 
+        // function expressions with object rest destructuring are ES Next syntax
+        if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+            transformFlags |= TransformFlags.AssertESNext;
+        }
+
+
         // If a FunctionExpression's subtree has marked the container as needing to capture the
         // lexical this, or the function contains parameters with initializers, then this node is
         // ES6 syntax.
@@ -2885,6 +2923,11 @@ namespace ts {
             transformFlags |= TransformFlags.AssertES2017;
         }
 
+        // arrow functions with object rest destructuring are ES Next syntax
+        if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+            transformFlags |= TransformFlags.AssertESNext;
+        }
+
         // If an ArrowFunction contains a lexical this, its container must capture the lexical this.
         if (subtreeFlags & TransformFlags.ContainsLexicalThis) {
             transformFlags |= TransformFlags.ContainsCapturedLexicalThis;
@@ -2913,8 +2956,13 @@ namespace ts {
         let transformFlags = subtreeFlags;
         const nameKind = node.name.kind;
 
-        // A VariableDeclaration with a binding pattern is ES6 syntax.
-        if (nameKind === SyntaxKind.ObjectBindingPattern || nameKind === SyntaxKind.ArrayBindingPattern) {
+        // A VariableDeclaration with an object binding pattern is ES2015 syntax
+        // and possibly ESNext syntax if it contains an object binding pattern
+        if (nameKind === SyntaxKind.ObjectBindingPattern) {
+            transformFlags |= TransformFlags.AssertESNext | TransformFlags.AssertES2015 | TransformFlags.ContainsBindingPattern;
+        }
+        // A VariableDeclaration with an object binding pattern is ES2015 syntax.
+        else if (nameKind === SyntaxKind.ArrayBindingPattern) {
             transformFlags |= TransformFlags.AssertES2015 | TransformFlags.ContainsBindingPattern;
         }
 
@@ -3055,6 +3103,10 @@ namespace ts {
                 transformFlags |= TransformFlags.AssertJsx;
                 break;
 
+            case SyntaxKind.ForOfStatement:
+                // for-of might be ESNext if it has a rest destructuring
+                transformFlags |= TransformFlags.AssertESNext;
+                // FALLTHROUGH
             case SyntaxKind.NoSubstitutionTemplateLiteral:
             case SyntaxKind.TemplateHead:
             case SyntaxKind.TemplateMiddle:
@@ -3062,7 +3114,6 @@ namespace ts {
             case SyntaxKind.TemplateExpression:
             case SyntaxKind.TaggedTemplateExpression:
             case SyntaxKind.ShorthandPropertyAssignment:
-            case SyntaxKind.ForOfStatement:
             case SyntaxKind.StaticKeyword:
                 // These nodes are ES6 syntax.
                 transformFlags |= TransformFlags.AssertES2015;
@@ -3126,11 +3177,18 @@ namespace ts {
                 }
                 break;
 
-            case SyntaxKind.SpreadElementExpression:
-                // This node is ES6 syntax, but is handled by a containing node.
-                transformFlags |= TransformFlags.ContainsSpreadElementExpression;
+            case SyntaxKind.SpreadElement:
+            case SyntaxKind.SpreadAssignment:
+                // This node is ES6 or ES next syntax, but is handled by a containing node.
+                transformFlags |= TransformFlags.ContainsSpreadExpression;
                 break;
 
+            case SyntaxKind.BindingElement:
+                if ((node as BindingElement).dotDotDotToken) {
+                    // this node is ES2015 or ES next syntax, but is handled by a containing node.
+                    transformFlags |= TransformFlags.ContainsSpreadExpression;
+                }
+
             case SyntaxKind.SuperKeyword:
                 // This node is ES6 syntax.
                 transformFlags |= TransformFlags.AssertES2015;
@@ -3143,8 +3201,13 @@ namespace ts {
 
             case SyntaxKind.ObjectBindingPattern:
             case SyntaxKind.ArrayBindingPattern:
-                // These nodes are ES6 syntax.
-                transformFlags |= TransformFlags.AssertES2015 | TransformFlags.ContainsBindingPattern;
+                // These nodes are ES2015 or ES Next syntax.
+                if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+                    transformFlags |= TransformFlags.AssertESNext | TransformFlags.ContainsBindingPattern;
+                }
+                else {
+                    transformFlags |= TransformFlags.AssertES2015 | TransformFlags.ContainsBindingPattern;
+                }
                 break;
 
             case SyntaxKind.Decorator:
@@ -3166,13 +3229,19 @@ namespace ts {
                     transformFlags |= TransformFlags.ContainsLexicalThis;
                 }
 
+                if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+                    // If an ObjectLiteralExpression contains a spread element, then it
+                    // is an ES next node.
+                    transformFlags |= TransformFlags.AssertESNext;
+                }
+
                 break;
 
             case SyntaxKind.ArrayLiteralExpression:
             case SyntaxKind.NewExpression:
                 excludeFlags = TransformFlags.ArrayLiteralOrCallOrNewExcludes;
-                if (subtreeFlags & TransformFlags.ContainsSpreadElementExpression) {
-                    // If the this node contains a SpreadElementExpression, then it is an ES6
+                if (subtreeFlags & TransformFlags.ContainsSpreadExpression) {
+                    // If the this node contains a SpreadExpression, then it is an ES6
                     // node.
                     transformFlags |= TransformFlags.AssertES2015;
                 }
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 878323a41b8..789f2bd8104 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -335,6 +335,9 @@ namespace ts {
         });
 
         let jsxElementType: Type;
+        let _jsxNamespace: string;
+        let _jsxFactoryEntity: EntityName;
+
         /** Things we lazy load from the JSX namespace */
         const jsxTypes = createMap<Type>();
         const JsxNames = {
@@ -372,6 +375,22 @@ namespace ts {
 
         return checker;
 
+        function getJsxNamespace(): string {
+            if (_jsxNamespace === undefined) {
+                _jsxNamespace = "React";
+                if (compilerOptions.jsxFactory) {
+                    _jsxFactoryEntity = parseIsolatedEntityName(compilerOptions.jsxFactory, languageVersion);
+                    if (_jsxFactoryEntity) {
+                        _jsxNamespace = getFirstIdentifier(_jsxFactoryEntity).text;
+                    }
+                }
+                else if (compilerOptions.reactNamespace) {
+                    _jsxNamespace = compilerOptions.reactNamespace;
+                }
+            }
+            return _jsxNamespace;
+        }
+
         function getEmitResolver(sourceFile: SourceFile, cancellationToken: CancellationToken) {
             // Ensure we have all the type information in place for this file so that all the
             // emitter questions of this resolver will return the right information.
@@ -2494,6 +2513,13 @@ namespace ts {
                     writePunctuation(writer, SyntaxKind.OpenBraceToken);
                     writer.writeLine();
                     writer.increaseIndent();
+                    writeObjectLiteralType(resolved);
+                    writer.decreaseIndent();
+                    writePunctuation(writer, SyntaxKind.CloseBraceToken);
+                    inObjectTypeLiteral = saveInObjectTypeLiteral;
+                }
+
+                function writeObjectLiteralType(resolved: ResolvedType) {
                     for (const signature of resolved.callSignatures) {
                         buildSignatureDisplay(signature, writer, enclosingDeclaration, globalFlagsToPass, /*kind*/ undefined, symbolStack);
                         writePunctuation(writer, SyntaxKind.SemicolonToken);
@@ -2526,11 +2552,8 @@ namespace ts {
                             writer.writeLine();
                         }
                     }
-                    writer.decreaseIndent();
-                    writePunctuation(writer, SyntaxKind.CloseBraceToken);
-                    inObjectTypeLiteral = saveInObjectTypeLiteral;
                 }
-            }
+           }
 
             function buildTypeParameterDisplayFromSymbol(symbol: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags) {
                 const targetSymbol = getTargetSymbol(symbol);
@@ -2972,26 +2995,31 @@ namespace ts {
             return symbol && getSymbolLinks(symbol).type || getTypeForVariableLikeDeclaration(node, /*includeOptionality*/ false);
         }
 
-        function getTextOfPropertyName(name: PropertyName): string {
-            switch (name.kind) {
-                case SyntaxKind.Identifier:
-                    return (<Identifier>name).text;
-                case SyntaxKind.StringLiteral:
-                case SyntaxKind.NumericLiteral:
-                    return (<LiteralExpression>name).text;
-                case SyntaxKind.ComputedPropertyName:
-                    if (isStringOrNumericLiteral((<ComputedPropertyName>name).expression.kind)) {
-                        return (<LiteralExpression>(<ComputedPropertyName>name).expression).text;
-                    }
-            }
-
-            return undefined;
-        }
-
         function isComputedNonLiteralName(name: PropertyName): boolean {
             return name.kind === SyntaxKind.ComputedPropertyName && !isStringOrNumericLiteral((<ComputedPropertyName>name).expression.kind);
         }
 
+        function getRestType(source: Type, properties: PropertyName[], symbol: Symbol): Type {
+            Debug.assert(!!(source.flags & TypeFlags.Object), "Rest types only support object types right now.");
+            const members = createMap<Symbol>();
+            const names = createMap<true>();
+            for (const name of properties) {
+                names[getTextOfPropertyName(name)] = true;
+            }
+            for (const prop of getPropertiesOfType(source)) {
+                const inNamesToRemove = prop.name in names;
+                const isPrivate = getDeclarationModifierFlagsFromSymbol(prop) & (ModifierFlags.Private | ModifierFlags.Protected);
+                const isMethod = prop.flags & SymbolFlags.Method;
+                const isSetOnlyAccessor = prop.flags & SymbolFlags.SetAccessor && !(prop.flags & SymbolFlags.GetAccessor);
+                if (!inNamesToRemove && !isPrivate && !isMethod && !isSetOnlyAccessor) {
+                    members[prop.name] = prop;
+                }
+            }
+            const stringIndexInfo = getIndexInfoOfType(source, IndexKind.String);
+            const numberIndexInfo = getIndexInfoOfType(source, IndexKind.Number);
+            return createAnonymousType(symbol, members, emptyArray, emptyArray, stringIndexInfo, numberIndexInfo);
+        }
+
         /** Return the inferred type for a binding element */
         function getTypeForBindingElement(declaration: BindingElement): Type {
             const pattern = <BindingPattern>declaration.parent;
@@ -3012,26 +3040,41 @@ namespace ts {
 
             let type: Type;
             if (pattern.kind === SyntaxKind.ObjectBindingPattern) {
-                // Use explicitly specified property name ({ p: xxx } form), or otherwise the implied name ({ p } form)
-                const name = declaration.propertyName || <Identifier>declaration.name;
-                if (isComputedNonLiteralName(name)) {
-                    // computed properties with non-literal names are treated as 'any'
-                    return anyType;
-                }
-                if (declaration.initializer) {
-                    getContextualType(declaration.initializer);
+                if (declaration.dotDotDotToken) {
+                    if (!(parentType.flags & TypeFlags.Object)) {
+                        error(declaration, Diagnostics.Rest_types_may_only_be_created_from_object_types);
+                        return unknownType;
+                    }
+                    const literalMembers: PropertyName[] = [];
+                    for (const element of pattern.elements) {
+                        if (element.kind !== SyntaxKind.OmittedExpression && !(element as BindingElement).dotDotDotToken) {
+                            literalMembers.push(element.propertyName || element.name as Identifier);
+                        }
+                    }
+                    type = getRestType(parentType, literalMembers, declaration.symbol);
                 }
+                else {
+                    // Use explicitly specified property name ({ p: xxx } form), or otherwise the implied name ({ p } form)
+                    const name = declaration.propertyName || <Identifier>declaration.name;
+                    if (isComputedNonLiteralName(name)) {
+                        // computed properties with non-literal names are treated as 'any'
+                        return anyType;
+                    }
+                    if (declaration.initializer) {
+                        getContextualType(declaration.initializer);
+                    }
 
-                // Use type of the specified property, or otherwise, for a numeric name, the type of the numeric index signature,
-                // or otherwise the type of the string index signature.
-                const text = getTextOfPropertyName(name);
+                    // Use type of the specified property, or otherwise, for a numeric name, the type of the numeric index signature,
+                    // or otherwise the type of the string index signature.
+                    const text = getTextOfPropertyName(name);
 
-                type = getTypeOfPropertyOfType(parentType, text) ||
-                    isNumericLiteralName(text) && getIndexTypeOfType(parentType, IndexKind.Number) ||
-                    getIndexTypeOfType(parentType, IndexKind.String);
-                if (!type) {
-                    error(name, Diagnostics.Type_0_has_no_property_1_and_no_string_index_signature, typeToString(parentType), declarationNameToString(name));
-                    return unknownType;
+                    type = getTypeOfPropertyOfType(parentType, text) ||
+                        isNumericLiteralName(text) && getIndexTypeOfType(parentType, IndexKind.Number) ||
+                        getIndexTypeOfType(parentType, IndexKind.String);
+                    if (!type) {
+                        error(name, Diagnostics.Type_0_has_no_property_1_and_no_string_index_signature, typeToString(parentType), declarationNameToString(name));
+                        return unknownType;
+                    }
                 }
             }
             else {
@@ -3039,7 +3082,11 @@ namespace ts {
                 // present (aka the tuple element property). This call also checks that the parentType is in
                 // fact an iterable or array (depending on target language).
                 const elementType = checkIteratedTypeOrElementType(parentType, pattern, /*allowStringInput*/ false);
-                if (!declaration.dotDotDotToken) {
+                if (declaration.dotDotDotToken) {
+                    // Rest element has an array type with the same element type as the parent type
+                    type = createArrayType(elementType);
+                }
+                else {
                     // Use specific property type when parent is a tuple or numeric index type when parent is an array
                     const propName = "" + indexOf(pattern.elements, declaration);
                     type = isTupleLikeType(parentType)
@@ -3055,10 +3102,6 @@ namespace ts {
                         return unknownType;
                     }
                 }
-                else {
-                    // Rest element has an array type with the same element type as the parent type
-                    type = createArrayType(elementType);
-                }
             }
             // In strict null checking mode, if a default value of a non-undefined type is specified, remove
             // undefined from the final type.
@@ -3239,8 +3282,8 @@ namespace ts {
             let hasComputedProperties = false;
             forEach(pattern.elements, e => {
                 const name = e.propertyName || <Identifier>e.name;
-                if (isComputedNonLiteralName(name)) {
-                    // do not include computed properties in the implied type
+                if (isComputedNonLiteralName(name) || e.dotDotDotToken) {
+                    // do not include computed properties or rests in the implied type
                     hasComputedProperties = true;
                     return;
                 }
@@ -4337,6 +4380,11 @@ namespace ts {
                 getIntersectionType([info1.type, info2.type]), info1.isReadonly && info2.isReadonly);
         }
 
+        function unionSpreadIndexInfos(info1: IndexInfo, info2: IndexInfo): IndexInfo {
+            return info1 && info2 && createIndexInfo(
+                getUnionType([info1.type, info2.type]), info1.isReadonly || info2.isReadonly);
+        }
+
         function resolveIntersectionTypeMembers(type: IntersectionType) {
             // The members and properties collections are empty for intersection types. To get all properties of an
             // intersection type use getPropertiesOfType (only the language service uses this).
@@ -4473,7 +4521,9 @@ namespace ts {
 
         function getPropertiesOfType(type: Type): Symbol[] {
             type = getApparentType(type);
-            return type.flags & TypeFlags.UnionOrIntersection ? getPropertiesOfUnionOrIntersectionType(<UnionType>type) : getPropertiesOfObjectType(type);
+            return type.flags & TypeFlags.UnionOrIntersection ?
+                getPropertiesOfUnionOrIntersectionType(<UnionType>type) :
+                getPropertiesOfObjectType(type);
         }
 
         /**
@@ -4528,6 +4578,7 @@ namespace ts {
                         if (isReadonlySymbol(prop)) {
                             isReadonly = true;
                         }
+
                     }
                     else if (containingType.flags & TypeFlags.Union) {
                         isPartial = true;
@@ -5860,6 +5911,68 @@ namespace ts {
             return links.resolvedType;
         }
 
+        /**
+         * Since the source of spread types are object literals, which are not binary,
+         * this function should be called in a left folding style, with left = previous result of getSpreadType
+         * and right = the new element to be spread.
+         */
+        function getSpreadType(left: Type, right: Type, isFromObjectLiteral: boolean): ResolvedType | IntrinsicType {
+            Debug.assert(!!(left.flags & (TypeFlags.Object | TypeFlags.Any)) && !!(right.flags & (TypeFlags.Object | TypeFlags.Any)), "Only object types may be spread.");
+            if (left.flags & TypeFlags.Any || right.flags & TypeFlags.Any) {
+                return anyType;
+            }
+            const members = createMap<Symbol>();
+            const skippedPrivateMembers = createMap<boolean>();
+            let stringIndexInfo: IndexInfo;
+            let numberIndexInfo: IndexInfo;
+            if (left === emptyObjectType) {
+                // for the first spread element, left === emptyObjectType, so take the right's string indexer
+                stringIndexInfo = getIndexInfoOfType(right, IndexKind.String);
+                numberIndexInfo = getIndexInfoOfType(right, IndexKind.Number);
+            }
+            else {
+                stringIndexInfo = unionSpreadIndexInfos(getIndexInfoOfType(left, IndexKind.String), getIndexInfoOfType(right, IndexKind.String));
+                numberIndexInfo = unionSpreadIndexInfos(getIndexInfoOfType(left, IndexKind.Number), getIndexInfoOfType(right, IndexKind.Number));
+            }
+
+            for (const rightProp of getPropertiesOfType(right)) {
+                // we approximate own properties as non-methods plus methods that are inside the object literal
+                const isOwnProperty = !(rightProp.flags & SymbolFlags.Method) || isFromObjectLiteral;
+                const isSetterWithoutGetter = rightProp.flags & SymbolFlags.SetAccessor && !(rightProp.flags & SymbolFlags.GetAccessor);
+                if (getDeclarationModifierFlagsFromSymbol(rightProp) & (ModifierFlags.Private | ModifierFlags.Protected)) {
+                    skippedPrivateMembers[rightProp.name] = true;
+                }
+                else if (isOwnProperty && !isSetterWithoutGetter) {
+                    members[rightProp.name] = rightProp;
+                }
+            }
+            for (const leftProp of getPropertiesOfType(left)) {
+                if (leftProp.flags & SymbolFlags.SetAccessor && !(leftProp.flags & SymbolFlags.GetAccessor)
+                    || leftProp.name in skippedPrivateMembers) {
+                    continue;
+                }
+                if (leftProp.name in members) {
+                    const rightProp = members[leftProp.name];
+                    const rightType = getTypeOfSymbol(rightProp);
+                    if (maybeTypeOfKind(rightType, TypeFlags.Undefined) || rightProp.flags & SymbolFlags.Optional) {
+                        const declarations: Declaration[] = concatenate(leftProp.declarations, rightProp.declarations);
+                        const flags = SymbolFlags.Property | SymbolFlags.Transient | (leftProp.flags & SymbolFlags.Optional);
+                        const result = <TransientSymbol>createSymbol(flags, leftProp.name);
+                        result.type = getUnionType([getTypeOfSymbol(leftProp), getTypeWithFacts(rightType, TypeFacts.NEUndefined)]);
+                        result.leftSpread = leftProp;
+                        result.rightSpread = rightProp;
+                        result.declarations = declarations;
+                        result.isReadonly = isReadonlySymbol(leftProp) || isReadonlySymbol(rightProp);
+                        members[leftProp.name] = result;
+                    }
+                }
+                else {
+                    members[leftProp.name] = leftProp;
+                }
+            }
+            return createAnonymousType(undefined, members, emptyArray, emptyArray, stringIndexInfo, numberIndexInfo);
+        }
+
         function createLiteralType(flags: TypeFlags, text: string) {
             const type = <LiteralType>createType(flags);
             type.text = text;
@@ -6730,9 +6843,15 @@ namespace ts {
                 }
 
                 if (!message) {
-                    message = relation === comparableRelation ?
-                        Diagnostics.Type_0_is_not_comparable_to_type_1 :
-                        Diagnostics.Type_0_is_not_assignable_to_type_1;
+                    if (relation === comparableRelation) {
+                        message = Diagnostics.Type_0_is_not_comparable_to_type_1;
+                    }
+                    else if (sourceType === targetType) {
+                        message = Diagnostics.Type_0_is_not_assignable_to_type_1_Two_different_types_with_this_name_exist_but_they_are_unrelated;
+                    }
+                    else {
+                        message = Diagnostics.Type_0_is_not_assignable_to_type_1;
+                    }
                 }
 
                 reportError(message, sourceType, targetType);
@@ -8571,7 +8690,7 @@ namespace ts {
                 unknownType;
         }
 
-        function getTypeOfDestructuredSpreadElement(type: Type) {
+        function getTypeOfDestructuredSpreadExpression(type: Type) {
             return createArrayType(checkIteratedTypeOrElementType(type, /*errorNode*/ undefined, /*allowStringInput*/ false) || unknownType);
         }
 
@@ -8585,8 +8704,8 @@ namespace ts {
             return getTypeOfDestructuredArrayElement(getAssignedType(node), indexOf(node.elements, element));
         }
 
-        function getAssignedTypeOfSpreadElement(node: SpreadElementExpression): Type {
-            return getTypeOfDestructuredSpreadElement(getAssignedType(<ArrayLiteralExpression>node.parent));
+        function getAssignedTypeOfSpreadExpression(node: SpreadElement): Type {
+            return getTypeOfDestructuredSpreadExpression(getAssignedType(<ArrayLiteralExpression>node.parent));
         }
 
         function getAssignedTypeOfPropertyAssignment(node: PropertyAssignment | ShorthandPropertyAssignment): Type {
@@ -8610,8 +8729,8 @@ namespace ts {
                     return undefinedType;
                 case SyntaxKind.ArrayLiteralExpression:
                     return getAssignedTypeOfArrayLiteralElement(<ArrayLiteralExpression>parent, node);
-                case SyntaxKind.SpreadElementExpression:
-                    return getAssignedTypeOfSpreadElement(<SpreadElementExpression>parent);
+                case SyntaxKind.SpreadElement:
+                    return getAssignedTypeOfSpreadExpression(<SpreadElement>parent);
                 case SyntaxKind.PropertyAssignment:
                     return getAssignedTypeOfPropertyAssignment(<PropertyAssignment>parent);
                 case SyntaxKind.ShorthandPropertyAssignment:
@@ -8627,7 +8746,7 @@ namespace ts {
                 getTypeOfDestructuredProperty(parentType, node.propertyName || <Identifier>node.name) :
                 !node.dotDotDotToken ?
                     getTypeOfDestructuredArrayElement(parentType, indexOf(pattern.elements, node)) :
-                    getTypeOfDestructuredSpreadElement(parentType);
+                    getTypeOfDestructuredSpreadExpression(parentType);
             return getTypeWithDefault(type, node.initializer);
         }
 
@@ -10642,7 +10761,7 @@ namespace ts {
             return mapper && mapper.context;
         }
 
-        function checkSpreadElementExpression(node: SpreadElementExpression, contextualMapper?: TypeMapper): Type {
+        function checkSpreadExpression(node: SpreadElement, contextualMapper?: TypeMapper): Type {
             // It is usually not safe to call checkExpressionCached if we can be contextually typing.
             // You can tell that we are contextually typing because of the contextualMapper parameter.
             // While it is true that a spread element can have a contextual type, it does not do anything
@@ -10664,7 +10783,7 @@ namespace ts {
             const elementTypes: Type[] = [];
             const inDestructuringPattern = isAssignmentTarget(node);
             for (const e of elements) {
-                if (inDestructuringPattern && e.kind === SyntaxKind.SpreadElementExpression) {
+                if (inDestructuringPattern && e.kind === SyntaxKind.SpreadElement) {
                     // Given the following situation:
                     //    var c: {};
                     //    [...c] = ["", 0];
@@ -10677,7 +10796,7 @@ namespace ts {
                     // get the contextual element type from it. So we do something similar to
                     // getContextualTypeForElementExpression, which will crucially not error
                     // if there is no index type / iterated type.
-                    const restArrayType = checkExpression((<SpreadElementExpression>e).expression, contextualMapper);
+                    const restArrayType = checkExpression((<SpreadElement>e).expression, contextualMapper);
                     const restElementType = getIndexTypeOfType(restArrayType, IndexKind.Number) ||
                         (languageVersion >= ScriptTarget.ES2015 ? getElementTypeOfIterable(restArrayType, /*errorNode*/ undefined) : undefined);
                     if (restElementType) {
@@ -10688,7 +10807,7 @@ namespace ts {
                     const type = checkExpressionForMutableLocation(e, contextualMapper);
                     elementTypes.push(type);
                 }
-                hasSpreadElement = hasSpreadElement || e.kind === SyntaxKind.SpreadElementExpression;
+                hasSpreadElement = hasSpreadElement || e.kind === SyntaxKind.SpreadElement;
             }
             if (!hasSpreadElement) {
                 // If array literal is actually a destructuring pattern, mark it as an implied type. We do this such
@@ -10805,8 +10924,11 @@ namespace ts {
             // Grammar checking
             checkGrammarObjectLiteralExpression(node, inDestructuringPattern);
 
-            const propertiesTable = createMap<Symbol>();
-            const propertiesArray: Symbol[] = [];
+            let propertiesTable = createMap<Symbol>();
+            let propertiesArray: Symbol[] = [];
+            let spread: Type = emptyObjectType;
+            let propagatedFlags: TypeFlags = 0;
+
             const contextualType = getApparentTypeOfContextualType(node);
             const contextualTypeHasPattern = contextualType && contextualType.pattern &&
                 (contextualType.pattern.kind === SyntaxKind.ObjectBindingPattern || contextualType.pattern.kind === SyntaxKind.ObjectLiteralExpression);
@@ -10831,6 +10953,7 @@ namespace ts {
                         Debug.assert(memberDecl.kind === SyntaxKind.ShorthandPropertyAssignment);
                         type = checkExpressionForMutableLocation((<ShorthandPropertyAssignment>memberDecl).name, contextualMapper);
                     }
+
                     typeFlags |= type.flags;
                     const prop = <TransientSymbol>createSymbol(SymbolFlags.Property | SymbolFlags.Transient | member.flags, member.name);
                     if (inDestructuringPattern) {
@@ -10868,6 +10991,23 @@ namespace ts {
                     prop.target = member;
                     member = prop;
                 }
+                else if (memberDecl.kind === SyntaxKind.SpreadAssignment) {
+                    if (propertiesArray.length > 0) {
+                        spread = getSpreadType(spread, createObjectLiteralType(), /*isFromObjectLiteral*/ true);
+                        propertiesArray = [];
+                        propertiesTable = createMap<Symbol>();
+                        hasComputedStringProperty = false;
+                        hasComputedNumberProperty = false;
+                        typeFlags = 0;
+                    }
+                    const type = checkExpression((memberDecl as SpreadAssignment).expression);
+                    if (!(type.flags & (TypeFlags.Object | TypeFlags.Any))) {
+                        error(memberDecl, Diagnostics.Spread_types_may_only_be_created_from_object_types);
+                        return unknownType;
+                    }
+                    spread = getSpreadType(spread, type, /*isFromObjectLiteral*/ false);
+                    continue;
+                }
                 else {
                     // TypeScript 1.0 spec (April 2014)
                     // A get accessor declaration is processed in the same manner as
@@ -10907,20 +11047,36 @@ namespace ts {
                 }
             }
 
-            const stringIndexInfo = hasComputedStringProperty ? getObjectLiteralIndexInfo(node, propertiesArray, IndexKind.String) : undefined;
-            const numberIndexInfo = hasComputedNumberProperty ? getObjectLiteralIndexInfo(node, propertiesArray, IndexKind.Number) : undefined;
-            const result = createAnonymousType(node.symbol, propertiesTable, emptyArray, emptyArray, stringIndexInfo, numberIndexInfo);
-            const freshObjectLiteralFlag = compilerOptions.suppressExcessPropertyErrors ? 0 : TypeFlags.FreshLiteral;
-            result.flags |= TypeFlags.ContainsObjectLiteral | freshObjectLiteralFlag | (typeFlags & TypeFlags.PropagatingFlags);
-            result.objectFlags |= ObjectFlags.ObjectLiteral;
-            if (patternWithComputedProperties) {
-                result.objectFlags |= ObjectFlags.ObjectLiteralPatternWithComputedProperties;
+            if (spread !== emptyObjectType) {
+                if (propertiesArray.length > 0) {
+                    spread = getSpreadType(spread, createObjectLiteralType(), /*isFromObjectLiteral*/ true);
+                }
+                spread.flags |= propagatedFlags;
+                spread.symbol = node.symbol;
+                return spread;
             }
-            if (inDestructuringPattern) {
-                result.pattern = node;
+
+            return createObjectLiteralType();
+
+            function createObjectLiteralType() {
+                const stringIndexInfo = hasComputedStringProperty ? getObjectLiteralIndexInfo(node, propertiesArray, IndexKind.String) : undefined;
+                const numberIndexInfo = hasComputedNumberProperty ? getObjectLiteralIndexInfo(node, propertiesArray, IndexKind.Number) : undefined;
+                const result = createAnonymousType(node.symbol, propertiesTable, emptyArray, emptyArray, stringIndexInfo, numberIndexInfo);
+                const freshObjectLiteralFlag = compilerOptions.suppressExcessPropertyErrors ? 0 : TypeFlags.FreshLiteral;
+                result.flags |= TypeFlags.ContainsObjectLiteral | freshObjectLiteralFlag | (typeFlags & TypeFlags.PropagatingFlags);
+                result.objectFlags |= ObjectFlags.ObjectLiteral;
+                if (patternWithComputedProperties) {
+                    result.objectFlags |= ObjectFlags.ObjectLiteralPatternWithComputedProperties;
+                }
+                if (inDestructuringPattern) {
+                    result.pattern = node;
+                }
+                if (!(result.flags & TypeFlags.Nullable)) {
+                    propagatedFlags |= (result.flags & TypeFlags.PropagatingFlags);
+                }
+                return result;
             }
-            return result;
-        }
+       }
 
         function checkJsxSelfClosingElement(node: JsxSelfClosingElement) {
             checkJsxOpeningLikeElement(node);
@@ -11337,10 +11493,10 @@ namespace ts {
         function checkJsxOpeningLikeElement(node: JsxOpeningLikeElement) {
             checkGrammarJsxElement(node);
             checkJsxPreconditions(node);
-            // The reactNamespace symbol should be marked as 'used' so we don't incorrectly elide its import. And if there
-            // is no reactNamespace symbol in scope when targeting React emit, we should issue an error.
+            // The reactNamespace/jsxFactory's root symbol should be marked as 'used' so we don't incorrectly elide its import.
+            // And if there is no reactNamespace/jsxFactory's symbol in scope when targeting React emit, we should issue an error.
             const reactRefErr = compilerOptions.jsx === JsxEmit.React ? Diagnostics.Cannot_find_name_0 : undefined;
-            const reactNamespace = compilerOptions.reactNamespace ? compilerOptions.reactNamespace : "React";
+            const reactNamespace = getJsxNamespace();
             const reactSym = resolveName(node.tagName, reactNamespace, SymbolFlags.Value, reactRefErr, reactNamespace);
             if (reactSym) {
                 // Mark local symbol as referenced here because it might not have been marked
@@ -11819,7 +11975,7 @@ namespace ts {
         function getSpreadArgumentIndex(args: Expression[]): number {
             for (let i = 0; i < args.length; i++) {
                 const arg = args[i];
-                if (arg && arg.kind === SyntaxKind.SpreadElementExpression) {
+                if (arg && arg.kind === SyntaxKind.SpreadElement) {
                     return i;
                 }
             }
@@ -13785,6 +13941,11 @@ namespace ts {
                     error(name, Diagnostics.Type_0_has_no_property_1_and_no_string_index_signature, typeToString(objectLiteralType), declarationNameToString(name));
                 }
             }
+            else if (property.kind === SyntaxKind.SpreadAssignment) {
+                if (property.expression.kind !== SyntaxKind.Identifier) {
+                    error(property.expression, Diagnostics.An_object_rest_element_must_be_an_identifier);
+                }
+            }
             else {
                 error(property, Diagnostics.Property_assignment_expected);
             }
@@ -13807,7 +13968,7 @@ namespace ts {
             const elements = node.elements;
             const element = elements[elementIndex];
             if (element.kind !== SyntaxKind.OmittedExpression) {
-                if (element.kind !== SyntaxKind.SpreadElementExpression) {
+                if (element.kind !== SyntaxKind.SpreadElement) {
                     const propName = "" + elementIndex;
                     const type = isTypeAny(sourceType)
                         ? sourceType
@@ -13831,10 +13992,10 @@ namespace ts {
                 }
                 else {
                     if (elementIndex < elements.length - 1) {
-                        error(element, Diagnostics.A_rest_element_must_be_last_in_an_array_destructuring_pattern);
+                        error(element, Diagnostics.A_rest_element_must_be_last_in_a_destructuring_pattern);
                     }
                     else {
-                        const restExpression = (<SpreadElementExpression>element).expression;
+                        const restExpression = (<SpreadElement>element).expression;
                         if (restExpression.kind === SyntaxKind.BinaryExpression && (<BinaryExpression>restExpression).operatorToken.kind === SyntaxKind.EqualsToken) {
                             error((<BinaryExpression>restExpression).operatorToken, Diagnostics.A_rest_element_cannot_have_an_initializer);
                         }
@@ -14467,8 +14628,8 @@ namespace ts {
                     return checkBinaryExpression(<BinaryExpression>node, contextualMapper);
                 case SyntaxKind.ConditionalExpression:
                     return checkConditionalExpression(<ConditionalExpression>node, contextualMapper);
-                case SyntaxKind.SpreadElementExpression:
-                    return checkSpreadElementExpression(<SpreadElementExpression>node, contextualMapper);
+                case SyntaxKind.SpreadElement:
+                    return checkSpreadExpression(<SpreadElement>node, contextualMapper);
                 case SyntaxKind.OmittedExpression:
                     return undefinedWideningType;
                 case SyntaxKind.YieldExpression:
@@ -16980,6 +17141,7 @@ namespace ts {
             let hasDuplicateDefaultClause = false;
 
             const expressionType = checkExpression(node.expression);
+            const expressionIsLiteral = isLiteralType(expressionType);
             forEach(node.caseBlock.clauses, clause => {
                 // Grammar check for duplicate default clauses, skip if we already report duplicate default clause
                 if (clause.kind === SyntaxKind.DefaultClause && !hasDuplicateDefaultClause) {
@@ -17000,10 +17162,16 @@ namespace ts {
                     // TypeScript 1.0 spec (April 2014): 5.9
                     // In a 'switch' statement, each 'case' expression must be of a type that is comparable
                     // to or from the type of the 'switch' expression.
-                    const caseType = checkExpression(caseClause.expression);
-                    if (!isTypeEqualityComparableTo(expressionType, caseType)) {
+                    let caseType = checkExpression(caseClause.expression);
+                    const caseIsLiteral = isLiteralType(caseType);
+                    let comparedExpressionType = expressionType;
+                    if (!caseIsLiteral || !expressionIsLiteral) {
+                        caseType = caseIsLiteral ? getBaseTypeOfLiteralType(caseType) : caseType;
+                        comparedExpressionType = getBaseTypeOfLiteralType(expressionType);
+                    }
+                    if (!isTypeEqualityComparableTo(comparedExpressionType, caseType)) {
                         // expressionType is not comparable to caseType, try the reversed check and report errors if it fails
-                        checkTypeComparableTo(caseType, expressionType, caseClause.expression, /*headMessage*/ undefined);
+                        checkTypeComparableTo(caseType, comparedExpressionType, caseClause.expression, /*headMessage*/ undefined);
                     }
                 }
                 forEach(clause.statements, checkSourceElement);
@@ -19108,6 +19276,10 @@ namespace ts {
                 return symbols;
             }
             else if (symbol.flags & SymbolFlags.Transient) {
+                if ((symbol as SymbolLinks).leftSpread) {
+                    const links = symbol as SymbolLinks;
+                    return [links.leftSpread, links.rightSpread];
+                }
                 let target: Symbol;
                 let next = symbol;
                 while (next = getSymbolLinks(next).target) {
@@ -19596,7 +19768,8 @@ namespace ts {
                 getTypeReferenceDirectivesForEntityName,
                 getTypeReferenceDirectivesForSymbol,
                 isLiteralConstDeclaration,
-                writeLiteralConstValue
+                writeLiteralConstValue,
+                getJsxFactoryEntity: () => _jsxFactoryEntity
             };
 
             // defined here to avoid outer scope pollution
@@ -19808,9 +19981,13 @@ namespace ts {
                     if (requestedExternalEmitHelpers & NodeFlags.HasClassExtends && languageVersion < ScriptTarget.ES2015) {
                         verifyHelperSymbol(exports, "__extends", SymbolFlags.Value);
                     }
-                    if (requestedExternalEmitHelpers & NodeFlags.HasJsxSpreadAttributes && compilerOptions.jsx !== JsxEmit.Preserve) {
+                    if (requestedExternalEmitHelpers & NodeFlags.HasSpreadAttribute &&
+                        (languageVersion < ScriptTarget.ESNext || compilerOptions.jsx === JsxEmit.React)) {
                         verifyHelperSymbol(exports, "__assign", SymbolFlags.Value);
                     }
+                    if (languageVersion < ScriptTarget.ESNext && requestedExternalEmitHelpers & NodeFlags.HasRestAttribute) {
+                        verifyHelperSymbol(exports, "__rest", SymbolFlags.Value);
+                    }
                     if (requestedExternalEmitHelpers & NodeFlags.HasDecorators) {
                         verifyHelperSymbol(exports, "__decorate", SymbolFlags.Value);
                         if (compilerOptions.emitDecoratorMetadata) {
@@ -20371,7 +20548,6 @@ namespace ts {
                     checkGrammarHeritageClause(heritageClause);
                 }
             }
-
             return false;
         }
 
@@ -20419,6 +20595,9 @@ namespace ts {
             const GetOrSetAccessor = GetAccessor | SetAccessor;
 
             for (const prop of node.properties) {
+                if (prop.kind === SyntaxKind.SpreadAssignment) {
+                    continue;
+                }
                 const name = prop.name;
                 if (name.kind === SyntaxKind.ComputedPropertyName) {
                     // If the name is not a ComputedPropertyName, the grammar checking will skip it
@@ -20722,7 +20901,7 @@ namespace ts {
             if (node.dotDotDotToken) {
                 const elements = (<BindingPattern>node.parent).elements;
                 if (node !== lastOrUndefined(elements)) {
-                    return grammarErrorOnNode(node, Diagnostics.A_rest_element_must_be_last_in_an_array_destructuring_pattern);
+                    return grammarErrorOnNode(node, Diagnostics.A_rest_element_must_be_last_in_a_destructuring_pattern);
                 }
 
                 if (node.name.kind === SyntaxKind.ArrayBindingPattern || node.name.kind === SyntaxKind.ObjectBindingPattern) {
@@ -20730,7 +20909,7 @@ namespace ts {
                 }
 
                 if (node.initializer) {
-                    // Error on equals token which immediate precedes the initializer
+                    // Error on equals token which immediately precedes the initializer
                     return grammarErrorAtPos(getSourceFileOfNode(node), node.initializer.pos - 1, 1, Diagnostics.A_rest_element_cannot_have_an_initializer);
                 }
             }
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 50399fd5c38..df9c3c4abdd 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -77,6 +77,11 @@ namespace ts {
             type: "string",
             description: Diagnostics.Specify_the_object_invoked_for_createElement_and_spread_when_targeting_react_JSX_emit
         },
+        {
+            name: "jsxFactory",
+            type: "string",
+            description: Diagnostics.Specify_the_JSX_factory_function_to_use_when_targeting_react_JSX_emit_e_g_React_createElement_or_h
+        },
         {
             name: "listFiles",
             type: "boolean",
@@ -265,6 +270,7 @@ namespace ts {
                 "es2015": ScriptTarget.ES2015,
                 "es2016": ScriptTarget.ES2016,
                 "es2017": ScriptTarget.ES2017,
+                "esnext": ScriptTarget.ESNext,
             }),
             description: Diagnostics.Specify_ECMAScript_target_version_Colon_ES3_default_ES5_or_ES2015,
             paramType: Diagnostics.VERSION,
@@ -428,7 +434,8 @@ namespace ts {
                     "es2015.symbol.wellknown": "lib.es2015.symbol.wellknown.d.ts",
                     "es2016.array.include": "lib.es2016.array.include.d.ts",
                     "es2017.object": "lib.es2017.object.d.ts",
-                    "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts"
+                    "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
+                    "es2017.string": "lib.es2017.string.d.ts",
                 }),
             },
             description: Diagnostics.Specify_library_files_to_be_included_in_the_compilation_Colon
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 9a353e6fb36..ce5e59e509c 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1455,7 +1455,7 @@
         "category": "Error",
         "code": 2461
     },
-    "A rest element must be last in an array destructuring pattern": {
+    "A rest element must be last in a destructuring pattern": {
         "category": "Error",
         "code": 2462
     },
@@ -1983,6 +1983,18 @@
         "category": "Error",
         "code": 2697
     },
+    "Spread types may only be created from object types.": {
+        "category": "Error",
+        "code": 2698
+    },
+    "Rest types may only be created from object types.": {
+        "category": "Error",
+        "code": 2700
+    },
+    "An object rest element must be an identifier.": {
+        "category": "Error",
+        "code": 2701
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
@@ -2381,6 +2393,10 @@
         "category": "Error",
         "code": 5066
     },
+    "Invalid value for 'jsxFactory'. '{0}' is not a valid identifier or qualified-name.": {
+        "category": "Error",
+        "code": 5067
+    },
     "Concatenate and emit output to single file.": {
         "category": "Message",
         "code": 6001
@@ -2897,6 +2913,10 @@
         "category": "Message",
         "code": 6145
     },
+    "Specify the JSX factory function to use when targeting 'react' JSX emit, e.g. 'React.createElement' or 'h'.": {
+        "category": "Message",
+        "code": 6146
+    },
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",
         "code": 7005
@@ -3162,5 +3182,9 @@
     "Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig": {
         "category": "Error",
         "code": 90009
+    },
+    "Type '{0}' is not assignable to type '{1}'. Two different types with this name exist, but they are unrelated.": {
+        "category": "Error",
+        "code": 90010
     }
 }
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index f29ef0f4cf1..fa0d44a695f 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -42,6 +42,14 @@ var __assign = (this && this.__assign) || Object.assign || function(t) {
     return t;
 };`;
 
+        const restHelper = `
+var __rest = (this && this.__rest) || function (s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && !e.indexOf(p))
+        t[p] = s[p];
+    return t;
+};`;
+
         // emit output for the __decorate helper function
         const decorateHelper = `
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
@@ -226,6 +234,7 @@ const _super = (function (geti, seti) {
         let currentFileIdentifiers: Map<string>;
         let extendsEmitted: boolean;
         let assignEmitted: boolean;
+        let restEmitted: boolean;
         let decorateEmitted: boolean;
         let paramEmitted: boolean;
         let awaiterEmitted: boolean;
@@ -732,6 +741,8 @@ const _super = (function (geti, seti) {
                     return emitPropertyAssignment(<PropertyAssignment>node);
                 case SyntaxKind.ShorthandPropertyAssignment:
                     return emitShorthandPropertyAssignment(<ShorthandPropertyAssignment>node);
+                case SyntaxKind.SpreadAssignment:
+                    return emitSpreadAssignment(node as SpreadAssignment);
 
                 // Enum
                 case SyntaxKind.EnumMember:
@@ -822,8 +833,8 @@ const _super = (function (geti, seti) {
                     return emitTemplateExpression(<TemplateExpression>node);
                 case SyntaxKind.YieldExpression:
                     return emitYieldExpression(<YieldExpression>node);
-                case SyntaxKind.SpreadElementExpression:
-                    return emitSpreadElementExpression(<SpreadElementExpression>node);
+                case SyntaxKind.SpreadElement:
+                    return emitSpreadExpression(<SpreadElement>node);
                 case SyntaxKind.ClassExpression:
                     return emitClassExpression(<ClassExpression>node);
                 case SyntaxKind.OmittedExpression:
@@ -1374,7 +1385,7 @@ const _super = (function (geti, seti) {
             emitExpressionWithPrefix(" ", node.expression);
         }
 
-        function emitSpreadElementExpression(node: SpreadElementExpression) {
+        function emitSpreadExpression(node: SpreadElement) {
             write("...");
             emitExpression(node.expression);
         }
@@ -2102,6 +2113,13 @@ const _super = (function (geti, seti) {
             }
         }
 
+        function emitSpreadAssignment(node: SpreadAssignment) {
+            if (node.expression) {
+                write("...");
+                emitExpression(node.expression);
+            }
+        }
+
         //
         // Enum
         //
@@ -2205,11 +2223,19 @@ const _super = (function (geti, seti) {
                 helpersEmitted = true;
             }
 
-            if (compilerOptions.jsx !== JsxEmit.Preserve && !assignEmitted && (node.flags & NodeFlags.HasJsxSpreadAttributes)) {
+            if ((languageVersion < ScriptTarget.ESNext || currentSourceFile.scriptKind === ScriptKind.JSX || currentSourceFile.scriptKind === ScriptKind.TSX) &&
+                compilerOptions.jsx !== JsxEmit.Preserve &&
+                !assignEmitted &&
+                node.flags & NodeFlags.HasSpreadAttribute) {
                 writeLines(assignHelper);
                 assignEmitted = true;
             }
 
+            if (languageVersion < ScriptTarget.ESNext && !restEmitted && node.flags & NodeFlags.HasRestAttribute) {
+                writeLines(restHelper);
+                restEmitted = true;
+            }
+
             if (!decorateEmitted && node.flags & NodeFlags.HasDecorators) {
                 writeLines(decorateHelper);
                 if (compilerOptions.emitDecoratorMetadata) {
diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index c557e3514a5..e9935668676 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -692,12 +692,12 @@ namespace ts {
     }
 
     export function createSpread(expression: Expression, location?: TextRange) {
-        const node = <SpreadElementExpression>createNode(SyntaxKind.SpreadElementExpression, location);
+        const node = <SpreadElement>createNode(SyntaxKind.SpreadElement, location);
         node.expression = parenthesizeExpressionForList(expression);
         return node;
     }
 
-    export function updateSpread(node: SpreadElementExpression, expression: Expression) {
+    export function updateSpread(node: SpreadElement, expression: Expression) {
         if (node.expression !== expression) {
             return updateNode(createSpread(expression, node), node);
         }
@@ -1399,14 +1399,27 @@ namespace ts {
         return node;
     }
 
-    export function updateShorthandPropertyAssignment(node: ShorthandPropertyAssignment, name: Identifier, objectAssignmentInitializer: Expression) {
+    export function createSpreadAssignment(expression: Expression, location?: TextRange) {
+        const node = <SpreadAssignment>createNode(SyntaxKind.SpreadAssignment, location);
+        node.expression = expression !== undefined ? parenthesizeExpressionForList(expression) : undefined;
+        return node;
+    }
+
+   export function updateShorthandPropertyAssignment(node: ShorthandPropertyAssignment, name: Identifier, objectAssignmentInitializer: Expression) {
         if (node.name !== name || node.objectAssignmentInitializer !== objectAssignmentInitializer) {
             return updateNode(createShorthandPropertyAssignment(name, objectAssignmentInitializer, node), node);
         }
         return node;
     }
 
-    // Top-level nodes
+    export function updateSpreadAssignment(node: SpreadAssignment, expression: Expression) {
+        if (node.expression !== expression) {
+            return updateNode(createSpreadAssignment(expression, node), node);
+        }
+        return node;
+    }
+
+   // Top-level nodes
 
     export function updateSourceFileNode(node: SourceFile, statements: Statement[]) {
         if (node.statements !== statements) {
@@ -1628,7 +1641,34 @@ namespace ts {
         return react;
     }
 
-    export function createReactCreateElement(reactNamespace: string, tagName: Expression, props: Expression, children: Expression[], parentElement: JsxOpeningLikeElement, location: TextRange): LeftHandSideExpression {
+    function createJsxFactoryExpressionFromEntityName(jsxFactory: EntityName, parent: JsxOpeningLikeElement): Expression {
+        if (isQualifiedName(jsxFactory)) {
+            return createPropertyAccess(
+                createJsxFactoryExpressionFromEntityName(
+                    jsxFactory.left,
+                    parent
+                ),
+                setEmitFlags(
+                    getMutableClone(jsxFactory.right),
+                    EmitFlags.NoSourceMap
+                )
+            );
+        }
+        else {
+            return createReactNamespace(jsxFactory.text, parent);
+        }
+    }
+
+    function createJsxFactoryExpression(jsxFactoryEntity: EntityName, reactNamespace: string, parent: JsxOpeningLikeElement): Expression {
+        return jsxFactoryEntity ?
+            createJsxFactoryExpressionFromEntityName(jsxFactoryEntity, parent) :
+            createPropertyAccess(
+                createReactNamespace(reactNamespace, parent),
+                "createElement"
+            );
+    }
+
+    export function createExpressionForJsxElement(jsxFactoryEntity: EntityName, reactNamespace: string, tagName: Expression, props: Expression, children: Expression[], parentElement: JsxOpeningLikeElement, location: TextRange): LeftHandSideExpression {
         const argumentsList = [tagName];
         if (props) {
             argumentsList.push(props);
@@ -1651,10 +1691,7 @@ namespace ts {
         }
 
         return createCall(
-            createPropertyAccess(
-                createReactNamespace(reactNamespace, parentElement),
-                "createElement"
-            ),
+            createJsxFactoryExpression(jsxFactoryEntity, reactNamespace, parentElement),
             /*typeArguments*/ undefined,
             argumentsList,
             location
@@ -3055,4 +3092,538 @@ namespace ts {
     function tryGetModuleNameFromDeclaration(declaration: ImportEqualsDeclaration | ImportDeclaration | ExportDeclaration, host: EmitHost, resolver: EmitResolver, compilerOptions: CompilerOptions) {
         return tryGetModuleNameFromFile(resolver.getExternalModuleFileFromDeclaration(declaration), host, compilerOptions);
     }
+
+    /**
+     * Transforms the body of a function-like node.
+     *
+     * @param node A function-like node.
+     */
+    export function transformFunctionBody(node: FunctionLikeDeclaration,
+                                          visitor: (node: Node) => VisitResult<Node>,
+                                          currentSourceFile: SourceFile,
+                                          context: TransformationContext,
+                                          enableSubstitutionsForCapturedThis: () => void,
+                                          convertObjectRest?: boolean) {
+        let multiLine = false; // indicates whether the block *must* be emitted as multiple lines
+        let singleLine = false; // indicates whether the block *may* be emitted as a single line
+        let statementsLocation: TextRange;
+        let closeBraceLocation: TextRange;
+
+        const statements: Statement[] = [];
+        const body = node.body;
+        let statementOffset: number;
+
+        context.startLexicalEnvironment();
+        if (isBlock(body)) {
+            // ensureUseStrict is false because no new prologue-directive should be added.
+            // addPrologueDirectives will simply put already-existing directives at the beginning of the target statement-array
+            statementOffset = addPrologueDirectives(statements, body.statements, /*ensureUseStrict*/ false, visitor);
+        }
+
+        addCaptureThisForNodeIfNeeded(statements, node, enableSubstitutionsForCapturedThis);
+        addDefaultValueAssignmentsIfNeeded(statements, node, visitor, convertObjectRest);
+        addRestParameterIfNeeded(statements, node, /*inConstructorWithSynthesizedSuper*/ false);
+
+        // If we added any generated statements, this must be a multi-line block.
+        if (!multiLine && statements.length > 0) {
+            multiLine = true;
+        }
+
+        if (isBlock(body)) {
+            statementsLocation = body.statements;
+            addRange(statements, visitNodes(body.statements, visitor, isStatement, statementOffset));
+
+            // If the original body was a multi-line block, this must be a multi-line block.
+            if (!multiLine && body.multiLine) {
+                multiLine = true;
+            }
+        }
+        else {
+            Debug.assert(node.kind === SyntaxKind.ArrowFunction);
+
+            // To align with the old emitter, we use a synthetic end position on the location
+            // for the statement list we synthesize when we down-level an arrow function with
+            // an expression function body. This prevents both comments and source maps from
+            // being emitted for the end position only.
+            statementsLocation = moveRangeEnd(body, -1);
+
+            const equalsGreaterThanToken = (<ArrowFunction>node).equalsGreaterThanToken;
+            if (!nodeIsSynthesized(equalsGreaterThanToken) && !nodeIsSynthesized(body)) {
+                if (rangeEndIsOnSameLineAsRangeStart(equalsGreaterThanToken, body, currentSourceFile)) {
+                    singleLine = true;
+                }
+                else {
+                    multiLine = true;
+                }
+            }
+
+            const expression = visitNode(body, visitor, isExpression);
+            const returnStatement = createReturn(expression, /*location*/ body);
+            setEmitFlags(returnStatement, EmitFlags.NoTokenSourceMaps | EmitFlags.NoTrailingSourceMap | EmitFlags.NoTrailingComments);
+            statements.push(returnStatement);
+
+            // To align with the source map emit for the old emitter, we set a custom
+            // source map location for the close brace.
+            closeBraceLocation = body;
+        }
+
+        const lexicalEnvironment = context.endLexicalEnvironment();
+        addRange(statements, lexicalEnvironment);
+
+        // If we added any final generated statements, this must be a multi-line block
+        if (!multiLine && lexicalEnvironment && lexicalEnvironment.length) {
+            multiLine = true;
+        }
+
+        const block = createBlock(createNodeArray(statements, statementsLocation), node.body, multiLine);
+        if (!multiLine && singleLine) {
+            setEmitFlags(block, EmitFlags.SingleLine);
+        }
+
+        if (closeBraceLocation) {
+            setTokenSourceMapRange(block, SyntaxKind.CloseBraceToken, closeBraceLocation);
+        }
+
+        setOriginalNode(block, node.body);
+        return block;
+    }
+
+    /**
+     * Adds a statement to capture the `this` of a function declaration if it is needed.
+     *
+     * @param statements The statements for the new function body.
+     * @param node A node.
+     */
+    export function addCaptureThisForNodeIfNeeded(statements: Statement[], node: Node, enableSubstitutionsForCapturedThis: () => void): void {
+        if (node.transformFlags & TransformFlags.ContainsCapturedLexicalThis && node.kind !== SyntaxKind.ArrowFunction) {
+            captureThisForNode(statements, node, createThis(), enableSubstitutionsForCapturedThis);
+        }
+    }
+
+    export function captureThisForNode(statements: Statement[], node: Node, initializer: Expression | undefined, enableSubstitutionsForCapturedThis?: () => void, originalStatement?: Statement): void {
+        enableSubstitutionsForCapturedThis();
+        const captureThisStatement = createVariableStatement(
+            /*modifiers*/ undefined,
+            createVariableDeclarationList([
+                createVariableDeclaration(
+                    "_this",
+                    /*type*/ undefined,
+                    initializer
+                )
+            ]),
+            originalStatement
+        );
+
+        setEmitFlags(captureThisStatement, EmitFlags.NoComments | EmitFlags.CustomPrologue);
+        setSourceMapRange(captureThisStatement, node);
+        statements.push(captureThisStatement);
+    }
+
+    /**
+     * Gets a value indicating whether we need to add default value assignments for a
+     * function-like node.
+     *
+     * @param node A function-like node.
+     */
+    function shouldAddDefaultValueAssignments(node: FunctionLikeDeclaration): boolean {
+        return (node.transformFlags & TransformFlags.ContainsDefaultValueAssignments) !== 0;
+    }
+
+    /**
+     * Adds statements to the body of a function-like node if it contains parameters with
+     * binding patterns or initializers.
+     *
+     * @param statements The statements for the new function body.
+     * @param node A function-like node.
+     */
+    export function addDefaultValueAssignmentsIfNeeded(statements: Statement[],
+                                                       node: FunctionLikeDeclaration,
+                                                       visitor: (node: Node) => VisitResult<Node>,
+                                                       convertObjectRest: boolean): void {
+        if (!shouldAddDefaultValueAssignments(node)) {
+            return;
+        }
+
+        for (const parameter of node.parameters) {
+            const { name, initializer, dotDotDotToken } = parameter;
+
+            // A rest parameter cannot have a binding pattern or an initializer,
+            // so let's just ignore it.
+            if (dotDotDotToken) {
+                continue;
+            }
+
+            if (isBindingPattern(name)) {
+                addDefaultValueAssignmentForBindingPattern(statements, parameter, name, initializer, visitor, convertObjectRest);
+            }
+            else if (initializer) {
+                addDefaultValueAssignmentForInitializer(statements, parameter, name, initializer, visitor);
+            }
+        }
+    }
+
+    /**
+     * Adds statements to the body of a function-like node for parameters with binding patterns
+     *
+     * @param statements The statements for the new function body.
+     * @param parameter The parameter for the function.
+     * @param name The name of the parameter.
+     * @param initializer The initializer for the parameter.
+     */
+    function addDefaultValueAssignmentForBindingPattern(statements: Statement[],
+                                                        parameter: ParameterDeclaration,
+                                                        name: BindingPattern, initializer: Expression,
+                                                        visitor: (node: Node) => VisitResult<Node>,
+                                                        convertObjectRest: boolean): void {
+        const temp = getGeneratedNameForNode(parameter);
+
+        // In cases where a binding pattern is simply '[]' or '{}',
+        // we usually don't want to emit a var declaration; however, in the presence
+        // of an initializer, we must emit that expression to preserve side effects.
+        if (name.elements.length > 0) {
+            statements.push(
+                setEmitFlags(
+                    createVariableStatement(
+                        /*modifiers*/ undefined,
+                        createVariableDeclarationList(
+                            flattenParameterDestructuring(parameter, temp, visitor, convertObjectRest)
+                        )
+                    ),
+                    EmitFlags.CustomPrologue
+                )
+            );
+        }
+        else if (initializer) {
+            statements.push(
+                setEmitFlags(
+                    createStatement(
+                        createAssignment(
+                            temp,
+                            visitNode(initializer, visitor, isExpression)
+                        )
+                    ),
+                    EmitFlags.CustomPrologue
+                )
+            );
+        }
+    }
+
+    /**
+     * Adds statements to the body of a function-like node for parameters with initializers.
+     *
+     * @param statements The statements for the new function body.
+     * @param parameter The parameter for the function.
+     * @param name The name of the parameter.
+     * @param initializer The initializer for the parameter.
+     */
+    function addDefaultValueAssignmentForInitializer(statements: Statement[],
+                                                     parameter: ParameterDeclaration,
+                                                     name: Identifier,
+                                                     initializer: Expression,
+                                                     visitor: (node: Node) => VisitResult<Node>): void {
+        initializer = visitNode(initializer, visitor, isExpression);
+        const statement = createIf(
+            createStrictEquality(
+                getSynthesizedClone(name),
+                createVoidZero()
+            ),
+            setEmitFlags(
+                createBlock([
+                    createStatement(
+                        createAssignment(
+                            setEmitFlags(getMutableClone(name), EmitFlags.NoSourceMap),
+                            setEmitFlags(initializer, EmitFlags.NoSourceMap | getEmitFlags(initializer)),
+                            /*location*/ parameter
+                        )
+                    )
+                ], /*location*/ parameter),
+                EmitFlags.SingleLine | EmitFlags.NoTrailingSourceMap | EmitFlags.NoTokenSourceMaps
+            ),
+            /*elseStatement*/ undefined,
+            /*location*/ parameter
+        );
+        statement.startsOnNewLine = true;
+        setEmitFlags(statement, EmitFlags.NoTokenSourceMaps | EmitFlags.NoTrailingSourceMap | EmitFlags.CustomPrologue);
+        statements.push(statement);
+    }
+
+    /**
+     * Gets a value indicating whether we need to add statements to handle a rest parameter.
+     *
+     * @param node A ParameterDeclaration node.
+     * @param inConstructorWithSynthesizedSuper A value indicating whether the parameter is
+     *                                          part of a constructor declaration with a
+     *                                          synthesized call to `super`
+     */
+    function shouldAddRestParameter(node: ParameterDeclaration, inConstructorWithSynthesizedSuper: boolean) {
+        return node && node.dotDotDotToken && node.name.kind === SyntaxKind.Identifier && !inConstructorWithSynthesizedSuper;
+    }
+
+    /**
+     * Adds statements to the body of a function-like node if it contains a rest parameter.
+     *
+     * @param statements The statements for the new function body.
+     * @param node A function-like node.
+     * @param inConstructorWithSynthesizedSuper A value indicating whether the parameter is
+     *                                          part of a constructor declaration with a
+     *                                          synthesized call to `super`
+     */
+    export function addRestParameterIfNeeded(statements: Statement[], node: FunctionLikeDeclaration, inConstructorWithSynthesizedSuper: boolean): void {
+        const parameter = lastOrUndefined(node.parameters);
+        if (!shouldAddRestParameter(parameter, inConstructorWithSynthesizedSuper)) {
+            return;
+        }
+
+        // `declarationName` is the name of the local declaration for the parameter.
+        const declarationName = getMutableClone(<Identifier>parameter.name);
+        setEmitFlags(declarationName, EmitFlags.NoSourceMap);
+
+        // `expressionName` is the name of the parameter used in expressions.
+        const expressionName = getSynthesizedClone(<Identifier>parameter.name);
+        const restIndex = node.parameters.length - 1;
+        const temp = createLoopVariable();
+
+        // var param = [];
+        statements.push(
+            setEmitFlags(
+                createVariableStatement(
+                    /*modifiers*/ undefined,
+                    createVariableDeclarationList([
+                        createVariableDeclaration(
+                            declarationName,
+                            /*type*/ undefined,
+                            createArrayLiteral([])
+                        )
+                    ]),
+                    /*location*/ parameter
+                ),
+                EmitFlags.CustomPrologue
+            )
+        );
+
+        // for (var _i = restIndex; _i < arguments.length; _i++) {
+        //   param[_i - restIndex] = arguments[_i];
+        // }
+        const forStatement = createFor(
+            createVariableDeclarationList([
+                createVariableDeclaration(temp, /*type*/ undefined, createLiteral(restIndex))
+            ], /*location*/ parameter),
+            createLessThan(
+                temp,
+                createPropertyAccess(createIdentifier("arguments"), "length"),
+                /*location*/ parameter
+            ),
+            createPostfixIncrement(temp, /*location*/ parameter),
+            createBlock([
+                startOnNewLine(
+                    createStatement(
+                        createAssignment(
+                            createElementAccess(
+                                expressionName,
+                                createSubtract(temp, createLiteral(restIndex))
+                            ),
+                            createElementAccess(createIdentifier("arguments"), temp)
+                        ),
+                        /*location*/ parameter
+                    )
+                )
+            ])
+        );
+
+        setEmitFlags(forStatement, EmitFlags.CustomPrologue);
+        startOnNewLine(forStatement);
+        statements.push(forStatement);
+    }
+
+
+
+
+    export function convertForOf(node: ForOfStatement, convertedLoopBodyStatements: Statement[],
+                                 visitor: (node: Node) => VisitResult<Node>,
+                                 enableSubstitutionsForBlockScopedBindings: () => void,
+                                 context: TransformationContext,
+                                 convertObjectRest?: boolean): ForStatement | ForOfStatement {
+        // The following ES6 code:
+        //
+        //    for (let v of expr) { }
+        //
+        // should be emitted as
+        //
+        //    for (var _i = 0, _a = expr; _i < _a.length; _i++) {
+        //        var v = _a[_i];
+        //    }
+        //
+        // where _a and _i are temps emitted to capture the RHS and the counter,
+        // respectively.
+        // When the left hand side is an expression instead of a let declaration,
+        // the "let v" is not emitted.
+        // When the left hand side is a let/const, the v is renamed if there is
+        // another v in scope.
+        // Note that all assignments to the LHS are emitted in the body, including
+        // all destructuring.
+        // Note also that because an extra statement is needed to assign to the LHS,
+        // for-of bodies are always emitted as blocks.
+
+        const expression = visitNode(node.expression, visitor, isExpression);
+        const initializer = node.initializer;
+        const statements: Statement[] = [];
+
+        // In the case where the user wrote an identifier as the RHS, like this:
+        //
+        //     for (let v of arr) { }
+        //
+        // we don't want to emit a temporary variable for the RHS, just use it directly.
+        const counter = convertObjectRest ? undefined : createLoopVariable();
+        const rhsReference = expression.kind === SyntaxKind.Identifier
+            ? createUniqueName((<Identifier>expression).text)
+            : createTempVariable(/*recordTempVariable*/ undefined);
+        const elementAccess = convertObjectRest ? rhsReference : createElementAccess(rhsReference, counter);
+
+        // Initialize LHS
+        // var v = _a[_i];
+        if (isVariableDeclarationList(initializer)) {
+            if (initializer.flags & NodeFlags.BlockScoped) {
+                enableSubstitutionsForBlockScopedBindings();
+            }
+
+            const firstOriginalDeclaration = firstOrUndefined(initializer.declarations);
+            if (firstOriginalDeclaration && isBindingPattern(firstOriginalDeclaration.name)) {
+                // This works whether the declaration is a var, let, or const.
+                // It will use rhsIterationValue _a[_i] as the initializer.
+                const declarations = flattenVariableDestructuring(
+                    firstOriginalDeclaration,
+                    elementAccess,
+                    visitor,
+                    /*recordTempVariable*/ undefined,
+                    convertObjectRest
+                );
+
+                const declarationList = createVariableDeclarationList(declarations, /*location*/ initializer);
+                setOriginalNode(declarationList, initializer);
+
+                // Adjust the source map range for the first declaration to align with the old
+                // emitter.
+                const firstDeclaration = declarations[0];
+                const lastDeclaration = lastOrUndefined(declarations);
+                setSourceMapRange(declarationList, createRange(firstDeclaration.pos, lastDeclaration.end));
+
+                statements.push(
+                    createVariableStatement(
+                        /*modifiers*/ undefined,
+                        declarationList
+                    )
+                );
+            }
+            else {
+                // The following call does not include the initializer, so we have
+                // to emit it separately.
+                statements.push(
+                    createVariableStatement(
+                        /*modifiers*/ undefined,
+                        setOriginalNode(
+                            createVariableDeclarationList([
+                                createVariableDeclaration(
+                                    firstOriginalDeclaration ? firstOriginalDeclaration.name : createTempVariable(/*recordTempVariable*/ undefined),
+                                    /*type*/ undefined,
+                                    createElementAccess(rhsReference, counter)
+                                )
+                            ], /*location*/ moveRangePos(initializer, -1)),
+                            initializer
+                        ),
+                        /*location*/ moveRangeEnd(initializer, -1)
+                    )
+                );
+            }
+        }
+        else {
+            // Initializer is an expression. Emit the expression in the body, so that it's
+            // evaluated on every iteration.
+            const assignment = createAssignment(initializer, elementAccess);
+            if (isDestructuringAssignment(assignment)) {
+                // This is a destructuring pattern, so we flatten the destructuring instead.
+                statements.push(
+                    createStatement(
+                        flattenDestructuringAssignment(
+                            context,
+                            assignment,
+                            /*needsValue*/ false,
+                            context.hoistVariableDeclaration,
+                            visitor,
+                            convertObjectRest
+                        )
+                    )
+                );
+            }
+            else {
+                // Currently there is not way to check that assignment is binary expression of destructing assignment
+                // so we have to cast never type to binaryExpression
+                (<BinaryExpression>assignment).end = initializer.end;
+                statements.push(createStatement(assignment, /*location*/ moveRangeEnd(initializer, -1)));
+            }
+        }
+
+        let bodyLocation: TextRange;
+        let statementsLocation: TextRange;
+        if (convertedLoopBodyStatements) {
+            addRange(statements, convertedLoopBodyStatements);
+        }
+        else {
+            const statement = visitNode(node.statement, visitor, isStatement);
+            if (isBlock(statement)) {
+                addRange(statements, statement.statements);
+                bodyLocation = statement;
+                statementsLocation = statement.statements;
+            }
+            else {
+                statements.push(statement);
+            }
+        }
+
+        // The old emitter does not emit source maps for the expression
+        setEmitFlags(expression, EmitFlags.NoSourceMap | getEmitFlags(expression));
+
+        // The old emitter does not emit source maps for the block.
+        // We add the location to preserve comments.
+        const body = createBlock(
+            createNodeArray(statements, /*location*/ statementsLocation),
+            /*location*/ bodyLocation
+        );
+
+        setEmitFlags(body, EmitFlags.NoSourceMap | EmitFlags.NoTokenSourceMaps);
+
+        let forStatement: ForStatement | ForOfStatement;
+        if (convertObjectRest) {
+            forStatement = createForOf(
+                createVariableDeclarationList([
+                    createVariableDeclaration(rhsReference, /*type*/ undefined, /*initializer*/ undefined, /*location*/ node.expression)
+                ], /*location*/ node.expression),
+                node.expression,
+                body,
+                /*location*/ node
+            );
+        }
+        else {
+            forStatement = createFor(
+                setEmitFlags(
+                    createVariableDeclarationList([
+                        createVariableDeclaration(counter, /*type*/ undefined, createLiteral(0), /*location*/ moveRangePos(node.expression, -1)),
+                        createVariableDeclaration(rhsReference, /*type*/ undefined, expression, /*location*/ node.expression)
+                    ], /*location*/ node.expression),
+                    EmitFlags.NoHoisting
+                ),
+                createLessThan(
+                    counter,
+                    createPropertyAccess(rhsReference, "length"),
+                    /*location*/ node.expression
+                ),
+                createPostfixIncrement(counter, /*location*/ node.expression),
+                body,
+                /*location*/ node
+            );
+        }
+
+        // Disable trailing source maps for the OpenParenToken to align source map emit with the old emitter.
+        setEmitFlags(forStatement, EmitFlags.NoTokenTrailingSourceMaps);
+        return forStatement;
+    }
 }
diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
index 831a19c4000..045e90a6add 100644
--- a/src/compiler/moduleNameResolver.ts
+++ b/src/compiler/moduleNameResolver.ts
@@ -14,6 +14,11 @@ namespace ts {
         return compilerOptions.traceResolution && host.trace !== undefined;
     }
 
+    /** Array that is only intended to be pushed to, never read. */
+    interface Push<T> {
+        push(value: T): void;
+    }
+
     /**
      * Result of trying to resolve a module.
      * At least one of `ts` and `js` should be defined, or the whole thing should be `undefined`.
@@ -62,8 +67,7 @@ namespace ts {
 
     interface ModuleResolutionState {
         host: ModuleResolutionHost;
-        // We only use this subset of the compiler options.
-        compilerOptions: { rootDirs?: string[], baseUrl?: string, paths?: MapLike<string[]> };
+        compilerOptions: CompilerOptions;
         traceEnabled: boolean;
     }
 
@@ -128,7 +132,9 @@ namespace ts {
             currentDirectory = host.getCurrentDirectory();
         }
 
-        return currentDirectory !== undefined && getDefaultTypeRoots(currentDirectory, host);
+        if (currentDirectory !== undefined) {
+            return getDefaultTypeRoots(currentDirectory, host);
+        }
     }
 
     /**
@@ -142,20 +148,12 @@ namespace ts {
         }
 
         let typeRoots: string[];
-
-        while (true) {
-            const atTypes = combinePaths(currentDirectory, nodeModulesAtTypes);
+        forEachAncestorDirectory(currentDirectory, directory => {
+            const atTypes = combinePaths(directory, nodeModulesAtTypes);
             if (host.directoryExists(atTypes)) {
                 (typeRoots || (typeRoots = [])).push(atTypes);
             }
-
-            const parent = getDirectoryPath(currentDirectory);
-            if (parent === currentDirectory) {
-                break;
-            }
-            currentDirectory = parent;
-        }
-
+        });
         return typeRoots;
     }
     const nodeModulesAtTypes = combinePaths("node_modules", "@types");
@@ -233,7 +231,7 @@ namespace ts {
             if (traceEnabled) {
                 trace(host, Diagnostics.Looking_up_in_node_modules_folder_initial_location_0, initialLocationForSecondaryLookup);
             }
-            resolvedFile = resolvedTypeScriptOnly(loadModuleFromNodeModules(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, failedLookupLocations, moduleResolutionState, /*checkOneLevel*/ false));
+            resolvedFile = resolvedTypeScriptOnly(loadModuleFromNodeModules(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, failedLookupLocations, moduleResolutionState));
             if (traceEnabled) {
                 if (resolvedFile) {
                     trace(host, Diagnostics.Type_reference_directive_0_was_successfully_resolved_to_1_primary_Colon_2, typeReferenceDirectiveName, resolvedFile, false);
@@ -341,7 +339,7 @@ namespace ts {
      * 'typings' entry or file 'index' with some supported extension
      * - Classic loader will only try to interpret '/a/b/c' as file.
      */
-    type ResolutionKindSpecificLoader = (extensions: Extensions, candidate: string, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState) => Resolved | undefined;
+    type ResolutionKindSpecificLoader = (extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState) => Resolved | undefined;
 
     /**
      * Any module resolution kind can be augmented with optional settings: 'baseUrl', 'paths' and 'rootDirs' - they are used to
@@ -404,7 +402,7 @@ namespace ts {
      * entries in 'rootDirs', use them to build absolute path out of (*) and try to resolve module from this location.
      */
     function tryLoadModuleUsingOptionalResolutionSettings(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
-        failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+        failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
 
         if (moduleHasNonRelativeName(moduleName)) {
             return tryLoadModuleUsingBaseUrl(extensions, moduleName, loader, failedLookupLocations, state);
@@ -415,7 +413,7 @@ namespace ts {
     }
 
     function tryLoadModuleUsingRootDirs(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
-        failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+        failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
 
         if (!state.compilerOptions.rootDirs) {
             return undefined;
@@ -491,7 +489,7 @@ namespace ts {
         return undefined;
     }
 
-    function tryLoadModuleUsingBaseUrl(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+    function tryLoadModuleUsingBaseUrl(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
         if (!state.compilerOptions.baseUrl) {
             return undefined;
         }
@@ -565,7 +563,7 @@ namespace ts {
                 if (traceEnabled) {
                     trace(host, Diagnostics.Loading_module_0_from_node_modules_folder, moduleName);
                 }
-                const resolved = loadModuleFromNodeModules(extensions, moduleName, containingDirectory, failedLookupLocations, state, /*checkOneLevel*/ false);
+                const resolved = loadModuleFromNodeModules(extensions, moduleName, containingDirectory, failedLookupLocations, state);
                 return resolved && { resolved, isExternalLibraryImport: true };
             }
             else {
@@ -588,7 +586,7 @@ namespace ts {
         return { path: real, extension: resolved.extension };
     }
 
-    function nodeLoadModuleByRelativeName(extensions: Extensions, candidate: string, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function nodeLoadModuleByRelativeName(extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         if (state.traceEnabled) {
             trace(state.host, Diagnostics.Loading_module_as_file_Slash_folder_candidate_module_location_0, candidate);
         }
@@ -607,7 +605,7 @@ namespace ts {
      * @param {boolean} onlyRecordFailures - if true then function won't try to actually load files but instead record all attempts as failures. This flag is necessary
      * in cases when we know upfront that all load attempts will fail (because containing folder does not exists) however we still need to record all failed lookup locations.
      */
-    function loadModuleFromFile(extensions: Extensions, candidate: string, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function loadModuleFromFile(extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         // First, try adding an extension. An import of "foo" could be matched by a file "foo.ts", or "foo.js" by "foo.js.ts"
         const resolvedByAddingExtension = tryAddingExtensions(candidate, extensions, failedLookupLocations, onlyRecordFailures, state);
         if (resolvedByAddingExtension) {
@@ -627,7 +625,7 @@ namespace ts {
     }
 
     /** Try to return an existing file that adds one of the `extensions` to `candidate`. */
-    function tryAddingExtensions(candidate: string, extensions: Extensions, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function tryAddingExtensions(candidate: string, extensions: Extensions, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         if (!onlyRecordFailures) {
             // check if containing folder exists - if it doesn't then just record failures for all supported extensions without disk probing
             const directory = getDirectoryPath(candidate);
@@ -652,7 +650,7 @@ namespace ts {
     }
 
     /** Return the file if it exists. */
-    function tryFile(fileName: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
+    function tryFile(fileName: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
         if (!onlyRecordFailures && state.host.fileExists(fileName)) {
             if (state.traceEnabled) {
                 trace(state.host, Diagnostics.File_0_exist_use_it_as_a_name_resolution_result, fileName);
@@ -663,12 +661,12 @@ namespace ts {
             if (state.traceEnabled) {
                 trace(state.host, Diagnostics.File_0_does_not_exist, fileName);
             }
-            failedLookupLocation.push(fileName);
+            failedLookupLocations.push(fileName);
             return undefined;
         }
     }
 
-    function loadNodeModuleFromDirectory(extensions: Extensions, candidate: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function loadNodeModuleFromDirectory(extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         const packageJsonPath = pathToPackageJson(candidate);
         const directoryExists = !onlyRecordFailures && directoryProbablyExists(candidate, state.host);
 
@@ -680,12 +678,12 @@ namespace ts {
             if (typesFile) {
                 const onlyRecordFailures = !directoryProbablyExists(getDirectoryPath(typesFile), state.host);
                 // A package.json "typings" may specify an exact filename, or may choose to omit an extension.
-                const fromFile = tryFile(typesFile, failedLookupLocation, onlyRecordFailures, state);
+                const fromFile = tryFile(typesFile, failedLookupLocations, onlyRecordFailures, state);
                 if (fromFile) {
                     // Note: this would allow a package.json to specify a ".js" file as typings. Maybe that should be forbidden.
                     return resolvedFromAnyFile(fromFile);
                 }
-                const x = tryAddingExtensions(typesFile, Extensions.TypeScript, failedLookupLocation, onlyRecordFailures, state);
+                const x = tryAddingExtensions(typesFile, Extensions.TypeScript, failedLookupLocations, onlyRecordFailures, state);
                 if (x) {
                     return x;
                 }
@@ -701,17 +699,17 @@ namespace ts {
                 trace(state.host, Diagnostics.File_0_does_not_exist, packageJsonPath);
             }
             // record package json as one of failed lookup locations - in the future if this file will appear it will invalidate resolution results
-            failedLookupLocation.push(packageJsonPath);
+            failedLookupLocations.push(packageJsonPath);
         }
 
-        return loadModuleFromFile(extensions, combinePaths(candidate, "index"), failedLookupLocation, !directoryExists, state);
+        return loadModuleFromFile(extensions, combinePaths(candidate, "index"), failedLookupLocations, !directoryExists, state);
     }
 
     function pathToPackageJson(directory: string): string {
         return combinePaths(directory, "package.json");
     }
 
-    function loadModuleFromNodeModulesFolder(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+    function loadModuleFromNodeModulesFolder(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
         const nodeModulesFolder = combinePaths(directory, "node_modules");
         const nodeModulesFolderExists = directoryProbablyExists(nodeModulesFolder, state.host);
         const candidate = normalizePath(combinePaths(nodeModulesFolder, moduleName));
@@ -720,34 +718,30 @@ namespace ts {
             loadNodeModuleFromDirectory(extensions, candidate, failedLookupLocations, !nodeModulesFolderExists, state);
     }
 
-    function loadModuleFromNodeModules(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState, checkOneLevel: boolean): Resolved | undefined {
-        return loadModuleFromNodeModulesWorker(extensions, moduleName, directory, failedLookupLocations, state, checkOneLevel, /*typesOnly*/ false);
+    function loadModuleFromNodeModules(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
+        return loadModuleFromNodeModulesWorker(extensions, moduleName, directory, failedLookupLocations, state, /*typesOnly*/ false);
     }
-    function loadModuleFromNodeModulesAtTypes(moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
-        return loadModuleFromNodeModulesWorker(Extensions.TypeScript, moduleName, directory, failedLookupLocations, state, /*checkOneLevel*/ false, /*typesOnly*/ true);
+    function loadModuleFromNodeModulesAtTypes(moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
+        // Extensions parameter here doesn't actually matter, because typesOnly ensures we're just doing @types lookup, which is always DtsOnly.
+        return loadModuleFromNodeModulesWorker(Extensions.DtsOnly, moduleName, directory, failedLookupLocations, state, /*typesOnly*/ true);
     }
 
-    function loadModuleFromNodeModulesWorker(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState, checkOneLevel: boolean, typesOnly: boolean): Resolved | undefined {
-        directory = normalizeSlashes(directory);
-        while (true) {
-            if (getBaseFileName(directory) !== "node_modules") {
-                const resolved = tryInDirectory();
-                if (resolved) {
-                    return resolved;
-                }
+    function loadModuleFromNodeModulesWorker(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState, typesOnly: boolean): Resolved | undefined {
+        return forEachAncestorDirectory(normalizeSlashes(directory), ancestorDirectory => {
+            if (getBaseFileName(ancestorDirectory) !== "node_modules") {
+                return loadModuleFromNodeModulesOneLevel(extensions, moduleName, ancestorDirectory, failedLookupLocations, state, typesOnly);
             }
+        });
+    }
 
-            const parentPath = getDirectoryPath(directory);
-            if (parentPath === directory || checkOneLevel) {
-                return undefined;
-            }
-
-            directory = parentPath;
+    /** Load a module from a single node_modules directory, but not from any ancestors' node_modules directories. */
+    function loadModuleFromNodeModulesOneLevel(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState, typesOnly = false): Resolved | undefined {
+        const packageResult = typesOnly ? undefined : loadModuleFromNodeModulesFolder(extensions, moduleName, directory, failedLookupLocations, state);
+        if (packageResult) {
+            return packageResult;
         }
-
-        function tryInDirectory(): Resolved | undefined {
-            const packageResult = typesOnly ? undefined : loadModuleFromNodeModulesFolder(extensions, moduleName, directory, failedLookupLocations, state);
-            return packageResult || loadModuleFromNodeModulesFolder(extensions, combinePaths("@types", moduleName), directory, failedLookupLocations, state);
+        if (extensions !== Extensions.JavaScript) {
+            return loadModuleFromNodeModulesFolder(Extensions.DtsOnly, combinePaths("@types", moduleName), directory, failedLookupLocations, state);
         }
     }
 
@@ -767,7 +761,11 @@ namespace ts {
             }
 
             if (moduleHasNonRelativeName(moduleName)) {
-                const resolved = loadModuleFromAncestorDirectories(extensions, moduleName, containingDirectory, failedLookupLocations, state);
+                // Climb up parent directories looking for a module.
+                const resolved = forEachAncestorDirectory(containingDirectory, directory => {
+                    const searchName = normalizePath(combinePaths(directory, moduleName));
+                    return loadModuleFromFile(extensions, searchName, failedLookupLocations, /*onlyRecordFailures*/ false, state);
+                });
                 if (resolved) {
                     return resolved;
                 }
@@ -783,22 +781,6 @@ namespace ts {
         }
     }
 
-    /** Climb up parent directories looking for a module. */
-    function loadModuleFromAncestorDirectories(extensions: Extensions, moduleName: string, containingDirectory: string, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
-        while (true) {
-            const searchName = normalizePath(combinePaths(containingDirectory, moduleName));
-            const referencedSourceFile = loadModuleFromFile(extensions, searchName, failedLookupLocations, /*onlyRecordFailures*/ false, state);
-            if (referencedSourceFile) {
-                return referencedSourceFile;
-            }
-            const parentPath = getDirectoryPath(containingDirectory);
-            if (parentPath === containingDirectory) {
-                return undefined;
-            }
-            containingDirectory = parentPath;
-        }
-    }
-
     /**
      * LSHost may load a module from a global cache of typings.
      * This is the minumum code needed to expose that functionality; the rest is in LSHost.
@@ -811,8 +793,24 @@ namespace ts {
         }
         const state: ModuleResolutionState = { compilerOptions, host, traceEnabled };
         const failedLookupLocations: string[] = [];
-        const resolved = loadModuleFromNodeModules(Extensions.TypeScript, moduleName, globalCache, failedLookupLocations, state, /*checkOneLevel*/ true) ||
-            loadModuleFromNodeModules(Extensions.JavaScript, moduleName, globalCache, failedLookupLocations, state, /*checkOneLevel*/ true);
+        const resolved = loadModuleFromNodeModulesOneLevel(Extensions.DtsOnly, moduleName, globalCache, failedLookupLocations, state);
         return createResolvedModuleWithFailedLookupLocations(resolved, /*isExternalLibraryImport*/ true, failedLookupLocations);
     }
+
+    /** Calls `callback` on `directory` and every ancestor directory it has, returning the first defined result. */
+    function forEachAncestorDirectory<T>(directory: string, callback: (directory: string) => T | undefined): T | undefined {
+        while (true) {
+            const result = callback(directory);
+            if (result !== undefined) {
+                return result;
+            }
+
+            const parentPath = getDirectoryPath(directory);
+            if (parentPath === directory) {
+                return undefined;
+            }
+
+            directory = parentPath;
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 92a3dcbef11..943a677ef5d 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -74,6 +74,8 @@ namespace ts {
                     visitNode(cbNode, (<ShorthandPropertyAssignment>node).questionToken) ||
                     visitNode(cbNode, (<ShorthandPropertyAssignment>node).equalsToken) ||
                     visitNode(cbNode, (<ShorthandPropertyAssignment>node).objectAssignmentInitializer);
+            case SyntaxKind.SpreadAssignment:
+                return visitNode(cbNode, (<SpreadAssignment>node).expression);
             case SyntaxKind.Parameter:
             case SyntaxKind.PropertyDeclaration:
             case SyntaxKind.PropertySignature:
@@ -197,8 +199,8 @@ namespace ts {
                     visitNode(cbNode, (<ConditionalExpression>node).whenTrue) ||
                     visitNode(cbNode, (<ConditionalExpression>node).colonToken) ||
                     visitNode(cbNode, (<ConditionalExpression>node).whenFalse);
-            case SyntaxKind.SpreadElementExpression:
-                return visitNode(cbNode, (<SpreadElementExpression>node).expression);
+            case SyntaxKind.SpreadElement:
+                return visitNode(cbNode, (<SpreadElement>node).expression);
             case SyntaxKind.Block:
             case SyntaxKind.ModuleBlock:
                 return visitNodes(cbNodes, (<Block>node).statements);
@@ -438,6 +440,10 @@ namespace ts {
         return result;
     }
 
+    export function parseIsolatedEntityName(text: string, languageVersion: ScriptTarget): EntityName {
+        return Parser.parseIsolatedEntityName(text, languageVersion);
+    }
+
     export function isExternalModule(file: SourceFile): boolean {
         return file.externalModuleIndicator !== undefined;
     }
@@ -589,6 +595,16 @@ namespace ts {
             return result;
         }
 
+        export function parseIsolatedEntityName(content: string, languageVersion: ScriptTarget): EntityName {
+            initializeState(content, languageVersion, /*syntaxCursor*/ undefined, ScriptKind.JS);
+            // Prime the scanner.
+            nextToken();
+            const entityName = parseEntityName(/*allowReservedWords*/ true);
+            const isInvalid = token() === SyntaxKind.EndOfFileToken && !parseDiagnostics.length;
+            clearState();
+            return isInvalid ? entityName : undefined;
+        }
+
         function getLanguageVariant(scriptKind: ScriptKind) {
             // .tsx and .jsx files are treated as jsx language variant.
             return scriptKind === ScriptKind.TSX || scriptKind === ScriptKind.JSX || scriptKind === ScriptKind.JS ? LanguageVariant.JSX : LanguageVariant.Standard;
@@ -1269,9 +1285,11 @@ namespace ts {
                     // which would be a candidate for improved error reporting.
                     return token() === SyntaxKind.OpenBracketToken || isLiteralPropertyName();
                 case ParsingContext.ObjectLiteralMembers:
-                    return token() === SyntaxKind.OpenBracketToken || token() === SyntaxKind.AsteriskToken || isLiteralPropertyName();
+                    return token() === SyntaxKind.OpenBracketToken || token() === SyntaxKind.AsteriskToken || token() === SyntaxKind.DotDotDotToken || isLiteralPropertyName();
+                case ParsingContext.RestProperties:
+                    return isLiteralPropertyName();
                 case ParsingContext.ObjectBindingElements:
-                    return token() === SyntaxKind.OpenBracketToken || isLiteralPropertyName();
+                    return token() === SyntaxKind.OpenBracketToken || token() === SyntaxKind.DotDotDotToken || isLiteralPropertyName();
                 case ParsingContext.HeritageClauseElement:
                     // If we see { } then only consume it as an expression if it is followed by , or {
                     // That way we won't consume the body of a class in its heritage clause.
@@ -1398,6 +1416,7 @@ namespace ts {
                 case ParsingContext.ArrayBindingElements:
                     return token() === SyntaxKind.CloseBracketToken;
                 case ParsingContext.Parameters:
+                case ParsingContext.RestProperties:
                     // Tokens other than ')' and ']' (the latter for index signatures) are here for better error recovery
                     return token() === SyntaxKind.CloseParenToken || token() === SyntaxKind.CloseBracketToken /*|| token === SyntaxKind.OpenBraceToken*/;
                 case ParsingContext.TypeArguments:
@@ -1583,6 +1602,9 @@ namespace ts {
                 case ParsingContext.Parameters:
                     return isReusableParameter(node);
 
+                case ParsingContext.RestProperties:
+                    return false;
+
                 // Any other lists we do not care about reusing nodes in.  But feel free to add if
                 // you can do so safely.  Danger areas involve nodes that may involve speculative
                 // parsing.  If speculative parsing is involved with the node, then the range the
@@ -1780,6 +1802,7 @@ namespace ts {
                 case ParsingContext.BlockStatements: return Diagnostics.Declaration_or_statement_expected;
                 case ParsingContext.SwitchClauses: return Diagnostics.case_or_default_expected;
                 case ParsingContext.SwitchClauseStatements: return Diagnostics.Statement_expected;
+                case ParsingContext.RestProperties: // fallthrough
                 case ParsingContext.TypeMembers: return Diagnostics.Property_or_signature_expected;
                 case ParsingContext.ClassMembers: return Diagnostics.Unexpected_token_A_constructor_method_accessor_or_property_was_expected;
                 case ParsingContext.EnumMembers: return Diagnostics.Enum_member_expected;
@@ -4122,7 +4145,7 @@ namespace ts {
         }
 
         function parseSpreadElement(): Expression {
-            const node = <SpreadElementExpression>createNode(SyntaxKind.SpreadElementExpression);
+            const node = <SpreadElement>createNode(SyntaxKind.SpreadElement);
             parseExpected(SyntaxKind.DotDotDotToken);
             node.expression = parseAssignmentExpressionOrHigher();
             return finishNode(node);
@@ -4162,6 +4185,12 @@ namespace ts {
 
         function parseObjectLiteralElement(): ObjectLiteralElementLike {
             const fullStart = scanner.getStartPos();
+            const dotDotDotToken = parseOptionalToken(SyntaxKind.DotDotDotToken);
+            if (dotDotDotToken) {
+                const spreadElement = <SpreadAssignment>createNode(SyntaxKind.SpreadAssignment, fullStart);
+                spreadElement.expression = parseAssignmentExpressionOrHigher();
+                return addJSDocComment(finishNode(spreadElement));
+            }
             const decorators = parseDecorators();
             const modifiers = parseModifiers();
 
@@ -4865,6 +4894,7 @@ namespace ts {
 
         function parseObjectBindingElement(): BindingElement {
             const node = <BindingElement>createNode(SyntaxKind.BindingElement);
+            node.dotDotDotToken = parseOptionalToken(SyntaxKind.DotDotDotToken);
             const tokenIsIdentifier = isIdentifier();
             const propertyName = parsePropertyName();
             if (tokenIsIdentifier && token() !== SyntaxKind.ColonToken) {
@@ -5809,6 +5839,7 @@ namespace ts {
             JsxChildren,               // Things between opening and closing JSX tags
             ArrayLiteralMembers,       // Members in array literal
             Parameters,                // Parameters in parameter list
+            RestProperties,            // Property names in a rest type list
             TypeParameters,            // Type parameters in type parameter list
             TypeArguments,             // Type arguments in type argument list
             TupleElementTypes,         // Element types in tuple element type list
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 1b36d99d7c9..cf62a6fc7fa 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -5,7 +5,7 @@
 namespace ts {
     /** The version of the TypeScript compiler release */
 
-    export const version = "2.1.0";
+    export const version = "2.2.0";
 
     const emptyArray: any[] = [];
 
@@ -431,13 +431,14 @@ namespace ts {
         return program;
 
         function getCommonSourceDirectory() {
-            if (typeof commonSourceDirectory === "undefined") {
-                if (options.rootDir && checkSourceFilesBelongToPath(files, options.rootDir)) {
+            if (commonSourceDirectory === undefined) {
+                const emittedFiles = filterSourceFilesInDirectory(files, isSourceFileFromExternalLibrary);
+                if (options.rootDir && checkSourceFilesBelongToPath(emittedFiles, options.rootDir)) {
                     // If a rootDir is specified and is valid use it as the commonSourceDirectory
                     commonSourceDirectory = getNormalizedAbsolutePath(options.rootDir, currentDirectory);
                 }
                 else {
-                    commonSourceDirectory = computeCommonSourceDirectory(files);
+                    commonSourceDirectory = computeCommonSourceDirectory(emittedFiles);
                 }
                 if (commonSourceDirectory && commonSourceDirectory[commonSourceDirectory.length - 1] !== directorySeparator) {
                     // Make sure directory path ends with directory separator so this string can directly
@@ -476,7 +477,7 @@ namespace ts {
                 return resolveModuleNamesWorker(moduleNames, containingFile);
             }
 
-            // at this point we know that either 
+            // at this point we know that either
             // - file has local declarations for ambient modules
             // OR
             // - old program state is available
@@ -670,7 +671,7 @@ namespace ts {
             }
 
             const modifiedFilePaths = modifiedSourceFiles.map(f => f.newFile.path);
-            // try to verify results of module resolution 
+            // try to verify results of module resolution
             for (const { oldFile: oldSourceFile, newFile: newSourceFile } of modifiedSourceFiles) {
                 const newSourceFilePath = getNormalizedAbsolutePath(newSourceFile.fileName, currentDirectory);
                 if (resolveModuleNamesWorker) {
@@ -908,48 +909,24 @@ namespace ts {
         function getJavaScriptSyntacticDiagnosticsForFile(sourceFile: SourceFile): Diagnostic[] {
             return runWithCancellationToken(() => {
                 const diagnostics: Diagnostic[] = [];
+                let parent: Node = sourceFile;
                 walk(sourceFile);
 
                 return diagnostics;
 
-                function walk(node: Node): boolean {
-                    if (!node) {
-                        return false;
-                    }
+                function walk(node: Node) {
+                    // Return directly from the case if the given node doesnt want to visit each child
+                    // Otherwise break to visit each child
 
-                    switch (node.kind) {
-                        case SyntaxKind.ImportEqualsDeclaration:
-                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.import_can_only_be_used_in_a_ts_file));
-                            return true;
-                        case SyntaxKind.ExportAssignment:
-                            if ((<ExportAssignment>node).isExportEquals) {
-                                diagnostics.push(createDiagnosticForNode(node, Diagnostics.export_can_only_be_used_in_a_ts_file));
-                                return true;
+                    switch (parent.kind) {
+                        case SyntaxKind.Parameter:
+                        case SyntaxKind.PropertyDeclaration:
+                            if ((<ParameterDeclaration | PropertyDeclaration>parent).questionToken === node) {
+                                diagnostics.push(createDiagnosticForNode(node, Diagnostics._0_can_only_be_used_in_a_ts_file, "?"));
+                                return;
                             }
-                            break;
-                        case SyntaxKind.ClassDeclaration:
-                            let classDeclaration = <ClassDeclaration>node;
-                            if (checkModifiers(classDeclaration.modifiers) ||
-                                checkTypeParameters(classDeclaration.typeParameters)) {
-                                return true;
-                            }
-                            break;
-                        case SyntaxKind.HeritageClause:
-                            let heritageClause = <HeritageClause>node;
-                            if (heritageClause.token === SyntaxKind.ImplementsKeyword) {
-                                diagnostics.push(createDiagnosticForNode(node, Diagnostics.implements_clauses_can_only_be_used_in_a_ts_file));
-                                return true;
-                            }
-                            break;
-                        case SyntaxKind.InterfaceDeclaration:
-                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.interface_declarations_can_only_be_used_in_a_ts_file));
-                            return true;
-                        case SyntaxKind.ModuleDeclaration:
-                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.module_declarations_can_only_be_used_in_a_ts_file));
-                            return true;
-                        case SyntaxKind.TypeAliasDeclaration:
-                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.type_aliases_can_only_be_used_in_a_ts_file));
-                            return true;
+
+                        // Pass through
                         case SyntaxKind.MethodDeclaration:
                         case SyntaxKind.MethodSignature:
                         case SyntaxKind.Constructor:
@@ -959,124 +936,151 @@ namespace ts {
                         case SyntaxKind.FunctionDeclaration:
                         case SyntaxKind.ArrowFunction:
                         case SyntaxKind.FunctionDeclaration:
-                            const functionDeclaration = <FunctionLikeDeclaration>node;
-                            if (checkModifiers(functionDeclaration.modifiers) ||
-                                checkTypeParameters(functionDeclaration.typeParameters) ||
-                                checkTypeAnnotation(functionDeclaration.type)) {
-                                return true;
-                            }
-                            break;
-                        case SyntaxKind.VariableStatement:
-                            const variableStatement = <VariableStatement>node;
-                            if (checkModifiers(variableStatement.modifiers)) {
-                                return true;
-                            }
-                            break;
                         case SyntaxKind.VariableDeclaration:
-                            const variableDeclaration = <VariableDeclaration>node;
-                            if (checkTypeAnnotation(variableDeclaration.type)) {
-                                return true;
+                            // type annotation
+                            if ((<FunctionLikeDeclaration | VariableDeclaration | ParameterDeclaration | PropertyDeclaration>parent).type === node) {
+                                diagnostics.push(createDiagnosticForNode(node, Diagnostics.types_can_only_be_used_in_a_ts_file));
+                                return;
+                            }
+                    }
+
+                    switch (node.kind) {
+                        case SyntaxKind.ImportEqualsDeclaration:
+                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.import_can_only_be_used_in_a_ts_file));
+                            return;
+                        case SyntaxKind.ExportAssignment:
+                            if ((<ExportAssignment>node).isExportEquals) {
+                                diagnostics.push(createDiagnosticForNode(node, Diagnostics.export_can_only_be_used_in_a_ts_file));
+                                return;
+                            }
+                            break;
+                        case SyntaxKind.HeritageClause:
+                            let heritageClause = <HeritageClause>node;
+                            if (heritageClause.token === SyntaxKind.ImplementsKeyword) {
+                                diagnostics.push(createDiagnosticForNode(node, Diagnostics.implements_clauses_can_only_be_used_in_a_ts_file));
+                                return;
+                            }
+                            break;
+                        case SyntaxKind.InterfaceDeclaration:
+                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.interface_declarations_can_only_be_used_in_a_ts_file));
+                            return;
+                        case SyntaxKind.ModuleDeclaration:
+                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.module_declarations_can_only_be_used_in_a_ts_file));
+                            return;
+                        case SyntaxKind.TypeAliasDeclaration:
+                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.type_aliases_can_only_be_used_in_a_ts_file));
+                            return;
+                        case SyntaxKind.EnumDeclaration:
+                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.enum_declarations_can_only_be_used_in_a_ts_file));
+                            return;
+                        case SyntaxKind.TypeAssertionExpression:
+                            let typeAssertionExpression = <TypeAssertion>node;
+                            diagnostics.push(createDiagnosticForNode(typeAssertionExpression.type, Diagnostics.type_assertion_expressions_can_only_be_used_in_a_ts_file));
+                            return;
+                    }
+
+                    const prevParent = parent;
+                    parent = node;
+                    forEachChild(node, walk, walkArray);
+                    parent = prevParent;
+                }
+
+                function walkArray(nodes: NodeArray<Node>) {
+                    if (parent.decorators === nodes && !options.experimentalDecorators) {
+                        diagnostics.push(createDiagnosticForNode(parent, Diagnostics.Experimental_support_for_decorators_is_a_feature_that_is_subject_to_change_in_a_future_release_Set_the_experimentalDecorators_option_to_remove_this_warning));
+                    }
+
+                    switch (parent.kind) {
+                        case SyntaxKind.ClassDeclaration:
+                        case SyntaxKind.MethodDeclaration:
+                        case SyntaxKind.MethodSignature:
+                        case SyntaxKind.Constructor:
+                        case SyntaxKind.GetAccessor:
+                        case SyntaxKind.SetAccessor:
+                        case SyntaxKind.FunctionExpression:
+                        case SyntaxKind.FunctionDeclaration:
+                        case SyntaxKind.ArrowFunction:
+                        case SyntaxKind.FunctionDeclaration:
+                            // Check type parameters
+                            if (nodes === (<ClassDeclaration | FunctionLikeDeclaration>parent).typeParameters) {
+                                diagnostics.push(createDiagnosticForNodeArray(nodes, Diagnostics.type_parameter_declarations_can_only_be_used_in_a_ts_file));
+                                return;
+                            }
+                            // pass through
+                        case SyntaxKind.VariableStatement:
+                            // Check modifiers
+                            if (nodes === (<ClassDeclaration | FunctionLikeDeclaration | VariableStatement>parent).modifiers) {
+                                return checkModifiers(<NodeArray<Modifier>>nodes, parent.kind === SyntaxKind.VariableStatement);
+                            }
+                            break;
+                        case SyntaxKind.PropertyDeclaration:
+                            // Check modifiers of property declaration
+                            if (nodes === (<PropertyDeclaration>parent).modifiers) {
+                                for (const modifier of <NodeArray<Modifier>>nodes) {
+                                    if (modifier.kind !== SyntaxKind.StaticKeyword) {
+                                        diagnostics.push(createDiagnosticForNode(modifier, Diagnostics._0_can_only_be_used_in_a_ts_file, tokenToString(modifier.kind)));
+                                    }
+                                }
+                                return;
+                            }
+                            break;
+                        case SyntaxKind.Parameter:
+                            // Check modifiers of parameter declaration
+                            if (nodes === (<ParameterDeclaration>parent).modifiers) {
+                                diagnostics.push(createDiagnosticForNodeArray(nodes, Diagnostics.parameter_modifiers_can_only_be_used_in_a_ts_file));
+                                return;
                             }
                             break;
                         case SyntaxKind.CallExpression:
                         case SyntaxKind.NewExpression:
-                            const expression = <CallExpression>node;
-                            if (expression.typeArguments && expression.typeArguments.length > 0) {
-                                const start = expression.typeArguments.pos;
-                                diagnostics.push(createFileDiagnostic(sourceFile, start, expression.typeArguments.end - start,
-                                    Diagnostics.type_arguments_can_only_be_used_in_a_ts_file));
-                                return true;
+                        case SyntaxKind.ExpressionWithTypeArguments:
+                            // Check type arguments
+                            if (nodes === (<CallExpression | NewExpression | ExpressionWithTypeArguments>parent).typeArguments) {
+                                diagnostics.push(createDiagnosticForNodeArray(nodes, Diagnostics.type_arguments_can_only_be_used_in_a_ts_file));
+                                return;
                             }
                             break;
-                        case SyntaxKind.Parameter:
-                            const parameter = <ParameterDeclaration>node;
-                            if (parameter.modifiers) {
-                                const start = parameter.modifiers.pos;
-                                diagnostics.push(createFileDiagnostic(sourceFile, start, parameter.modifiers.end - start,
-                                    Diagnostics.parameter_modifiers_can_only_be_used_in_a_ts_file));
-                                return true;
-                            }
-                            if (parameter.questionToken) {
-                                diagnostics.push(createDiagnosticForNode(parameter.questionToken, Diagnostics._0_can_only_be_used_in_a_ts_file, "?"));
-                                return true;
-                            }
-                            if (parameter.type) {
-                                diagnostics.push(createDiagnosticForNode(parameter.type, Diagnostics.types_can_only_be_used_in_a_ts_file));
-                                return true;
-                            }
-                            break;
-                        case SyntaxKind.PropertyDeclaration:
-                            const propertyDeclaration = <PropertyDeclaration>node;
-                            if (propertyDeclaration.modifiers) {
-                                for (const modifier of propertyDeclaration.modifiers) {
-                                    if (modifier.kind !== SyntaxKind.StaticKeyword) {
-                                        diagnostics.push(createDiagnosticForNode(modifier, Diagnostics._0_can_only_be_used_in_a_ts_file, tokenToString(modifier.kind)));
-                                        return true;
-                                    }
+                    }
+
+                    for (const node of nodes) {
+                        walk(node);
+                    }
+                }
+
+                function checkModifiers(modifiers: NodeArray<Modifier>, isConstValid: boolean) {
+                    for (const modifier of modifiers) {
+                        switch (modifier.kind) {
+                            case SyntaxKind.ConstKeyword:
+                                if (isConstValid) {
+                                    continue;
                                 }
-                            }
-                            if (checkTypeAnnotation((<PropertyDeclaration>node).type)) {
-                                return true;
-                            }
-                            break;
-                        case SyntaxKind.EnumDeclaration:
-                            diagnostics.push(createDiagnosticForNode(node, Diagnostics.enum_declarations_can_only_be_used_in_a_ts_file));
-                            return true;
-                        case SyntaxKind.TypeAssertionExpression:
-                            let typeAssertionExpression = <TypeAssertion>node;
-                            diagnostics.push(createDiagnosticForNode(typeAssertionExpression.type, Diagnostics.type_assertion_expressions_can_only_be_used_in_a_ts_file));
-                            return true;
-                        case SyntaxKind.Decorator:
-                            if (!options.experimentalDecorators) {
-                                diagnostics.push(createDiagnosticForNode(node, Diagnostics.Experimental_support_for_decorators_is_a_feature_that_is_subject_to_change_in_a_future_release_Set_the_experimentalDecorators_option_to_remove_this_warning));
-                            }
-                            return true;
-                    }
+                                // Fallthrough to report error
+                            case SyntaxKind.PublicKeyword:
+                            case SyntaxKind.PrivateKeyword:
+                            case SyntaxKind.ProtectedKeyword:
+                            case SyntaxKind.ReadonlyKeyword:
+                            case SyntaxKind.DeclareKeyword:
+                            case SyntaxKind.AbstractKeyword:
+                                diagnostics.push(createDiagnosticForNode(modifier, Diagnostics._0_can_only_be_used_in_a_ts_file, tokenToString(modifier.kind)));
+                                break;
 
-                    return forEachChild(node, walk);
-                }
-
-                function checkTypeParameters(typeParameters: NodeArray<TypeParameterDeclaration>): boolean {
-                    if (typeParameters) {
-                        const start = typeParameters.pos;
-                        diagnostics.push(createFileDiagnostic(sourceFile, start, typeParameters.end - start, Diagnostics.type_parameter_declarations_can_only_be_used_in_a_ts_file));
-                        return true;
-                    }
-                    return false;
-                }
-
-                function checkTypeAnnotation(type: TypeNode): boolean {
-                    if (type) {
-                        diagnostics.push(createDiagnosticForNode(type, Diagnostics.types_can_only_be_used_in_a_ts_file));
-                        return true;
-                    }
-
-                    return false;
-                }
-
-                function checkModifiers(modifiers: NodeArray<Modifier>): boolean {
-                    if (modifiers) {
-                        for (const modifier of modifiers) {
-                            switch (modifier.kind) {
-                                case SyntaxKind.PublicKeyword:
-                                case SyntaxKind.PrivateKeyword:
-                                case SyntaxKind.ProtectedKeyword:
-                                case SyntaxKind.ReadonlyKeyword:
-                                case SyntaxKind.DeclareKeyword:
-                                    diagnostics.push(createDiagnosticForNode(modifier, Diagnostics._0_can_only_be_used_in_a_ts_file, tokenToString(modifier.kind)));
-                                    return true;
-
-                                // These are all legal modifiers.
-                                case SyntaxKind.StaticKeyword:
-                                case SyntaxKind.ExportKeyword:
-                                case SyntaxKind.ConstKeyword:
-                                case SyntaxKind.DefaultKeyword:
-                                case SyntaxKind.AbstractKeyword:
-                            }
+                            // These are all legal modifiers.
+                            case SyntaxKind.StaticKeyword:
+                            case SyntaxKind.ExportKeyword:
+                            case SyntaxKind.DefaultKeyword:
                         }
                     }
+                }
 
-                    return false;
+                function createDiagnosticForNodeArray(nodes: NodeArray<Node>, message: DiagnosticMessage, arg0?: string | number, arg1?: string | number, arg2?: string | number): Diagnostic {
+                    const start = nodes.pos;
+                    return createFileDiagnostic(sourceFile, start, nodes.end - start, message, arg0, arg1, arg2);
+                }
+
+                // Since these are syntactic diagnostics, parent might not have been set
+                // this means the sourceFile cannot be infered from the node
+                function createDiagnosticForNode(node: Node, message: DiagnosticMessage, arg0?: string | number, arg1?: string | number, arg2?: string | number): Diagnostic {
+                    return createDiagnosticForNodeInSourceFile(sourceFile, node, message, arg0, arg1, arg2);
                 }
             });
         }
@@ -1140,9 +1144,14 @@ namespace ts {
             if (options.importHelpers
                 && (options.isolatedModules || isExternalModuleFile)
                 && !file.isDeclarationFile) {
-                const externalHelpersModuleReference = <StringLiteral>createNode(SyntaxKind.StringLiteral);
+                // synthesize 'import "tslib"' declaration
+                const externalHelpersModuleReference = <StringLiteral>createSynthesizedNode(SyntaxKind.StringLiteral);
                 externalHelpersModuleReference.text = externalHelpersModuleNameText;
-                externalHelpersModuleReference.parent = file;
+                const importDecl = createSynthesizedNode(SyntaxKind.ImportDeclaration);
+
+                importDecl.parent = file;
+                externalHelpersModuleReference.parent = importDecl;
+
                 imports = [externalHelpersModuleReference];
             }
 
@@ -1439,7 +1448,9 @@ namespace ts {
             collectExternalModuleReferences(file);
             if (file.imports.length || file.moduleAugmentations.length) {
                 file.resolvedModules = createMap<ResolvedModuleFull>();
-                const moduleNames = map(concatenate(file.imports, file.moduleAugmentations), getTextOfLiteral);
+                // Because global augmentation doesn't have string literal name, we can check for global augmentation as such.
+                const nonGlobalAugmentation = filter(file.moduleAugmentations, (moduleAugmentation) => moduleAugmentation.kind === SyntaxKind.StringLiteral);
+                const moduleNames = map(concatenate(file.imports, nonGlobalAugmentation), getTextOfLiteral);
                 const resolutions = resolveModuleNamesReusingOldState(moduleNames, getNormalizedAbsolutePath(file.fileName, currentDirectory), file);
                 Debug.assert(resolutions.length === moduleNames.length);
                 for (let i = 0; i < moduleNames.length; i++) {
@@ -1670,7 +1681,15 @@ namespace ts {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "emitDecoratorMetadata", "experimentalDecorators"));
             }
 
-            if (options.reactNamespace && !isIdentifierText(options.reactNamespace, languageVersion)) {
+            if (options.jsxFactory) {
+                if (options.reactNamespace) {
+                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_with_option_1, "reactNamespace", "jsxFactory"));
+                }
+                if (!parseIsolatedEntityName(options.jsxFactory, languageVersion)) {
+                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Invalid_value_for_jsxFactory_0_is_not_a_valid_identifier_or_qualified_name, options.jsxFactory));
+                }
+            }
+            else if (options.reactNamespace && !isIdentifierText(options.reactNamespace, languageVersion)) {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Invalid_value_for_reactNamespace_0_is_not_a_valid_identifier, options.reactNamespace));
             }
 
@@ -1690,18 +1709,13 @@ namespace ts {
                     const emitFilePath = toPath(emitFileName, currentDirectory, getCanonicalFileName);
                     // Report error if the output overwrites input file
                     if (filesByName.contains(emitFilePath)) {
-                        if (options.noEmitOverwritenFiles && !options.out && !options.outDir && !options.outFile) {
-                            blockEmittingOfFile(emitFileName);
-                        }
-                        else {
-                            let chain: DiagnosticMessageChain;
-                            if (!options.configFilePath) {
-                                // The program is from either an inferred project or an external project
-                                chain = chainDiagnosticMessages(/*details*/ undefined, Diagnostics.Adding_a_tsconfig_json_file_will_help_organize_projects_that_contain_both_TypeScript_and_JavaScript_files_Learn_more_at_https_Colon_Slash_Slashaka_ms_Slashtsconfig);
-                            }
-                            chain = chainDiagnosticMessages(chain, Diagnostics.Cannot_write_file_0_because_it_would_overwrite_input_file, emitFileName);
-                            blockEmittingOfFile(emitFileName, createCompilerDiagnosticFromMessageChain(chain));
+                        let chain: DiagnosticMessageChain;
+                        if (!options.configFilePath) {
+                            // The program is from either an inferred project or an external project
+                            chain = chainDiagnosticMessages(/*details*/ undefined, Diagnostics.Adding_a_tsconfig_json_file_will_help_organize_projects_that_contain_both_TypeScript_and_JavaScript_files_Learn_more_at_https_Colon_Slash_Slashaka_ms_Slashtsconfig);
                         }
+                        chain = chainDiagnosticMessages(chain, Diagnostics.Cannot_write_file_0_because_it_would_overwrite_input_file, emitFileName);
+                        blockEmittingOfFile(emitFileName, createCompilerDiagnosticFromMessageChain(chain));
                     }
 
                     // Report error if multiple files write into same file
@@ -1716,11 +1730,9 @@ namespace ts {
             }
         }
 
-        function blockEmittingOfFile(emitFileName: string, diag?: Diagnostic) {
+        function blockEmittingOfFile(emitFileName: string, diag: Diagnostic) {
             hasEmitBlockingDiagnostics.set(toPath(emitFileName, currentDirectory, getCanonicalFileName), true);
-            if (diag) {
-                programDiagnostics.add(diag);
-            }
+            programDiagnostics.add(diag);
         }
     }
 
diff --git a/src/compiler/transformer.ts b/src/compiler/transformer.ts
index ee9c081e6eb..b005b1906f6 100644
--- a/src/compiler/transformer.ts
+++ b/src/compiler/transformer.ts
@@ -1,6 +1,7 @@
 /// <reference path="visitor.ts" />
 /// <reference path="transformers/ts.ts" />
 /// <reference path="transformers/jsx.ts" />
+/// <reference path="transformers/esnext.ts" />
 /// <reference path="transformers/es2017.ts" />
 /// <reference path="transformers/es2016.ts" />
 /// <reference path="transformers/es2015.ts" />
@@ -116,6 +117,10 @@ namespace ts {
             transformers.push(transformJsx);
         }
 
+        if (languageVersion < ScriptTarget.ESNext) {
+            transformers.push(transformESNext);
+        }
+
         if (languageVersion < ScriptTarget.ES2017) {
             transformers.push(transformES2017);
         }
diff --git a/src/compiler/transformers/destructuring.ts b/src/compiler/transformers/destructuring.ts
index ab5c4629e95..a8c00776741 100644
--- a/src/compiler/transformers/destructuring.ts
+++ b/src/compiler/transformers/destructuring.ts
@@ -17,7 +17,8 @@ namespace ts {
         node: BinaryExpression,
         needsValue: boolean,
         recordTempVariable: (node: Identifier) => void,
-        visitor?: (node: Node) => VisitResult<Node>): Expression {
+        visitor?: (node: Node) => VisitResult<Node>,
+        transformRest?: boolean): Expression {
 
         if (isEmptyObjectLiteralOrArrayLiteral(node.left)) {
             const right = node.right;
@@ -51,7 +52,7 @@ namespace ts {
             location = value;
         }
 
-        flattenDestructuring(node, value, location, emitAssignment, emitTempVariableAssignment, visitor);
+        flattenDestructuring(node, value, location, emitAssignment, emitTempVariableAssignment, recordTempVariable, emitRestAssignment, transformRest, visitor);
 
         if (needsValue) {
             expressions.push(value);
@@ -61,7 +62,7 @@ namespace ts {
         aggregateTransformFlags(expression);
         return expression;
 
-        function emitAssignment(name: Identifier, value: Expression, location: TextRange) {
+        function emitAssignment(name: Identifier | ObjectLiteralExpression, value: Expression, location: TextRange) {
             const expression = createAssignment(name, value, location);
 
             // NOTE: this completely disables source maps, but aligns with the behavior of
@@ -77,6 +78,10 @@ namespace ts {
             emitAssignment(name, value, location);
             return name;
         }
+
+        function emitRestAssignment(elements: ObjectLiteralElementLike[], value: Expression, location: TextRange) {
+            emitAssignment(createObjectLiteral(elements), value, location);
+        }
     }
 
     /**
@@ -89,14 +94,15 @@ namespace ts {
     export function flattenParameterDestructuring(
         node: ParameterDeclaration,
         value: Expression,
-        visitor?: (node: Node) => VisitResult<Node>) {
+        visitor?: (node: Node) => VisitResult<Node>,
+        transformRest?: boolean) {
         const declarations: VariableDeclaration[] = [];
 
-        flattenDestructuring(node, value, node, emitAssignment, emitTempVariableAssignment, visitor);
+        flattenDestructuring(node, value, node, emitAssignment, emitTempVariableAssignment, noop, emitRestAssignment, transformRest, visitor);
 
         return declarations;
 
-        function emitAssignment(name: Identifier, value: Expression, location: TextRange) {
+        function emitAssignment(name: Identifier | BindingPattern, value: Expression, location: TextRange) {
             const declaration = createVariableDeclaration(name, /*type*/ undefined, value, location);
 
             // NOTE: this completely disables source maps, but aligns with the behavior of
@@ -112,6 +118,10 @@ namespace ts {
             emitAssignment(name, value, location);
             return name;
         }
+
+        function emitRestAssignment(elements: BindingElement[], value: Expression, location: TextRange) {
+            emitAssignment(createObjectBindingPattern(elements), value, location);
+        }
     }
 
     /**
@@ -125,15 +135,16 @@ namespace ts {
         node: VariableDeclaration,
         value?: Expression,
         visitor?: (node: Node) => VisitResult<Node>,
-        recordTempVariable?: (node: Identifier) => void) {
+        recordTempVariable?: (node: Identifier) => void,
+        transformRest?: boolean) {
         const declarations: VariableDeclaration[] = [];
 
         let pendingAssignments: Expression[];
-        flattenDestructuring(node, value, node, emitAssignment, emitTempVariableAssignment, visitor);
+        flattenDestructuring(node, value, node, emitAssignment, emitTempVariableAssignment, recordTempVariable, emitRestAssignment, transformRest, visitor);
 
         return declarations;
 
-        function emitAssignment(name: Identifier, value: Expression, location: TextRange, original: Node) {
+        function emitAssignment(name: Identifier | BindingPattern, value: Expression, location: TextRange, original: Node) {
             if (pendingAssignments) {
                 pendingAssignments.push(value);
                 value = inlineExpressions(pendingAssignments);
@@ -167,6 +178,10 @@ namespace ts {
             }
             return name;
         }
+
+        function emitRestAssignment(elements: BindingElement[], value: Expression, location: TextRange, original: Node) {
+            emitAssignment(createObjectBindingPattern(elements), value, location, original);
+        }
     }
 
     /**
@@ -186,15 +201,17 @@ namespace ts {
 
         const pendingAssignments: Expression[] = [];
 
-        flattenDestructuring(node, /*value*/ undefined, node, emitAssignment, emitTempVariableAssignment, visitor);
+        flattenDestructuring(node, /*value*/ undefined, node, emitAssignment, emitTempVariableAssignment, noop, emitRestAssignment, /*transformRest*/ false, visitor);
 
         const expression = inlineExpressions(pendingAssignments);
         aggregateTransformFlags(expression);
         return expression;
 
-        function emitAssignment(name: Identifier, value: Expression, location: TextRange, original: Node) {
+        function emitAssignment(name: Identifier | ObjectLiteralExpression, value: Expression, location: TextRange, original: Node) {
             const expression = createAssignmentCallback
-                ? createAssignmentCallback(name, value, location)
+                ? createAssignmentCallback(name.kind === SyntaxKind.Identifier ? name : emitTempVariableAssignment(name, location),
+                                           value,
+                                           location)
                 : createAssignment(name, value, location);
 
             emitPendingAssignment(expression, original);
@@ -206,6 +223,10 @@ namespace ts {
             return name;
         }
 
+        function emitRestAssignment(elements: ObjectLiteralElementLike[], value: Expression, location: TextRange, original: Node) {
+            emitAssignment(createObjectLiteral(elements), value, location, original);
+        }
+
         function emitPendingAssignment(expression: Expression, original: Node) {
             expression.original = original;
 
@@ -223,6 +244,9 @@ namespace ts {
         location: TextRange,
         emitAssignment: (name: Identifier, value: Expression, location: TextRange, original: Node) => void,
         emitTempVariableAssignment: (value: Expression, location: TextRange) => Identifier,
+        recordTempVariable: (node: Identifier) => void,
+        emitRestAssignment: (elements: (ObjectLiteralElementLike[] | BindingElement[]), value: Expression, location: TextRange, original: Node) => void,
+        transformRest: boolean,
         visitor?: (node: Node) => VisitResult<Node>) {
         if (value && visitor) {
             value = visitNode(value, visitor, isExpression);
@@ -284,23 +308,92 @@ namespace ts {
                 value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment);
             }
 
-            for (const p of properties) {
+            let bindingElements: ObjectLiteralElementLike[] = [];
+            for (let i = 0; i < properties.length; i++) {
+                const p = properties[i];
                 if (p.kind === SyntaxKind.PropertyAssignment || p.kind === SyntaxKind.ShorthandPropertyAssignment) {
-                    const propName = <Identifier | LiteralExpression>(<PropertyAssignment>p).name;
-                    const target = p.kind === SyntaxKind.ShorthandPropertyAssignment ? <ShorthandPropertyAssignment>p : (<PropertyAssignment>p).initializer || propName;
-                    // Assignment for target = value.propName should highligh whole property, hence use p as source map node
-                    emitDestructuringAssignment(target, createDestructuringPropertyAccess(value, propName), p);
+                    if (!transformRest ||
+                        p.transformFlags & TransformFlags.ContainsSpreadExpression ||
+                        (p.kind === SyntaxKind.PropertyAssignment && p.initializer.transformFlags & TransformFlags.ContainsSpreadExpression)) {
+                        if (bindingElements.length) {
+                            emitRestAssignment(bindingElements, value, location, target);
+                            bindingElements = [];
+                        }
+                        const propName = <Identifier | LiteralExpression>(<PropertyAssignment>p).name;
+                        const bindingTarget = p.kind === SyntaxKind.ShorthandPropertyAssignment ? <ShorthandPropertyAssignment>p : (<PropertyAssignment>p).initializer || propName;
+                        // Assignment for bindingTarget = value.propName should highlight whole property, hence use p as source map node
+                        emitDestructuringAssignment(bindingTarget, createDestructuringPropertyAccess(value, propName), p);
+                    }
+                    else {
+                        bindingElements.push(p);
+                    }
                 }
+                else if (i === properties.length - 1 &&
+                         p.kind === SyntaxKind.SpreadAssignment &&
+                         p.expression.kind === SyntaxKind.Identifier) {
+                    if (bindingElements.length) {
+                        emitRestAssignment(bindingElements, value, location, target);
+                        bindingElements = [];
+                    }
+                    const propName = (p as SpreadAssignment).expression as Identifier;
+                    const restCall = createRestCall(value, target.properties, p => p.name, target);
+                    emitDestructuringAssignment(propName, restCall, p);
+                }
+            }
+            if (bindingElements.length) {
+                emitRestAssignment(bindingElements, value, location, target);
+                bindingElements = [];
             }
         }
 
         function emitArrayLiteralAssignment(target: ArrayLiteralExpression, value: Expression, location: TextRange) {
+            if (transformRest) {
+                emitESNextArrayLiteralAssignment(target, value, location);
+            }
+            else {
+                emitES2015ArrayLiteralAssignment(target, value, location);
+            }
+        }
+
+        function emitESNextArrayLiteralAssignment(target: ArrayLiteralExpression, value: Expression, location: TextRange) {
             const elements = target.elements;
             const numElements = elements.length;
             if (numElements !== 1) {
                 // For anything but a single element destructuring we need to generate a temporary
                 // to ensure value is evaluated exactly once.
-                // When doing so we want to hightlight the passed in source map node since thats the one needing this temp assignment
+                // When doing so we want to highlight the passed-in source map node since thats the one needing this temp assignment
+                value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment);
+            }
+
+            const expressions: Expression[] = [];
+            const spreadContainingExpressions: [Expression, Identifier][] = [];
+            for (let i = 0; i < numElements; i++) {
+                const e = elements[i];
+                if (e.kind === SyntaxKind.OmittedExpression) {
+                    continue;
+                }
+                if (e.transformFlags & TransformFlags.ContainsSpreadExpression && i < numElements - 1) {
+                    const tmp = createTempVariable(recordTempVariable);
+                    spreadContainingExpressions.push([e, tmp]);
+                    expressions.push(tmp);
+                }
+                else {
+                    expressions.push(e);
+                }
+            }
+            emitAssignment(updateArrayLiteral(target, expressions) as any as Identifier, value, undefined, undefined);
+            for (const [e, tmp] of spreadContainingExpressions) {
+                emitDestructuringAssignment(e, tmp, e);
+            }
+        }
+
+        function emitES2015ArrayLiteralAssignment(target: ArrayLiteralExpression, value: Expression, location: TextRange) {
+            const elements = target.elements;
+            const numElements = elements.length;
+            if (numElements !== 1) {
+                // For anything but a single element destructuring we need to generate a temporary
+                // to ensure value is evaluated exactly once.
+                // When doing so we want to highlight the passed-in source map node since thats the one needing this temp assignment
                 value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment);
             }
 
@@ -308,20 +401,41 @@ namespace ts {
                 const e = elements[i];
                 if (e.kind !== SyntaxKind.OmittedExpression) {
                     // Assignment for target = value.propName should highligh whole property, hence use e as source map node
-                    if (e.kind !== SyntaxKind.SpreadElementExpression) {
+                    if (e.kind !== SyntaxKind.SpreadElement) {
                         emitDestructuringAssignment(e, createElementAccess(value, createLiteral(i)), e);
                     }
                     else if (i === numElements - 1) {
-                        emitDestructuringAssignment((<SpreadElementExpression>e).expression, createArraySlice(value, i), e);
+                        emitDestructuringAssignment((<SpreadElement>e).expression, createArraySlice(value, i), e);
                     }
                 }
             }
         }
 
+        /** Given value: o, propName: p, pattern: { a, b, ...p } from the original statement
+         * `{ a, b, ...p } = o`, create `p = __rest(o, ["a", "b"]);`*/
+        function createRestCall<T extends Node>(value: Expression, elements: T[], getPropertyName: (element: T) => PropertyName, location: TextRange): Expression {
+            const propertyNames: LiteralExpression[] = [];
+            for (let i = 0; i < elements.length - 1; i++) {
+                if (isOmittedExpression(elements[i])) {
+                    continue;
+                }
+                const str = <StringLiteral>createSynthesizedNode(SyntaxKind.StringLiteral);
+                str.pos = location.pos;
+                str.end = location.end;
+                str.text = getTextOfPropertyName(getPropertyName(elements[i]));
+                propertyNames.push(str);
+            }
+            const args = createSynthesizedNodeArray([value, createArrayLiteral(propertyNames, location)]);
+            return createCall(createIdentifier("__rest"), undefined, args);
+        }
+
         function emitBindingElement(target: VariableDeclaration | ParameterDeclaration | BindingElement, value: Expression) {
             // Any temporary assignments needed to emit target = value should point to target
             const initializer = visitor ? visitNode(target.initializer, visitor, isExpression) : target.initializer;
-            if (initializer) {
+            if (transformRest) {
+                value = value || initializer;
+            }
+            else if (initializer) {
                 // Combine value and initializer
                 value = value ? createDefaultValueCheck(value, initializer, target) : initializer;
             }
@@ -331,9 +445,11 @@ namespace ts {
             }
 
             const name = target.name;
-            if (isBindingPattern(name)) {
-                const elements = name.elements;
-                const numElements = elements.length;
+            if (!isBindingPattern(name)) {
+                emitAssignment(name, value, target, target);
+            }
+            else {
+                const numElements = name.elements.length;
                 if (numElements !== 1) {
                     // For anything other than a single-element destructuring we need to generate a temporary
                     // to ensure value is evaluated exactly once. Additionally, if we have zero elements
@@ -341,29 +457,104 @@ namespace ts {
                     // so in that case, we'll intentionally create that temporary.
                     value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ numElements !== 0, target, emitTempVariableAssignment);
                 }
-                for (let i = 0; i < numElements; i++) {
-                    const element = elements[i];
-                    if (isOmittedExpression(element)) {
-                        continue;
-                    }
-                    else if (name.kind === SyntaxKind.ObjectBindingPattern) {
-                        // Rewrite element to a declaration with an initializer that fetches property
-                        const propName = element.propertyName || <Identifier>element.name;
-                        emitBindingElement(element, createDestructuringPropertyAccess(value, propName));
-                    }
-                    else {
-                        if (!element.dotDotDotToken) {
-                            // Rewrite element to a declaration that accesses array element at index i
-                            emitBindingElement(element, createElementAccess(value, i));
-                        }
-                        else if (i === numElements - 1) {
-                            emitBindingElement(element, createArraySlice(value, i));
-                        }
-                    }
+                if (name.kind === SyntaxKind.ArrayBindingPattern) {
+                    emitArrayBindingElement(name as ArrayBindingPattern, value);
+                }
+                else {
+                    emitObjectBindingElement(target, value);
                 }
             }
+        }
+
+        function emitArrayBindingElement(name: ArrayBindingPattern, value: Expression) {
+            if (transformRest) {
+                emitESNextArrayBindingElement(name, value);
+            }
             else {
-                emitAssignment(name, value, target, target);
+                emitES2015ArrayBindingElement(name, value);
+            }
+        }
+
+        function emitES2015ArrayBindingElement(name: ArrayBindingPattern, value: Expression) {
+            const elements = name.elements;
+            const numElements = elements.length;
+            for (let i = 0; i < numElements; i++) {
+                const element = elements[i];
+                if (isOmittedExpression(element)) {
+                    continue;
+                }
+                if (!element.dotDotDotToken) {
+                    // Rewrite element to a declaration that accesses array element at index i
+                    emitBindingElement(element, createElementAccess(value, i));
+                }
+                else if (i === numElements - 1) {
+                    emitBindingElement(element, createArraySlice(value, i));
+                }
+            }
+        }
+
+        function emitESNextArrayBindingElement(name: ArrayBindingPattern, value: Expression) {
+            const elements = name.elements;
+            const numElements = elements.length;
+            const bindingElements: BindingElement[] = [];
+            const spreadContainingElements: BindingElement[] = [];
+            for (let i = 0; i < numElements; i++) {
+                const element = elements[i];
+                if (isOmittedExpression(element)) {
+                    continue;
+                }
+                if (element.transformFlags & TransformFlags.ContainsSpreadExpression && i < numElements - 1) {
+                    spreadContainingElements.push(element);
+                    bindingElements.push(createBindingElement(undefined, undefined, getGeneratedNameForNode(element), undefined, value));
+                }
+                else {
+                    bindingElements.push(element);
+                }
+            }
+            emitAssignment(updateArrayBindingPattern(name, bindingElements) as any as Identifier, value, undefined, undefined);
+            for (const element of spreadContainingElements) {
+                emitBindingElement(element, getGeneratedNameForNode(element));
+            }
+        }
+
+        function emitObjectBindingElement(target: VariableDeclaration | ParameterDeclaration | BindingElement, value: Expression) {
+            const name = target.name as BindingPattern;
+            const elements = name.elements;
+            const numElements = elements.length;
+            let bindingElements: BindingElement[] = [];
+            for (let i = 0; i < numElements; i++) {
+                const element = elements[i];
+                if (isOmittedExpression(element)) {
+                    continue;
+                }
+                if (i === numElements - 1 && element.dotDotDotToken) {
+                    if (bindingElements.length) {
+                        emitRestAssignment(bindingElements, value, target, target);
+                        bindingElements = [];
+                    }
+                    const restCall = createRestCall(value,
+                                                    name.elements,
+                                                    element => (element as BindingElement).propertyName || <Identifier>(element as BindingElement).name,
+                                                    name);
+                    emitBindingElement(element, restCall);
+                }
+                else if (transformRest && !(element.transformFlags & TransformFlags.ContainsSpreadExpression)) {
+                    // do not emit until we have a complete bundle of ES2015 syntax
+                    bindingElements.push(element);
+                }
+                else {
+                    if (bindingElements.length) {
+                        emitRestAssignment(bindingElements, value, target, target);
+                        bindingElements = [];
+                    }
+                    // Rewrite element to a declaration with an initializer that fetches property
+                    const propName = element.propertyName || <Identifier>element.name;
+                    emitBindingElement(element, createDestructuringPropertyAccess(value, propName));
+                }
+            }
+            if (bindingElements.length) {
+                emitRestAssignment(bindingElements, value, target, target);
+                bindingElements = [];
             }
         }
 
diff --git a/src/compiler/transformers/es2015.ts b/src/compiler/transformers/es2015.ts
index 25c15305c4a..e4fb8a0aaf0 100644
--- a/src/compiler/transformers/es2015.ts
+++ b/src/compiler/transformers/es2015.ts
@@ -861,7 +861,7 @@ namespace ts {
             }
 
             if (constructor) {
-                addDefaultValueAssignmentsIfNeeded(statements, constructor);
+                addDefaultValueAssignmentsIfNeeded(statements, constructor, visitor, /*convertObjectRest*/ false);
                 addRestParameterIfNeeded(statements, constructor, hasSynthesizedSuper);
                 Debug.assert(statementOffset >= 0, "statementOffset not initialized correctly!");
 
@@ -954,7 +954,7 @@ namespace ts {
             // If this isn't a derived class, just capture 'this' for arrow functions if necessary.
             if (!hasExtendsClause) {
                 if (ctor) {
-                    addCaptureThisForNodeIfNeeded(statements, ctor);
+                    addCaptureThisForNodeIfNeeded(statements, ctor, enableSubstitutionsForCapturedThis);
                 }
                 return SuperCaptureResult.NoReplacement;
             }
@@ -1016,7 +1016,7 @@ namespace ts {
             }
 
             // Perform the capture.
-            captureThisForNode(statements, ctor, superCallExpression, firstStatement);
+            captureThisForNode(statements, ctor, superCallExpression, enableSubstitutionsForCapturedThis, firstStatement);
 
             // If we're actually replacing the original statement, we need to signal this to the caller.
             if (superCallExpression) {
@@ -1085,242 +1085,6 @@ namespace ts {
             }
         }
 
-        /**
-         * Gets a value indicating whether we need to add default value assignments for a
-         * function-like node.
-         *
-         * @param node A function-like node.
-         */
-        function shouldAddDefaultValueAssignments(node: FunctionLikeDeclaration): boolean {
-            return (node.transformFlags & TransformFlags.ContainsDefaultValueAssignments) !== 0;
-        }
-
-        /**
-         * Adds statements to the body of a function-like node if it contains parameters with
-         * binding patterns or initializers.
-         *
-         * @param statements The statements for the new function body.
-         * @param node A function-like node.
-         */
-        function addDefaultValueAssignmentsIfNeeded(statements: Statement[], node: FunctionLikeDeclaration): void {
-            if (!shouldAddDefaultValueAssignments(node)) {
-                return;
-            }
-
-            for (const parameter of node.parameters) {
-                const { name, initializer, dotDotDotToken } = parameter;
-
-                // A rest parameter cannot have a binding pattern or an initializer,
-                // so let's just ignore it.
-                if (dotDotDotToken) {
-                    continue;
-                }
-
-                if (isBindingPattern(name)) {
-                    addDefaultValueAssignmentForBindingPattern(statements, parameter, name, initializer);
-                }
-                else if (initializer) {
-                    addDefaultValueAssignmentForInitializer(statements, parameter, name, initializer);
-                }
-            }
-        }
-
-        /**
-         * Adds statements to the body of a function-like node for parameters with binding patterns
-         *
-         * @param statements The statements for the new function body.
-         * @param parameter The parameter for the function.
-         * @param name The name of the parameter.
-         * @param initializer The initializer for the parameter.
-         */
-        function addDefaultValueAssignmentForBindingPattern(statements: Statement[], parameter: ParameterDeclaration, name: BindingPattern, initializer: Expression): void {
-            const temp = getGeneratedNameForNode(parameter);
-
-            // In cases where a binding pattern is simply '[]' or '{}',
-            // we usually don't want to emit a var declaration; however, in the presence
-            // of an initializer, we must emit that expression to preserve side effects.
-            if (name.elements.length > 0) {
-                statements.push(
-                    setEmitFlags(
-                        createVariableStatement(
-                            /*modifiers*/ undefined,
-                            createVariableDeclarationList(
-                                flattenParameterDestructuring(parameter, temp, visitor)
-                            )
-                        ),
-                        EmitFlags.CustomPrologue
-                    )
-                );
-            }
-            else if (initializer) {
-                statements.push(
-                    setEmitFlags(
-                        createStatement(
-                            createAssignment(
-                                temp,
-                                visitNode(initializer, visitor, isExpression)
-                            )
-                        ),
-                        EmitFlags.CustomPrologue
-                    )
-                );
-            }
-        }
-
-        /**
-         * Adds statements to the body of a function-like node for parameters with initializers.
-         *
-         * @param statements The statements for the new function body.
-         * @param parameter The parameter for the function.
-         * @param name The name of the parameter.
-         * @param initializer The initializer for the parameter.
-         */
-        function addDefaultValueAssignmentForInitializer(statements: Statement[], parameter: ParameterDeclaration, name: Identifier, initializer: Expression): void {
-            initializer = visitNode(initializer, visitor, isExpression);
-            const statement = createIf(
-                createStrictEquality(
-                    getSynthesizedClone(name),
-                    createVoidZero()
-                ),
-                setEmitFlags(
-                    createBlock([
-                        createStatement(
-                            createAssignment(
-                                setEmitFlags(getMutableClone(name), EmitFlags.NoSourceMap),
-                                setEmitFlags(initializer, EmitFlags.NoSourceMap | getEmitFlags(initializer)),
-                                /*location*/ parameter
-                            )
-                        )
-                    ], /*location*/ parameter),
-                    EmitFlags.SingleLine | EmitFlags.NoTrailingSourceMap | EmitFlags.NoTokenSourceMaps
-                ),
-                /*elseStatement*/ undefined,
-                /*location*/ parameter
-            );
-            statement.startsOnNewLine = true;
-            setEmitFlags(statement, EmitFlags.NoTokenSourceMaps | EmitFlags.NoTrailingSourceMap | EmitFlags.CustomPrologue);
-            statements.push(statement);
-        }
-
-        /**
-         * Gets a value indicating whether we need to add statements to handle a rest parameter.
-         *
-         * @param node A ParameterDeclaration node.
-         * @param inConstructorWithSynthesizedSuper A value indicating whether the parameter is
-         *                                          part of a constructor declaration with a
-         *                                          synthesized call to `super`
-         */
-        function shouldAddRestParameter(node: ParameterDeclaration, inConstructorWithSynthesizedSuper: boolean) {
-            return node && node.dotDotDotToken && node.name.kind === SyntaxKind.Identifier && !inConstructorWithSynthesizedSuper;
-        }
-
-        /**
-         * Adds statements to the body of a function-like node if it contains a rest parameter.
-         *
-         * @param statements The statements for the new function body.
-         * @param node A function-like node.
-         * @param inConstructorWithSynthesizedSuper A value indicating whether the parameter is
-         *                                          part of a constructor declaration with a
-         *                                          synthesized call to `super`
-         */
-        function addRestParameterIfNeeded(statements: Statement[], node: FunctionLikeDeclaration, inConstructorWithSynthesizedSuper: boolean): void {
-            const parameter = lastOrUndefined(node.parameters);
-            if (!shouldAddRestParameter(parameter, inConstructorWithSynthesizedSuper)) {
-                return;
-            }
-
-            // `declarationName` is the name of the local declaration for the parameter.
-            const declarationName = getMutableClone(<Identifier>parameter.name);
-            setEmitFlags(declarationName, EmitFlags.NoSourceMap);
-
-            // `expressionName` is the name of the parameter used in expressions.
-            const expressionName = getSynthesizedClone(<Identifier>parameter.name);
-            const restIndex = node.parameters.length - 1;
-            const temp = createLoopVariable();
-
-            // var param = [];
-            statements.push(
-                setEmitFlags(
-                    createVariableStatement(
-                        /*modifiers*/ undefined,
-                        createVariableDeclarationList([
-                            createVariableDeclaration(
-                                declarationName,
-                                /*type*/ undefined,
-                                createArrayLiteral([])
-                            )
-                        ]),
-                        /*location*/ parameter
-                    ),
-                    EmitFlags.CustomPrologue
-                )
-            );
-
-            // for (var _i = restIndex; _i < arguments.length; _i++) {
-            //   param[_i - restIndex] = arguments[_i];
-            // }
-            const forStatement = createFor(
-                createVariableDeclarationList([
-                    createVariableDeclaration(temp, /*type*/ undefined, createLiteral(restIndex))
-                ], /*location*/ parameter),
-                createLessThan(
-                    temp,
-                    createPropertyAccess(createIdentifier("arguments"), "length"),
-                    /*location*/ parameter
-                ),
-                createPostfixIncrement(temp, /*location*/ parameter),
-                createBlock([
-                    startOnNewLine(
-                        createStatement(
-                            createAssignment(
-                                createElementAccess(
-                                    expressionName,
-                                    createSubtract(temp, createLiteral(restIndex))
-                                ),
-                                createElementAccess(createIdentifier("arguments"), temp)
-                            ),
-                            /*location*/ parameter
-                        )
-                    )
-                ])
-            );
-
-            setEmitFlags(forStatement, EmitFlags.CustomPrologue);
-            startOnNewLine(forStatement);
-            statements.push(forStatement);
-        }
-
-        /**
-         * Adds a statement to capture the `this` of a function declaration if it is needed.
-         *
-         * @param statements The statements for the new function body.
-         * @param node A node.
-         */
-        function addCaptureThisForNodeIfNeeded(statements: Statement[], node: Node): void {
-            if (node.transformFlags & TransformFlags.ContainsCapturedLexicalThis && node.kind !== SyntaxKind.ArrowFunction) {
-                captureThisForNode(statements, node, createThis());
-            }
-        }
-
-        function captureThisForNode(statements: Statement[], node: Node, initializer: Expression | undefined, originalStatement?: Statement): void {
-            enableSubstitutionsForCapturedThis();
-            const captureThisStatement = createVariableStatement(
-                /*modifiers*/ undefined,
-                createVariableDeclarationList([
-                    createVariableDeclaration(
-                        "_this",
-                        /*type*/ undefined,
-                        initializer
-                    )
-                ]),
-                originalStatement
-            );
-
-            setEmitFlags(captureThisStatement, EmitFlags.NoComments | EmitFlags.CustomPrologue);
-            setSourceMapRange(captureThisStatement, node);
-            statements.push(captureThisStatement);
-        }
-
         /**
          * Adds statements to the class body function for a class to define the members of the
          * class.
@@ -1518,7 +1282,7 @@ namespace ts {
                     /*typeParameters*/ undefined,
                     visitNodes(node.parameters, visitor, isParameter),
                     /*type*/ undefined,
-                    transformFunctionBody(node),
+                    transformFunctionBody(node, visitor, currentSourceFile, context, enableSubstitutionsForCapturedThis),
                     /*location*/ node
                 ),
                 /*original*/ node);
@@ -1545,7 +1309,7 @@ namespace ts {
                     /*typeParameters*/ undefined,
                     visitNodes(node.parameters, visitor, isParameter),
                     /*type*/ undefined,
-                    saveStateAndInvoke(node, transformFunctionBody),
+                    saveStateAndInvoke(node, node => transformFunctionBody(node, visitor, currentSourceFile, context, enableSubstitutionsForCapturedThis)),
                     location
                 ),
                 /*original*/ node
@@ -1555,96 +1319,6 @@ namespace ts {
             return expression;
         }
 
-        /**
-         * Transforms the body of a function-like node.
-         *
-         * @param node A function-like node.
-         */
-        function transformFunctionBody(node: FunctionLikeDeclaration) {
-            let multiLine = false; // indicates whether the block *must* be emitted as multiple lines
-            let singleLine = false; // indicates whether the block *may* be emitted as a single line
-            let statementsLocation: TextRange;
-            let closeBraceLocation: TextRange;
-
-            const statements: Statement[] = [];
-            const body = node.body;
-            let statementOffset: number;
-
-            startLexicalEnvironment();
-            if (isBlock(body)) {
-                // ensureUseStrict is false because no new prologue-directive should be added.
-                // addPrologueDirectives will simply put already-existing directives at the beginning of the target statement-array
-                statementOffset = addPrologueDirectives(statements, body.statements, /*ensureUseStrict*/ false, visitor);
-            }
-
-            addCaptureThisForNodeIfNeeded(statements, node);
-            addDefaultValueAssignmentsIfNeeded(statements, node);
-            addRestParameterIfNeeded(statements, node, /*inConstructorWithSynthesizedSuper*/ false);
-
-            // If we added any generated statements, this must be a multi-line block.
-            if (!multiLine && statements.length > 0) {
-                multiLine = true;
-            }
-
-            if (isBlock(body)) {
-                statementsLocation = body.statements;
-                addRange(statements, visitNodes(body.statements, visitor, isStatement, statementOffset));
-
-                // If the original body was a multi-line block, this must be a multi-line block.
-                if (!multiLine && body.multiLine) {
-                    multiLine = true;
-                }
-            }
-            else {
-                Debug.assert(node.kind === SyntaxKind.ArrowFunction);
-
-                // To align with the old emitter, we use a synthetic end position on the location
-                // for the statement list we synthesize when we down-level an arrow function with
-                // an expression function body. This prevents both comments and source maps from
-                // being emitted for the end position only.
-                statementsLocation = moveRangeEnd(body, -1);
-
-                const equalsGreaterThanToken = (<ArrowFunction>node).equalsGreaterThanToken;
-                if (!nodeIsSynthesized(equalsGreaterThanToken) && !nodeIsSynthesized(body)) {
-                    if (rangeEndIsOnSameLineAsRangeStart(equalsGreaterThanToken, body, currentSourceFile)) {
-                        singleLine = true;
-                    }
-                    else {
-                        multiLine = true;
-                    }
-                }
-
-                const expression = visitNode(body, visitor, isExpression);
-                const returnStatement = createReturn(expression, /*location*/ body);
-                setEmitFlags(returnStatement, EmitFlags.NoTokenSourceMaps | EmitFlags.NoTrailingSourceMap | EmitFlags.NoTrailingComments);
-                statements.push(returnStatement);
-
-                // To align with the source map emit for the old emitter, we set a custom
-                // source map location for the close brace.
-                closeBraceLocation = body;
-            }
-
-            const lexicalEnvironment = endLexicalEnvironment();
-            addRange(statements, lexicalEnvironment);
-
-            // If we added any final generated statements, this must be a multi-line block
-            if (!multiLine && lexicalEnvironment && lexicalEnvironment.length) {
-                multiLine = true;
-            }
-
-            const block = createBlock(createNodeArray(statements, statementsLocation), node.body, multiLine);
-            if (!multiLine && singleLine) {
-                setEmitFlags(block, EmitFlags.SingleLine);
-            }
-
-            if (closeBraceLocation) {
-                setTokenSourceMapRange(block, SyntaxKind.CloseBraceToken, closeBraceLocation);
-            }
-
-            setOriginalNode(block, node.body);
-            return block;
-        }
-
         /**
          * Visits an ExpressionStatement that contains a destructuring assignment.
          *
@@ -1926,171 +1600,7 @@ namespace ts {
         }
 
         function convertForOfToFor(node: ForOfStatement, convertedLoopBodyStatements: Statement[]): ForStatement {
-            // The following ES6 code:
-            //
-            //    for (let v of expr) { }
-            //
-            // should be emitted as
-            //
-            //    for (var _i = 0, _a = expr; _i < _a.length; _i++) {
-            //        var v = _a[_i];
-            //    }
-            //
-            // where _a and _i are temps emitted to capture the RHS and the counter,
-            // respectively.
-            // When the left hand side is an expression instead of a let declaration,
-            // the "let v" is not emitted.
-            // When the left hand side is a let/const, the v is renamed if there is
-            // another v in scope.
-            // Note that all assignments to the LHS are emitted in the body, including
-            // all destructuring.
-            // Note also that because an extra statement is needed to assign to the LHS,
-            // for-of bodies are always emitted as blocks.
-
-            const expression = visitNode(node.expression, visitor, isExpression);
-            const initializer = node.initializer;
-            const statements: Statement[] = [];
-
-            // In the case where the user wrote an identifier as the RHS, like this:
-            //
-            //     for (let v of arr) { }
-            //
-            // we don't want to emit a temporary variable for the RHS, just use it directly.
-            const counter = createLoopVariable();
-            const rhsReference = expression.kind === SyntaxKind.Identifier
-                ? createUniqueName((<Identifier>expression).text)
-                : createTempVariable(/*recordTempVariable*/ undefined);
-
-            // Initialize LHS
-            // var v = _a[_i];
-            if (isVariableDeclarationList(initializer)) {
-                if (initializer.flags & NodeFlags.BlockScoped) {
-                    enableSubstitutionsForBlockScopedBindings();
-                }
-
-                const firstOriginalDeclaration = firstOrUndefined(initializer.declarations);
-                if (firstOriginalDeclaration && isBindingPattern(firstOriginalDeclaration.name)) {
-                    // This works whether the declaration is a var, let, or const.
-                    // It will use rhsIterationValue _a[_i] as the initializer.
-                    const declarations = flattenVariableDestructuring(
-                        firstOriginalDeclaration,
-                        createElementAccess(rhsReference, counter),
-                        visitor
-                    );
-
-                    const declarationList = createVariableDeclarationList(declarations, /*location*/ initializer);
-                    setOriginalNode(declarationList, initializer);
-
-                    // Adjust the source map range for the first declaration to align with the old
-                    // emitter.
-                    const firstDeclaration = declarations[0];
-                    const lastDeclaration = lastOrUndefined(declarations);
-                    setSourceMapRange(declarationList, createRange(firstDeclaration.pos, lastDeclaration.end));
-
-                    statements.push(
-                        createVariableStatement(
-                            /*modifiers*/ undefined,
-                            declarationList
-                        )
-                    );
-                }
-                else {
-                    // The following call does not include the initializer, so we have
-                    // to emit it separately.
-                    statements.push(
-                        createVariableStatement(
-                            /*modifiers*/ undefined,
-                            setOriginalNode(
-                                createVariableDeclarationList([
-                                    createVariableDeclaration(
-                                        firstOriginalDeclaration ? firstOriginalDeclaration.name : createTempVariable(/*recordTempVariable*/ undefined),
-                                        /*type*/ undefined,
-                                        createElementAccess(rhsReference, counter)
-                                    )
-                                ], /*location*/ moveRangePos(initializer, -1)),
-                                initializer
-                            ),
-                            /*location*/ moveRangeEnd(initializer, -1)
-                        )
-                    );
-                }
-            }
-            else {
-                // Initializer is an expression. Emit the expression in the body, so that it's
-                // evaluated on every iteration.
-                const assignment = createAssignment(initializer, createElementAccess(rhsReference, counter));
-                if (isDestructuringAssignment(assignment)) {
-                    // This is a destructuring pattern, so we flatten the destructuring instead.
-                    statements.push(
-                        createStatement(
-                            flattenDestructuringAssignment(
-                                context,
-                                assignment,
-                                /*needsValue*/ false,
-                                hoistVariableDeclaration,
-                                visitor
-                            )
-                        )
-                    );
-                }
-                else {
-                    // Currently there is not way to check that assignment is binary expression of destructing assignment
-                    // so we have to cast never type to binaryExpression
-                    (<BinaryExpression>assignment).end = initializer.end;
-                    statements.push(createStatement(assignment, /*location*/ moveRangeEnd(initializer, -1)));
-                }
-            }
-
-            let bodyLocation: TextRange;
-            let statementsLocation: TextRange;
-            if (convertedLoopBodyStatements) {
-                addRange(statements, convertedLoopBodyStatements);
-            }
-            else {
-                const statement = visitNode(node.statement, visitor, isStatement);
-                if (isBlock(statement)) {
-                    addRange(statements, statement.statements);
-                    bodyLocation = statement;
-                    statementsLocation = statement.statements;
-                }
-                else {
-                    statements.push(statement);
-                }
-            }
-
-            // The old emitter does not emit source maps for the expression
-            setEmitFlags(expression, EmitFlags.NoSourceMap | getEmitFlags(expression));
-
-            // The old emitter does not emit source maps for the block.
-            // We add the location to preserve comments.
-            const body = createBlock(
-                createNodeArray(statements, /*location*/ statementsLocation),
-                /*location*/ bodyLocation
-            );
-
-            setEmitFlags(body, EmitFlags.NoSourceMap | EmitFlags.NoTokenSourceMaps);
-
-            const forStatement = createFor(
-                setEmitFlags(
-                    createVariableDeclarationList([
-                        createVariableDeclaration(counter, /*type*/ undefined, createLiteral(0), /*location*/ moveRangePos(node.expression, -1)),
-                        createVariableDeclaration(rhsReference, /*type*/ undefined, expression, /*location*/ node.expression)
-                    ], /*location*/ node.expression),
-                    EmitFlags.NoHoisting
-                ),
-                createLessThan(
-                    counter,
-                    createPropertyAccess(rhsReference, "length"),
-                    /*location*/ node.expression
-                ),
-                createPostfixIncrement(counter, /*location*/ node.expression),
-                body,
-                /*location*/ node
-            );
-
-            // Disable trailing source maps for the OpenParenToken to align source map emit with the old emitter.
-            setEmitFlags(forStatement, EmitFlags.NoTokenTrailingSourceMaps);
-            return forStatement;
+            return <ForStatement>convertForOf(node, convertedLoopBodyStatements, visitor, enableSubstitutionsForBlockScopedBindings, context, /*transformRest*/ false);
         }
 
         /**
@@ -2751,7 +2261,7 @@ namespace ts {
                 setEmitFlags(thisArg, EmitFlags.NoSubstitution);
             }
             let resultingCall: CallExpression | BinaryExpression;
-            if (node.transformFlags & TransformFlags.ContainsSpreadElementExpression) {
+            if (node.transformFlags & TransformFlags.ContainsSpreadExpression) {
                 // [source]
                 //      f(...a, b)
                 //      x.m(...a, b)
@@ -2813,7 +2323,7 @@ namespace ts {
          */
         function visitNewExpression(node: NewExpression): LeftHandSideExpression {
             // We are here because we contain a SpreadElementExpression.
-            Debug.assert((node.transformFlags & TransformFlags.ContainsSpreadElementExpression) !== 0);
+            Debug.assert((node.transformFlags & TransformFlags.ContainsSpreadExpression) !== 0);
 
             // [source]
             //      new C(...a)
@@ -2834,7 +2344,7 @@ namespace ts {
         }
 
         /**
-         * Transforms an array of Expression nodes that contains a SpreadElementExpression.
+         * Transforms an array of Expression nodes that contains a SpreadExpression.
          *
          * @param elements The array of Expression nodes.
          * @param needsUniqueCopy A value indicating whether to ensure that the result is a fresh array.
@@ -2851,14 +2361,14 @@ namespace ts {
             // expressions into an array literal.
             const numElements = elements.length;
             const segments = flatten(
-                spanMap(elements, partitionSpreadElement, (partition, visitPartition, _start, end) =>
+                spanMap(elements, partitionSpread, (partition, visitPartition, _start, end) =>
                     visitPartition(partition, multiLine, hasTrailingComma && end === numElements)
                 )
             );
 
             if (segments.length === 1) {
                 const firstElement = elements[0];
-                return needsUniqueCopy && isSpreadElementExpression(firstElement) && firstElement.expression.kind !== SyntaxKind.ArrayLiteralExpression
+                return needsUniqueCopy && isSpreadExpression(firstElement) && firstElement.expression.kind !== SyntaxKind.ArrayLiteralExpression
                     ? createArraySlice(segments[0])
                     : segments[0];
             }
@@ -2867,17 +2377,17 @@ namespace ts {
             return createArrayConcat(segments.shift(), segments);
         }
 
-        function partitionSpreadElement(node: Expression) {
-            return isSpreadElementExpression(node)
-                ? visitSpanOfSpreadElements
-                : visitSpanOfNonSpreadElements;
+        function partitionSpread(node: Expression) {
+            return isSpreadExpression(node)
+                ? visitSpanOfSpreads
+                : visitSpanOfNonSpreads;
         }
 
-        function visitSpanOfSpreadElements(chunk: Expression[]): VisitResult<Expression> {
-            return map(chunk, visitExpressionOfSpreadElement);
+        function visitSpanOfSpreads(chunk: Expression[]): VisitResult<Expression> {
+            return map(chunk, visitExpressionOfSpread);
         }
 
-        function visitSpanOfNonSpreadElements(chunk: Expression[], multiLine: boolean, hasTrailingComma: boolean): VisitResult<Expression> {
+        function visitSpanOfNonSpreads(chunk: Expression[], multiLine: boolean, hasTrailingComma: boolean): VisitResult<Expression> {
             return createArrayLiteral(
                 visitNodes(createNodeArray(chunk, /*location*/ undefined, hasTrailingComma), visitor, isExpression),
                 /*location*/ undefined,
@@ -2886,11 +2396,11 @@ namespace ts {
         }
 
         /**
-         * Transforms the expression of a SpreadElementExpression node.
+         * Transforms the expression of a SpreadExpression node.
          *
-         * @param node A SpreadElementExpression node.
+         * @param node A SpreadExpression node.
          */
-        function visitExpressionOfSpreadElement(node: SpreadElementExpression) {
+        function visitExpressionOfSpread(node: SpreadElement) {
             return visitNode(node.expression, visitor, isExpression);
         }
 
@@ -3076,7 +2586,7 @@ namespace ts {
             const statements: Statement[] = [];
             startLexicalEnvironment();
             addRange(statements, prologue);
-            addCaptureThisForNodeIfNeeded(statements, node);
+            addCaptureThisForNodeIfNeeded(statements, node, enableSubstitutionsForCapturedThis);
             addRange(statements, visitNodes(createNodeArray(remaining), visitor, isStatement));
             addRange(statements, endLexicalEnvironment());
             const clone = getMutableClone(node);
@@ -3266,11 +2776,11 @@ namespace ts {
             }
 
             const callArgument = singleOrUndefined((<CallExpression>statementExpression).arguments);
-            if (!callArgument || !nodeIsSynthesized(callArgument) || callArgument.kind !== SyntaxKind.SpreadElementExpression) {
+            if (!callArgument || !nodeIsSynthesized(callArgument) || callArgument.kind !== SyntaxKind.SpreadElement) {
                 return false;
             }
 
-            const expression = (<SpreadElementExpression>callArgument).expression;
+            const expression = (<SpreadElement>callArgument).expression;
             return isIdentifier(expression) && expression === parameter.name;
         }
     }
diff --git a/src/compiler/transformers/es2016.ts b/src/compiler/transformers/es2016.ts
index fba1d300903..56d7fb0249a 100644
--- a/src/compiler/transformers/es2016.ts
+++ b/src/compiler/transformers/es2016.ts
@@ -32,7 +32,6 @@ namespace ts {
             switch (node.kind) {
                 case SyntaxKind.BinaryExpression:
                     return visitBinaryExpression(<BinaryExpression>node);
-
                 default:
                     Debug.failBadSyntaxKind(node);
                     return visitEachChild(node, visitor, context);
diff --git a/src/compiler/transformers/esnext.ts b/src/compiler/transformers/esnext.ts
new file mode 100644
index 00000000000..1fad209bdb3
--- /dev/null
+++ b/src/compiler/transformers/esnext.ts
@@ -0,0 +1,272 @@
+/// <reference path="../factory.ts" />
+/// <reference path="../visitor.ts" />
+
+/*@internal*/
+namespace ts {
+    export function transformESNext(context: TransformationContext) {
+        const {
+            hoistVariableDeclaration,
+        } = context;
+        let currentSourceFile: SourceFile;
+        return transformSourceFile;
+
+        function transformSourceFile(node: SourceFile) {
+            currentSourceFile = node;
+            return visitEachChild(node, visitor, context);
+        }
+
+        function visitor(node: Node): VisitResult<Node> {
+            if (node.transformFlags & TransformFlags.ESNext) {
+                return visitorWorker(node);
+            }
+            else if (node.transformFlags & TransformFlags.ContainsESNext) {
+                return visitEachChild(node, visitor, context);
+            }
+            else {
+                return node;
+            }
+        }
+
+        function visitorWorker(node: Node): VisitResult<Node> {
+            switch (node.kind) {
+                case SyntaxKind.ObjectLiteralExpression:
+                    return visitObjectLiteralExpression(node as ObjectLiteralExpression);
+                case SyntaxKind.BinaryExpression:
+                    return visitBinaryExpression(node as BinaryExpression);
+                case SyntaxKind.VariableDeclaration:
+                    return visitVariableDeclaration(node as VariableDeclaration);
+                case SyntaxKind.ForOfStatement:
+                    return visitForOfStatement(node as ForOfStatement);
+                case SyntaxKind.ObjectBindingPattern:
+                case SyntaxKind.ArrayBindingPattern:
+                    return node;
+                case SyntaxKind.FunctionDeclaration:
+                    return visitFunctionDeclaration(node as FunctionDeclaration);
+                case SyntaxKind.FunctionExpression:
+                    return visitFunctionExpression(node as FunctionExpression);
+                case SyntaxKind.ArrowFunction:
+                    return visitArrowFunction(node as ArrowFunction);
+                case SyntaxKind.Parameter:
+                    return visitParameter(node as ParameterDeclaration);
+                default:
+                    Debug.failBadSyntaxKind(node);
+                    return visitEachChild(node, visitor, context);
+            }
+        }
+
+        function chunkObjectLiteralElements(elements: ObjectLiteralElement[]): Expression[] {
+            let chunkObject: (ShorthandPropertyAssignment | PropertyAssignment)[];
+            const objects: Expression[] = [];
+            for (const e of elements) {
+                if (e.kind === SyntaxKind.SpreadAssignment) {
+                    if (chunkObject) {
+                        objects.push(createObjectLiteral(chunkObject));
+                        chunkObject = undefined;
+                    }
+                    const target = (e as SpreadAssignment).expression;
+                    objects.push(visitNode(target, visitor, isExpression));
+                }
+                else {
+                    if (!chunkObject) {
+                        chunkObject = [];
+                    }
+                    if (e.kind === SyntaxKind.PropertyAssignment) {
+                        const p = e as PropertyAssignment;
+                        chunkObject.push(createPropertyAssignment(p.name, visitNode(p.initializer, visitor, isExpression)));
+                    }
+                    else {
+                        chunkObject.push(e as ShorthandPropertyAssignment);
+                    }
+                }
+            }
+            if (chunkObject) {
+                objects.push(createObjectLiteral(chunkObject));
+            }
+
+            return objects;
+        }
+
+        function visitObjectLiteralExpression(node: ObjectLiteralExpression): Expression {
+            // spread elements emit like so:
+            // non-spread elements are chunked together into object literals, and then all are passed to __assign:
+            //     { a, ...o, b } => __assign({a}, o, {b});
+            // If the first element is a spread element, then the first argument to __assign is {}:
+            //     { ...o, a, b, ...o2 } => __assign({}, o, {a, b}, o2)
+            const objects = chunkObjectLiteralElements(node.properties);
+            if (objects.length && objects[0].kind !== SyntaxKind.ObjectLiteralExpression) {
+                objects.unshift(createObjectLiteral());
+            }
+            return createCall(createIdentifier("__assign"), undefined, objects);
+        }
+
+        /**
+         * Visits a BinaryExpression that contains a destructuring assignment.
+         *
+         * @param node A BinaryExpression node.
+         */
+        function visitBinaryExpression(node: BinaryExpression): Expression {
+            if (isDestructuringAssignment(node) && node.left.transformFlags & TransformFlags.AssertESNext) {
+                return flattenDestructuringAssignment(context, node, /*needsDestructuringValue*/ true, hoistVariableDeclaration, visitor, /*transformRest*/ true);
+            }
+
+            return visitEachChild(node, visitor, context);
+        }
+
+        /**
+         * Visits a VariableDeclaration node with a binding pattern.
+         *
+         * @param node A VariableDeclaration node.
+         */
+        function visitVariableDeclaration(node: VariableDeclaration): VisitResult<VariableDeclaration> {
+            // If we are here it is because the name contains a binding pattern with a rest somewhere in it.
+            if (isBindingPattern(node.name) && node.name.transformFlags & TransformFlags.AssertESNext) {
+                const result = flattenVariableDestructuring(node, /*value*/ undefined, visitor, /*recordTempVariable*/ undefined, /*transformRest*/ true);
+                return result;
+            }
+
+            return visitEachChild(node, visitor, context);
+        }
+
+        /**
+         * Visits a ForOfStatement and converts it into a ES2015-compatible ForOfStatement.
+         *
+         * @param node A ForOfStatement.
+         */
+        function visitForOfStatement(node: ForOfStatement): VisitResult<Statement> {
+            // The following ESNext code:
+            //
+            //    for (let { x, y, ...rest } of expr) { }
+            //
+            // should be emitted as
+            //
+            //    for (var _a of expr) {
+            //        let { x, y } = _a, rest = __rest(_a, ["x", "y"]);
+            //    }
+            //
+            // where _a is a temp emitted to capture the RHS.
+            // When the left hand side is an expression instead of a let declaration,
+            // the `let` before the `{ x, y }` is not emitted.
+            // When the left hand side is a let/const, the v is renamed if there is
+            // another v in scope.
+            // Note that all assignments to the LHS are emitted in the body, including
+            // all destructuring.
+            // Note also that because an extra statement is needed to assign to the LHS,
+            // for-of bodies are always emitted as blocks.
+
+            // for (<init> of <expression>) <statement>
+            // where <init> is [let] variabledeclarationlist | expression
+            const initializer = node.initializer;
+            if (!isRestBindingPattern(initializer) && !isRestAssignment(initializer)) {
+                return visitEachChild(node, visitor, context);
+            }
+
+            return convertForOf(node, undefined, visitor, noop, context, /*transformRest*/ true);
+        }
+
+        function isRestBindingPattern(initializer: ForInitializer) {
+            if (isVariableDeclarationList(initializer)) {
+                const declaration = firstOrUndefined(initializer.declarations);
+                return declaration && declaration.name &&
+                    declaration.name.kind === SyntaxKind.ObjectBindingPattern &&
+                    !!(declaration.name.transformFlags & TransformFlags.ContainsSpreadExpression);
+            }
+            return false;
+        }
+
+        function isRestAssignment(initializer: ForInitializer) {
+            return initializer.kind === SyntaxKind.ObjectLiteralExpression &&
+                initializer.transformFlags & TransformFlags.ContainsSpreadExpression;
+        }
+
+        function visitParameter(node: ParameterDeclaration): ParameterDeclaration {
+            if (isObjectRestParameter(node)) {
+                // Binding patterns are converted into a generated name and are
+                // evaluated inside the function body.
+                return setOriginalNode(
+                    createParameter(
+                        /*decorators*/ undefined,
+                        /*modifiers*/ undefined,
+                        /*dotDotDotToken*/ undefined,
+                        getGeneratedNameForNode(node),
+                        /*questionToken*/ undefined,
+                        /*type*/ undefined,
+                        node.initializer,
+                        /*location*/ node
+                    ),
+                    /*original*/ node
+                );
+            }
+            else {
+                return node;
+            }
+        }
+
+        function isObjectRestParameter(node: ParameterDeclaration) {
+            return node.name &&
+                node.name.kind === SyntaxKind.ObjectBindingPattern &&
+                !!(node.name.transformFlags & TransformFlags.ContainsSpreadExpression);
+        }
+
+        function visitFunctionDeclaration(node: FunctionDeclaration): FunctionDeclaration {
+            const hasRest = forEach(node.parameters, isObjectRestParameter);
+            const body = hasRest ?
+                transformFunctionBody(node, visitor, currentSourceFile, context, noop, /*convertObjectRest*/ true) as Block :
+                visitEachChild(node.body, visitor, context);
+
+            return setOriginalNode(
+                createFunctionDeclaration(
+                    /*decorators*/ undefined,
+                    node.modifiers,
+                    node.asteriskToken,
+                    node.name,
+                    /*typeParameters*/ undefined,
+                    visitNodes(node.parameters, visitor, isParameter),
+                    /*type*/ undefined,
+                    body,
+                    /*location*/ node
+                ),
+                /*original*/ node);
+        }
+
+        function visitArrowFunction(node: ArrowFunction) {
+            const hasRest = forEach(node.parameters, isObjectRestParameter);
+            const body = hasRest ?
+                transformFunctionBody(node, visitor, currentSourceFile, context, noop, /*convertObjectRest*/ true) as Block :
+                visitEachChild(node.body, visitor, context);
+            const func = setOriginalNode(
+                createArrowFunction(
+                    /*modifiers*/ undefined,
+                    /*typeParameters*/ undefined,
+                    visitNodes(node.parameters, visitor, isParameter),
+                    /*type*/ undefined,
+                    node.equalsGreaterThanToken,
+                    body,
+                    /*location*/ node
+                ),
+                /*original*/ node
+            );
+            setEmitFlags(func, EmitFlags.CapturesThis);
+            return func;
+        }
+
+        function visitFunctionExpression(node: FunctionExpression): Expression {
+            const hasRest = forEach(node.parameters, isObjectRestParameter);
+            const body = hasRest ?
+                transformFunctionBody(node, visitor, currentSourceFile, context, noop, /*convertObjectRest*/ true) as Block :
+                visitEachChild(node.body, visitor, context);
+            return setOriginalNode(
+                createFunctionExpression(
+                    /*modifiers*/ undefined,
+                    node.asteriskToken,
+                    name,
+                    /*typeParameters*/ undefined,
+                    visitNodes(node.parameters, visitor, isParameter),
+                    /*type*/ undefined,
+                    body,
+                    /*location*/ node
+                ),
+                /*original*/ node
+            );
+        }
+    }
+}
diff --git a/src/compiler/transformers/jsx.ts b/src/compiler/transformers/jsx.ts
index 95a4016bb0a..ba762cc5f12 100644
--- a/src/compiler/transformers/jsx.ts
+++ b/src/compiler/transformers/jsx.ts
@@ -113,7 +113,8 @@ namespace ts {
                     || createAssignHelper(currentSourceFile.externalHelpersModuleName, segments);
             }
 
-            const element = createReactCreateElement(
+            const element = createExpressionForJsxElement(
+                context.getEmitResolver().getJsxFactoryEntity(),
                 compilerOptions.reactNamespace,
                 tagName,
                 objectProperties,
diff --git a/src/compiler/transformers/module/system.ts b/src/compiler/transformers/module/system.ts
index adc9385935b..0524b9354d2 100644
--- a/src/compiler/transformers/module/system.ts
+++ b/src/compiler/transformers/module/system.ts
@@ -1474,7 +1474,7 @@ namespace ts {
             if (isAssignmentExpression(node)) {
                 return hasExportedReferenceInDestructuringTarget(node.left);
             }
-            else if (isSpreadElementExpression(node)) {
+            else if (isSpreadExpression(node)) {
                 return hasExportedReferenceInDestructuringTarget(node.expression);
             }
             else if (isObjectLiteralExpression(node)) {
diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index 1362746ba57..89fa039100a 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -471,7 +471,11 @@ namespace ts {
             currentSourceFile = node;
 
             // ensure "use strict" is emitted in all scenarios in alwaysStrict mode
-            if (compilerOptions.alwaysStrict) {
+            // There is no need to emit "use strict" in the following cases:
+            //      1. The file is an external module and target is es2015 or higher
+            //      or 2. The file is an external module and module-kind is es6 or es2015 as such value is not allowed when targeting es5 or lower
+            if (compilerOptions.alwaysStrict &&
+                !(isExternalModule(node) && (compilerOptions.target >= ScriptTarget.ES2015 || compilerOptions.module === ModuleKind.ES2015))) {
                 node = ensureUseStrict(node);
             }
 
diff --git a/src/compiler/tsconfig.json b/src/compiler/tsconfig.json
index f63bdf20e34..bd70a0afb10 100644
--- a/src/compiler/tsconfig.json
+++ b/src/compiler/tsconfig.json
@@ -27,6 +27,7 @@
         "visitor.ts",
         "transformers/ts.ts",
         "transformers/jsx.ts",
+        "transformers/esnext.ts",
         "transformers/es2017.ts",
         "transformers/es2016.ts",
         "transformers/es2015.ts",
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index fb1dffad87d..c814a2b1d46 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -246,7 +246,7 @@ namespace ts {
         ConditionalExpression,
         TemplateExpression,
         YieldExpression,
-        SpreadElementExpression,
+        SpreadElement,
         ClassExpression,
         OmittedExpression,
         ExpressionWithTypeArguments,
@@ -320,6 +320,7 @@ namespace ts {
         // Property assignments
         PropertyAssignment,
         ShorthandPropertyAssignment,
+        SpreadAssignment,
 
         // Enum
         EnumMember,
@@ -418,20 +419,21 @@ namespace ts {
         HasDecorators =      1 << 11, // If the file has decorators (initialized by binding)
         HasParamDecorators = 1 << 12, // If the file has parameter decorators (initialized by binding)
         HasAsyncFunctions =  1 << 13, // If the file has async functions (initialized by binding)
-        HasJsxSpreadAttributes = 1 << 14, // If the file as JSX spread attributes (initialized by binding)
-        DisallowInContext =  1 << 15, // If node was parsed in a context where 'in-expressions' are not allowed
-        YieldContext =       1 << 16, // If node was parsed in the 'yield' context created when parsing a generator
-        DecoratorContext =   1 << 17, // If node was parsed as part of a decorator
-        AwaitContext =       1 << 18, // If node was parsed in the 'await' context created when parsing an async function
-        ThisNodeHasError =   1 << 19, // If the parser encountered an error when parsing the code that created this node
-        JavaScriptFile =     1 << 20, // If node was parsed in a JavaScript
-        ThisNodeOrAnySubNodesHasError = 1 << 21, // If this node or any of its children had an error
-        HasAggregatedChildData = 1 << 22, // If we've computed data from children and cached it in this node
+        HasSpreadAttribute = 1 << 14, // If the file as JSX spread attributes (initialized by binding)
+        HasRestAttribute =   1 << 15, // If the file has object destructure elements
+        DisallowInContext =  1 << 16, // If node was parsed in a context where 'in-expressions' are not allowed
+        YieldContext =       1 << 17, // If node was parsed in the 'yield' context created when parsing a generator
+        DecoratorContext =   1 << 18, // If node was parsed as part of a decorator
+        AwaitContext =       1 << 19, // If node was parsed in the 'await' context created when parsing an async function
+        ThisNodeHasError =   1 << 20, // If the parser encountered an error when parsing the code that created this node
+        JavaScriptFile =     1 << 21, // If node was parsed in a JavaScript
+        ThisNodeOrAnySubNodesHasError = 1 << 22, // If this node or any of its children had an error
+        HasAggregatedChildData = 1 << 23, // If we've computed data from children and cached it in this node
 
         BlockScoped = Let | Const,
 
         ReachabilityCheckFlags = HasImplicitReturn | HasExplicitReturn,
-        EmitHelperFlags = HasClassExtends | HasDecorators | HasParamDecorators | HasAsyncFunctions | HasJsxSpreadAttributes,
+        EmitHelperFlags = HasClassExtends | HasDecorators | HasParamDecorators | HasAsyncFunctions | HasSpreadAttribute | HasRestAttribute,
         ReachabilityAndEmitFlags = ReachabilityCheckFlags | EmitHelperFlags,
 
         // Parsing context flags
@@ -454,7 +456,6 @@ namespace ts {
         Async =              1 << 8,  // Property/Method/Function
         Default =            1 << 9,  // Function/Class (export default declaration)
         Const =              1 << 11, // Variable declaration
-
         HasComputedFlags =   1 << 29, // Modifier flags have been computed
 
         AccessibilityModifier = Public | Private | Protected,
@@ -649,7 +650,7 @@ namespace ts {
     export interface BindingElement extends Declaration {
         kind: SyntaxKind.BindingElement;
         propertyName?: PropertyName;        // Binding property name (in object binding pattern)
-        dotDotDotToken?: DotDotDotToken;              // Present on rest binding element
+        dotDotDotToken?: DotDotDotToken;    // Present on rest element (in object binding pattern)
         name: BindingName;                  // Declared binding element name
         initializer?: Expression;           // Optional initializer
     }
@@ -675,7 +676,7 @@ namespace ts {
         name?: PropertyName;
     }
 
-    export type ObjectLiteralElementLike = PropertyAssignment | ShorthandPropertyAssignment | MethodDeclaration | AccessorDeclaration;
+    export type ObjectLiteralElementLike = PropertyAssignment | ShorthandPropertyAssignment | MethodDeclaration | AccessorDeclaration | SpreadAssignment;
 
     export interface PropertyAssignment extends ObjectLiteralElement {
         kind: SyntaxKind.PropertyAssignment;
@@ -694,6 +695,11 @@ namespace ts {
         objectAssignmentInitializer?: Expression;
     }
 
+    export interface SpreadAssignment extends ObjectLiteralElement {
+        kind: SyntaxKind.SpreadAssignment;
+        expression: Expression;
+    }
+
     // SyntaxKind.VariableDeclaration
     // SyntaxKind.Parameter
     // SyntaxKind.BindingElement
@@ -1279,8 +1285,8 @@ namespace ts {
         multiLine?: boolean;
     }
 
-    export interface SpreadElementExpression extends Expression {
-        kind: SyntaxKind.SpreadElementExpression;
+    export interface SpreadElement extends Expression {
+        kind: SyntaxKind.SpreadElement;
         expression: Expression;
     }
 
@@ -2381,6 +2387,12 @@ namespace ts {
         CannotBeNamed
     }
 
+    /* @internal */
+    export const enum SyntheticSymbolKind {
+        UnionOrIntersection,
+        Spread
+    }
+
     export const enum TypePredicateKind {
         This,
         Identifier
@@ -2473,6 +2485,7 @@ namespace ts {
         getTypeReferenceDirectivesForSymbol(symbol: Symbol, meaning?: SymbolFlags): string[];
         isLiteralConstDeclaration(node: VariableDeclaration | PropertyDeclaration | PropertySignature | ParameterDeclaration): boolean;
         writeLiteralConstValue(node: VariableDeclaration | PropertyDeclaration | PropertySignature | ParameterDeclaration, writer: SymbolWriter): void;
+        getJsxFactoryEntity(): EntityName;
     }
 
     export const enum SymbolFlags {
@@ -2592,7 +2605,9 @@ namespace ts {
         instantiations?: Map<Type>;         // Instantiations of generic type alias (undefined if non-generic)
         mapper?: TypeMapper;                // Type mapper for instantiation alias
         referenced?: boolean;               // True if alias symbol has been referenced as a value
-        containingType?: UnionOrIntersectionType; // Containing union or intersection type for synthetic property
+        containingType?: UnionOrIntersectionType;  // Containing union or intersection type for synthetic property
+        leftSpread?: Symbol;                // Left source for synthetic spread property
+        rightSpread?: Symbol;               // Right source for synthetic spread property
         hasNonUniformType?: boolean;        // True if constituents have non-uniform types
         isPartial?: boolean;                // True if syntheric property of union type occurs in some but not all constituents
         isDiscriminantProperty?: boolean;   // True if discriminant synthetic property
@@ -3060,7 +3075,7 @@ namespace ts {
         moduleResolution?: ModuleResolutionKind;
         newLine?: NewLineKind;
         noEmit?: boolean;
-        /*@internal*/noEmitOverwritenFiles?: boolean;
+        /*@internal*/noEmitForJsFiles?: boolean;
         noEmitHelpers?: boolean;
         noEmitOnError?: boolean;
         noErrorTruncation?: boolean;
@@ -3081,6 +3096,7 @@ namespace ts {
         project?: string;
         /* @internal */ pretty?: DiagnosticStyle;
         reactNamespace?: string;
+        jsxFactory?: string;
         removeComments?: boolean;
         rootDir?: string;
         rootDirs?: string[];
@@ -3163,7 +3179,8 @@ namespace ts {
         ES2015 = 2,
         ES2016 = 3,
         ES2017 = 4,
-        Latest = ES2017,
+        ESNext = 5,
+        Latest = ESNext,
     }
 
     export const enum LanguageVariant {
@@ -3478,32 +3495,34 @@ namespace ts {
         ContainsTypeScript = 1 << 1,
         Jsx = 1 << 2,
         ContainsJsx = 1 << 3,
-        ES2017 = 1 << 4,
-        ContainsES2017 = 1 << 5,
-        ES2016 = 1 << 6,
-        ContainsES2016 = 1 << 7,
-        ES2015 = 1 << 8,
-        ContainsES2015 = 1 << 9,
-        Generator = 1 << 10,
-        ContainsGenerator = 1 << 11,
-        DestructuringAssignment = 1 << 12,
-        ContainsDestructuringAssignment = 1 << 13,
+        ESNext = 1 << 4,
+        ContainsESNext = 1 << 5,
+        ES2017 = 1 << 6,
+        ContainsES2017 = 1 << 7,
+        ES2016 = 1 << 8,
+        ContainsES2016 = 1 << 9,
+        ES2015 = 1 << 10,
+        ContainsES2015 = 1 << 11,
+        Generator = 1 << 12,
+        ContainsGenerator = 1 << 13,
+        DestructuringAssignment = 1 << 14,
+        ContainsDestructuringAssignment = 1 << 15,
 
         // Markers
         // - Flags used to indicate that a subtree contains a specific transformation.
-        ContainsDecorators = 1 << 14,
-        ContainsPropertyInitializer = 1 << 15,
-        ContainsLexicalThis = 1 << 16,
-        ContainsCapturedLexicalThis = 1 << 17,
-        ContainsLexicalThisInComputedPropertyName = 1 << 18,
-        ContainsDefaultValueAssignments = 1 << 19,
-        ContainsParameterPropertyAssignments = 1 << 20,
-        ContainsSpreadElementExpression = 1 << 21,
-        ContainsComputedPropertyName = 1 << 22,
-        ContainsBlockScopedBinding = 1 << 23,
-        ContainsBindingPattern = 1 << 24,
-        ContainsYield = 1 << 25,
-        ContainsHoistedDeclarationOrCompletion = 1 << 26,
+        ContainsDecorators = 1 << 16,
+        ContainsPropertyInitializer = 1 << 17,
+        ContainsLexicalThis = 1 << 18,
+        ContainsCapturedLexicalThis = 1 << 19,
+        ContainsLexicalThisInComputedPropertyName = 1 << 20,
+        ContainsDefaultValueAssignments = 1 << 21,
+        ContainsParameterPropertyAssignments = 1 << 22,
+        ContainsSpreadExpression = 1 << 23,
+        ContainsComputedPropertyName = 1 << 24,
+        ContainsBlockScopedBinding = 1 << 25,
+        ContainsBindingPattern = 1 << 26,
+        ContainsYield = 1 << 27,
+        ContainsHoistedDeclarationOrCompletion = 1 << 28,
 
         HasComputedFlags = 1 << 29, // Transform flags have been computed.
 
@@ -3511,6 +3530,7 @@ namespace ts {
         // - Bitmasks that are used to assert facts about the syntax of a node and its subtree.
         AssertTypeScript = TypeScript | ContainsTypeScript,
         AssertJsx = Jsx | ContainsJsx,
+        AssertESNext = ESNext | ContainsESNext,
         AssertES2017 = ES2017 | ContainsES2017,
         AssertES2016 = ES2016 | ContainsES2016,
         AssertES2015 = ES2015 | ContainsES2015,
@@ -3520,7 +3540,7 @@ namespace ts {
         // Scope Exclusions
         // - Bitmasks that exclude flags from propagating out of a specific context
         //   into the subtree flags of their container.
-        NodeExcludes = TypeScript | Jsx | ES2017 | ES2016 | ES2015 | DestructuringAssignment | Generator | HasComputedFlags,
+        NodeExcludes = TypeScript | Jsx | ESNext | ES2017 | ES2016 | ES2015 | DestructuringAssignment | Generator | HasComputedFlags,
         ArrowFunctionExcludes = NodeExcludes | ContainsDecorators | ContainsDefaultValueAssignments | ContainsLexicalThis | ContainsParameterPropertyAssignments | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
         FunctionExcludes = NodeExcludes | ContainsDecorators | ContainsDefaultValueAssignments | ContainsCapturedLexicalThis | ContainsLexicalThis | ContainsParameterPropertyAssignments | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
         ConstructorExcludes = NodeExcludes | ContainsDefaultValueAssignments | ContainsLexicalThis | ContainsCapturedLexicalThis | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
@@ -3529,7 +3549,7 @@ namespace ts {
         ModuleExcludes = NodeExcludes | ContainsDecorators | ContainsLexicalThis | ContainsCapturedLexicalThis | ContainsBlockScopedBinding | ContainsHoistedDeclarationOrCompletion,
         TypeExcludes = ~ContainsTypeScript,
         ObjectLiteralExcludes = NodeExcludes | ContainsDecorators | ContainsComputedPropertyName | ContainsLexicalThisInComputedPropertyName,
-        ArrayLiteralOrCallOrNewExcludes = NodeExcludes | ContainsSpreadElementExpression,
+        ArrayLiteralOrCallOrNewExcludes = NodeExcludes | ContainsSpreadExpression,
         VariableDeclarationListExcludes = NodeExcludes | ContainsBindingPattern,
         ParameterExcludes = NodeExcludes | ContainsBindingPattern,
 
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 299f91be662..a9f2429d376 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -192,7 +192,7 @@ namespace ts {
     export function nodePosToString(node: Node): string {
         const file = getSourceFileOfNode(node);
         const loc = getLineAndCharacterOfPosition(file, node.pos);
-        return `${ file.fileName }(${ loc.line + 1 },${ loc.character + 1 })`;
+        return `${file.fileName}(${loc.line + 1},${loc.character + 1})`;
     }
 
     export function getStartPosOfNode(node: Node): number {
@@ -439,7 +439,7 @@ namespace ts {
     }
 
     export function isBlockScope(node: Node, parentNode: Node) {
-        switch (node.kind)  {
+        switch (node.kind) {
             case SyntaxKind.SourceFile:
             case SyntaxKind.CaseBlock:
             case SyntaxKind.CatchClause:
@@ -485,6 +485,22 @@ namespace ts {
         return getFullWidth(name) === 0 ? "(Missing)" : getTextOfNode(name);
     }
 
+    export function getTextOfPropertyName(name: PropertyName): string {
+        switch (name.kind) {
+        case SyntaxKind.Identifier:
+            return (<Identifier>name).text;
+        case SyntaxKind.StringLiteral:
+        case SyntaxKind.NumericLiteral:
+            return (<LiteralExpression>name).text;
+        case SyntaxKind.ComputedPropertyName:
+            if (isStringOrNumericLiteral((<ComputedPropertyName>name).expression.kind)) {
+                return (<LiteralExpression>(<ComputedPropertyName>name).expression).text;
+            }
+        }
+
+        return undefined;
+    }
+
     export function entityNameToString(name: EntityNameOrEntityNameExpression): string {
         switch (name.kind) {
             case SyntaxKind.Identifier:
@@ -498,6 +514,10 @@ namespace ts {
 
     export function createDiagnosticForNode(node: Node, message: DiagnosticMessage, arg0?: string | number, arg1?: string | number, arg2?: string | number): Diagnostic {
         const sourceFile = getSourceFileOfNode(node);
+        return createDiagnosticForNodeInSourceFile(sourceFile, node, message, arg0, arg1, arg2);
+    }
+
+    export function createDiagnosticForNodeInSourceFile(sourceFile: SourceFile, node: Node, message: DiagnosticMessage, arg0?: string | number, arg1?: string | number, arg2?: string | number): Diagnostic {
         const span = getErrorSpanForNode(sourceFile, node);
         return createFileDiagnostic(sourceFile, span.start, span.length, message, arg0, arg1, arg2);
     }
@@ -624,9 +644,9 @@ namespace ts {
 
     export function getJsDocCommentsFromText(node: Node, text: string) {
         const commentRanges = (node.kind === SyntaxKind.Parameter ||
-                               node.kind === SyntaxKind.TypeParameter ||
-                               node.kind === SyntaxKind.FunctionExpression ||
-                               node.kind === SyntaxKind.ArrowFunction) ?
+            node.kind === SyntaxKind.TypeParameter ||
+            node.kind === SyntaxKind.FunctionExpression ||
+            node.kind === SyntaxKind.ArrowFunction) ?
             concatenate(getTrailingCommentRanges(text, node.pos), getLeadingCommentRanges(text, node.pos)) :
             getLeadingCommentRangesOfNodeFromText(node, text);
         return filter(commentRanges, isJsDocComment);
@@ -891,7 +911,7 @@ namespace ts {
     export function isObjectLiteralOrClassExpressionMethod(node: Node): node is MethodDeclaration {
         return node.kind === SyntaxKind.MethodDeclaration &&
             (node.parent.kind === SyntaxKind.ObjectLiteralExpression ||
-            node.parent.kind === SyntaxKind.ClassExpression);
+                node.parent.kind === SyntaxKind.ClassExpression);
     }
 
     export function isIdentifierTypePredicate(predicate: TypePredicate): predicate is IdentifierTypePredicate {
@@ -1113,8 +1133,8 @@ namespace ts {
                 // if the parameter's parent has a body and its grandparent is a class declaration, this is a valid target;
                 return (<FunctionLikeDeclaration>node.parent).body !== undefined
                     && (node.parent.kind === SyntaxKind.Constructor
-                    || node.parent.kind === SyntaxKind.MethodDeclaration
-                    || node.parent.kind === SyntaxKind.SetAccessor)
+                        || node.parent.kind === SyntaxKind.MethodDeclaration
+                        || node.parent.kind === SyntaxKind.SetAccessor)
                     && node.parent.parent.kind === SyntaxKind.ClassDeclaration;
         }
 
@@ -1179,7 +1199,7 @@ namespace ts {
             case SyntaxKind.PostfixUnaryExpression:
             case SyntaxKind.BinaryExpression:
             case SyntaxKind.ConditionalExpression:
-            case SyntaxKind.SpreadElementExpression:
+            case SyntaxKind.SpreadElement:
             case SyntaxKind.TemplateExpression:
             case SyntaxKind.NoSubstitutionTemplateLiteral:
             case SyntaxKind.OmittedExpression:
@@ -1461,7 +1481,7 @@ namespace ts {
         }, tags => tags);
     }
 
-   function getJSDocs<T>(node: Node, checkParentVariableStatement: boolean, getDocs: (docs: JSDoc[]) => T[], getTags: (tags: JSDocTag[]) => T[]): T[] {
+    function getJSDocs<T>(node: Node, checkParentVariableStatement: boolean, getDocs: (docs: JSDoc[]) => T[], getTags: (tags: JSDocTag[]) => T[]): T[] {
         // TODO: Get rid of getJsDocComments and friends (note the lowercase 's' in Js)
         // TODO: A lot of this work should be cached, maybe. I guess it's only used in services right now...
         let result: T[] = undefined;
@@ -1482,8 +1502,8 @@ namespace ts {
 
             const variableStatementNode =
                 isInitializerOfVariableDeclarationInStatement ? node.parent.parent.parent :
-                isVariableOfVariableDeclarationStatement ? node.parent.parent :
-                undefined;
+                    isVariableOfVariableDeclarationStatement ? node.parent.parent :
+                        undefined;
             if (variableStatementNode) {
                 result = append(result, getJSDocs(variableStatementNode, checkParentVariableStatement, getDocs, getTags));
             }
@@ -1641,14 +1661,14 @@ namespace ts {
                     return (<ForInStatement | ForOfStatement>parent).initializer === node ? AssignmentKind.Definite : AssignmentKind.None;
                 case SyntaxKind.ParenthesizedExpression:
                 case SyntaxKind.ArrayLiteralExpression:
-                case SyntaxKind.SpreadElementExpression:
+                case SyntaxKind.SpreadElement:
                     node = parent;
                     break;
                 case SyntaxKind.ShorthandPropertyAssignment:
                     if ((<ShorthandPropertyAssignment>parent).name !== node) {
                         return AssignmentKind.None;
                     }
-                    // Fall through
+                // Fall through
                 case SyntaxKind.PropertyAssignment:
                     node = parent.parent;
                     break;
@@ -2226,7 +2246,7 @@ namespace ts {
             case SyntaxKind.YieldExpression:
                 return 2;
 
-            case SyntaxKind.SpreadElementExpression:
+            case SyntaxKind.SpreadElement:
                 return 1;
 
             default:
@@ -2550,22 +2570,39 @@ namespace ts {
         if (options.outFile || options.out) {
             const moduleKind = getEmitModuleKind(options);
             const moduleEmitEnabled = moduleKind === ModuleKind.AMD || moduleKind === ModuleKind.System;
-            const sourceFiles = host.getSourceFiles();
+            const sourceFiles = getAllEmittableSourceFiles();
             // Can emit only sources that are not declaration file and are either non module code or module with --module or --target es6 specified
             return filter(sourceFiles, moduleEmitEnabled ? isNonDeclarationFile : isBundleEmitNonExternalModule);
         }
         else {
-            const sourceFiles = targetSourceFile === undefined ? host.getSourceFiles() : [targetSourceFile];
-            return filter(sourceFiles, isNonDeclarationFile);
+            const sourceFiles = targetSourceFile === undefined ? getAllEmittableSourceFiles() : [targetSourceFile];
+            return filterSourceFilesInDirectory(sourceFiles, file => host.isSourceFileFromExternalLibrary(file));
         }
+
+        function getAllEmittableSourceFiles() {
+            return options.noEmitForJsFiles ? filter(host.getSourceFiles(), sourceFile => !isSourceFileJavaScript(sourceFile)) : host.getSourceFiles();
+        }
+    }
+
+    /** Don't call this for `--outFile`, just for `--outDir` or plain emit. */
+    export function filterSourceFilesInDirectory(sourceFiles: SourceFile[], isSourceFileFromExternalLibrary: (file: SourceFile) => boolean): SourceFile[] {
+        return filter(sourceFiles, file => shouldEmitInDirectory(file, isSourceFileFromExternalLibrary));
     }
 
     function isNonDeclarationFile(sourceFile: SourceFile) {
         return !isDeclarationFile(sourceFile);
     }
 
+    /**
+     * Whether a file should be emitted in a non-`--outFile` case.
+     * Don't emit if source file is a declaration file, or was located under node_modules
+     */
+    function shouldEmitInDirectory(sourceFile: SourceFile, isSourceFileFromExternalLibrary: (file: SourceFile) => boolean): boolean {
+        return isNonDeclarationFile(sourceFile) && !isSourceFileFromExternalLibrary(sourceFile);
+    }
+
     function isBundleEmitNonExternalModule(sourceFile: SourceFile) {
-        return !isDeclarationFile(sourceFile) && !isExternalModule(sourceFile);
+        return isNonDeclarationFile(sourceFile) && !isExternalModule(sourceFile);
     }
 
     /**
@@ -2589,7 +2626,7 @@ namespace ts {
         }
         else {
             for (const sourceFile of sourceFiles) {
-                 // Don't emit if source file is a declaration file, or was located under node_modules
+                // Don't emit if source file is a declaration file, or was located under node_modules
                 if (!isDeclarationFile(sourceFile) && !host.isSourceFileFromExternalLibrary(sourceFile)) {
                     onSingleFileEmit(host, sourceFile);
                 }
@@ -2651,10 +2688,9 @@ namespace ts {
             onBundledEmit(host);
         }
         else {
-            const sourceFiles = targetSourceFile === undefined ? host.getSourceFiles() : [targetSourceFile];
+            const sourceFiles = targetSourceFile === undefined ? getSourceFilesToEmit(host) : [targetSourceFile];
             for (const sourceFile of sourceFiles) {
-                // Don't emit if source file is a declaration file, or was located under node_modules
-                if (!isDeclarationFile(sourceFile) && !host.isSourceFileFromExternalLibrary(sourceFile)) {
+                if (shouldEmitInDirectory(sourceFile, file => host.isSourceFileFromExternalLibrary(file))) {
                     onSingleFileEmit(host, sourceFile);
                 }
             }
@@ -2689,11 +2725,11 @@ namespace ts {
         function onBundledEmit(host: EmitHost) {
             // Can emit only sources that are not declaration file and are either non module code or module with
             // --module or --target es6 specified. Files included by searching under node_modules are also not emitted.
-            const bundledSources = filter(host.getSourceFiles(),
+            const bundledSources = filter(getSourceFilesToEmit(host),
                 sourceFile => !isDeclarationFile(sourceFile) &&
-                              !host.isSourceFileFromExternalLibrary(sourceFile) &&
-                              (!isExternalModule(sourceFile) ||
-                               !!getEmitModuleKind(options)));
+                    !host.isSourceFileFromExternalLibrary(sourceFile) &&
+                    (!isExternalModule(sourceFile) ||
+                        !!getEmitModuleKind(options)));
             if (bundledSources.length) {
                 const jsFilePath = options.outFile || options.out;
                 const emitFileNames: EmitFileNames = {
@@ -2879,7 +2915,7 @@ namespace ts {
         writeComment: (text: string, lineMap: number[], writer: EmitTextWriter, commentPos: number, commentEnd: number, newLine: string) => void,
         node: TextRange, newLine: string, removeComments: boolean) {
         let leadingComments: CommentRange[];
-        let currentDetachedCommentInfo: {nodePos: number, detachedCommentEndPos: number};
+        let currentDetachedCommentInfo: { nodePos: number, detachedCommentEndPos: number };
         if (removeComments) {
             // removeComments is true, only reserve pinned comment at the top of file
             // For example:
@@ -3226,10 +3262,10 @@ namespace ts {
 
     function stringifyValue(value: any): string {
         return typeof value === "string" ? `"${escapeString(value)}"`
-             : typeof value === "number" ? isFinite(value) ? String(value) : "null"
-             : typeof value === "boolean" ? value ? "true" : "false"
-             : typeof value === "object" && value ? isArray(value) ? cycleCheck(stringifyArray, value) : cycleCheck(stringifyObject, value)
-             : /*fallback*/ "null";
+            : typeof value === "number" ? isFinite(value) ? String(value) : "null"
+                : typeof value === "boolean" ? value ? "true" : "false"
+                    : typeof value === "object" && value ? isArray(value) ? cycleCheck(stringifyArray, value) : cycleCheck(stringifyObject, value)
+                        : /*fallback*/ "null";
     }
 
     function cycleCheck(cb: (value: any) => string, value: any) {
@@ -3254,7 +3290,7 @@ namespace ts {
 
     function stringifyProperty(memo: string, value: any, key: string) {
         return value === undefined || typeof value === "function" || key === "__cycle" ? memo
-             : (memo ? memo + "," : memo) + `"${escapeString(key)}":${stringifyValue(value)}`;
+            : (memo ? memo + "," : memo) + `"${escapeString(key)}":${stringifyValue(value)}`;
     }
 
     const base64Digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
@@ -3499,7 +3535,7 @@ namespace ts {
      * @param token The token.
      */
     export function createTokenRange(pos: number, token: SyntaxKind): TextRange {
-        return createRange(pos,  pos + tokenToString(token).length);
+        return createRange(pos, pos + tokenToString(token).length);
     }
 
     export function rangeIsOnSingleLine(range: TextRange, sourceFile: SourceFile) {
@@ -3862,6 +3898,7 @@ namespace ts {
         const kind = node.kind;
         return kind === SyntaxKind.PropertyAssignment
             || kind === SyntaxKind.ShorthandPropertyAssignment
+            || kind === SyntaxKind.SpreadAssignment
             || kind === SyntaxKind.MethodDeclaration
             || kind === SyntaxKind.GetAccessor
             || kind === SyntaxKind.SetAccessor
@@ -3949,8 +3986,8 @@ namespace ts {
             || kind === SyntaxKind.NoSubstitutionTemplateLiteral;
     }
 
-    export function isSpreadElementExpression(node: Node): node is SpreadElementExpression {
-        return node.kind === SyntaxKind.SpreadElementExpression;
+    export function isSpreadExpression(node: Node): node is SpreadElement {
+        return node.kind === SyntaxKind.SpreadElement;
     }
 
     export function isExpressionWithTypeArguments(node: Node): node is ExpressionWithTypeArguments {
@@ -4008,7 +4045,7 @@ namespace ts {
             || kind === SyntaxKind.YieldExpression
             || kind === SyntaxKind.ArrowFunction
             || kind === SyntaxKind.BinaryExpression
-            || kind === SyntaxKind.SpreadElementExpression
+            || kind === SyntaxKind.SpreadElement
             || kind === SyntaxKind.AsExpression
             || kind === SyntaxKind.OmittedExpression
             || isUnaryExpressionKind(kind);
@@ -4310,6 +4347,7 @@ namespace ts {
 namespace ts {
     export function getDefaultLibFileName(options: CompilerOptions): string {
         switch (options.target) {
+            case ScriptTarget.ESNext:
             case ScriptTarget.ES2017:
                 return "lib.es2017.d.ts";
             case ScriptTarget.ES2016:
diff --git a/src/compiler/visitor.ts b/src/compiler/visitor.ts
index 34cc2e07436..cc27d5c9ddf 100644
--- a/src/compiler/visitor.ts
+++ b/src/compiler/visitor.ts
@@ -267,9 +267,9 @@ namespace ts {
             case SyntaxKind.VoidExpression:
             case SyntaxKind.AwaitExpression:
             case SyntaxKind.YieldExpression:
-            case SyntaxKind.SpreadElementExpression:
+            case SyntaxKind.SpreadElement:
             case SyntaxKind.NonNullExpression:
-                result = reduceNode((<ParenthesizedExpression | DeleteExpression | TypeOfExpression | VoidExpression | AwaitExpression | YieldExpression | SpreadElementExpression | NonNullExpression>node).expression, f, result);
+                result = reduceNode((<ParenthesizedExpression | DeleteExpression | TypeOfExpression | VoidExpression | AwaitExpression | YieldExpression | SpreadElement | NonNullExpression>node).expression, f, result);
                 break;
 
             case SyntaxKind.PrefixUnaryExpression:
@@ -510,6 +510,10 @@ namespace ts {
                 result = reduceNode((<ShorthandPropertyAssignment>node).objectAssignmentInitializer, f, result);
                 break;
 
+            case SyntaxKind.SpreadAssignment:
+                result = reduceNode((node as SpreadAssignment).expression, f, result);
+                break;
+
             // Top-level nodes
             case SyntaxKind.SourceFile:
                 result = reduceLeft((<SourceFile>node).statements, f, result);
@@ -872,9 +876,9 @@ namespace ts {
                 return updateYield(<YieldExpression>node,
                     visitNode((<YieldExpression>node).expression, visitor, isExpression));
 
-            case SyntaxKind.SpreadElementExpression:
-                return updateSpread(<SpreadElementExpression>node,
-                    visitNode((<SpreadElementExpression>node).expression, visitor, isExpression));
+            case SyntaxKind.SpreadElement:
+                return updateSpread(<SpreadElement>node,
+                    visitNode((<SpreadElement>node).expression, visitor, isExpression));
 
             case SyntaxKind.ClassExpression:
                 return updateClassExpression(<ClassExpression>node,
@@ -1127,7 +1131,11 @@ namespace ts {
                     visitNode((<ShorthandPropertyAssignment>node).name, visitor, isIdentifier),
                     visitNode((<ShorthandPropertyAssignment>node).objectAssignmentInitializer, visitor, isExpression));
 
-            // Top-level nodes
+            case SyntaxKind.SpreadAssignment:
+                return updateSpreadAssignment(node as SpreadAssignment,
+                    visitNode((node as SpreadAssignment).expression, visitor, isExpression));
+
+           // Top-level nodes
             case SyntaxKind.SourceFile:
                 context.startLexicalEnvironment();
                 return updateSourceFileNode(<SourceFile>node,
diff --git a/src/harness/compilerRunner.ts b/src/harness/compilerRunner.ts
index 70c6fdac329..327932f3667 100644
--- a/src/harness/compilerRunner.ts
+++ b/src/harness/compilerRunner.ts
@@ -170,7 +170,7 @@ class CompilerBaselineRunner extends RunnerBase {
             });
 
             it("Correct Sourcemap output for " + fileName, () => {
-                Harness.Compiler.doSourcemapBaseline(justName, options, result);
+                Harness.Compiler.doSourcemapBaseline(justName, options, result, harnessSettings);
             });
 
             it("Correct type/symbol baselines for " + fileName, () => {
diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index ae32fe3db16..6ff4dccdee3 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -1026,7 +1026,7 @@ namespace FourSlash {
                 ts.displayPartsToString(help.suffixDisplayParts), expected);
         }
 
-        public verifyCurrentParameterIsletiable(isVariable: boolean) {
+        public verifyCurrentParameterIsVariable(isVariable: boolean) {
             const signature = this.getActiveSignatureHelpItem();
             assert.isOk(signature);
             assert.equal(isVariable, signature.isVariadic);
@@ -1053,6 +1053,10 @@ namespace FourSlash {
             assert.equal(this.getActiveSignatureHelpItem().parameters.length, expectedCount);
         }
 
+        public verifyCurrentSignatureHelpIsVariadic(expected: boolean) {
+            assert.equal(this.getActiveSignatureHelpItem().isVariadic, expected);
+        }
+
         public verifyCurrentSignatureHelpDocComment(docComment: string) {
             const actualDocComment = this.getActiveSignatureHelpItem().documentation;
             assert.equal(ts.displayPartsToString(actualDocComment), docComment, this.assertionMessageAtLastKnownMarker("current signature help doc comment"));
@@ -3231,6 +3235,10 @@ namespace FourSlashInterface {
             this.state.verifySignatureHelpCount(expected);
         }
 
+        public signatureHelpCurrentArgumentListIsVariadic(expected: boolean) {
+            this.state.verifyCurrentSignatureHelpIsVariadic(expected);
+        }
+
         public signatureHelpArgumentCountIs(expected: number) {
             this.state.verifySignatureHelpArgumentCount(expected);
         }
diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index a6e1ffad7f7..6c5e49a70d7 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -470,19 +470,6 @@ namespace Utils {
     }
 }
 
-namespace Harness.Path {
-    export function getFileName(fullPath: string) {
-        return fullPath.replace(/^.*[\\\/]/, "");
-    }
-
-    export function filePath(fullPath: string) {
-        fullPath = ts.normalizeSlashes(fullPath);
-        const components = fullPath.split("/");
-        const path: string[] = components.slice(0, components.length - 1);
-        return path.join("/") + "/";
-    }
-}
-
 namespace Harness {
     export interface IO {
         newLine(): string;
@@ -1090,7 +1077,9 @@ namespace Harness {
             { name: "suppressOutputPathCheck", type: "boolean" },
             { name: "noImplicitReferences", type: "boolean" },
             { name: "currentDirectory", type: "string" },
-            { name: "symlink", type: "string" }
+            { name: "symlink", type: "string" },
+            // Emitted js baseline will print full paths for every output file
+            { name: "fullEmitPaths", type: "boolean" }
         ];
 
         let optionsIndex: ts.Map<ts.CommandLineOption>;
@@ -1483,7 +1472,7 @@ namespace Harness {
             }
 
             if (typesError && symbolsError) {
-                throw new Error(typesError.message + ts.sys.newLine + symbolsError.message);
+                throw new Error(typesError.message + Harness.IO.newLine() + symbolsError.message);
             }
 
             if (typesError) {
@@ -1565,7 +1554,7 @@ namespace Harness {
             return file.writeByteOrderMark ? "\u00EF\u00BB\u00BF" : "";
         }
 
-        export function doSourcemapBaseline(baselinePath: string, options: ts.CompilerOptions, result: CompilerResult) {
+        export function doSourcemapBaseline(baselinePath: string, options: ts.CompilerOptions, result: CompilerResult, harnessSettings: Harness.TestCaseParser.CompilerSettings) {
             if (options.inlineSourceMap) {
                 if (result.sourceMaps.length > 0) {
                     throw new Error("No sourcemap files should be generated if inlineSourceMaps was set.");
@@ -1587,10 +1576,8 @@ namespace Harness {
                     }
 
                     let sourceMapCode = "";
-                    for (let i = 0; i < result.sourceMaps.length; i++) {
-                        sourceMapCode += "//// [" + Harness.Path.getFileName(result.sourceMaps[i].fileName) + "]\r\n";
-                        sourceMapCode += getByteOrderMarkText(result.sourceMaps[i]);
-                        sourceMapCode += result.sourceMaps[i].code;
+                    for (const sourceMap of result.sourceMaps) {
+                        sourceMapCode += fileOutput(sourceMap, harnessSettings);
                     }
 
                     return sourceMapCode;
@@ -1611,23 +1598,19 @@ namespace Harness {
                     tsCode += "//// [" + header + "] ////\r\n\r\n";
                 }
                 for (let i = 0; i < tsSources.length; i++) {
-                    tsCode += "//// [" + Harness.Path.getFileName(tsSources[i].unitName) + "]\r\n";
+                    tsCode += "//// [" + ts.getBaseFileName(tsSources[i].unitName) + "]\r\n";
                     tsCode += tsSources[i].content + (i < (tsSources.length - 1) ? "\r\n" : "");
                 }
 
                 let jsCode = "";
-                for (let i = 0; i < result.files.length; i++) {
-                    jsCode += "//// [" + Harness.Path.getFileName(result.files[i].fileName) + "]\r\n";
-                    jsCode += getByteOrderMarkText(result.files[i]);
-                    jsCode += result.files[i].code;
+                for (const file of result.files) {
+                    jsCode += fileOutput(file, harnessSettings);
                 }
 
                 if (result.declFilesCode.length > 0) {
                     jsCode += "\r\n\r\n";
-                    for (let i = 0; i < result.declFilesCode.length; i++) {
-                        jsCode += "//// [" + Harness.Path.getFileName(result.declFilesCode[i].fileName) + "]\r\n";
-                        jsCode += getByteOrderMarkText(result.declFilesCode[i]);
-                        jsCode += result.declFilesCode[i].code;
+                    for (const declFile of result.declFilesCode) {
+                        jsCode += fileOutput(declFile, harnessSettings);
                     }
                 }
 
@@ -1652,6 +1635,11 @@ namespace Harness {
             });
         }
 
+        function fileOutput(file: GeneratedFile, harnessSettings: Harness.TestCaseParser.CompilerSettings): string {
+            const fileName = harnessSettings["fullEmitPaths"] ? file.fileName : ts.getBaseFileName(file.fileName);
+            return "//// [" + fileName + "]\r\n" + getByteOrderMarkText(file) + file.code;
+        }
+
         export function collateOutputs(outputFiles: Harness.Compiler.GeneratedFile[]): string {
             // Collect, test, and sort the fileNames
             outputFiles.sort((a, b) => ts.compareStrings(cleanName(a.fileName), cleanName(b.fileName)));
@@ -1768,7 +1756,7 @@ namespace Harness {
         }
 
         // Regex for parsing options in the format "@Alpha: Value of any sort"
-        const optionRegex = /^[\/]{2}\s*@(\w+)\s*:\s*(\S*)/gm;  // multiple matches on multiple lines
+        const optionRegex = /^[\/]{2}\s*@(\w+)\s*:\s*([^\r\n]*)/gm;  // multiple matches on multiple lines
 
         function extractCompilerSettings(content: string): CompilerSettings {
             const opts: CompilerSettings = {};
@@ -1777,7 +1765,7 @@ namespace Harness {
             /* tslint:disable:no-null-keyword */
             while ((match = optionRegex.exec(content)) !== null) {
             /* tslint:enable:no-null-keyword */
-                opts[match[1]] = match[2];
+                opts[match[1]] = match[2].trim();
             }
 
             return opts;
@@ -1805,7 +1793,7 @@ namespace Harness {
                     // Comment line, check for global/file @options and record them
                     optionRegex.lastIndex = 0;
                     const metaDataName = testMetaData[1].toLowerCase();
-                    currentFileOptions[testMetaData[1]] = testMetaData[2];
+                    currentFileOptions[testMetaData[1]] = testMetaData[2].trim();
                     if (metaDataName !== "filename") {
                         continue;
                     }
@@ -1825,12 +1813,12 @@ namespace Harness {
                         // Reset local data
                         currentFileContent = undefined;
                         currentFileOptions = {};
-                        currentFileName = testMetaData[2];
+                        currentFileName = testMetaData[2].trim();
                         refs = [];
                     }
                     else {
                         // First metadata marker in the file
-                        currentFileName = testMetaData[2];
+                        currentFileName = testMetaData[2].trim();
                     }
                 }
                 else {
@@ -1848,7 +1836,7 @@ namespace Harness {
             }
 
             // normalize the fileName for the single file case
-            currentFileName = testUnitData.length > 0 || currentFileName ? currentFileName : Path.getFileName(fileName);
+            currentFileName = testUnitData.length > 0 || currentFileName ? currentFileName : ts.getBaseFileName(fileName);
 
             // EOF, push whatever remains
             const newTestFile2 = {
@@ -2012,7 +2000,7 @@ namespace Harness {
 
     export function isDefaultLibraryFile(filePath: string): boolean {
         // We need to make sure that the filePath is prefixed with "lib." not just containing "lib." and end with ".d.ts"
-        const fileName = Path.getFileName(filePath);
+        const fileName = ts.getBaseFileName(filePath);
         return ts.startsWith(fileName, "lib.") && ts.endsWith(fileName, ".d.ts");
     }
 
diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index 889d4f28ce9..a49f8926729 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -720,6 +720,10 @@ namespace Harness.LanguageService {
         clearImmediate(timeoutId: any): void {
             clearImmediate(timeoutId);
         }
+
+        createHash(s: string) {
+            return s;
+        }
     }
 
     export class ServerLanguageServiceAdapter implements LanguageServiceAdapter {
diff --git a/src/harness/runnerbase.ts b/src/harness/runnerbase.ts
index 346382b7a57..d50604803ed 100644
--- a/src/harness/runnerbase.ts
+++ b/src/harness/runnerbase.ts
@@ -32,7 +32,7 @@ abstract class RunnerBase {
     /** Replaces instances of full paths with fileNames only */
     static removeFullPaths(path: string) {
         // If its a full path (starts with "C:" or "/") replace with just the filename
-        let fixedPath = /^(\w:|\/)/.test(path) ? Harness.Path.getFileName(path) : path;
+        let fixedPath = /^(\w:|\/)/.test(path) ? ts.getBaseFileName(path) : path;
 
         // when running in the browser the 'full path' is the host name, shows up in error baselines
         const localHost = /http:\/localhost:\d+/g;
diff --git a/src/harness/tsconfig.json b/src/harness/tsconfig.json
index 8bf3139b9de..d3a814f26ca 100644
--- a/src/harness/tsconfig.json
+++ b/src/harness/tsconfig.json
@@ -29,6 +29,7 @@
         "../compiler/visitor.ts",
         "../compiler/transformers/ts.ts",
         "../compiler/transformers/jsx.ts",
+        "../compiler/transformers/esnext.ts",
         "../compiler/transformers/es2017.ts",
         "../compiler/transformers/es2016.ts",
         "../compiler/transformers/es2015.ts",
diff --git a/src/harness/unittests/cachingInServerLSHost.ts b/src/harness/unittests/cachingInServerLSHost.ts
index 1100bb3663b..4286d3555d8 100644
--- a/src/harness/unittests/cachingInServerLSHost.ts
+++ b/src/harness/unittests/cachingInServerLSHost.ts
@@ -43,7 +43,8 @@ namespace ts {
             setTimeout,
             clearTimeout,
             setImmediate: typeof setImmediate !== "undefined" ? setImmediate : action => setTimeout(action, 0),
-            clearImmediate: typeof clearImmediate !== "undefined" ? clearImmediate : clearTimeout
+            clearImmediate: typeof clearImmediate !== "undefined" ? clearImmediate : clearTimeout,
+            createHash: s => s
         };
     }
 
diff --git a/src/harness/unittests/commandLineParsing.ts b/src/harness/unittests/commandLineParsing.ts
index c15490738fa..8c691992043 100644
--- a/src/harness/unittests/commandLineParsing.ts
+++ b/src/harness/unittests/commandLineParsing.ts
@@ -60,7 +60,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,invalidOption", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -165,7 +165,7 @@ namespace ts {
                         start: undefined,
                         length: undefined,
                     }, {
-                            messageText: "Argument for '--target' option must be: 'es3', 'es5', 'es6', 'es2015', 'es2016', 'es2017'",
+                            messageText: "Argument for '--target' option must be: 'es3', 'es5', 'es6', 'es2015', 'es2016', 'es2017', 'esnext'",
                             category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                             code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -263,7 +263,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -283,7 +283,7 @@ namespace ts {
             assertParseResult(["--lib", "es5, ", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
diff --git a/src/harness/unittests/compileOnSave.ts b/src/harness/unittests/compileOnSave.ts
index 797268000eb..d7731a625fe 100644
--- a/src/harness/unittests/compileOnSave.ts
+++ b/src/harness/unittests/compileOnSave.ts
@@ -492,5 +492,45 @@ namespace ts.projectSystem {
             assert.isTrue(host.fileExists(expectedEmittedFileName));
             assert.equal(host.readFile(expectedEmittedFileName), `"use strict";\r\nfunction Foo() { return 10; }\r\nexports.Foo = Foo;\r\n`);
         });
+
+        it("shoud not emit js files in external projects", () => {
+            const file1 = {
+                path: "/a/b/file1.ts",
+                content: "consonle.log('file1');"
+            };
+            // file2 has errors. The emitting should not be blocked.
+            const file2 = {
+                path: "/a/b/file2.js",
+                content: "console.log'file2');"
+            };
+            const file3 = {
+                path: "/a/b/file3.js",
+                content: "console.log('file3');"
+            };
+            const externalProjectName = "externalproject";
+            const host = createServerHost([file1, file2, file3, libFile]);
+            const session = createSession(host);
+            const projectService = session.getProjectService();
+
+            projectService.openExternalProject({
+                rootFiles: toExternalFiles([file1.path, file2.path]),
+                options: {
+                    allowJs: true,
+                    outFile: "dist.js",
+                    compileOnSave: true
+                },
+                projectFileName: externalProjectName
+            });
+
+            const emitRequest = makeSessionRequest<server.protocol.CompileOnSaveEmitFileRequestArgs>(CommandNames.CompileOnSaveEmitFile, { file: file1.path });
+            session.executeCommand(emitRequest);
+
+            const expectedOutFileName = "/a/b/dist.js";
+            assert.isTrue(host.fileExists(expectedOutFileName));
+            const outFileContent = host.readFile(expectedOutFileName);
+            assert.isTrue(outFileContent.indexOf(file1.content) !== -1);
+            assert.isTrue(outFileContent.indexOf(file2.content) === -1);
+            assert.isTrue(outFileContent.indexOf(file3.content) === -1);
+        });
     });
 }
\ No newline at end of file
diff --git a/src/harness/unittests/convertCompilerOptionsFromJson.ts b/src/harness/unittests/convertCompilerOptionsFromJson.ts
index 2942675f0ac..f44dc259710 100644
--- a/src/harness/unittests/convertCompilerOptionsFromJson.ts
+++ b/src/harness/unittests/convertCompilerOptionsFromJson.ts
@@ -176,7 +176,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--target' option must be: 'es3', 'es5', 'es6', 'es2015', 'es2016', 'es2017'",
+                        messageText: "Argument for '--target' option must be: 'es3', 'es5', 'es6', 'es2015', 'es2016', 'es2017', 'esnext'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -233,7 +233,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -264,7 +264,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -295,7 +295,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -326,7 +326,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
diff --git a/src/harness/unittests/moduleResolution.ts b/src/harness/unittests/moduleResolution.ts
index 0e391445eba..35313e15308 100644
--- a/src/harness/unittests/moduleResolution.ts
+++ b/src/harness/unittests/moduleResolution.ts
@@ -197,13 +197,9 @@ namespace ts {
                     "/a/b/c/d/node_modules/foo/index.tsx",
                     "/a/b/c/d/node_modules/foo/index.d.ts",
 
-                    "/a/b/c/d/node_modules/@types/foo.ts",
-                    "/a/b/c/d/node_modules/@types/foo.tsx",
                     "/a/b/c/d/node_modules/@types/foo.d.ts",
                     "/a/b/c/d/node_modules/@types/foo/package.json",
 
-                    "/a/b/c/d/node_modules/@types/foo/index.ts",
-                    "/a/b/c/d/node_modules/@types/foo/index.tsx",
                     "/a/b/c/d/node_modules/@types/foo/index.d.ts",
 
                     "/a/b/c/node_modules/foo.ts",
@@ -215,13 +211,9 @@ namespace ts {
                     "/a/b/c/node_modules/foo/index.tsx",
                     "/a/b/c/node_modules/foo/index.d.ts",
 
-                    "/a/b/c/node_modules/@types/foo.ts",
-                    "/a/b/c/node_modules/@types/foo.tsx",
                     "/a/b/c/node_modules/@types/foo.d.ts",
                     "/a/b/c/node_modules/@types/foo/package.json",
 
-                    "/a/b/c/node_modules/@types/foo/index.ts",
-                    "/a/b/c/node_modules/@types/foo/index.tsx",
                     "/a/b/c/node_modules/@types/foo/index.d.ts",
                 ]);
             }
@@ -257,13 +249,9 @@ namespace ts {
                     "/a/node_modules/b/c/node_modules/d/node_modules/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/d/node_modules/foo/index.d.ts",
 
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo.ts",
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo.tsx",
                     "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo.d.ts",
                     "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/package.json",
 
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/index.ts",
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/index.d.ts",
 
                     "/a/node_modules/b/c/node_modules/foo.ts",
@@ -275,13 +263,9 @@ namespace ts {
                     "/a/node_modules/b/c/node_modules/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/foo/index.d.ts",
 
-                    "/a/node_modules/b/c/node_modules/@types/foo.ts",
-                    "/a/node_modules/b/c/node_modules/@types/foo.tsx",
                     "/a/node_modules/b/c/node_modules/@types/foo.d.ts",
                     "/a/node_modules/b/c/node_modules/@types/foo/package.json",
 
-                    "/a/node_modules/b/c/node_modules/@types/foo/index.ts",
-                    "/a/node_modules/b/c/node_modules/@types/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/@types/foo/index.d.ts",
 
                     "/a/node_modules/b/node_modules/foo.ts",
@@ -293,13 +277,9 @@ namespace ts {
                     "/a/node_modules/b/node_modules/foo/index.tsx",
                     "/a/node_modules/b/node_modules/foo/index.d.ts",
 
-                    "/a/node_modules/b/node_modules/@types/foo.ts",
-                    "/a/node_modules/b/node_modules/@types/foo.tsx",
                     "/a/node_modules/b/node_modules/@types/foo.d.ts",
                     "/a/node_modules/b/node_modules/@types/foo/package.json",
 
-                    "/a/node_modules/b/node_modules/@types/foo/index.ts",
-                    "/a/node_modules/b/node_modules/@types/foo/index.tsx",
                     "/a/node_modules/b/node_modules/@types/foo/index.d.ts",
 
                     "/a/node_modules/foo.ts",
@@ -709,13 +689,9 @@ import b = require("./moduleB");
                     "/root/folder1/node_modules/file6/index.tsx",
                     "/root/folder1/node_modules/file6/index.d.ts",
 
-                    "/root/folder1/node_modules/@types/file6.ts",
-                    "/root/folder1/node_modules/@types/file6.tsx",
                     "/root/folder1/node_modules/@types/file6.d.ts",
 
                     "/root/folder1/node_modules/@types/file6/package.json",
-                    "/root/folder1/node_modules/@types/file6/index.ts",
-                    "/root/folder1/node_modules/@types/file6/index.tsx",
                     "/root/folder1/node_modules/@types/file6/index.d.ts",
                     // success on /root/node_modules/file6.ts
                 ], /*isExternalLibraryImport*/ true);
diff --git a/src/harness/unittests/reuseProgramStructure.ts b/src/harness/unittests/reuseProgramStructure.ts
index 386e02e2450..6dbd74e71d2 100644
--- a/src/harness/unittests/reuseProgramStructure.ts
+++ b/src/harness/unittests/reuseProgramStructure.ts
@@ -394,26 +394,14 @@ namespace ts {
                     "File '/fs.ts' does not exist.",
                     "File '/fs.tsx' does not exist.",
                     "File '/fs.d.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/b/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/node_modules/@types/fs.ts' does not exist.",
-                    "File '/node_modules/@types/fs.tsx' does not exist.",
                     "File '/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/node_modules/@types/fs/index.d.ts' does not exist.",
                     "File '/a/b/fs.js' does not exist.",
                     "File '/a/b/fs.jsx' does not exist.",
@@ -448,26 +436,14 @@ namespace ts {
                     "File '/fs.ts' does not exist.",
                     "File '/fs.tsx' does not exist.",
                     "File '/fs.d.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/b/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/node_modules/@types/fs.ts' does not exist.",
-                    "File '/node_modules/@types/fs.tsx' does not exist.",
                     "File '/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/node_modules/@types/fs/index.d.ts' does not exist.",
                     "File '/a/b/fs.js' does not exist.",
                     "File '/a/b/fs.jsx' does not exist.",
diff --git a/src/harness/unittests/session.ts b/src/harness/unittests/session.ts
index 05f62c4b9f6..8800e84474b 100644
--- a/src/harness/unittests/session.ts
+++ b/src/harness/unittests/session.ts
@@ -24,7 +24,8 @@ namespace ts.server {
         setTimeout() { return 0; },
         clearTimeout: noop,
         setImmediate: () => 0,
-        clearImmediate: noop
+        clearImmediate: noop,
+        createHash: s => s
     };
     const nullCancellationToken: HostCancellationToken = { isCancellationRequested: () => false };
     const mockLogger: Logger = {
diff --git a/src/harness/unittests/transpile.ts b/src/harness/unittests/transpile.ts
index 35b4f808350..20552ab9c2e 100644
--- a/src/harness/unittests/transpile.ts
+++ b/src/harness/unittests/transpile.ts
@@ -385,6 +385,10 @@ var x = 0;`, {
             options: { compilerOptions: { reactNamespace: "react" }, fileName: "input.js", reportDiagnostics: true }
         });
 
+        transpilesCorrectly("Supports setting 'jsxFactory'", "x;", {
+            options: { compilerOptions: { jsxFactory: "createElement" }, fileName: "input.js", reportDiagnostics: true }
+        });
+
         transpilesCorrectly("Supports setting 'removeComments'", "x;", {
             options: { compilerOptions: { removeComments: true }, fileName: "input.js", reportDiagnostics: true }
         });
diff --git a/src/harness/unittests/tsserverProjectSystem.ts b/src/harness/unittests/tsserverProjectSystem.ts
index 62c0957d6a3..9c3c7a4cd5b 100644
--- a/src/harness/unittests/tsserverProjectSystem.ts
+++ b/src/harness/unittests/tsserverProjectSystem.ts
@@ -434,6 +434,10 @@ namespace ts.projectSystem {
             };
         }
 
+        createHash(s: string): string {
+            return s;
+        }
+
         triggerDirectoryWatcherCallback(directoryName: string, fileName: string): void {
             const path = this.toPath(directoryName);
             const callbacks = this.watchedDirectories[path];
@@ -1658,12 +1662,8 @@ namespace ts.projectSystem {
                 "File '/a/b/node_modules/lib/index.ts' does not exist.",
                 "File '/a/b/node_modules/lib/index.tsx' does not exist.",
                 "File '/a/b/node_modules/lib/index.d.ts' does not exist.",
-                "File '/a/b/node_modules/@types/lib.ts' does not exist.",
-                "File '/a/b/node_modules/@types/lib.tsx' does not exist.",
                 "File '/a/b/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/a/b/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/a/b/node_modules/@types/lib/index.d.ts' does not exist.",
                 "File '/a/node_modules/lib.ts' does not exist.",
                 "File '/a/node_modules/lib.tsx' does not exist.",
@@ -1672,12 +1672,8 @@ namespace ts.projectSystem {
                 "File '/a/node_modules/lib/index.ts' does not exist.",
                 "File '/a/node_modules/lib/index.tsx' does not exist.",
                 "File '/a/node_modules/lib/index.d.ts' does not exist.",
-                "File '/a/node_modules/@types/lib.ts' does not exist.",
-                "File '/a/node_modules/@types/lib.tsx' does not exist.",
                 "File '/a/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/a/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/a/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/a/node_modules/@types/lib/index.d.ts' does not exist.",
                 "File '/node_modules/lib.ts' does not exist.",
                 "File '/node_modules/lib.tsx' does not exist.",
@@ -1686,12 +1682,8 @@ namespace ts.projectSystem {
                 "File '/node_modules/lib/index.ts' does not exist.",
                 "File '/node_modules/lib/index.tsx' does not exist.",
                 "File '/node_modules/lib/index.d.ts' does not exist.",
-                "File '/node_modules/@types/lib.ts' does not exist.",
-                "File '/node_modules/@types/lib.tsx' does not exist.",
                 "File '/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/node_modules/@types/lib/package.json' does not exist.",
-                "File '/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/node_modules/@types/lib/index.d.ts' does not exist.",
                 "Loading module 'lib' from 'node_modules' folder.",
                 "File '/a/b/node_modules/lib.js' does not exist.",
@@ -1699,46 +1691,23 @@ namespace ts.projectSystem {
                 "File '/a/b/node_modules/lib/package.json' does not exist.",
                 "File '/a/b/node_modules/lib/index.js' does not exist.",
                 "File '/a/b/node_modules/lib/index.jsx' does not exist.",
-                "File '/a/b/node_modules/@types/lib.js' does not exist.",
-                "File '/a/b/node_modules/@types/lib.jsx' does not exist.",
-                "File '/a/b/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.js' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.jsx' does not exist.",
                 "File '/a/node_modules/lib.js' does not exist.",
                 "File '/a/node_modules/lib.jsx' does not exist.",
                 "File '/a/node_modules/lib/package.json' does not exist.",
                 "File '/a/node_modules/lib/index.js' does not exist.",
                 "File '/a/node_modules/lib/index.jsx' does not exist.",
-                "File '/a/node_modules/@types/lib.js' does not exist.",
-                "File '/a/node_modules/@types/lib.jsx' does not exist.",
-                "File '/a/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/node_modules/@types/lib/index.js' does not exist.",
-                "File '/a/node_modules/@types/lib/index.jsx' does not exist.",
                 "File '/node_modules/lib.js' does not exist.",
                 "File '/node_modules/lib.jsx' does not exist.",
                 "File '/node_modules/lib/package.json' does not exist.",
                 "File '/node_modules/lib/index.js' does not exist.",
                 "File '/node_modules/lib/index.jsx' does not exist.",
-                "File '/node_modules/@types/lib.js' does not exist.",
-                "File '/node_modules/@types/lib.jsx' does not exist.",
-                "File '/node_modules/@types/lib/package.json' does not exist.",
-                "File '/node_modules/@types/lib/index.js' does not exist.",
-                "File '/node_modules/@types/lib/index.jsx' does not exist.",
                 "======== Module name 'lib' was not resolved. ========",
                 `Auto discovery for typings is enabled in project '${proj.getProjectName()}'. Running extra resolution pass for module 'lib' using cache location '/a/cache'.`,
-                "File '/a/cache/node_modules/lib.ts' does not exist.",
-                "File '/a/cache/node_modules/lib.tsx' does not exist.",
                 "File '/a/cache/node_modules/lib.d.ts' does not exist.",
                 "File '/a/cache/node_modules/lib/package.json' does not exist.",
-                "File '/a/cache/node_modules/lib/index.ts' does not exist.",
-                "File '/a/cache/node_modules/lib/index.tsx' does not exist.",
                 "File '/a/cache/node_modules/lib/index.d.ts' does not exist.",
-                "File '/a/cache/node_modules/@types/lib.ts' does not exist.",
-                "File '/a/cache/node_modules/@types/lib.tsx' does not exist.",
                 "File '/a/cache/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/a/cache/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/cache/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/a/cache/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/a/cache/node_modules/@types/lib/index.d.ts' exist - use it as a name resolution result.",
             ]);
             checkProjectActualFiles(proj, [file1.path, lib.path]);
@@ -2572,4 +2541,21 @@ namespace ts.projectSystem {
             assert.isTrue(diags.length === 0);
         });
     });
+
+    describe("import helpers", () => {
+        it("should not crash in tsserver", () => {
+            const f1 = {
+                path: "/a/app.ts",
+                content: "export async function foo() { return 100; }"
+            };
+            const tslib = {
+                path: "/a/node_modules/tslib/index.d.ts",
+                content: ""
+            };
+            const host = createServerHost([f1, tslib]);
+            const service = createProjectService(host);
+            service.openExternalProject({ projectFileName: "p", rootFiles: [toExternalFile(f1.path)], options: { importHelpers: true } });
+            service.checkNumberOfProjects({ externalProjects: 1 });
+        });
+    });
 }
\ No newline at end of file
diff --git a/src/lib/es2017.d.ts b/src/lib/es2017.d.ts
index 13f9d93f444..c234a9edb24 100644
--- a/src/lib/es2017.d.ts
+++ b/src/lib/es2017.d.ts
@@ -1,3 +1,4 @@
 /// <reference path="lib.es2016.d.ts" />
 /// <reference path="lib.es2017.object.d.ts" />
-/// <reference path="lib.es2017.sharedmemory.d.ts" />
\ No newline at end of file
+/// <reference path="lib.es2017.sharedmemory.d.ts" />
+/// <reference path="lib.es2017.string.d.ts" />
diff --git a/src/lib/es2017.string.d.ts b/src/lib/es2017.string.d.ts
new file mode 100644
index 00000000000..51f8e410ecf
--- /dev/null
+++ b/src/lib/es2017.string.d.ts
@@ -0,0 +1,27 @@
+interface String {
+    /**
+      * Pads the current string with a given string (possibly repeated) so that the resulting string reaches a given length.
+      * The padding is applied from the start (left) of the current string.
+      *
+      * @param maxLength The length of the resulting string once the current string has been padded.
+      *        If this parameter is smaller than the current string's length, the current string will be returned as it is.
+      *
+      * @param fillString The string to pad the current string with.
+      *        If this string is too long, it will be truncated and the left-most part will be applied.
+      *        The default value for this parameter is " " (U+0020).
+      */
+    padStart(maxLength: number, fillString?: string): string;
+
+    /**
+      * Pads the current string with a given string (possibly repeated) so that the resulting string reaches a given length.
+      * The padding is applied from the end (right) of the current string.
+      *
+      * @param maxLength The length of the resulting string once the current string has been padded.
+      *        If this parameter is smaller than the current string's length, the current string will be returned as it is.
+      *
+      * @param fillString The string to pad the current string with.
+      *        If this string is too long, it will be truncated and the left-most part will be applied.
+      *        The default value for this parameter is " " (U+0020).
+      */
+    padEnd(maxLength: number, fillString?: string): string;
+}
diff --git a/src/server/builder.ts b/src/server/builder.ts
index 548a3ac854c..5354e7ed508 100644
--- a/src/server/builder.ts
+++ b/src/server/builder.ts
@@ -5,15 +5,6 @@
 
 namespace ts.server {
 
-    interface Hash {
-        update(data: any, input_encoding?: string): Hash;
-        digest(encoding: string): any;
-    }
-
-    const crypto: {
-        createHash(algorithm: string): Hash
-    } = require("crypto");
-
     export function shouldEmitFile(scriptInfo: ScriptInfo) {
         return !scriptInfo.hasMixedContent;
     }
@@ -49,9 +40,7 @@ namespace ts.server {
         }
 
         private computeHash(text: string): string {
-            return crypto.createHash("md5")
-                .update(text)
-                .digest("base64");
+            return this.project.projectService.host.createHash(text);
         }
 
         private getSourceFile(): SourceFile {
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 269eea06464..d7dcfc810b4 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -250,6 +250,8 @@ namespace ts.server {
             readonly typingsInstaller: ITypingsInstaller = nullTypingsInstaller,
             private readonly eventHandler?: ProjectServiceEventHandler) {
 
+            Debug.assert(!!host.createHash, "'ServerHost.createHash' is required for ProjectService");
+
             this.toCanonicalFileName = createGetCanonicalFileName(host.useCaseSensitiveFileNames);
             this.directoryWatchers = new DirectoryWatchers(this);
             this.throttledOperations = new ThrottledOperations(host);
diff --git a/src/server/project.ts b/src/server/project.ts
index d01df728248..db862af7e0d 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -161,8 +161,8 @@ namespace ts.server {
                 this.compilerOptions.allowNonTsExtensions = true;
             }
 
-            if (this.projectKind === ProjectKind.Inferred) {
-                this.compilerOptions.noEmitOverwritenFiles = true;
+            if (this.projectKind === ProjectKind.Inferred || this.projectKind === ProjectKind.External) {
+                this.compilerOptions.noEmitForJsFiles = true;
             }
 
             if (languageServiceEnabled) {
diff --git a/src/server/typingsInstaller/typingsInstaller.ts b/src/server/typingsInstaller/typingsInstaller.ts
index da97dbcd194..0873d5c328b 100644
--- a/src/server/typingsInstaller/typingsInstaller.ts
+++ b/src/server/typingsInstaller/typingsInstaller.ts
@@ -69,7 +69,7 @@ namespace ts.server.typingsInstaller {
         requestId: number;
         args: string[];
         cwd: string;
-        onRequestCompleted: RequestCompletedAction
+        onRequestCompleted: RequestCompletedAction;
     };
 
     export abstract class TypingsInstaller {
@@ -380,7 +380,7 @@ namespace ts.server.typingsInstaller {
                 compilerOptions: request.compilerOptions,
                 typings,
                 unresolvedImports: request.unresolvedImports,
-                kind: server.ActionSet
+                kind: ActionSet
             };
         }
 
diff --git a/src/services/breakpoints.ts b/src/services/breakpoints.ts
index bf7fb981daa..6825ccb6371 100644
--- a/src/services/breakpoints.ts
+++ b/src/services/breakpoints.ts
@@ -264,7 +264,7 @@ namespace ts.BreakpointResolver {
                         // a or ...c  or d: x from
                         // [a, b, ...c] or { a, b } or { d: x } from destructuring pattern
                         if ((node.kind === SyntaxKind.Identifier ||
-                            node.kind == SyntaxKind.SpreadElementExpression ||
+                            node.kind == SyntaxKind.SpreadElement ||
                             node.kind === SyntaxKind.PropertyAssignment ||
                             node.kind === SyntaxKind.ShorthandPropertyAssignment) &&
                             isArrayLiteralOrObjectLiteralDestructuringPattern(node.parent)) {
diff --git a/src/services/shims.ts b/src/services/shims.ts
index b1fac14674c..f2984186790 100644
--- a/src/services/shims.ts
+++ b/src/services/shims.ts
@@ -1266,6 +1266,6 @@ namespace TypeScript.Services {
 // TODO: it should be moved into a namespace though.
 
 /* @internal */
-const toolsVersion = "2.1";
+const toolsVersion = "2.2";
 
 /* tslint:enable:no-unused-variable */
diff --git a/src/services/signatureHelp.ts b/src/services/signatureHelp.ts
index 211e55b23ba..44c2ede9fbb 100644
--- a/src/services/signatureHelp.ts
+++ b/src/services/signatureHelp.ts
@@ -557,7 +557,9 @@ namespace ts.SignatureHelp {
                 addRange(prefixDisplayParts, callTargetDisplayParts);
             }
 
+            let isVariadic: boolean;
             if (isTypeParameterList) {
+                isVariadic = false; // type parameter lists are not variadic
                 prefixDisplayParts.push(punctuationPart(SyntaxKind.LessThanToken));
                 const typeParameters = candidateSignature.typeParameters;
                 signatureHelpParameters = typeParameters && typeParameters.length > 0 ? map(typeParameters, createSignatureHelpParameterForTypeParameter) : emptyArray;
@@ -567,6 +569,7 @@ namespace ts.SignatureHelp {
                 addRange(suffixDisplayParts, parameterParts);
             }
             else {
+                isVariadic = candidateSignature.hasRestParameter;
                 const typeParameterParts = mapToDisplayParts(writer =>
                     typeChecker.getSymbolDisplayBuilder().buildDisplayForTypeParametersAndDelimiters(candidateSignature.typeParameters, writer, invocation));
                 addRange(prefixDisplayParts, typeParameterParts);
@@ -582,7 +585,7 @@ namespace ts.SignatureHelp {
             addRange(suffixDisplayParts, returnTypeParts);
 
             return {
-                isVariadic: candidateSignature.hasRestParameter,
+                isVariadic,
                 prefixDisplayParts,
                 suffixDisplayParts,
                 separatorDisplayParts: [punctuationPart(SyntaxKind.CommaToken), spacePart()],
diff --git a/src/services/tsconfig.json b/src/services/tsconfig.json
index a585236c666..9c3e068918d 100644
--- a/src/services/tsconfig.json
+++ b/src/services/tsconfig.json
@@ -28,6 +28,7 @@
         "../compiler/visitor.ts",
         "../compiler/transformers/ts.ts",
         "../compiler/transformers/jsx.ts",
+        "../compiler/transformers/esnext.ts",
         "../compiler/transformers/es2017.ts",
         "../compiler/transformers/es2016.ts",
         "../compiler/transformers/es2015.ts",
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index 8fd5f510be0..cfb6aae010b 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -530,8 +530,8 @@ namespace ts {
             case SyntaxKind.DeleteExpression:
             case SyntaxKind.VoidExpression:
             case SyntaxKind.YieldExpression:
-            case SyntaxKind.SpreadElementExpression:
-                const unaryWordExpression = (<TypeOfExpression | DeleteExpression | VoidExpression | YieldExpression | SpreadElementExpression>n);
+            case SyntaxKind.SpreadElement:
+                const unaryWordExpression = n as (TypeOfExpression | DeleteExpression | VoidExpression | YieldExpression | SpreadElement);
                 return isCompletedNode(unaryWordExpression.expression, sourceFile);
 
             case SyntaxKind.TaggedTemplateExpression:
diff --git a/tests/baselines/reference/alwaysStrictModule3.js b/tests/baselines/reference/alwaysStrictModule3.js
new file mode 100644
index 00000000000..894bad25143
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule3.js
@@ -0,0 +1,8 @@
+//// [alwaysStrictModule3.ts]
+
+// module ES2015
+export const a = 1;
+
+//// [alwaysStrictModule3.js]
+// module ES2015
+export var a = 1;
diff --git a/tests/baselines/reference/alwaysStrictModule3.symbols b/tests/baselines/reference/alwaysStrictModule3.symbols
new file mode 100644
index 00000000000..6f053673f0e
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule3.symbols
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/alwaysStrictModule3.ts ===
+
+// module ES2015
+export const a = 1;
+>a : Symbol(a, Decl(alwaysStrictModule3.ts, 2, 12))
+
diff --git a/tests/baselines/reference/alwaysStrictModule3.types b/tests/baselines/reference/alwaysStrictModule3.types
new file mode 100644
index 00000000000..75b11206a4f
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule3.types
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/alwaysStrictModule3.ts ===
+
+// module ES2015
+export const a = 1;
+>a : 1
+>1 : 1
+
diff --git a/tests/baselines/reference/alwaysStrictModule4.js b/tests/baselines/reference/alwaysStrictModule4.js
new file mode 100644
index 00000000000..1444f351bbd
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule4.js
@@ -0,0 +1,9 @@
+//// [alwaysStrictModule4.ts]
+
+// Module commonjs
+export const a = 1
+
+//// [alwaysStrictModule4.js]
+"use strict";
+// Module commonjs
+exports.a = 1;
diff --git a/tests/baselines/reference/alwaysStrictModule4.symbols b/tests/baselines/reference/alwaysStrictModule4.symbols
new file mode 100644
index 00000000000..4b8a968ae16
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule4.symbols
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/alwaysStrictModule4.ts ===
+
+// Module commonjs
+export const a = 1
+>a : Symbol(a, Decl(alwaysStrictModule4.ts, 2, 12))
+
diff --git a/tests/baselines/reference/alwaysStrictModule4.types b/tests/baselines/reference/alwaysStrictModule4.types
new file mode 100644
index 00000000000..fff87967605
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule4.types
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/alwaysStrictModule4.ts ===
+
+// Module commonjs
+export const a = 1
+>a : 1
+>1 : 1
+
diff --git a/tests/baselines/reference/alwaysStrictModule5.js b/tests/baselines/reference/alwaysStrictModule5.js
new file mode 100644
index 00000000000..74b9d72263c
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule5.js
@@ -0,0 +1,8 @@
+//// [alwaysStrictModule5.ts]
+
+// Targeting ES6
+export const a = 1; 
+
+//// [alwaysStrictModule5.js]
+// Targeting ES6
+export const a = 1;
diff --git a/tests/baselines/reference/alwaysStrictModule5.symbols b/tests/baselines/reference/alwaysStrictModule5.symbols
new file mode 100644
index 00000000000..903bf3c5c98
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule5.symbols
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/alwaysStrictModule5.ts ===
+
+// Targeting ES6
+export const a = 1; 
+>a : Symbol(a, Decl(alwaysStrictModule5.ts, 2, 12))
+
diff --git a/tests/baselines/reference/alwaysStrictModule5.types b/tests/baselines/reference/alwaysStrictModule5.types
new file mode 100644
index 00000000000..2bfa329ad7e
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule5.types
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/alwaysStrictModule5.ts ===
+
+// Targeting ES6
+export const a = 1; 
+>a : 1
+>1 : 1
+
diff --git a/tests/baselines/reference/alwaysStrictModule6.js b/tests/baselines/reference/alwaysStrictModule6.js
new file mode 100644
index 00000000000..9a603926169
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule6.js
@@ -0,0 +1,9 @@
+//// [alwaysStrictModule6.ts]
+
+// Targeting ES5
+export const a = 1; 
+
+//// [alwaysStrictModule6.js]
+"use strict";
+// Targeting ES5
+exports.a = 1;
diff --git a/tests/baselines/reference/alwaysStrictModule6.symbols b/tests/baselines/reference/alwaysStrictModule6.symbols
new file mode 100644
index 00000000000..59a70f3e5b5
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule6.symbols
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/alwaysStrictModule6.ts ===
+
+// Targeting ES5
+export const a = 1; 
+>a : Symbol(a, Decl(alwaysStrictModule6.ts, 2, 12))
+
diff --git a/tests/baselines/reference/alwaysStrictModule6.types b/tests/baselines/reference/alwaysStrictModule6.types
new file mode 100644
index 00000000000..0970380911e
--- /dev/null
+++ b/tests/baselines/reference/alwaysStrictModule6.types
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/alwaysStrictModule6.ts ===
+
+// Targeting ES5
+export const a = 1; 
+>a : 1
+>1 : 1
+
diff --git a/tests/baselines/reference/commonSourceDirectory.js b/tests/baselines/reference/commonSourceDirectory.js
new file mode 100644
index 00000000000..1a863dbecbd
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory.js
@@ -0,0 +1,29 @@
+//// [tests/cases/compiler/commonSourceDirectory.ts] ////
+
+//// [index.ts]
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+
+export const x = 0;
+
+//// [bar.d.ts]
+declare module "bar" {
+    export const y = 0;
+}
+
+//// [index.ts]
+/// <reference path="../types/bar.d.ts"/>
+import { x } from "foo";
+import { y } from "bar";
+x + y;
+
+
+//// [/app/bin/index.js]
+"use strict";
+/// <reference path="../types/bar.d.ts"/>
+var foo_1 = require("foo");
+var bar_1 = require("bar");
+foo_1.x + bar_1.y;
+//# sourceMappingURL=/app/myMapRoot/index.js.map
+
+//// [/app/bin/index.d.ts]
+/// <reference path="../../types/bar.d.ts" />
diff --git a/tests/baselines/reference/commonSourceDirectory.js.map b/tests/baselines/reference/commonSourceDirectory.js.map
new file mode 100644
index 00000000000..8e3f925eee9
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory.js.map
@@ -0,0 +1,2 @@
+//// [/app/bin/index.js.map]
+{"version":3,"file":"index.js","sourceRoot":"/app/mySourceRoot/","sources":["index.ts"],"names":[],"mappings":";AAAA,yCAAyC;AACzC,2BAAwB;AACxB,2BAAwB;AACxB,OAAC,GAAG,OAAC,CAAC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/commonSourceDirectory.sourcemap.txt b/tests/baselines/reference/commonSourceDirectory.sourcemap.txt
new file mode 100644
index 00000000000..ac198eaf02c
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory.sourcemap.txt
@@ -0,0 +1,58 @@
+===================================================================
+JsFile: index.js
+mapUrl: /app/myMapRoot/index.js.map
+sourceRoot: /app/mySourceRoot/
+sources: index.ts
+===================================================================
+-------------------------------------------------------------------
+emittedFile:/app/bin/index.js
+sourceFile:index.ts
+-------------------------------------------------------------------
+>>>"use strict";
+>>>/// <reference path="../types/bar.d.ts"/>
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1 >
+2 >/// <reference path="../types/bar.d.ts"/>
+1 >Emitted(2, 1) Source(1, 1) + SourceIndex(0)
+2 >Emitted(2, 42) Source(1, 42) + SourceIndex(0)
+---
+>>>var foo_1 = require("foo");
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^
+3 >                           ^->
+1 >
+  >
+2 >import { x } from "foo";
+1 >Emitted(3, 1) Source(2, 1) + SourceIndex(0)
+2 >Emitted(3, 28) Source(2, 25) + SourceIndex(0)
+---
+>>>var bar_1 = require("bar");
+1->
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1->
+  >
+2 >import { y } from "bar";
+1->Emitted(4, 1) Source(3, 1) + SourceIndex(0)
+2 >Emitted(4, 28) Source(3, 25) + SourceIndex(0)
+---
+>>>foo_1.x + bar_1.y;
+1 >
+2 >^^^^^^^
+3 >       ^^^
+4 >          ^^^^^^^
+5 >                 ^
+6 >                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >
+2 >x
+3 >        + 
+4 >          y
+5 >                 ;
+1 >Emitted(5, 1) Source(4, 1) + SourceIndex(0)
+2 >Emitted(5, 8) Source(4, 2) + SourceIndex(0)
+3 >Emitted(5, 11) Source(4, 5) + SourceIndex(0)
+4 >Emitted(5, 18) Source(4, 6) + SourceIndex(0)
+5 >Emitted(5, 19) Source(4, 7) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=/app/myMapRoot/index.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/commonSourceDirectory.symbols b/tests/baselines/reference/commonSourceDirectory.symbols
new file mode 100644
index 00000000000..5409286ede5
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory.symbols
@@ -0,0 +1,24 @@
+=== /app/index.ts ===
+/// <reference path="../types/bar.d.ts"/>
+import { x } from "foo";
+>x : Symbol(x, Decl(index.ts, 1, 8))
+
+import { y } from "bar";
+>y : Symbol(y, Decl(index.ts, 2, 8))
+
+x + y;
+>x : Symbol(x, Decl(index.ts, 1, 8))
+>y : Symbol(y, Decl(index.ts, 2, 8))
+
+=== /node_modules/foo/index.ts ===
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+
+export const x = 0;
+>x : Symbol(x, Decl(index.ts, 2, 12))
+
+=== /types/bar.d.ts ===
+declare module "bar" {
+    export const y = 0;
+>y : Symbol(y, Decl(bar.d.ts, 1, 16))
+}
+
diff --git a/tests/baselines/reference/commonSourceDirectory.types b/tests/baselines/reference/commonSourceDirectory.types
new file mode 100644
index 00000000000..ce0169582d7
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory.types
@@ -0,0 +1,27 @@
+=== /app/index.ts ===
+/// <reference path="../types/bar.d.ts"/>
+import { x } from "foo";
+>x : 0
+
+import { y } from "bar";
+>y : 0
+
+x + y;
+>x + y : number
+>x : 0
+>y : 0
+
+=== /node_modules/foo/index.ts ===
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+
+export const x = 0;
+>x : 0
+>0 : 0
+
+=== /types/bar.d.ts ===
+declare module "bar" {
+    export const y = 0;
+>y : 0
+>0 : 0
+}
+
diff --git a/tests/baselines/reference/commonSourceDirectory_dts.js b/tests/baselines/reference/commonSourceDirectory_dts.js
new file mode 100644
index 00000000000..8aa0bd04e11
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory_dts.js
@@ -0,0 +1,21 @@
+//// [tests/cases/compiler/commonSourceDirectory_dts.ts] ////
+
+//// [bar.d.ts]
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+
+declare const y: number;
+
+//// [index.ts]
+/// <reference path="../lib/bar.d.ts" />
+export const x = y;
+
+
+//// [/app/bin/index.js]
+"use strict";
+/// <reference path="../lib/bar.d.ts" />
+exports.x = y;
+//# sourceMappingURL=/app/myMapRoot/index.js.map
+
+//// [/app/bin/index.d.ts]
+/// <reference path="../lib/bar.d.ts" />
+export declare const x: number;
diff --git a/tests/baselines/reference/commonSourceDirectory_dts.js.map b/tests/baselines/reference/commonSourceDirectory_dts.js.map
new file mode 100644
index 00000000000..b33518dd04c
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory_dts.js.map
@@ -0,0 +1,2 @@
+//// [/app/bin/index.js.map]
+{"version":3,"file":"index.js","sourceRoot":"/app/mySourceRoot/","sources":["index.ts"],"names":[],"mappings":";AAAA,wCAAwC;AAC3B,QAAA,CAAC,GAAG,CAAC,CAAC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/commonSourceDirectory_dts.sourcemap.txt b/tests/baselines/reference/commonSourceDirectory_dts.sourcemap.txt
new file mode 100644
index 00000000000..90603ae3652
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory_dts.sourcemap.txt
@@ -0,0 +1,42 @@
+===================================================================
+JsFile: index.js
+mapUrl: /app/myMapRoot/index.js.map
+sourceRoot: /app/mySourceRoot/
+sources: index.ts
+===================================================================
+-------------------------------------------------------------------
+emittedFile:/app/bin/index.js
+sourceFile:index.ts
+-------------------------------------------------------------------
+>>>"use strict";
+>>>/// <reference path="../lib/bar.d.ts" />
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1 >
+2 >/// <reference path="../lib/bar.d.ts" />
+1 >Emitted(2, 1) Source(1, 1) + SourceIndex(0)
+2 >Emitted(2, 41) Source(1, 41) + SourceIndex(0)
+---
+>>>exports.x = y;
+1 >
+2 >^^^^^^^^
+3 >        ^
+4 >         ^^^
+5 >            ^
+6 >             ^
+7 >              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >export const 
+2 >
+3 >        x
+4 >          = 
+5 >            y
+6 >             ;
+1 >Emitted(3, 1) Source(2, 14) + SourceIndex(0)
+2 >Emitted(3, 9) Source(2, 14) + SourceIndex(0)
+3 >Emitted(3, 10) Source(2, 15) + SourceIndex(0)
+4 >Emitted(3, 13) Source(2, 18) + SourceIndex(0)
+5 >Emitted(3, 14) Source(2, 19) + SourceIndex(0)
+6 >Emitted(3, 15) Source(2, 20) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=/app/myMapRoot/index.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/commonSourceDirectory_dts.symbols b/tests/baselines/reference/commonSourceDirectory_dts.symbols
new file mode 100644
index 00000000000..740a8aef921
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory_dts.symbols
@@ -0,0 +1,12 @@
+=== /app/src/index.ts ===
+/// <reference path="../lib/bar.d.ts" />
+export const x = y;
+>x : Symbol(x, Decl(index.ts, 1, 12))
+>y : Symbol(y, Decl(bar.d.ts, 2, 13))
+
+=== /app/lib/bar.d.ts ===
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+
+declare const y: number;
+>y : Symbol(y, Decl(bar.d.ts, 2, 13))
+
diff --git a/tests/baselines/reference/commonSourceDirectory_dts.types b/tests/baselines/reference/commonSourceDirectory_dts.types
new file mode 100644
index 00000000000..b41b91c978f
--- /dev/null
+++ b/tests/baselines/reference/commonSourceDirectory_dts.types
@@ -0,0 +1,12 @@
+=== /app/src/index.ts ===
+/// <reference path="../lib/bar.d.ts" />
+export const x = y;
+>x : number
+>y : number
+
+=== /app/lib/bar.d.ts ===
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+
+declare const y: number;
+>y : number
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.js b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.js
new file mode 100644
index 00000000000..d5bf31bd755
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.js
@@ -0,0 +1,17 @@
+//// [declarationEmitTypeAliasWithTypeParameters2.ts]
+
+export type Bar<X, Y, Z> = () => [X, Y, Z];
+export type Baz<M, N> = Bar<M, string, N>;
+export type Baa<Y> = Baz<boolean, Y>;
+export const y = (x: Baa<number>) => 1
+
+//// [declarationEmitTypeAliasWithTypeParameters2.js]
+"use strict";
+exports.y = function (x) { return 1; };
+
+
+//// [declarationEmitTypeAliasWithTypeParameters2.d.ts]
+export declare type Bar<X, Y, Z> = () => [X, Y, Z];
+export declare type Baz<M, N> = Bar<M, string, N>;
+export declare type Baa<Y> = Baz<boolean, Y>;
+export declare const y: (x: Bar<boolean, string, number>) => number;
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.symbols b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.symbols
new file mode 100644
index 00000000000..cc13e9fd30b
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.symbols
@@ -0,0 +1,30 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters2.ts ===
+
+export type Bar<X, Y, Z> = () => [X, Y, Z];
+>Bar : Symbol(Bar, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 0, 0))
+>X : Symbol(X, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 16))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 18))
+>Z : Symbol(Z, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 21))
+>X : Symbol(X, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 16))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 18))
+>Z : Symbol(Z, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 21))
+
+export type Baz<M, N> = Bar<M, string, N>;
+>Baz : Symbol(Baz, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 43))
+>M : Symbol(M, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 2, 16))
+>N : Symbol(N, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 2, 18))
+>Bar : Symbol(Bar, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 0, 0))
+>M : Symbol(M, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 2, 16))
+>N : Symbol(N, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 2, 18))
+
+export type Baa<Y> = Baz<boolean, Y>;
+>Baa : Symbol(Baa, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 2, 42))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 3, 16))
+>Baz : Symbol(Baz, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 1, 43))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 3, 16))
+
+export const y = (x: Baa<number>) => 1
+>y : Symbol(y, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 4, 12))
+>x : Symbol(x, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 4, 18))
+>Baa : Symbol(Baa, Decl(declarationEmitTypeAliasWithTypeParameters2.ts, 2, 42))
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.types b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.types
new file mode 100644
index 00000000000..74becc49765
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.types
@@ -0,0 +1,32 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters2.ts ===
+
+export type Bar<X, Y, Z> = () => [X, Y, Z];
+>Bar : Bar<X, Y, Z>
+>X : X
+>Y : Y
+>Z : Z
+>X : X
+>Y : Y
+>Z : Z
+
+export type Baz<M, N> = Bar<M, string, N>;
+>Baz : Bar<M, string, N>
+>M : M
+>N : N
+>Bar : Bar<X, Y, Z>
+>M : M
+>N : N
+
+export type Baa<Y> = Baz<boolean, Y>;
+>Baa : Bar<boolean, string, Y>
+>Y : Y
+>Baz : Bar<M, string, N>
+>Y : Y
+
+export const y = (x: Baa<number>) => 1
+>y : (x: Bar<boolean, string, number>) => number
+>(x: Baa<number>) => 1 : (x: Bar<boolean, string, number>) => number
+>x : Bar<boolean, string, number>
+>Baa : Bar<boolean, string, Y>
+>1 : 1
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.js b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.js
new file mode 100644
index 00000000000..9e2a366a685
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.js
@@ -0,0 +1,21 @@
+//// [declarationEmitTypeAliasWithTypeParameters3.ts]
+
+type Foo<T> = {
+    foo<U>(): Foo<U>
+};
+function bar() {
+    return {} as Foo<number>;
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters3.js]
+function bar() {
+    return {};
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters3.d.ts]
+declare type Foo<T> = {
+    foo<U>(): Foo<U>;
+};
+declare function bar(): Foo<number>;
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.symbols b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.symbols
new file mode 100644
index 00000000000..a18b1372cf1
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.symbols
@@ -0,0 +1,20 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters3.ts ===
+
+type Foo<T> = {
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 0, 0))
+>T : Symbol(T, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 1, 9))
+
+    foo<U>(): Foo<U>
+>foo : Symbol(foo, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 1, 15))
+>U : Symbol(U, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 2, 8))
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 0, 0))
+>U : Symbol(U, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 2, 8))
+
+};
+function bar() {
+>bar : Symbol(bar, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 3, 2))
+
+    return {} as Foo<number>;
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters3.ts, 0, 0))
+}
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.types b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.types
new file mode 100644
index 00000000000..1b2ff140178
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters3.types
@@ -0,0 +1,22 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters3.ts ===
+
+type Foo<T> = {
+>Foo : Foo<T>
+>T : T
+
+    foo<U>(): Foo<U>
+>foo : <U>() => Foo<U>
+>U : U
+>Foo : Foo<T>
+>U : U
+
+};
+function bar() {
+>bar : () => Foo<number>
+
+    return {} as Foo<number>;
+>{} as Foo<number> : Foo<number>
+>{} : {}
+>Foo : Foo<T>
+}
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.js b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.js
new file mode 100644
index 00000000000..26908d915e0
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.js
@@ -0,0 +1,24 @@
+//// [declarationEmitTypeAliasWithTypeParameters4.ts]
+
+type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>
+};
+type SubFoo<R> = Foo<string, R>;
+
+function foo() {
+    return {} as SubFoo<number>;
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters4.js]
+function foo() {
+    return {};
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters4.d.ts]
+declare type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>;
+};
+declare type SubFoo<R> = Foo<string, R>;
+declare function foo(): Foo<string, number>;
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.symbols b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.symbols
new file mode 100644
index 00000000000..de73f544645
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.symbols
@@ -0,0 +1,29 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters4.ts ===
+
+type Foo<T, Y> = {
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 0, 0))
+>T : Symbol(T, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 1, 9))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 1, 11))
+
+    foo<U, J>(): Foo<U, J>
+>foo : Symbol(foo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 1, 18))
+>U : Symbol(U, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 2, 8))
+>J : Symbol(J, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 2, 10))
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 0, 0))
+>U : Symbol(U, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 2, 8))
+>J : Symbol(J, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 2, 10))
+
+};
+type SubFoo<R> = Foo<string, R>;
+>SubFoo : Symbol(SubFoo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 3, 2))
+>R : Symbol(R, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 4, 12))
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 0, 0))
+>R : Symbol(R, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 4, 12))
+
+function foo() {
+>foo : Symbol(foo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 4, 32))
+
+    return {} as SubFoo<number>;
+>SubFoo : Symbol(SubFoo, Decl(declarationEmitTypeAliasWithTypeParameters4.ts, 3, 2))
+}
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.types b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.types
new file mode 100644
index 00000000000..c545ac6bb05
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.types
@@ -0,0 +1,31 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters4.ts ===
+
+type Foo<T, Y> = {
+>Foo : Foo<T, Y>
+>T : T
+>Y : Y
+
+    foo<U, J>(): Foo<U, J>
+>foo : <U, J>() => Foo<U, J>
+>U : U
+>J : J
+>Foo : Foo<T, Y>
+>U : U
+>J : J
+
+};
+type SubFoo<R> = Foo<string, R>;
+>SubFoo : Foo<string, R>
+>R : R
+>Foo : Foo<T, Y>
+>R : R
+
+function foo() {
+>foo : () => Foo<string, number>
+
+    return {} as SubFoo<number>;
+>{} as SubFoo<number> : Foo<string, number>
+>{} : {}
+>SubFoo : Foo<string, R>
+}
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.errors.txt b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.errors.txt
new file mode 100644
index 00000000000..7f683dcc7b7
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.errors.txt
@@ -0,0 +1,16 @@
+tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters5.ts(5,25): error TS4081: Exported type alias 'SubFoo' has or is using private name 'Foo'.
+
+
+==== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters5.ts (1 errors) ====
+    
+    type Foo<T, Y> = {
+        foo<U, J>(): Foo<U, J>
+    };
+    export type SubFoo<R> = Foo<string, R>;
+                            ~~~
+!!! error TS4081: Exported type alias 'SubFoo' has or is using private name 'Foo'.
+    
+    function foo() {
+        return {} as SubFoo<number>;
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.js b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.js
new file mode 100644
index 00000000000..2f4fff7d72c
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.js
@@ -0,0 +1,17 @@
+//// [declarationEmitTypeAliasWithTypeParameters5.ts]
+
+type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>
+};
+export type SubFoo<R> = Foo<string, R>;
+
+function foo() {
+    return {} as SubFoo<number>;
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters5.js]
+"use strict";
+function foo() {
+    return {};
+}
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.js b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.js
new file mode 100644
index 00000000000..c8001446e3e
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.js
@@ -0,0 +1,24 @@
+//// [declarationEmitTypeAliasWithTypeParameters6.ts]
+
+type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>
+};
+type SubFoo<R, S> = Foo<S, R>;
+
+function foo() {
+    return {} as SubFoo<number, string>;
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters6.js]
+function foo() {
+    return {};
+}
+
+
+//// [declarationEmitTypeAliasWithTypeParameters6.d.ts]
+declare type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>;
+};
+declare type SubFoo<R, S> = Foo<S, R>;
+declare function foo(): Foo<string, number>;
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.symbols b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.symbols
new file mode 100644
index 00000000000..ec29989f078
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.symbols
@@ -0,0 +1,31 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters6.ts ===
+
+type Foo<T, Y> = {
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 0, 0))
+>T : Symbol(T, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 1, 9))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 1, 11))
+
+    foo<U, J>(): Foo<U, J>
+>foo : Symbol(foo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 1, 18))
+>U : Symbol(U, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 2, 8))
+>J : Symbol(J, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 2, 10))
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 0, 0))
+>U : Symbol(U, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 2, 8))
+>J : Symbol(J, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 2, 10))
+
+};
+type SubFoo<R, S> = Foo<S, R>;
+>SubFoo : Symbol(SubFoo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 3, 2))
+>R : Symbol(R, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 4, 12))
+>S : Symbol(S, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 4, 14))
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 0, 0))
+>S : Symbol(S, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 4, 14))
+>R : Symbol(R, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 4, 12))
+
+function foo() {
+>foo : Symbol(foo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 4, 30))
+
+    return {} as SubFoo<number, string>;
+>SubFoo : Symbol(SubFoo, Decl(declarationEmitTypeAliasWithTypeParameters6.ts, 3, 2))
+}
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.types b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.types
new file mode 100644
index 00000000000..b02ccbc2be7
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.types
@@ -0,0 +1,33 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters6.ts ===
+
+type Foo<T, Y> = {
+>Foo : Foo<T, Y>
+>T : T
+>Y : Y
+
+    foo<U, J>(): Foo<U, J>
+>foo : <U, J>() => Foo<U, J>
+>U : U
+>J : J
+>Foo : Foo<T, Y>
+>U : U
+>J : J
+
+};
+type SubFoo<R, S> = Foo<S, R>;
+>SubFoo : Foo<S, R>
+>R : R
+>S : S
+>Foo : Foo<T, Y>
+>S : S
+>R : R
+
+function foo() {
+>foo : () => Foo<string, number>
+
+    return {} as SubFoo<number, string>;
+>{} as SubFoo<number, string> : Foo<string, number>
+>{} : {}
+>SubFoo : Foo<S, R>
+}
+
diff --git a/tests/baselines/reference/decoratorInJsFile.errors.txt b/tests/baselines/reference/decoratorInJsFile.errors.txt
new file mode 100644
index 00000000000..93bd5143b74
--- /dev/null
+++ b/tests/baselines/reference/decoratorInJsFile.errors.txt
@@ -0,0 +1,13 @@
+tests/cases/compiler/a.js(4,12): error TS8010: 'types' can only be used in a .ts file.
+
+
+==== tests/cases/compiler/a.js (1 errors) ====
+    
+    @SomeDecorator
+    class SomeClass {
+        foo(x: number) {
+               ~~~~~~
+!!! error TS8010: 'types' can only be used in a .ts file.
+    
+        }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/decoratorInJsFile1.errors.txt b/tests/baselines/reference/decoratorInJsFile1.errors.txt
new file mode 100644
index 00000000000..f4422c0c2d9
--- /dev/null
+++ b/tests/baselines/reference/decoratorInJsFile1.errors.txt
@@ -0,0 +1,16 @@
+tests/cases/compiler/a.js(3,7): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set the 'experimentalDecorators' option to remove this warning.
+tests/cases/compiler/a.js(4,12): error TS8010: 'types' can only be used in a .ts file.
+
+
+==== tests/cases/compiler/a.js (2 errors) ====
+    
+    @SomeDecorator
+    class SomeClass {
+          ~~~~~~~~~
+!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set the 'experimentalDecorators' option to remove this warning.
+        foo(x: number) {
+               ~~~~~~
+!!! error TS8010: 'types' can only be used in a .ts file.
+    
+        }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.errors.txt b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.errors.txt
index bb4b79987e3..33344b9b5eb 100644
--- a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.errors.txt
+++ b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.errors.txt
@@ -5,16 +5,12 @@ tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAs
 tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(4,6): error TS2459: Type 'string | number | {}' has no property 'i1' and no string index signature.
 tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(5,12): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(5,21): error TS2353: Object literal may only specify known properties, and 'f212' does not exist in type '{ f21: any; }'.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(6,7): error TS1180: Property destructuring pattern expected.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(7,5): error TS2353: Object literal may only specify known properties, and 'a' does not exist in type '{ d1: any; }'.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(7,11): error TS2353: Object literal may only specify known properties, and 'b' does not exist in type '{ d1: any; }'.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(7,24): error TS2353: Object literal may only specify known properties, and 'e' does not exist in type '{ d1: any; }'.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(9,7): error TS1005: ':' expected.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(9,15): error TS1005: ':' expected.
-tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(10,12): error TS1005: ':' expected.
+tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(6,7): error TS1005: ':' expected.
+tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(6,15): error TS1005: ':' expected.
+tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts(7,12): error TS1005: ':' expected.
 
 
-==== tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts (13 errors) ====
+==== tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts (9 errors) ====
     // Error
     var {h?} = { h?: 1 };
           ~
@@ -33,17 +29,6 @@ tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAs
 !!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
                         ~~~~
 !!! error TS2353: Object literal may only specify known properties, and 'f212' does not exist in type '{ f21: any; }'.
-    var { ...d1 } = {
-          ~~~
-!!! error TS1180: Property destructuring pattern expected.
-        a: 1, b: 1, d1: 9, e: 10
-        ~
-!!! error TS2353: Object literal may only specify known properties, and 'a' does not exist in type '{ d1: any; }'.
-              ~
-!!! error TS2353: Object literal may only specify known properties, and 'b' does not exist in type '{ d1: any; }'.
-                           ~
-!!! error TS2353: Object literal may only specify known properties, and 'e' does not exist in type '{ d1: any; }'.
-    }
     var {1} = { 1 };
           ~
 !!! error TS1005: ':' expected.
@@ -51,4 +36,5 @@ tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAs
 !!! error TS1005: ':' expected.
     var {"prop"} = { "prop": 1 };
                ~
-!!! error TS1005: ':' expected.
\ No newline at end of file
+!!! error TS1005: ':' expected.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.js b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.js
index 77288e6a542..0872a71c73b 100644
--- a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.js
+++ b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.js
@@ -4,11 +4,9 @@ var {h?} = { h?: 1 };
 var {i}: string | number = { i: 2 };
 var {i1}: string | number| {} = { i1: 2 };
 var { f2: {f21} = { f212: "string" } }: any = undefined;
-var { ...d1 } = {
-    a: 1, b: 1, d1: 9, e: 10
-}
 var {1} = { 1 };
-var {"prop"} = { "prop": 1 };
+var {"prop"} = { "prop": 1 };
+
 
 //// [destructuringObjectBindingPatternAndAssignment3.js]
 // Error
@@ -16,8 +14,5 @@ var h = { h: 1 }.h;
 var i = { i: 2 }.i;
 var i1 = { i1: 2 }.i1;
 var _a = undefined.f2, f21 = (_a === void 0 ? { f212: "string" } : _a).f21;
-var d1 = {
-    a: 1, b: 1, d1: 9, e: 10
-}.d1;
 var  = { 1:  }[1];
 var  = { "prop": 1 }["prop"];
diff --git a/tests/baselines/reference/globalAugmentationModuleResolution.js b/tests/baselines/reference/globalAugmentationModuleResolution.js
new file mode 100644
index 00000000000..e1a4ebce8c5
--- /dev/null
+++ b/tests/baselines/reference/globalAugmentationModuleResolution.js
@@ -0,0 +1,10 @@
+//// [a.ts]
+
+export { };
+
+declare global {
+  var x: number;
+}
+
+//// [a.js]
+"use strict";
diff --git a/tests/baselines/reference/globalAugmentationModuleResolution.symbols b/tests/baselines/reference/globalAugmentationModuleResolution.symbols
new file mode 100644
index 00000000000..614860d654e
--- /dev/null
+++ b/tests/baselines/reference/globalAugmentationModuleResolution.symbols
@@ -0,0 +1,10 @@
+=== tests/cases/conformance/externalModules/a.ts ===
+
+export { };
+
+declare global {
+>global : Symbol(global, Decl(a.ts, 1, 11))
+
+  var x: number;
+>x : Symbol(x, Decl(a.ts, 4, 5))
+}
diff --git a/tests/baselines/reference/globalAugmentationModuleResolution.trace.json b/tests/baselines/reference/globalAugmentationModuleResolution.trace.json
new file mode 100644
index 00000000000..0637a088a01
--- /dev/null
+++ b/tests/baselines/reference/globalAugmentationModuleResolution.trace.json
@@ -0,0 +1 @@
+[]
\ No newline at end of file
diff --git a/tests/baselines/reference/globalAugmentationModuleResolution.types b/tests/baselines/reference/globalAugmentationModuleResolution.types
new file mode 100644
index 00000000000..c057ea2943d
--- /dev/null
+++ b/tests/baselines/reference/globalAugmentationModuleResolution.types
@@ -0,0 +1,10 @@
+=== tests/cases/conformance/externalModules/a.ts ===
+
+export { };
+
+declare global {
+>global : any
+
+  var x: number;
+>x : number
+}
diff --git a/tests/baselines/reference/importHelpersNoHelpers.errors.txt b/tests/baselines/reference/importHelpersNoHelpers.errors.txt
index ebb25dbd7c9..fa9a935c8d8 100644
--- a/tests/baselines/reference/importHelpersNoHelpers.errors.txt
+++ b/tests/baselines/reference/importHelpersNoHelpers.errors.txt
@@ -1,13 +1,17 @@
+error TS2305: Module 'tslib' has no exported member '__assign'.
 error TS2305: Module 'tslib' has no exported member '__decorate'.
 error TS2305: Module 'tslib' has no exported member '__extends'.
 error TS2305: Module 'tslib' has no exported member '__metadata'.
 error TS2305: Module 'tslib' has no exported member '__param'.
+error TS2305: Module 'tslib' has no exported member '__rest'.
 
 
+!!! error TS2305: Module 'tslib' has no exported member '__assign'.
 !!! error TS2305: Module 'tslib' has no exported member '__decorate'.
 !!! error TS2305: Module 'tslib' has no exported member '__extends'.
 !!! error TS2305: Module 'tslib' has no exported member '__metadata'.
 !!! error TS2305: Module 'tslib' has no exported member '__param'.
+!!! error TS2305: Module 'tslib' has no exported member '__rest'.
 ==== tests/cases/compiler/external.ts (0 errors) ====
     export class A { }
     export class B extends A { }
@@ -20,6 +24,10 @@ error TS2305: Module 'tslib' has no exported member '__param'.
         }
     }
     
+    const o = { a: 1 };
+    const y = { ...o };
+    const { ...x } = y;
+    
 ==== tests/cases/compiler/script.ts (0 errors) ====
     class A { }
     class B extends A { }
@@ -33,4 +41,5 @@ error TS2305: Module 'tslib' has no exported member '__param'.
     }
     
 ==== tests/cases/compiler/tslib.d.ts (0 errors) ====
-    export {}
\ No newline at end of file
+    export {}
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/importHelpersNoHelpers.js b/tests/baselines/reference/importHelpersNoHelpers.js
index e22d1f4353d..690a6c05f17 100644
--- a/tests/baselines/reference/importHelpersNoHelpers.js
+++ b/tests/baselines/reference/importHelpersNoHelpers.js
@@ -11,6 +11,10 @@ class C {
     method(@dec x: number) {
     }
 }
+
+const o = { a: 1 };
+const y = { ...o };
+const { ...x } = y;
 
 //// [script.ts]
 class A { }
@@ -25,7 +29,8 @@ class C {
 }
 
 //// [tslib.d.ts]
-export {}
+export {}
+
 
 //// [external.js]
 "use strict";
@@ -61,6 +66,9 @@ C = tslib_1.__decorate([
     dec,
     tslib_1.__metadata("design:paramtypes", [])
 ], C);
+var o = { a: 1 };
+var y = __assign({}, o);
+var x = __rest(y, []);
 //// [script.js]
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
diff --git a/tests/baselines/reference/incompatibleAssignmentOfIdenticallyNamedTypes.errors.txt b/tests/baselines/reference/incompatibleAssignmentOfIdenticallyNamedTypes.errors.txt
new file mode 100644
index 00000000000..3f1de47c347
--- /dev/null
+++ b/tests/baselines/reference/incompatibleAssignmentOfIdenticallyNamedTypes.errors.txt
@@ -0,0 +1,15 @@
+tests/cases/compiler/incompatibleAssignmentOfIdenticallyNamedTypes.ts(6,9): error TS90010: Type 'T' is not assignable to type 'T'. Two different types with this name exist, but they are unrelated.
+
+
+==== tests/cases/compiler/incompatibleAssignmentOfIdenticallyNamedTypes.ts (1 errors) ====
+    interface T { }
+    declare const a: T;
+    class Foo<T> {
+        x: T;
+        fn() {
+            this.x = a;
+            ~~~~~~
+!!! error TS90010: Type 'T' is not assignable to type 'T'. Two different types with this name exist, but they are unrelated.
+        }
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/incompatibleAssignmentOfIdenticallyNamedTypes.js b/tests/baselines/reference/incompatibleAssignmentOfIdenticallyNamedTypes.js
new file mode 100644
index 00000000000..677d177a4d0
--- /dev/null
+++ b/tests/baselines/reference/incompatibleAssignmentOfIdenticallyNamedTypes.js
@@ -0,0 +1,20 @@
+//// [incompatibleAssignmentOfIdenticallyNamedTypes.ts]
+interface T { }
+declare const a: T;
+class Foo<T> {
+    x: T;
+    fn() {
+        this.x = a;
+    }
+}
+
+
+//// [incompatibleAssignmentOfIdenticallyNamedTypes.js]
+var Foo = (function () {
+    function Foo() {
+    }
+    Foo.prototype.fn = function () {
+        this.x = a;
+    };
+    return Foo;
+}());
diff --git a/tests/baselines/reference/interfaceSpread.errors.txt b/tests/baselines/reference/interfaceSpread.errors.txt
new file mode 100644
index 00000000000..c6acc633912
--- /dev/null
+++ b/tests/baselines/reference/interfaceSpread.errors.txt
@@ -0,0 +1,21 @@
+tests/cases/conformance/types/spread/interfaceSpread.ts(2,5): error TS2698: Interface declaration cannot contain a spread property.
+tests/cases/conformance/types/spread/interfaceSpread.ts(7,10): error TS2339: Property 'jam' does not exist on type 'Congealed<{ jam: number; }, { peanutButter: number; }>'.
+tests/cases/conformance/types/spread/interfaceSpread.ts(8,10): error TS2339: Property 'peanutButter' does not exist on type 'Congealed<{ jam: number; }, { peanutButter: number; }>'.
+
+
+==== tests/cases/conformance/types/spread/interfaceSpread.ts (3 errors) ====
+    interface Congealed<T, U> {
+        ...T
+        ~~~~
+!!! error TS2698: Interface declaration cannot contain a spread property.
+        ...U
+    }
+    
+    let sandwich: Congealed<{jam: number }, { peanutButter: number }>;
+    sandwich.jam;
+             ~~~
+!!! error TS2339: Property 'jam' does not exist on type 'Congealed<{ jam: number; }, { peanutButter: number; }>'.
+    sandwich.peanutButter;
+             ~~~~~~~~~~~~
+!!! error TS2339: Property 'peanutButter' does not exist on type 'Congealed<{ jam: number; }, { peanutButter: number; }>'.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/interfaceSpread.js b/tests/baselines/reference/interfaceSpread.js
new file mode 100644
index 00000000000..89f25314366
--- /dev/null
+++ b/tests/baselines/reference/interfaceSpread.js
@@ -0,0 +1,15 @@
+//// [interfaceSpread.ts]
+interface Congealed<T, U> {
+    ...T
+    ...U
+}
+
+let sandwich: Congealed<{jam: number }, { peanutButter: number }>;
+sandwich.jam;
+sandwich.peanutButter;
+
+
+//// [interfaceSpread.js]
+var sandwich;
+sandwich.jam;
+sandwich.peanutButter;
diff --git a/tests/baselines/reference/jsFileCompilationAbstractModifier.errors.txt b/tests/baselines/reference/jsFileCompilationAbstractModifier.errors.txt
new file mode 100644
index 00000000000..c7d2ad270be
--- /dev/null
+++ b/tests/baselines/reference/jsFileCompilationAbstractModifier.errors.txt
@@ -0,0 +1,16 @@
+error TS5055: Cannot write file 'tests/cases/compiler/a.js' because it would overwrite input file.
+  Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig
+tests/cases/compiler/a.js(1,1): error TS8009: 'abstract' can only be used in a .ts file.
+tests/cases/compiler/a.js(2,5): error TS8009: 'abstract' can only be used in a .ts file.
+
+
+!!! error TS5055: Cannot write file 'tests/cases/compiler/a.js' because it would overwrite input file.
+!!! error TS5055:   Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig
+==== tests/cases/compiler/a.js (2 errors) ====
+    abstract class c {
+    ~~~~~~~~
+!!! error TS8009: 'abstract' can only be used in a .ts file.
+        abstract x;
+        ~~~~~~~~
+!!! error TS8009: 'abstract' can only be used in a .ts file.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/jsFileCompilationConstModifier.symbols b/tests/baselines/reference/jsFileCompilationConstModifier.symbols
new file mode 100644
index 00000000000..137dafd3473
--- /dev/null
+++ b/tests/baselines/reference/jsFileCompilationConstModifier.symbols
@@ -0,0 +1,4 @@
+=== tests/cases/compiler/a.js ===
+const c = 10;
+>c : Symbol(c, Decl(a.js, 0, 5))
+
diff --git a/tests/baselines/reference/jsFileCompilationConstModifier.types b/tests/baselines/reference/jsFileCompilationConstModifier.types
new file mode 100644
index 00000000000..8e74679f2a5
--- /dev/null
+++ b/tests/baselines/reference/jsFileCompilationConstModifier.types
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/a.js ===
+const c = 10;
+>c : 10
+>10 : 10
+
diff --git a/tests/baselines/reference/jsxFactoryAndReactNamespace.errors.txt b/tests/baselines/reference/jsxFactoryAndReactNamespace.errors.txt
new file mode 100644
index 00000000000..c4859fd534c
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryAndReactNamespace.errors.txt
@@ -0,0 +1,53 @@
+error TS5053: Option 'reactNamespace' cannot be specified with option 'jsxFactory'.
+
+
+!!! error TS5053: Option 'reactNamespace' cannot be specified with option 'jsxFactory'.
+==== tests/cases/compiler/Element.ts (0 errors) ====
+    
+    declare namespace JSX {
+        interface Element {
+            name: string;
+            isIntrinsic: boolean;
+            isCustomElement: boolean;
+            toString(renderId?: number): string;
+            bindDOM(renderId?: number): number;
+            resetComponent(): void;
+            instantiateComponents(renderId?: number): number;
+            props: any;
+        }
+    }
+    export namespace Element {
+        export function isElement(el: any): el is JSX.Element {
+            return el.markAsChildOfRootElement !== undefined;
+        }
+    
+        export function createElement(args: any[]) {
+    
+            return {
+            }
+        }
+    }
+    
+    export let createElement = Element.createElement;
+    
+    function toCamelCase(text: string): string {
+        return text[0].toLowerCase() + text.substring(1);
+    }
+    
+==== tests/cases/compiler/test.tsx (0 errors) ====
+    import { Element} from './Element';
+    
+    let c: {
+    	a?: {
+    		b: string
+    	}
+    };
+    
+    class A {
+    	view() {
+    		return [
+    			<meta content="helloworld"></meta>,
+    			<meta content={c.a!.b}></meta>
+    		];
+    	}
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryAndReactNamespace.js b/tests/baselines/reference/jsxFactoryAndReactNamespace.js
new file mode 100644
index 00000000000..0a6402ca70c
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryAndReactNamespace.js
@@ -0,0 +1,81 @@
+//// [tests/cases/compiler/jsxFactoryAndReactNamespace.ts] ////
+
+//// [Element.ts]
+
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+//// [test.tsx]
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
+
+//// [Element.js]
+"use strict";
+var Element;
+(function (Element) {
+    function isElement(el) {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+    Element.isElement = isElement;
+    function createElement(args) {
+        return {};
+    }
+    Element.createElement = createElement;
+})(Element = exports.Element || (exports.Element = {}));
+exports.createElement = Element.createElement;
+function toCamelCase(text) {
+    return text[0].toLowerCase() + text.substring(1);
+}
+//// [test.js]
+"use strict";
+const Element_1 = require("./Element");
+let c;
+class A {
+    view() {
+        return [
+            Element_1.Element.createElement("meta", { content: "helloworld" }),
+            Element_1.Element.createElement("meta", { content: c.a.b })
+        ];
+    }
+}
diff --git a/tests/baselines/reference/jsxFactoryIdentifier.js b/tests/baselines/reference/jsxFactoryIdentifier.js
new file mode 100644
index 00000000000..82c8f6410e6
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifier.js
@@ -0,0 +1,83 @@
+//// [tests/cases/compiler/jsxFactoryIdentifier.ts] ////
+
+//// [Element.ts]
+
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+//// [test.tsx]
+import { Element} from './Element';
+let createElement = Element.createElement;
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
+
+//// [Element.js]
+"use strict";
+var Element;
+(function (Element) {
+    function isElement(el) {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+    Element.isElement = isElement;
+    function createElement(args) {
+        return {};
+    }
+    Element.createElement = createElement;
+})(Element = exports.Element || (exports.Element = {}));
+exports.createElement = Element.createElement;
+function toCamelCase(text) {
+    return text[0].toLowerCase() + text.substring(1);
+}
+//# sourceMappingURL=Element.js.map//// [test.js]
+"use strict";
+const Element_1 = require("./Element");
+let createElement = Element_1.Element.createElement;
+let c;
+class A {
+    view() {
+        return [
+            createElement("meta", { content: "helloworld" }),
+            createElement("meta", { content: c.a.b })
+        ];
+    }
+}
+//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifier.js.map b/tests/baselines/reference/jsxFactoryIdentifier.js.map
new file mode 100644
index 00000000000..cad196b8ba5
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifier.js.map
@@ -0,0 +1,3 @@
+//// [Element.js.map]
+{"version":3,"file":"Element.js","sourceRoot":"","sources":["Element.ts"],"names":[],"mappings":";AAaA,IAAiB,OAAO,CAUvB;AAVD,WAAiB,OAAO;IACpB,mBAA0B,EAAO;QAC7B,MAAM,CAAC,EAAE,CAAC,wBAAwB,KAAK,SAAS,CAAC;IACrD,CAAC;IAFe,iBAAS,YAExB,CAAA;IAED,uBAA8B,IAAW;QAErC,MAAM,CAAC,EACN,CAAA;IACL,CAAC;IAJe,qBAAa,gBAI5B,CAAA;AACL,CAAC,EAVgB,OAAO,GAAP,eAAO,KAAP,eAAO,QAUvB;AAEU,QAAA,aAAa,GAAG,OAAO,CAAC,aAAa,CAAC;AAEjD,qBAAqB,IAAY;IAC7B,MAAM,CAAC,IAAI,CAAC,CAAC,CAAC,CAAC,WAAW,EAAE,GAAG,IAAI,CAAC,SAAS,CAAC,CAAC,CAAC,CAAC;AACrD,CAAC"}//// [test.js.map]
+{"version":3,"file":"test.js","sourceRoot":"","sources":["test.tsx"],"names":[],"mappings":";AAAA,uCAAmC;AACnC,IAAI,aAAa,GAAG,iBAAO,CAAC,aAAa,CAAC;AAC1C,IAAI,CAIH,CAAC;AAEF;IACC,IAAI;QACH,MAAM,CAAC;YACN,wBAAM,OAAO,EAAC,YAAY,GAAQ;YAClC,wBAAM,OAAO,EAAE,CAAC,CAAC,CAAE,CAAC,CAAC,GAAS;SAC9B,CAAC;IACH,CAAC;CACD"}
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifier.sourcemap.txt b/tests/baselines/reference/jsxFactoryIdentifier.sourcemap.txt
new file mode 100644
index 00000000000..a4ddc8c050b
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifier.sourcemap.txt
@@ -0,0 +1,520 @@
+===================================================================
+JsFile: Element.js
+mapUrl: Element.js.map
+sourceRoot: 
+sources: Element.ts
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/Element.js
+sourceFile:Element.ts
+-------------------------------------------------------------------
+>>>"use strict";
+>>>var Element;
+1 >
+2 >^^^^
+3 >    ^^^^^^^
+4 >           ^
+5 >            ^^^^^^^^^^->
+1 >
+  >declare namespace JSX {
+  >    interface Element {
+  >        name: string;
+  >        isIntrinsic: boolean;
+  >        isCustomElement: boolean;
+  >        toString(renderId?: number): string;
+  >        bindDOM(renderId?: number): number;
+  >        resetComponent(): void;
+  >        instantiateComponents(renderId?: number): number;
+  >        props: any;
+  >    }
+  >}
+  >
+2 >export namespace 
+3 >    Element
+4 >            {
+  >               export function isElement(el: any): el is JSX.Element {
+  >                   return el.markAsChildOfRootElement !== undefined;
+  >               }
+  >           
+  >               export function createElement(args: any[]) {
+  >           
+  >                   return {
+  >                   }
+  >               }
+  >           }
+1 >Emitted(2, 1) Source(14, 1) + SourceIndex(0)
+2 >Emitted(2, 5) Source(14, 18) + SourceIndex(0)
+3 >Emitted(2, 12) Source(14, 25) + SourceIndex(0)
+4 >Emitted(2, 13) Source(24, 2) + SourceIndex(0)
+---
+>>>(function (Element) {
+1->
+2 >^^^^^^^^^^^
+3 >           ^^^^^^^
+4 >                  ^^^^^^^^^^^->
+1->
+2 >export namespace 
+3 >           Element
+1->Emitted(3, 1) Source(14, 1) + SourceIndex(0)
+2 >Emitted(3, 12) Source(14, 18) + SourceIndex(0)
+3 >Emitted(3, 19) Source(14, 25) + SourceIndex(0)
+---
+>>>    function isElement(el) {
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^^^
+3 >                       ^^
+4 >                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1-> {
+  >    
+2 >    export function isElement(
+3 >                       el: any
+1->Emitted(4, 5) Source(15, 5) + SourceIndex(0)
+2 >Emitted(4, 24) Source(15, 31) + SourceIndex(0)
+3 >Emitted(4, 26) Source(15, 38) + SourceIndex(0)
+---
+>>>        return el.markAsChildOfRootElement !== undefined;
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^
+5 >                 ^
+6 >                  ^^^^^^^^^^^^^^^^^^^^^^^^
+7 >                                          ^^^^^
+8 >                                               ^^^^^^^^^
+9 >                                                        ^
+1->): el is JSX.Element {
+  >        
+2 >        return
+3 >               
+4 >               el
+5 >                 .
+6 >                  markAsChildOfRootElement
+7 >                                           !== 
+8 >                                               undefined
+9 >                                                        ;
+1->Emitted(5, 9) Source(16, 9) + SourceIndex(0)
+2 >Emitted(5, 15) Source(16, 15) + SourceIndex(0)
+3 >Emitted(5, 16) Source(16, 16) + SourceIndex(0)
+4 >Emitted(5, 18) Source(16, 18) + SourceIndex(0)
+5 >Emitted(5, 19) Source(16, 19) + SourceIndex(0)
+6 >Emitted(5, 43) Source(16, 43) + SourceIndex(0)
+7 >Emitted(5, 48) Source(16, 48) + SourceIndex(0)
+8 >Emitted(5, 57) Source(16, 57) + SourceIndex(0)
+9 >Emitted(5, 58) Source(16, 58) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+3 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >    
+2 >    }
+1 >Emitted(6, 5) Source(17, 5) + SourceIndex(0)
+2 >Emitted(6, 6) Source(17, 6) + SourceIndex(0)
+---
+>>>    Element.isElement = isElement;
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^
+3 >                     ^^^^^^^^^^^^
+4 >                                 ^
+5 >                                  ^->
+1->
+2 >    isElement
+3 >                     (el: any): el is JSX.Element {
+  >                             return el.markAsChildOfRootElement !== undefined;
+  >                         }
+4 >                                 
+1->Emitted(7, 5) Source(15, 21) + SourceIndex(0)
+2 >Emitted(7, 22) Source(15, 30) + SourceIndex(0)
+3 >Emitted(7, 34) Source(17, 6) + SourceIndex(0)
+4 >Emitted(7, 35) Source(17, 6) + SourceIndex(0)
+---
+>>>    function createElement(args) {
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^^^^^^^
+3 >                           ^^^^
+1->
+  >
+  >    
+2 >    export function createElement(
+3 >                           args: any[]
+1->Emitted(8, 5) Source(19, 5) + SourceIndex(0)
+2 >Emitted(8, 28) Source(19, 35) + SourceIndex(0)
+3 >Emitted(8, 32) Source(19, 46) + SourceIndex(0)
+---
+>>>        return {};
+1 >^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^
+5 >                 ^
+1 >) {
+  >
+  >        
+2 >        return
+3 >               
+4 >               {
+  >                       }
+5 >                 
+1 >Emitted(9, 9) Source(21, 9) + SourceIndex(0)
+2 >Emitted(9, 15) Source(21, 15) + SourceIndex(0)
+3 >Emitted(9, 16) Source(21, 16) + SourceIndex(0)
+4 >Emitted(9, 18) Source(22, 10) + SourceIndex(0)
+5 >Emitted(9, 19) Source(22, 10) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+3 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >    
+2 >    }
+1 >Emitted(10, 5) Source(23, 5) + SourceIndex(0)
+2 >Emitted(10, 6) Source(23, 6) + SourceIndex(0)
+---
+>>>    Element.createElement = createElement;
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^^^^^
+3 >                         ^^^^^^^^^^^^^^^^
+4 >                                         ^
+5 >                                          ^^^^^^^^^^^^^^^->
+1->
+2 >    createElement
+3 >                         (args: any[]) {
+  >                         
+  >                                 return {
+  >                                 }
+  >                             }
+4 >                                         
+1->Emitted(11, 5) Source(19, 21) + SourceIndex(0)
+2 >Emitted(11, 26) Source(19, 34) + SourceIndex(0)
+3 >Emitted(11, 42) Source(23, 6) + SourceIndex(0)
+4 >Emitted(11, 43) Source(23, 6) + SourceIndex(0)
+---
+>>>})(Element = exports.Element || (exports.Element = {}));
+1->
+2 >^
+3 > ^^
+4 >   ^^^^^^^
+5 >          ^^^
+6 >             ^^^^^^^^^^^^^^^
+7 >                            ^^^^^
+8 >                                 ^^^^^^^^^^^^^^^
+9 >                                                ^^^^^^^^
+1->
+  >
+2 >}
+3 > 
+4 >   Element
+5 >          
+6 >             Element
+7 >                            
+8 >                                 Element
+9 >                                                 {
+  >                                                    export function isElement(el: any): el is JSX.Element {
+  >                                                        return el.markAsChildOfRootElement !== undefined;
+  >                                                    }
+  >                                                
+  >                                                    export function createElement(args: any[]) {
+  >                                                
+  >                                                        return {
+  >                                                        }
+  >                                                    }
+  >                                                }
+1->Emitted(12, 1) Source(24, 1) + SourceIndex(0)
+2 >Emitted(12, 2) Source(24, 2) + SourceIndex(0)
+3 >Emitted(12, 4) Source(14, 18) + SourceIndex(0)
+4 >Emitted(12, 11) Source(14, 25) + SourceIndex(0)
+5 >Emitted(12, 14) Source(14, 18) + SourceIndex(0)
+6 >Emitted(12, 29) Source(14, 25) + SourceIndex(0)
+7 >Emitted(12, 34) Source(14, 18) + SourceIndex(0)
+8 >Emitted(12, 49) Source(14, 25) + SourceIndex(0)
+9 >Emitted(12, 57) Source(24, 2) + SourceIndex(0)
+---
+>>>exports.createElement = Element.createElement;
+1 >
+2 >^^^^^^^^
+3 >        ^^^^^^^^^^^^^
+4 >                     ^^^
+5 >                        ^^^^^^^
+6 >                               ^
+7 >                                ^^^^^^^^^^^^^
+8 >                                             ^
+1 >
+  >
+  >export let 
+2 >
+3 >        createElement
+4 >                      = 
+5 >                        Element
+6 >                               .
+7 >                                createElement
+8 >                                             ;
+1 >Emitted(13, 1) Source(26, 12) + SourceIndex(0)
+2 >Emitted(13, 9) Source(26, 12) + SourceIndex(0)
+3 >Emitted(13, 22) Source(26, 25) + SourceIndex(0)
+4 >Emitted(13, 25) Source(26, 28) + SourceIndex(0)
+5 >Emitted(13, 32) Source(26, 35) + SourceIndex(0)
+6 >Emitted(13, 33) Source(26, 36) + SourceIndex(0)
+7 >Emitted(13, 46) Source(26, 49) + SourceIndex(0)
+8 >Emitted(13, 47) Source(26, 50) + SourceIndex(0)
+---
+>>>function toCamelCase(text) {
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^
+3 >                     ^^^^
+4 >                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >
+  >
+2 >function toCamelCase(
+3 >                     text: string
+1 >Emitted(14, 1) Source(28, 1) + SourceIndex(0)
+2 >Emitted(14, 22) Source(28, 22) + SourceIndex(0)
+3 >Emitted(14, 26) Source(28, 34) + SourceIndex(0)
+---
+>>>    return text[0].toLowerCase() + text.substring(1);
+1->^^^^
+2 >    ^^^^^^
+3 >          ^
+4 >           ^^^^
+5 >               ^
+6 >                ^
+7 >                 ^
+8 >                  ^
+9 >                   ^^^^^^^^^^^
+10>                              ^^
+11>                                ^^^
+12>                                   ^^^^
+13>                                       ^
+14>                                        ^^^^^^^^^
+15>                                                 ^
+16>                                                  ^
+17>                                                   ^
+18>                                                    ^
+1->): string {
+  >    
+2 >    return
+3 >           
+4 >           text
+5 >               [
+6 >                0
+7 >                 ]
+8 >                  .
+9 >                   toLowerCase
+10>                              ()
+11>                                 + 
+12>                                   text
+13>                                       .
+14>                                        substring
+15>                                                 (
+16>                                                  1
+17>                                                   )
+18>                                                    ;
+1->Emitted(15, 5) Source(29, 5) + SourceIndex(0)
+2 >Emitted(15, 11) Source(29, 11) + SourceIndex(0)
+3 >Emitted(15, 12) Source(29, 12) + SourceIndex(0)
+4 >Emitted(15, 16) Source(29, 16) + SourceIndex(0)
+5 >Emitted(15, 17) Source(29, 17) + SourceIndex(0)
+6 >Emitted(15, 18) Source(29, 18) + SourceIndex(0)
+7 >Emitted(15, 19) Source(29, 19) + SourceIndex(0)
+8 >Emitted(15, 20) Source(29, 20) + SourceIndex(0)
+9 >Emitted(15, 31) Source(29, 31) + SourceIndex(0)
+10>Emitted(15, 33) Source(29, 33) + SourceIndex(0)
+11>Emitted(15, 36) Source(29, 36) + SourceIndex(0)
+12>Emitted(15, 40) Source(29, 40) + SourceIndex(0)
+13>Emitted(15, 41) Source(29, 41) + SourceIndex(0)
+14>Emitted(15, 50) Source(29, 50) + SourceIndex(0)
+15>Emitted(15, 51) Source(29, 51) + SourceIndex(0)
+16>Emitted(15, 52) Source(29, 52) + SourceIndex(0)
+17>Emitted(15, 53) Source(29, 53) + SourceIndex(0)
+18>Emitted(15, 54) Source(29, 54) + SourceIndex(0)
+---
+>>>}
+1 >
+2 >^
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >
+2 >}
+1 >Emitted(16, 1) Source(30, 1) + SourceIndex(0)
+2 >Emitted(16, 2) Source(30, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=Element.js.map===================================================================
+JsFile: test.js
+mapUrl: test.js.map
+sourceRoot: 
+sources: test.tsx
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/test.js
+sourceFile:test.tsx
+-------------------------------------------------------------------
+>>>"use strict";
+>>>const Element_1 = require("./Element");
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+3 >                                       ^^^^^^^^^^^^^^->
+1 >
+2 >import { Element} from './Element';
+1 >Emitted(2, 1) Source(1, 1) + SourceIndex(0)
+2 >Emitted(2, 40) Source(1, 36) + SourceIndex(0)
+---
+>>>let createElement = Element_1.Element.createElement;
+1->
+2 >^^^^
+3 >    ^^^^^^^^^^^^^
+4 >                 ^^^
+5 >                    ^^^^^^^^^^^^^^^^^
+6 >                                     ^
+7 >                                      ^^^^^^^^^^^^^
+8 >                                                   ^
+1->
+  >
+2 >let 
+3 >    createElement
+4 >                  = 
+5 >                    Element
+6 >                                     .
+7 >                                      createElement
+8 >                                                   ;
+1->Emitted(3, 1) Source(2, 1) + SourceIndex(0)
+2 >Emitted(3, 5) Source(2, 5) + SourceIndex(0)
+3 >Emitted(3, 18) Source(2, 18) + SourceIndex(0)
+4 >Emitted(3, 21) Source(2, 21) + SourceIndex(0)
+5 >Emitted(3, 38) Source(2, 28) + SourceIndex(0)
+6 >Emitted(3, 39) Source(2, 29) + SourceIndex(0)
+7 >Emitted(3, 52) Source(2, 42) + SourceIndex(0)
+8 >Emitted(3, 53) Source(2, 43) + SourceIndex(0)
+---
+>>>let c;
+1 >
+2 >^^^^
+3 >    ^
+4 >     ^
+5 >      ^^^^->
+1 >
+  >
+2 >let 
+3 >    c: {
+  >    	a?: {
+  >    		b: string
+  >    	}
+  >    }
+4 >     ;
+1 >Emitted(4, 1) Source(3, 1) + SourceIndex(0)
+2 >Emitted(4, 5) Source(3, 5) + SourceIndex(0)
+3 >Emitted(4, 6) Source(7, 2) + SourceIndex(0)
+4 >Emitted(4, 7) Source(7, 3) + SourceIndex(0)
+---
+>>>class A {
+1->
+2 >^^^^^^^^^^^^^->
+1->
+  >
+  >
+1->Emitted(5, 1) Source(9, 1) + SourceIndex(0)
+---
+>>>    view() {
+1->^^^^
+2 >    ^^^^
+3 >        ^^^^^^^^^->
+1->class A {
+  >	
+2 >    view
+1->Emitted(6, 5) Source(10, 2) + SourceIndex(0)
+2 >Emitted(6, 9) Source(10, 6) + SourceIndex(0)
+---
+>>>        return [
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1->() {
+  >		
+2 >        return
+3 >               
+1->Emitted(7, 9) Source(11, 3) + SourceIndex(0)
+2 >Emitted(7, 15) Source(11, 9) + SourceIndex(0)
+3 >Emitted(7, 16) Source(11, 10) + SourceIndex(0)
+---
+>>>            createElement("meta", { content: "helloworld" }),
+1->^^^^^^^^^^^^
+2 >            ^^^^^^^^^^^^^^^^^^^^^^^^
+3 >                                    ^^^^^^^
+4 >                                           ^^
+5 >                                             ^^^^^^^^^^^^
+6 >                                                         ^^^
+1->[
+  >			
+2 >            <meta 
+3 >                                    content
+4 >                                           =
+5 >                                             "helloworld"
+6 >                                                         ></meta>
+1->Emitted(8, 13) Source(12, 4) + SourceIndex(0)
+2 >Emitted(8, 37) Source(12, 10) + SourceIndex(0)
+3 >Emitted(8, 44) Source(12, 17) + SourceIndex(0)
+4 >Emitted(8, 46) Source(12, 18) + SourceIndex(0)
+5 >Emitted(8, 58) Source(12, 30) + SourceIndex(0)
+6 >Emitted(8, 61) Source(12, 38) + SourceIndex(0)
+---
+>>>            createElement("meta", { content: c.a.b })
+1 >^^^^^^^^^^^^
+2 >            ^^^^^^^^^^^^^^^^^^^^^^^^
+3 >                                    ^^^^^^^
+4 >                                           ^^
+5 >                                             ^
+6 >                                              ^
+7 >                                               ^
+8 >                                                ^
+9 >                                                 ^
+10>                                                  ^^^
+1 >,
+  >			
+2 >            <meta 
+3 >                                    content
+4 >                                           ={
+5 >                                             c
+6 >                                              .
+7 >                                               a!
+8 >                                                .
+9 >                                                 b
+10>                                                  }></meta>
+1 >Emitted(9, 13) Source(13, 4) + SourceIndex(0)
+2 >Emitted(9, 37) Source(13, 10) + SourceIndex(0)
+3 >Emitted(9, 44) Source(13, 17) + SourceIndex(0)
+4 >Emitted(9, 46) Source(13, 19) + SourceIndex(0)
+5 >Emitted(9, 47) Source(13, 20) + SourceIndex(0)
+6 >Emitted(9, 48) Source(13, 21) + SourceIndex(0)
+7 >Emitted(9, 49) Source(13, 23) + SourceIndex(0)
+8 >Emitted(9, 50) Source(13, 24) + SourceIndex(0)
+9 >Emitted(9, 51) Source(13, 25) + SourceIndex(0)
+10>Emitted(9, 54) Source(13, 34) + SourceIndex(0)
+---
+>>>        ];
+1 >^^^^^^^^^
+2 >         ^
+1 >
+  >		]
+2 >         ;
+1 >Emitted(10, 10) Source(14, 4) + SourceIndex(0)
+2 >Emitted(10, 11) Source(14, 5) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+1 >
+  >	
+2 >    }
+1 >Emitted(11, 5) Source(15, 2) + SourceIndex(0)
+2 >Emitted(11, 6) Source(15, 3) + SourceIndex(0)
+---
+>>>}
+1 >^
+2 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >}
+1 >Emitted(12, 2) Source(16, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifier.symbols b/tests/baselines/reference/jsxFactoryIdentifier.symbols
new file mode 100644
index 00000000000..0d0f1e80490
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifier.symbols
@@ -0,0 +1,125 @@
+=== tests/cases/compiler/Element.ts ===
+
+declare namespace JSX {
+>JSX : Symbol(JSX, Decl(Element.ts, 0, 0))
+
+    interface Element {
+>Element : Symbol(Element, Decl(Element.ts, 1, 23))
+
+        name: string;
+>name : Symbol(Element.name, Decl(Element.ts, 2, 23))
+
+        isIntrinsic: boolean;
+>isIntrinsic : Symbol(Element.isIntrinsic, Decl(Element.ts, 3, 21))
+
+        isCustomElement: boolean;
+>isCustomElement : Symbol(Element.isCustomElement, Decl(Element.ts, 4, 29))
+
+        toString(renderId?: number): string;
+>toString : Symbol(Element.toString, Decl(Element.ts, 5, 33))
+>renderId : Symbol(renderId, Decl(Element.ts, 6, 17))
+
+        bindDOM(renderId?: number): number;
+>bindDOM : Symbol(Element.bindDOM, Decl(Element.ts, 6, 44))
+>renderId : Symbol(renderId, Decl(Element.ts, 7, 16))
+
+        resetComponent(): void;
+>resetComponent : Symbol(Element.resetComponent, Decl(Element.ts, 7, 43))
+
+        instantiateComponents(renderId?: number): number;
+>instantiateComponents : Symbol(Element.instantiateComponents, Decl(Element.ts, 8, 31))
+>renderId : Symbol(renderId, Decl(Element.ts, 9, 30))
+
+        props: any;
+>props : Symbol(Element.props, Decl(Element.ts, 9, 57))
+    }
+}
+export namespace Element {
+>Element : Symbol(Element, Decl(Element.ts, 12, 1))
+
+    export function isElement(el: any): el is JSX.Element {
+>isElement : Symbol(isElement, Decl(Element.ts, 13, 26))
+>el : Symbol(el, Decl(Element.ts, 14, 30))
+>el : Symbol(el, Decl(Element.ts, 14, 30))
+>JSX : Symbol(JSX, Decl(Element.ts, 0, 0))
+>Element : Symbol(JSX.Element, Decl(Element.ts, 1, 23))
+
+        return el.markAsChildOfRootElement !== undefined;
+>el : Symbol(el, Decl(Element.ts, 14, 30))
+>undefined : Symbol(undefined)
+    }
+
+    export function createElement(args: any[]) {
+>createElement : Symbol(createElement, Decl(Element.ts, 16, 5))
+>args : Symbol(args, Decl(Element.ts, 18, 34))
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+>createElement : Symbol(createElement, Decl(Element.ts, 25, 10))
+>Element.createElement : Symbol(Element.createElement, Decl(Element.ts, 16, 5))
+>Element : Symbol(Element, Decl(Element.ts, 12, 1))
+>createElement : Symbol(Element.createElement, Decl(Element.ts, 16, 5))
+
+function toCamelCase(text: string): string {
+>toCamelCase : Symbol(toCamelCase, Decl(Element.ts, 25, 49))
+>text : Symbol(text, Decl(Element.ts, 27, 21))
+
+    return text[0].toLowerCase() + text.substring(1);
+>text[0].toLowerCase : Symbol(String.toLowerCase, Decl(lib.es5.d.ts, --, --))
+>text : Symbol(text, Decl(Element.ts, 27, 21))
+>toLowerCase : Symbol(String.toLowerCase, Decl(lib.es5.d.ts, --, --))
+>text.substring : Symbol(String.substring, Decl(lib.es5.d.ts, --, --))
+>text : Symbol(text, Decl(Element.ts, 27, 21))
+>substring : Symbol(String.substring, Decl(lib.es5.d.ts, --, --))
+}
+
+=== tests/cases/compiler/test.tsx ===
+import { Element} from './Element';
+>Element : Symbol(Element, Decl(test.tsx, 0, 8))
+
+let createElement = Element.createElement;
+>createElement : Symbol(createElement, Decl(test.tsx, 1, 3))
+>Element.createElement : Symbol(Element.createElement, Decl(Element.ts, 16, 5))
+>Element : Symbol(Element, Decl(test.tsx, 0, 8))
+>createElement : Symbol(Element.createElement, Decl(Element.ts, 16, 5))
+
+let c: {
+>c : Symbol(c, Decl(test.tsx, 2, 3))
+
+	a?: {
+>a : Symbol(a, Decl(test.tsx, 2, 8))
+
+		b: string
+>b : Symbol(b, Decl(test.tsx, 3, 6))
+	}
+};
+
+class A {
+>A : Symbol(A, Decl(test.tsx, 6, 2))
+
+	view() {
+>view : Symbol(A.view, Decl(test.tsx, 8, 9))
+
+		return [
+			<meta content="helloworld"></meta>,
+>meta : Symbol(unknown)
+>content : Symbol(unknown)
+>meta : Symbol(unknown)
+
+			<meta content={c.a!.b}></meta>
+>meta : Symbol(unknown)
+>content : Symbol(unknown)
+>c.a!.b : Symbol(b, Decl(test.tsx, 3, 6))
+>c.a : Symbol(a, Decl(test.tsx, 2, 8))
+>c : Symbol(c, Decl(test.tsx, 2, 3))
+>a : Symbol(a, Decl(test.tsx, 2, 8))
+>b : Symbol(b, Decl(test.tsx, 3, 6))
+>meta : Symbol(unknown)
+
+		];
+	}
+}
diff --git a/tests/baselines/reference/jsxFactoryIdentifier.types b/tests/baselines/reference/jsxFactoryIdentifier.types
new file mode 100644
index 00000000000..c946c90559d
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifier.types
@@ -0,0 +1,140 @@
+=== tests/cases/compiler/Element.ts ===
+
+declare namespace JSX {
+>JSX : any
+
+    interface Element {
+>Element : Element
+
+        name: string;
+>name : string
+
+        isIntrinsic: boolean;
+>isIntrinsic : boolean
+
+        isCustomElement: boolean;
+>isCustomElement : boolean
+
+        toString(renderId?: number): string;
+>toString : (renderId?: number) => string
+>renderId : number
+
+        bindDOM(renderId?: number): number;
+>bindDOM : (renderId?: number) => number
+>renderId : number
+
+        resetComponent(): void;
+>resetComponent : () => void
+
+        instantiateComponents(renderId?: number): number;
+>instantiateComponents : (renderId?: number) => number
+>renderId : number
+
+        props: any;
+>props : any
+    }
+}
+export namespace Element {
+>Element : typeof Element
+
+    export function isElement(el: any): el is JSX.Element {
+>isElement : (el: any) => el is JSX.Element
+>el : any
+>el : any
+>JSX : any
+>Element : JSX.Element
+
+        return el.markAsChildOfRootElement !== undefined;
+>el.markAsChildOfRootElement !== undefined : boolean
+>el.markAsChildOfRootElement : any
+>el : any
+>markAsChildOfRootElement : any
+>undefined : undefined
+    }
+
+    export function createElement(args: any[]) {
+>createElement : (args: any[]) => {}
+>args : any[]
+
+        return {
+>{        } : {}
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+>createElement : (args: any[]) => {}
+>Element.createElement : (args: any[]) => {}
+>Element : typeof Element
+>createElement : (args: any[]) => {}
+
+function toCamelCase(text: string): string {
+>toCamelCase : (text: string) => string
+>text : string
+
+    return text[0].toLowerCase() + text.substring(1);
+>text[0].toLowerCase() + text.substring(1) : string
+>text[0].toLowerCase() : string
+>text[0].toLowerCase : () => string
+>text[0] : string
+>text : string
+>0 : 0
+>toLowerCase : () => string
+>text.substring(1) : string
+>text.substring : (start: number, end?: number) => string
+>text : string
+>substring : (start: number, end?: number) => string
+>1 : 1
+}
+
+=== tests/cases/compiler/test.tsx ===
+import { Element} from './Element';
+>Element : typeof Element
+
+let createElement = Element.createElement;
+>createElement : (args: any[]) => {}
+>Element.createElement : (args: any[]) => {}
+>Element : typeof Element
+>createElement : (args: any[]) => {}
+
+let c: {
+>c : { a?: { b: string; }; }
+
+	a?: {
+>a : { b: string; }
+
+		b: string
+>b : string
+	}
+};
+
+class A {
+>A : A
+
+	view() {
+>view : () => any[]
+
+		return [
+>[			<meta content="helloworld"></meta>,			<meta content={c.a!.b}></meta>		] : any[]
+
+			<meta content="helloworld"></meta>,
+><meta content="helloworld"></meta> : any
+>meta : any
+>content : any
+>meta : any
+
+			<meta content={c.a!.b}></meta>
+><meta content={c.a!.b}></meta> : any
+>meta : any
+>content : any
+>c.a!.b : string
+>c.a! : { b: string; }
+>c.a : { b: string; }
+>c : { a?: { b: string; }; }
+>a : { b: string; }
+>b : string
+>meta : any
+
+		];
+	}
+}
diff --git a/tests/baselines/reference/jsxFactoryIdentifierAsParameter.js b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.js
new file mode 100644
index 00000000000..ffec40ff7b6
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.js
@@ -0,0 +1,24 @@
+//// [test.tsx]
+
+declare module JSX {
+    interface IntrinsicElements {
+        [s: string]: any;
+    }
+}
+
+export class AppComponent {
+    render(createElement) {
+        return <div />;
+    }
+}
+
+
+//// [test.js]
+"use strict";
+class AppComponent {
+    render(createElement) {
+        return createElement("div", null);
+    }
+}
+exports.AppComponent = AppComponent;
+//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifierAsParameter.js.map b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.js.map
new file mode 100644
index 00000000000..c108b93a913
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.js.map
@@ -0,0 +1,2 @@
+//// [test.js.map]
+{"version":3,"file":"test.js","sourceRoot":"","sources":["test.tsx"],"names":[],"mappings":";AAOA;IACI,MAAM,CAAC,aAAa;QAChB,MAAM,CAAC,0BAAO,CAAC;IACnB,CAAC;CACJ;AAJD,oCAIC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifierAsParameter.sourcemap.txt b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.sourcemap.txt
new file mode 100644
index 00000000000..c7867fc54e0
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.sourcemap.txt
@@ -0,0 +1,87 @@
+===================================================================
+JsFile: test.js
+mapUrl: test.js.map
+sourceRoot: 
+sources: test.tsx
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/test.js
+sourceFile:test.tsx
+-------------------------------------------------------------------
+>>>"use strict";
+>>>class AppComponent {
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >declare module JSX {
+  >    interface IntrinsicElements {
+  >        [s: string]: any;
+  >    }
+  >}
+  >
+  >
+1 >Emitted(2, 1) Source(8, 1) + SourceIndex(0)
+---
+>>>    render(createElement) {
+1->^^^^
+2 >    ^^^^^^
+3 >          ^
+4 >           ^^^^^^^^^^^^^
+5 >                        ^^^^^^^^^^^^^^^^^^^->
+1->export class AppComponent {
+  >    
+2 >    render
+3 >          (
+4 >           createElement
+1->Emitted(3, 5) Source(9, 5) + SourceIndex(0)
+2 >Emitted(3, 11) Source(9, 11) + SourceIndex(0)
+3 >Emitted(3, 12) Source(9, 12) + SourceIndex(0)
+4 >Emitted(3, 25) Source(9, 25) + SourceIndex(0)
+---
+>>>        return createElement("div", null);
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^^^^^^^^^^^^^^^^^^^^^^^^^
+5 >                                         ^
+1->) {
+  >        
+2 >        return
+3 >               
+4 >               <div />
+5 >                                         ;
+1->Emitted(4, 9) Source(10, 9) + SourceIndex(0)
+2 >Emitted(4, 15) Source(10, 15) + SourceIndex(0)
+3 >Emitted(4, 16) Source(10, 16) + SourceIndex(0)
+4 >Emitted(4, 42) Source(10, 23) + SourceIndex(0)
+5 >Emitted(4, 43) Source(10, 24) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+1 >
+  >    
+2 >    }
+1 >Emitted(5, 5) Source(11, 5) + SourceIndex(0)
+2 >Emitted(5, 6) Source(11, 6) + SourceIndex(0)
+---
+>>>}
+1 >^
+2 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >}
+1 >Emitted(6, 2) Source(12, 2) + SourceIndex(0)
+---
+>>>exports.AppComponent = AppComponent;
+1->
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1->
+2 >export class AppComponent {
+  >    render(createElement) {
+  >        return <div />;
+  >    }
+  >}
+1->Emitted(7, 1) Source(8, 1) + SourceIndex(0)
+2 >Emitted(7, 37) Source(12, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifierAsParameter.symbols b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.symbols
new file mode 100644
index 00000000000..865292092a5
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.symbols
@@ -0,0 +1,25 @@
+=== tests/cases/compiler/test.tsx ===
+
+declare module JSX {
+>JSX : Symbol(JSX, Decl(test.tsx, 0, 0))
+
+    interface IntrinsicElements {
+>IntrinsicElements : Symbol(IntrinsicElements, Decl(test.tsx, 1, 20))
+
+        [s: string]: any;
+>s : Symbol(s, Decl(test.tsx, 3, 9))
+    }
+}
+
+export class AppComponent {
+>AppComponent : Symbol(AppComponent, Decl(test.tsx, 5, 1))
+
+    render(createElement) {
+>render : Symbol(AppComponent.render, Decl(test.tsx, 7, 27))
+>createElement : Symbol(createElement, Decl(test.tsx, 8, 11))
+
+        return <div />;
+>div : Symbol(unknown)
+    }
+}
+
diff --git a/tests/baselines/reference/jsxFactoryIdentifierAsParameter.types b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.types
new file mode 100644
index 00000000000..d55737d98ae
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierAsParameter.types
@@ -0,0 +1,26 @@
+=== tests/cases/compiler/test.tsx ===
+
+declare module JSX {
+>JSX : any
+
+    interface IntrinsicElements {
+>IntrinsicElements : IntrinsicElements
+
+        [s: string]: any;
+>s : string
+    }
+}
+
+export class AppComponent {
+>AppComponent : AppComponent
+
+    render(createElement) {
+>render : (createElement: any) => any
+>createElement : any
+
+        return <div />;
+><div /> : any
+>div : any
+    }
+}
+
diff --git a/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.errors.txt b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.errors.txt
new file mode 100644
index 00000000000..99e039a045f
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.errors.txt
@@ -0,0 +1,19 @@
+tests/cases/compiler/test.tsx(10,17): error TS2304: Cannot find name 'createElement'.
+
+
+==== tests/cases/compiler/test.tsx (1 errors) ====
+    
+    declare module JSX {
+        interface IntrinsicElements {
+            [s: string]: any;
+        }
+    }
+    
+    export class AppComponent {
+        render() {
+            return <div />;
+                    ~~~
+!!! error TS2304: Cannot find name 'createElement'.
+        }
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.js b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.js
new file mode 100644
index 00000000000..23f6f44e0c7
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.js
@@ -0,0 +1,24 @@
+//// [test.tsx]
+
+declare module JSX {
+    interface IntrinsicElements {
+        [s: string]: any;
+    }
+}
+
+export class AppComponent {
+    render() {
+        return <div />;
+    }
+}
+
+
+//// [test.js]
+"use strict";
+class AppComponent {
+    render() {
+        return createElement("div", null);
+    }
+}
+exports.AppComponent = AppComponent;
+//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.js.map b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.js.map
new file mode 100644
index 00000000000..715014ff53f
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.js.map
@@ -0,0 +1,2 @@
+//// [test.js.map]
+{"version":3,"file":"test.js","sourceRoot":"","sources":["test.tsx"],"names":[],"mappings":";AAOA;IACI,MAAM;QACF,MAAM,CAAC,0BAAO,CAAC;IACnB,CAAC;CACJ;AAJD,oCAIC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.sourcemap.txt b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.sourcemap.txt
new file mode 100644
index 00000000000..f1ebaf49870
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryIdentifierWithAbsentParameter.sourcemap.txt
@@ -0,0 +1,81 @@
+===================================================================
+JsFile: test.js
+mapUrl: test.js.map
+sourceRoot: 
+sources: test.tsx
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/test.js
+sourceFile:test.tsx
+-------------------------------------------------------------------
+>>>"use strict";
+>>>class AppComponent {
+1 >
+2 >^^^^^^^^^^^^^^^->
+1 >
+  >declare module JSX {
+  >    interface IntrinsicElements {
+  >        [s: string]: any;
+  >    }
+  >}
+  >
+  >
+1 >Emitted(2, 1) Source(8, 1) + SourceIndex(0)
+---
+>>>    render() {
+1->^^^^
+2 >    ^^^^^^
+3 >          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1->export class AppComponent {
+  >    
+2 >    render
+1->Emitted(3, 5) Source(9, 5) + SourceIndex(0)
+2 >Emitted(3, 11) Source(9, 11) + SourceIndex(0)
+---
+>>>        return createElement("div", null);
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^^^^^^^^^^^^^^^^^^^^^^^^^
+5 >                                         ^
+1->() {
+  >        
+2 >        return
+3 >               
+4 >               <div />
+5 >                                         ;
+1->Emitted(4, 9) Source(10, 9) + SourceIndex(0)
+2 >Emitted(4, 15) Source(10, 15) + SourceIndex(0)
+3 >Emitted(4, 16) Source(10, 16) + SourceIndex(0)
+4 >Emitted(4, 42) Source(10, 23) + SourceIndex(0)
+5 >Emitted(4, 43) Source(10, 24) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+1 >
+  >    
+2 >    }
+1 >Emitted(5, 5) Source(11, 5) + SourceIndex(0)
+2 >Emitted(5, 6) Source(11, 6) + SourceIndex(0)
+---
+>>>}
+1 >^
+2 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >}
+1 >Emitted(6, 2) Source(12, 2) + SourceIndex(0)
+---
+>>>exports.AppComponent = AppComponent;
+1->
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1->
+2 >export class AppComponent {
+  >    render() {
+  >        return <div />;
+  >    }
+  >}
+1->Emitted(7, 1) Source(8, 1) + SourceIndex(0)
+2 >Emitted(7, 37) Source(12, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName.errors.txt b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName.errors.txt
new file mode 100644
index 00000000000..e14f5f988f8
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName.errors.txt
@@ -0,0 +1,59 @@
+error TS5067: Invalid value for 'jsxFactory'. 'Element.createElement=' is not a valid identifier or qualified-name.
+tests/cases/compiler/test.tsx(12,5): error TS2304: Cannot find name 'React'.
+tests/cases/compiler/test.tsx(13,5): error TS2304: Cannot find name 'React'.
+
+
+!!! error TS5067: Invalid value for 'jsxFactory'. 'Element.createElement=' is not a valid identifier or qualified-name.
+==== tests/cases/compiler/Element.ts (0 errors) ====
+    
+    declare namespace JSX {
+        interface Element {
+            name: string;
+            isIntrinsic: boolean;
+            isCustomElement: boolean;
+            toString(renderId?: number): string;
+            bindDOM(renderId?: number): number;
+            resetComponent(): void;
+            instantiateComponents(renderId?: number): number;
+            props: any;
+        }
+    }
+    export namespace Element {
+        export function isElement(el: any): el is JSX.Element {
+            return el.markAsChildOfRootElement !== undefined;
+        }
+    
+        export function createElement(args: any[]) {
+    
+            return {
+            }
+        }
+    }
+    
+    export let createElement = Element.createElement;
+    
+    function toCamelCase(text: string): string {
+        return text[0].toLowerCase() + text.substring(1);
+    }
+    
+==== tests/cases/compiler/test.tsx (2 errors) ====
+    import { Element} from './Element';
+    
+    let c: {
+    	a?: {
+    		b: string
+    	}
+    };
+    
+    class A {
+    	view() {
+    		return [
+    			<meta content="helloworld"></meta>,
+    			 ~~~~
+!!! error TS2304: Cannot find name 'React'.
+    			<meta content={c.a!.b}></meta>
+    			 ~~~~
+!!! error TS2304: Cannot find name 'React'.
+    		];
+    	}
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName.js b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName.js
new file mode 100644
index 00000000000..90bb675442a
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName.js
@@ -0,0 +1,80 @@
+//// [tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName.ts] ////
+
+//// [Element.ts]
+
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+//// [test.tsx]
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
+
+//// [Element.js]
+"use strict";
+var Element;
+(function (Element) {
+    function isElement(el) {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+    Element.isElement = isElement;
+    function createElement(args) {
+        return {};
+    }
+    Element.createElement = createElement;
+})(Element = exports.Element || (exports.Element = {}));
+exports.createElement = Element.createElement;
+function toCamelCase(text) {
+    return text[0].toLowerCase() + text.substring(1);
+}
+//// [test.js]
+"use strict";
+let c;
+class A {
+    view() {
+        return [
+            React.createElement("meta", { content: "helloworld" }),
+            React.createElement("meta", { content: c.a.b })
+        ];
+    }
+}
diff --git a/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName2.errors.txt b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName2.errors.txt
new file mode 100644
index 00000000000..1c33f3a7a51
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName2.errors.txt
@@ -0,0 +1,59 @@
+error TS5067: Invalid value for 'jsxFactory'. 'id1 id2' is not a valid identifier or qualified-name.
+tests/cases/compiler/test.tsx(12,5): error TS2304: Cannot find name 'React'.
+tests/cases/compiler/test.tsx(13,5): error TS2304: Cannot find name 'React'.
+
+
+!!! error TS5067: Invalid value for 'jsxFactory'. 'id1 id2' is not a valid identifier or qualified-name.
+==== tests/cases/compiler/Element.ts (0 errors) ====
+    
+    declare namespace JSX {
+        interface Element {
+            name: string;
+            isIntrinsic: boolean;
+            isCustomElement: boolean;
+            toString(renderId?: number): string;
+            bindDOM(renderId?: number): number;
+            resetComponent(): void;
+            instantiateComponents(renderId?: number): number;
+            props: any;
+        }
+    }
+    export namespace Element {
+        export function isElement(el: any): el is JSX.Element {
+            return el.markAsChildOfRootElement !== undefined;
+        }
+    
+        export function createElement(args: any[]) {
+    
+            return {
+            }
+        }
+    }
+    
+    export let createElement = Element.createElement;
+    
+    function toCamelCase(text: string): string {
+        return text[0].toLowerCase() + text.substring(1);
+    }
+    
+==== tests/cases/compiler/test.tsx (2 errors) ====
+    import { Element} from './Element';
+    
+    let c: {
+    	a?: {
+    		b: string
+    	}
+    };
+    
+    class A {
+    	view() {
+    		return [
+    			<meta content="helloworld"></meta>,
+    			 ~~~~
+!!! error TS2304: Cannot find name 'React'.
+    			<meta content={c.a!.b}></meta>
+    			 ~~~~
+!!! error TS2304: Cannot find name 'React'.
+    		];
+    	}
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName2.js b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName2.js
new file mode 100644
index 00000000000..0bc0c6e57c5
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryNotIdentifierOrQualifiedName2.js
@@ -0,0 +1,80 @@
+//// [tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName2.ts] ////
+
+//// [Element.ts]
+
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+//// [test.tsx]
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
+
+//// [Element.js]
+"use strict";
+var Element;
+(function (Element) {
+    function isElement(el) {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+    Element.isElement = isElement;
+    function createElement(args) {
+        return {};
+    }
+    Element.createElement = createElement;
+})(Element = exports.Element || (exports.Element = {}));
+exports.createElement = Element.createElement;
+function toCamelCase(text) {
+    return text[0].toLowerCase() + text.substring(1);
+}
+//// [test.js]
+"use strict";
+let c;
+class A {
+    view() {
+        return [
+            React.createElement("meta", { content: "helloworld" }),
+            React.createElement("meta", { content: c.a.b })
+        ];
+    }
+}
diff --git a/tests/baselines/reference/jsxFactoryQualifiedName.js b/tests/baselines/reference/jsxFactoryQualifiedName.js
new file mode 100644
index 00000000000..80a77d35302
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedName.js
@@ -0,0 +1,82 @@
+//// [tests/cases/compiler/jsxFactoryQualifiedName.ts] ////
+
+//// [Element.ts]
+
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+//// [test.tsx]
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
+
+//// [Element.js]
+"use strict";
+var Element;
+(function (Element) {
+    function isElement(el) {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+    Element.isElement = isElement;
+    function createElement(args) {
+        return {};
+    }
+    Element.createElement = createElement;
+})(Element = exports.Element || (exports.Element = {}));
+exports.createElement = Element.createElement;
+function toCamelCase(text) {
+    return text[0].toLowerCase() + text.substring(1);
+}
+//# sourceMappingURL=Element.js.map//// [test.js]
+"use strict";
+const Element_1 = require("./Element");
+let c;
+class A {
+    view() {
+        return [
+            Element_1.Element.createElement("meta", { content: "helloworld" }),
+            Element_1.Element.createElement("meta", { content: c.a.b })
+        ];
+    }
+}
+//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryQualifiedName.js.map b/tests/baselines/reference/jsxFactoryQualifiedName.js.map
new file mode 100644
index 00000000000..f8cef24a0f0
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedName.js.map
@@ -0,0 +1,3 @@
+//// [Element.js.map]
+{"version":3,"file":"Element.js","sourceRoot":"","sources":["Element.ts"],"names":[],"mappings":";AAaA,IAAiB,OAAO,CAUvB;AAVD,WAAiB,OAAO;IACpB,mBAA0B,EAAO;QAC7B,MAAM,CAAC,EAAE,CAAC,wBAAwB,KAAK,SAAS,CAAC;IACrD,CAAC;IAFe,iBAAS,YAExB,CAAA;IAED,uBAA8B,IAAW;QAErC,MAAM,CAAC,EACN,CAAA;IACL,CAAC;IAJe,qBAAa,gBAI5B,CAAA;AACL,CAAC,EAVgB,OAAO,GAAP,eAAO,KAAP,eAAO,QAUvB;AAEU,QAAA,aAAa,GAAG,OAAO,CAAC,aAAa,CAAC;AAEjD,qBAAqB,IAAY;IAC7B,MAAM,CAAC,IAAI,CAAC,CAAC,CAAC,CAAC,WAAW,EAAE,GAAG,IAAI,CAAC,SAAS,CAAC,CAAC,CAAC,CAAC;AACrD,CAAC"}//// [test.js.map]
+{"version":3,"file":"test.js","sourceRoot":"","sources":["test.tsx"],"names":[],"mappings":";AAAA,uCAAmC;AAEnC,IAAI,CAIH,CAAC;AAEF;IACC,IAAI;QACH,MAAM,CAAC;YACN,0CAAM,OAAO,EAAC,YAAY,GAAQ;YAClC,0CAAM,OAAO,EAAE,CAAC,CAAC,CAAE,CAAC,CAAC,GAAS;SAC9B,CAAC;IACH,CAAC;CACD"}
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryQualifiedName.sourcemap.txt b/tests/baselines/reference/jsxFactoryQualifiedName.sourcemap.txt
new file mode 100644
index 00000000000..98517620c73
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedName.sourcemap.txt
@@ -0,0 +1,493 @@
+===================================================================
+JsFile: Element.js
+mapUrl: Element.js.map
+sourceRoot: 
+sources: Element.ts
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/Element.js
+sourceFile:Element.ts
+-------------------------------------------------------------------
+>>>"use strict";
+>>>var Element;
+1 >
+2 >^^^^
+3 >    ^^^^^^^
+4 >           ^
+5 >            ^^^^^^^^^^->
+1 >
+  >declare namespace JSX {
+  >    interface Element {
+  >        name: string;
+  >        isIntrinsic: boolean;
+  >        isCustomElement: boolean;
+  >        toString(renderId?: number): string;
+  >        bindDOM(renderId?: number): number;
+  >        resetComponent(): void;
+  >        instantiateComponents(renderId?: number): number;
+  >        props: any;
+  >    }
+  >}
+  >
+2 >export namespace 
+3 >    Element
+4 >            {
+  >               export function isElement(el: any): el is JSX.Element {
+  >                   return el.markAsChildOfRootElement !== undefined;
+  >               }
+  >           
+  >               export function createElement(args: any[]) {
+  >           
+  >                   return {
+  >                   }
+  >               }
+  >           }
+1 >Emitted(2, 1) Source(14, 1) + SourceIndex(0)
+2 >Emitted(2, 5) Source(14, 18) + SourceIndex(0)
+3 >Emitted(2, 12) Source(14, 25) + SourceIndex(0)
+4 >Emitted(2, 13) Source(24, 2) + SourceIndex(0)
+---
+>>>(function (Element) {
+1->
+2 >^^^^^^^^^^^
+3 >           ^^^^^^^
+4 >                  ^^^^^^^^^^^->
+1->
+2 >export namespace 
+3 >           Element
+1->Emitted(3, 1) Source(14, 1) + SourceIndex(0)
+2 >Emitted(3, 12) Source(14, 18) + SourceIndex(0)
+3 >Emitted(3, 19) Source(14, 25) + SourceIndex(0)
+---
+>>>    function isElement(el) {
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^^^
+3 >                       ^^
+4 >                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1-> {
+  >    
+2 >    export function isElement(
+3 >                       el: any
+1->Emitted(4, 5) Source(15, 5) + SourceIndex(0)
+2 >Emitted(4, 24) Source(15, 31) + SourceIndex(0)
+3 >Emitted(4, 26) Source(15, 38) + SourceIndex(0)
+---
+>>>        return el.markAsChildOfRootElement !== undefined;
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^
+5 >                 ^
+6 >                  ^^^^^^^^^^^^^^^^^^^^^^^^
+7 >                                          ^^^^^
+8 >                                               ^^^^^^^^^
+9 >                                                        ^
+1->): el is JSX.Element {
+  >        
+2 >        return
+3 >               
+4 >               el
+5 >                 .
+6 >                  markAsChildOfRootElement
+7 >                                           !== 
+8 >                                               undefined
+9 >                                                        ;
+1->Emitted(5, 9) Source(16, 9) + SourceIndex(0)
+2 >Emitted(5, 15) Source(16, 15) + SourceIndex(0)
+3 >Emitted(5, 16) Source(16, 16) + SourceIndex(0)
+4 >Emitted(5, 18) Source(16, 18) + SourceIndex(0)
+5 >Emitted(5, 19) Source(16, 19) + SourceIndex(0)
+6 >Emitted(5, 43) Source(16, 43) + SourceIndex(0)
+7 >Emitted(5, 48) Source(16, 48) + SourceIndex(0)
+8 >Emitted(5, 57) Source(16, 57) + SourceIndex(0)
+9 >Emitted(5, 58) Source(16, 58) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+3 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >    
+2 >    }
+1 >Emitted(6, 5) Source(17, 5) + SourceIndex(0)
+2 >Emitted(6, 6) Source(17, 6) + SourceIndex(0)
+---
+>>>    Element.isElement = isElement;
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^
+3 >                     ^^^^^^^^^^^^
+4 >                                 ^
+5 >                                  ^->
+1->
+2 >    isElement
+3 >                     (el: any): el is JSX.Element {
+  >                             return el.markAsChildOfRootElement !== undefined;
+  >                         }
+4 >                                 
+1->Emitted(7, 5) Source(15, 21) + SourceIndex(0)
+2 >Emitted(7, 22) Source(15, 30) + SourceIndex(0)
+3 >Emitted(7, 34) Source(17, 6) + SourceIndex(0)
+4 >Emitted(7, 35) Source(17, 6) + SourceIndex(0)
+---
+>>>    function createElement(args) {
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^^^^^^^
+3 >                           ^^^^
+1->
+  >
+  >    
+2 >    export function createElement(
+3 >                           args: any[]
+1->Emitted(8, 5) Source(19, 5) + SourceIndex(0)
+2 >Emitted(8, 28) Source(19, 35) + SourceIndex(0)
+3 >Emitted(8, 32) Source(19, 46) + SourceIndex(0)
+---
+>>>        return {};
+1 >^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^
+5 >                 ^
+1 >) {
+  >
+  >        
+2 >        return
+3 >               
+4 >               {
+  >                       }
+5 >                 
+1 >Emitted(9, 9) Source(21, 9) + SourceIndex(0)
+2 >Emitted(9, 15) Source(21, 15) + SourceIndex(0)
+3 >Emitted(9, 16) Source(21, 16) + SourceIndex(0)
+4 >Emitted(9, 18) Source(22, 10) + SourceIndex(0)
+5 >Emitted(9, 19) Source(22, 10) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+3 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >    
+2 >    }
+1 >Emitted(10, 5) Source(23, 5) + SourceIndex(0)
+2 >Emitted(10, 6) Source(23, 6) + SourceIndex(0)
+---
+>>>    Element.createElement = createElement;
+1->^^^^
+2 >    ^^^^^^^^^^^^^^^^^^^^^
+3 >                         ^^^^^^^^^^^^^^^^
+4 >                                         ^
+5 >                                          ^^^^^^^^^^^^^^^->
+1->
+2 >    createElement
+3 >                         (args: any[]) {
+  >                         
+  >                                 return {
+  >                                 }
+  >                             }
+4 >                                         
+1->Emitted(11, 5) Source(19, 21) + SourceIndex(0)
+2 >Emitted(11, 26) Source(19, 34) + SourceIndex(0)
+3 >Emitted(11, 42) Source(23, 6) + SourceIndex(0)
+4 >Emitted(11, 43) Source(23, 6) + SourceIndex(0)
+---
+>>>})(Element = exports.Element || (exports.Element = {}));
+1->
+2 >^
+3 > ^^
+4 >   ^^^^^^^
+5 >          ^^^
+6 >             ^^^^^^^^^^^^^^^
+7 >                            ^^^^^
+8 >                                 ^^^^^^^^^^^^^^^
+9 >                                                ^^^^^^^^
+1->
+  >
+2 >}
+3 > 
+4 >   Element
+5 >          
+6 >             Element
+7 >                            
+8 >                                 Element
+9 >                                                 {
+  >                                                    export function isElement(el: any): el is JSX.Element {
+  >                                                        return el.markAsChildOfRootElement !== undefined;
+  >                                                    }
+  >                                                
+  >                                                    export function createElement(args: any[]) {
+  >                                                
+  >                                                        return {
+  >                                                        }
+  >                                                    }
+  >                                                }
+1->Emitted(12, 1) Source(24, 1) + SourceIndex(0)
+2 >Emitted(12, 2) Source(24, 2) + SourceIndex(0)
+3 >Emitted(12, 4) Source(14, 18) + SourceIndex(0)
+4 >Emitted(12, 11) Source(14, 25) + SourceIndex(0)
+5 >Emitted(12, 14) Source(14, 18) + SourceIndex(0)
+6 >Emitted(12, 29) Source(14, 25) + SourceIndex(0)
+7 >Emitted(12, 34) Source(14, 18) + SourceIndex(0)
+8 >Emitted(12, 49) Source(14, 25) + SourceIndex(0)
+9 >Emitted(12, 57) Source(24, 2) + SourceIndex(0)
+---
+>>>exports.createElement = Element.createElement;
+1 >
+2 >^^^^^^^^
+3 >        ^^^^^^^^^^^^^
+4 >                     ^^^
+5 >                        ^^^^^^^
+6 >                               ^
+7 >                                ^^^^^^^^^^^^^
+8 >                                             ^
+1 >
+  >
+  >export let 
+2 >
+3 >        createElement
+4 >                      = 
+5 >                        Element
+6 >                               .
+7 >                                createElement
+8 >                                             ;
+1 >Emitted(13, 1) Source(26, 12) + SourceIndex(0)
+2 >Emitted(13, 9) Source(26, 12) + SourceIndex(0)
+3 >Emitted(13, 22) Source(26, 25) + SourceIndex(0)
+4 >Emitted(13, 25) Source(26, 28) + SourceIndex(0)
+5 >Emitted(13, 32) Source(26, 35) + SourceIndex(0)
+6 >Emitted(13, 33) Source(26, 36) + SourceIndex(0)
+7 >Emitted(13, 46) Source(26, 49) + SourceIndex(0)
+8 >Emitted(13, 47) Source(26, 50) + SourceIndex(0)
+---
+>>>function toCamelCase(text) {
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^
+3 >                     ^^^^
+4 >                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >
+  >
+2 >function toCamelCase(
+3 >                     text: string
+1 >Emitted(14, 1) Source(28, 1) + SourceIndex(0)
+2 >Emitted(14, 22) Source(28, 22) + SourceIndex(0)
+3 >Emitted(14, 26) Source(28, 34) + SourceIndex(0)
+---
+>>>    return text[0].toLowerCase() + text.substring(1);
+1->^^^^
+2 >    ^^^^^^
+3 >          ^
+4 >           ^^^^
+5 >               ^
+6 >                ^
+7 >                 ^
+8 >                  ^
+9 >                   ^^^^^^^^^^^
+10>                              ^^
+11>                                ^^^
+12>                                   ^^^^
+13>                                       ^
+14>                                        ^^^^^^^^^
+15>                                                 ^
+16>                                                  ^
+17>                                                   ^
+18>                                                    ^
+1->): string {
+  >    
+2 >    return
+3 >           
+4 >           text
+5 >               [
+6 >                0
+7 >                 ]
+8 >                  .
+9 >                   toLowerCase
+10>                              ()
+11>                                 + 
+12>                                   text
+13>                                       .
+14>                                        substring
+15>                                                 (
+16>                                                  1
+17>                                                   )
+18>                                                    ;
+1->Emitted(15, 5) Source(29, 5) + SourceIndex(0)
+2 >Emitted(15, 11) Source(29, 11) + SourceIndex(0)
+3 >Emitted(15, 12) Source(29, 12) + SourceIndex(0)
+4 >Emitted(15, 16) Source(29, 16) + SourceIndex(0)
+5 >Emitted(15, 17) Source(29, 17) + SourceIndex(0)
+6 >Emitted(15, 18) Source(29, 18) + SourceIndex(0)
+7 >Emitted(15, 19) Source(29, 19) + SourceIndex(0)
+8 >Emitted(15, 20) Source(29, 20) + SourceIndex(0)
+9 >Emitted(15, 31) Source(29, 31) + SourceIndex(0)
+10>Emitted(15, 33) Source(29, 33) + SourceIndex(0)
+11>Emitted(15, 36) Source(29, 36) + SourceIndex(0)
+12>Emitted(15, 40) Source(29, 40) + SourceIndex(0)
+13>Emitted(15, 41) Source(29, 41) + SourceIndex(0)
+14>Emitted(15, 50) Source(29, 50) + SourceIndex(0)
+15>Emitted(15, 51) Source(29, 51) + SourceIndex(0)
+16>Emitted(15, 52) Source(29, 52) + SourceIndex(0)
+17>Emitted(15, 53) Source(29, 53) + SourceIndex(0)
+18>Emitted(15, 54) Source(29, 54) + SourceIndex(0)
+---
+>>>}
+1 >
+2 >^
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >
+2 >}
+1 >Emitted(16, 1) Source(30, 1) + SourceIndex(0)
+2 >Emitted(16, 2) Source(30, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=Element.js.map===================================================================
+JsFile: test.js
+mapUrl: test.js.map
+sourceRoot: 
+sources: test.tsx
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/test.js
+sourceFile:test.tsx
+-------------------------------------------------------------------
+>>>"use strict";
+>>>const Element_1 = require("./Element");
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1 >
+2 >import { Element} from './Element';
+1 >Emitted(2, 1) Source(1, 1) + SourceIndex(0)
+2 >Emitted(2, 40) Source(1, 36) + SourceIndex(0)
+---
+>>>let c;
+1 >
+2 >^^^^
+3 >    ^
+4 >     ^
+5 >      ^^^^->
+1 >
+  >
+  >
+2 >let 
+3 >    c: {
+  >    	a?: {
+  >    		b: string
+  >    	}
+  >    }
+4 >     ;
+1 >Emitted(3, 1) Source(3, 1) + SourceIndex(0)
+2 >Emitted(3, 5) Source(3, 5) + SourceIndex(0)
+3 >Emitted(3, 6) Source(7, 2) + SourceIndex(0)
+4 >Emitted(3, 7) Source(7, 3) + SourceIndex(0)
+---
+>>>class A {
+1->
+2 >^^^^^^^^^^^^^->
+1->
+  >
+  >
+1->Emitted(4, 1) Source(9, 1) + SourceIndex(0)
+---
+>>>    view() {
+1->^^^^
+2 >    ^^^^
+3 >        ^^^^^^^^^->
+1->class A {
+  >	
+2 >    view
+1->Emitted(5, 5) Source(10, 2) + SourceIndex(0)
+2 >Emitted(5, 9) Source(10, 6) + SourceIndex(0)
+---
+>>>        return [
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1->() {
+  >		
+2 >        return
+3 >               
+1->Emitted(6, 9) Source(11, 3) + SourceIndex(0)
+2 >Emitted(6, 15) Source(11, 9) + SourceIndex(0)
+3 >Emitted(6, 16) Source(11, 10) + SourceIndex(0)
+---
+>>>            Element_1.Element.createElement("meta", { content: "helloworld" }),
+1->^^^^^^^^^^^^
+2 >            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+3 >                                                      ^^^^^^^
+4 >                                                             ^^
+5 >                                                               ^^^^^^^^^^^^
+6 >                                                                           ^^^
+1->[
+  >			
+2 >            <meta 
+3 >                                                      content
+4 >                                                             =
+5 >                                                               "helloworld"
+6 >                                                                           ></meta>
+1->Emitted(7, 13) Source(12, 4) + SourceIndex(0)
+2 >Emitted(7, 55) Source(12, 10) + SourceIndex(0)
+3 >Emitted(7, 62) Source(12, 17) + SourceIndex(0)
+4 >Emitted(7, 64) Source(12, 18) + SourceIndex(0)
+5 >Emitted(7, 76) Source(12, 30) + SourceIndex(0)
+6 >Emitted(7, 79) Source(12, 38) + SourceIndex(0)
+---
+>>>            Element_1.Element.createElement("meta", { content: c.a.b })
+1 >^^^^^^^^^^^^
+2 >            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+3 >                                                      ^^^^^^^
+4 >                                                             ^^
+5 >                                                               ^
+6 >                                                                ^
+7 >                                                                 ^
+8 >                                                                  ^
+9 >                                                                   ^
+10>                                                                    ^^^
+1 >,
+  >			
+2 >            <meta 
+3 >                                                      content
+4 >                                                             ={
+5 >                                                               c
+6 >                                                                .
+7 >                                                                 a!
+8 >                                                                  .
+9 >                                                                   b
+10>                                                                    }></meta>
+1 >Emitted(8, 13) Source(13, 4) + SourceIndex(0)
+2 >Emitted(8, 55) Source(13, 10) + SourceIndex(0)
+3 >Emitted(8, 62) Source(13, 17) + SourceIndex(0)
+4 >Emitted(8, 64) Source(13, 19) + SourceIndex(0)
+5 >Emitted(8, 65) Source(13, 20) + SourceIndex(0)
+6 >Emitted(8, 66) Source(13, 21) + SourceIndex(0)
+7 >Emitted(8, 67) Source(13, 23) + SourceIndex(0)
+8 >Emitted(8, 68) Source(13, 24) + SourceIndex(0)
+9 >Emitted(8, 69) Source(13, 25) + SourceIndex(0)
+10>Emitted(8, 72) Source(13, 34) + SourceIndex(0)
+---
+>>>        ];
+1 >^^^^^^^^^
+2 >         ^
+1 >
+  >		]
+2 >         ;
+1 >Emitted(9, 10) Source(14, 4) + SourceIndex(0)
+2 >Emitted(9, 11) Source(14, 5) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+1 >
+  >	
+2 >    }
+1 >Emitted(10, 5) Source(15, 2) + SourceIndex(0)
+2 >Emitted(10, 6) Source(15, 3) + SourceIndex(0)
+---
+>>>}
+1 >^
+2 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >}
+1 >Emitted(11, 2) Source(16, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryQualifiedName.symbols b/tests/baselines/reference/jsxFactoryQualifiedName.symbols
new file mode 100644
index 00000000000..16cd35d1ca3
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedName.symbols
@@ -0,0 +1,119 @@
+=== tests/cases/compiler/Element.ts ===
+
+declare namespace JSX {
+>JSX : Symbol(JSX, Decl(Element.ts, 0, 0))
+
+    interface Element {
+>Element : Symbol(Element, Decl(Element.ts, 1, 23))
+
+        name: string;
+>name : Symbol(Element.name, Decl(Element.ts, 2, 23))
+
+        isIntrinsic: boolean;
+>isIntrinsic : Symbol(Element.isIntrinsic, Decl(Element.ts, 3, 21))
+
+        isCustomElement: boolean;
+>isCustomElement : Symbol(Element.isCustomElement, Decl(Element.ts, 4, 29))
+
+        toString(renderId?: number): string;
+>toString : Symbol(Element.toString, Decl(Element.ts, 5, 33))
+>renderId : Symbol(renderId, Decl(Element.ts, 6, 17))
+
+        bindDOM(renderId?: number): number;
+>bindDOM : Symbol(Element.bindDOM, Decl(Element.ts, 6, 44))
+>renderId : Symbol(renderId, Decl(Element.ts, 7, 16))
+
+        resetComponent(): void;
+>resetComponent : Symbol(Element.resetComponent, Decl(Element.ts, 7, 43))
+
+        instantiateComponents(renderId?: number): number;
+>instantiateComponents : Symbol(Element.instantiateComponents, Decl(Element.ts, 8, 31))
+>renderId : Symbol(renderId, Decl(Element.ts, 9, 30))
+
+        props: any;
+>props : Symbol(Element.props, Decl(Element.ts, 9, 57))
+    }
+}
+export namespace Element {
+>Element : Symbol(Element, Decl(Element.ts, 12, 1))
+
+    export function isElement(el: any): el is JSX.Element {
+>isElement : Symbol(isElement, Decl(Element.ts, 13, 26))
+>el : Symbol(el, Decl(Element.ts, 14, 30))
+>el : Symbol(el, Decl(Element.ts, 14, 30))
+>JSX : Symbol(JSX, Decl(Element.ts, 0, 0))
+>Element : Symbol(JSX.Element, Decl(Element.ts, 1, 23))
+
+        return el.markAsChildOfRootElement !== undefined;
+>el : Symbol(el, Decl(Element.ts, 14, 30))
+>undefined : Symbol(undefined)
+    }
+
+    export function createElement(args: any[]) {
+>createElement : Symbol(createElement, Decl(Element.ts, 16, 5))
+>args : Symbol(args, Decl(Element.ts, 18, 34))
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+>createElement : Symbol(createElement, Decl(Element.ts, 25, 10))
+>Element.createElement : Symbol(Element.createElement, Decl(Element.ts, 16, 5))
+>Element : Symbol(Element, Decl(Element.ts, 12, 1))
+>createElement : Symbol(Element.createElement, Decl(Element.ts, 16, 5))
+
+function toCamelCase(text: string): string {
+>toCamelCase : Symbol(toCamelCase, Decl(Element.ts, 25, 49))
+>text : Symbol(text, Decl(Element.ts, 27, 21))
+
+    return text[0].toLowerCase() + text.substring(1);
+>text[0].toLowerCase : Symbol(String.toLowerCase, Decl(lib.es5.d.ts, --, --))
+>text : Symbol(text, Decl(Element.ts, 27, 21))
+>toLowerCase : Symbol(String.toLowerCase, Decl(lib.es5.d.ts, --, --))
+>text.substring : Symbol(String.substring, Decl(lib.es5.d.ts, --, --))
+>text : Symbol(text, Decl(Element.ts, 27, 21))
+>substring : Symbol(String.substring, Decl(lib.es5.d.ts, --, --))
+}
+
+=== tests/cases/compiler/test.tsx ===
+import { Element} from './Element';
+>Element : Symbol(Element, Decl(test.tsx, 0, 8))
+
+let c: {
+>c : Symbol(c, Decl(test.tsx, 2, 3))
+
+	a?: {
+>a : Symbol(a, Decl(test.tsx, 2, 8))
+
+		b: string
+>b : Symbol(b, Decl(test.tsx, 3, 6))
+	}
+};
+
+class A {
+>A : Symbol(A, Decl(test.tsx, 6, 2))
+
+	view() {
+>view : Symbol(A.view, Decl(test.tsx, 8, 9))
+
+		return [
+			<meta content="helloworld"></meta>,
+>meta : Symbol(unknown)
+>content : Symbol(unknown)
+>meta : Symbol(unknown)
+
+			<meta content={c.a!.b}></meta>
+>meta : Symbol(unknown)
+>content : Symbol(unknown)
+>c.a!.b : Symbol(b, Decl(test.tsx, 3, 6))
+>c.a : Symbol(a, Decl(test.tsx, 2, 8))
+>c : Symbol(c, Decl(test.tsx, 2, 3))
+>a : Symbol(a, Decl(test.tsx, 2, 8))
+>b : Symbol(b, Decl(test.tsx, 3, 6))
+>meta : Symbol(unknown)
+
+		];
+	}
+}
diff --git a/tests/baselines/reference/jsxFactoryQualifiedName.types b/tests/baselines/reference/jsxFactoryQualifiedName.types
new file mode 100644
index 00000000000..663ba4b5bfc
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedName.types
@@ -0,0 +1,134 @@
+=== tests/cases/compiler/Element.ts ===
+
+declare namespace JSX {
+>JSX : any
+
+    interface Element {
+>Element : Element
+
+        name: string;
+>name : string
+
+        isIntrinsic: boolean;
+>isIntrinsic : boolean
+
+        isCustomElement: boolean;
+>isCustomElement : boolean
+
+        toString(renderId?: number): string;
+>toString : (renderId?: number) => string
+>renderId : number
+
+        bindDOM(renderId?: number): number;
+>bindDOM : (renderId?: number) => number
+>renderId : number
+
+        resetComponent(): void;
+>resetComponent : () => void
+
+        instantiateComponents(renderId?: number): number;
+>instantiateComponents : (renderId?: number) => number
+>renderId : number
+
+        props: any;
+>props : any
+    }
+}
+export namespace Element {
+>Element : typeof Element
+
+    export function isElement(el: any): el is JSX.Element {
+>isElement : (el: any) => el is JSX.Element
+>el : any
+>el : any
+>JSX : any
+>Element : JSX.Element
+
+        return el.markAsChildOfRootElement !== undefined;
+>el.markAsChildOfRootElement !== undefined : boolean
+>el.markAsChildOfRootElement : any
+>el : any
+>markAsChildOfRootElement : any
+>undefined : undefined
+    }
+
+    export function createElement(args: any[]) {
+>createElement : (args: any[]) => {}
+>args : any[]
+
+        return {
+>{        } : {}
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+>createElement : (args: any[]) => {}
+>Element.createElement : (args: any[]) => {}
+>Element : typeof Element
+>createElement : (args: any[]) => {}
+
+function toCamelCase(text: string): string {
+>toCamelCase : (text: string) => string
+>text : string
+
+    return text[0].toLowerCase() + text.substring(1);
+>text[0].toLowerCase() + text.substring(1) : string
+>text[0].toLowerCase() : string
+>text[0].toLowerCase : () => string
+>text[0] : string
+>text : string
+>0 : 0
+>toLowerCase : () => string
+>text.substring(1) : string
+>text.substring : (start: number, end?: number) => string
+>text : string
+>substring : (start: number, end?: number) => string
+>1 : 1
+}
+
+=== tests/cases/compiler/test.tsx ===
+import { Element} from './Element';
+>Element : typeof Element
+
+let c: {
+>c : { a?: { b: string; }; }
+
+	a?: {
+>a : { b: string; }
+
+		b: string
+>b : string
+	}
+};
+
+class A {
+>A : A
+
+	view() {
+>view : () => any[]
+
+		return [
+>[			<meta content="helloworld"></meta>,			<meta content={c.a!.b}></meta>		] : any[]
+
+			<meta content="helloworld"></meta>,
+><meta content="helloworld"></meta> : any
+>meta : any
+>content : any
+>meta : any
+
+			<meta content={c.a!.b}></meta>
+><meta content={c.a!.b}></meta> : any
+>meta : any
+>content : any
+>c.a!.b : string
+>c.a! : { b: string; }
+>c.a : { b: string; }
+>c : { a?: { b: string; }; }
+>a : { b: string; }
+>b : string
+>meta : any
+
+		];
+	}
+}
diff --git a/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.errors.txt b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.errors.txt
new file mode 100644
index 00000000000..97a05d840f0
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.errors.txt
@@ -0,0 +1,18 @@
+tests/cases/compiler/test.tsx(10,17): error TS2304: Cannot find name 'MyElement'.
+
+
+==== tests/cases/compiler/test.tsx (1 errors) ====
+    
+    declare module JSX {
+        interface IntrinsicElements {
+            [s: string]: any;
+        }
+    }
+    
+    export class AppComponent {
+        render(createElement) {
+            return <div />;
+                    ~~~
+!!! error TS2304: Cannot find name 'MyElement'.
+        }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.js b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.js
new file mode 100644
index 00000000000..6714b68a093
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.js
@@ -0,0 +1,23 @@
+//// [test.tsx]
+
+declare module JSX {
+    interface IntrinsicElements {
+        [s: string]: any;
+    }
+}
+
+export class AppComponent {
+    render(createElement) {
+        return <div />;
+    }
+}
+
+//// [test.js]
+"use strict";
+class AppComponent {
+    render(createElement) {
+        return MyElement.createElement("div", null);
+    }
+}
+exports.AppComponent = AppComponent;
+//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.js.map b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.js.map
new file mode 100644
index 00000000000..ac54c9638cd
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.js.map
@@ -0,0 +1,2 @@
+//// [test.js.map]
+{"version":3,"file":"test.js","sourceRoot":"","sources":["test.tsx"],"names":[],"mappings":";AAOA;IACI,MAAM,CAAC,aAAa;QAChB,MAAM,CAAC,oCAAO,CAAC;IACnB,CAAC;CACJ;AAJD,oCAIC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.sourcemap.txt b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.sourcemap.txt
new file mode 100644
index 00000000000..2616efcf63b
--- /dev/null
+++ b/tests/baselines/reference/jsxFactoryQualifiedNameResolutionError.sourcemap.txt
@@ -0,0 +1,87 @@
+===================================================================
+JsFile: test.js
+mapUrl: test.js.map
+sourceRoot: 
+sources: test.tsx
+===================================================================
+-------------------------------------------------------------------
+emittedFile:tests/cases/compiler/test.js
+sourceFile:test.tsx
+-------------------------------------------------------------------
+>>>"use strict";
+>>>class AppComponent {
+1 >
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >declare module JSX {
+  >    interface IntrinsicElements {
+  >        [s: string]: any;
+  >    }
+  >}
+  >
+  >
+1 >Emitted(2, 1) Source(8, 1) + SourceIndex(0)
+---
+>>>    render(createElement) {
+1->^^^^
+2 >    ^^^^^^
+3 >          ^
+4 >           ^^^^^^^^^^^^^
+5 >                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1->export class AppComponent {
+  >    
+2 >    render
+3 >          (
+4 >           createElement
+1->Emitted(3, 5) Source(9, 5) + SourceIndex(0)
+2 >Emitted(3, 11) Source(9, 11) + SourceIndex(0)
+3 >Emitted(3, 12) Source(9, 12) + SourceIndex(0)
+4 >Emitted(3, 25) Source(9, 25) + SourceIndex(0)
+---
+>>>        return MyElement.createElement("div", null);
+1->^^^^^^^^
+2 >        ^^^^^^
+3 >              ^
+4 >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+5 >                                                   ^
+1->) {
+  >        
+2 >        return
+3 >               
+4 >               <div />
+5 >                                                   ;
+1->Emitted(4, 9) Source(10, 9) + SourceIndex(0)
+2 >Emitted(4, 15) Source(10, 15) + SourceIndex(0)
+3 >Emitted(4, 16) Source(10, 16) + SourceIndex(0)
+4 >Emitted(4, 52) Source(10, 23) + SourceIndex(0)
+5 >Emitted(4, 53) Source(10, 24) + SourceIndex(0)
+---
+>>>    }
+1 >^^^^
+2 >    ^
+1 >
+  >    
+2 >    }
+1 >Emitted(5, 5) Source(11, 5) + SourceIndex(0)
+2 >Emitted(5, 6) Source(11, 6) + SourceIndex(0)
+---
+>>>}
+1 >^
+2 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+1 >
+  >}
+1 >Emitted(6, 2) Source(12, 2) + SourceIndex(0)
+---
+>>>exports.AppComponent = AppComponent;
+1->
+2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+1->
+2 >export class AppComponent {
+  >    render(createElement) {
+  >        return <div />;
+  >    }
+  >}
+1->Emitted(7, 1) Source(8, 1) + SourceIndex(0)
+2 >Emitted(7, 37) Source(12, 2) + SourceIndex(0)
+---
+>>>//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
index 3a9d8c4ea79..f6df1476088 100644
--- a/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
+++ b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
@@ -9,12 +9,8 @@
     "File '/node_modules/shortid/index.ts' does not exist.",
     "File '/node_modules/shortid/index.tsx' does not exist.",
     "File '/node_modules/shortid/index.d.ts' does not exist.",
-    "File '/node_modules/@types/shortid.ts' does not exist.",
-    "File '/node_modules/@types/shortid.tsx' does not exist.",
     "File '/node_modules/@types/shortid.d.ts' does not exist.",
     "File '/node_modules/@types/shortid/package.json' does not exist.",
-    "File '/node_modules/@types/shortid/index.ts' does not exist.",
-    "File '/node_modules/@types/shortid/index.tsx' does not exist.",
     "File '/node_modules/@types/shortid/index.d.ts' does not exist.",
     "Loading module 'shortid' from 'node_modules' folder.",
     "File '/node_modules/shortid.js' does not exist.",
diff --git a/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json b/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json
index 9c6d96fc190..8d4217a92bd 100644
--- a/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json
+++ b/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json
@@ -9,12 +9,8 @@
     "File '/node_modules/js/index.ts' does not exist.",
     "File '/node_modules/js/index.tsx' does not exist.",
     "File '/node_modules/js/index.d.ts' does not exist.",
-    "File '/node_modules/@types/js.ts' does not exist.",
-    "File '/node_modules/@types/js.tsx' does not exist.",
     "File '/node_modules/@types/js.d.ts' does not exist.",
     "File '/node_modules/@types/js/package.json' does not exist.",
-    "File '/node_modules/@types/js/index.ts' does not exist.",
-    "File '/node_modules/@types/js/index.tsx' does not exist.",
     "File '/node_modules/@types/js/index.d.ts' does not exist.",
     "Loading module 'js' from 'node_modules' folder.",
     "File '/node_modules/js.js' does not exist.",
diff --git a/tests/baselines/reference/objectRest.js b/tests/baselines/reference/objectRest.js
new file mode 100644
index 00000000000..a295ff7b9f1
--- /dev/null
+++ b/tests/baselines/reference/objectRest.js
@@ -0,0 +1,67 @@
+//// [objectRest.ts]
+let o = { a: 1, b: 'no' }
+var { ...clone } = o;
+var { a, ...justB } = o;
+var { a, b: renamed, ...empty } = o;
+var { ['b']: renamed, ...justA } = o;
+var { 'b': renamed, ...justA } = o;
+var { b: { '0': n, '1': oooo }, ...justA } = o;
+
+let o2 = { c: 'terrible idea?', d: 'yes' };
+var { d: renamed, ...d } = o2;
+
+let nestedrest: { x: number, n1: { y: number, n2: { z: number, n3: { n4: number } } }, rest: number, restrest: number };
+var { x, n1: { y, n2: { z, n3: { ...nr } } }, ...restrest } = nestedrest;
+
+let complex: { x: { ka, ki }, y: number };
+var { x: { ka, ...nested }, y: other, ...rest } = complex;
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+var { x, ...fresh } = { x: 1, y: 2 };
+({ x, ...fresh } = { x: 1, y: 2 });
+
+class Removable {
+    private x: number;
+    protected y: number;
+    set z(value: number) { }
+    get both(): number { return 12 }
+    set both(value: number) { }
+    m() { }
+    removed: string;
+    remainder: string;
+}
+var removable = new Removable();
+var { removed, ...removableRest } = removable;
+
+
+//// [objectRest.js]
+var __rest = (this && this.__rest) || function (s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && !e.indexOf(p))
+        t[p] = s[p];
+    return t;
+};
+let o = { a: 1, b: 'no' };
+var clone = __rest(o, []);
+var { a } = o, justB = __rest(o, ["a"]);
+var { a, b: renamed } = o, empty = __rest(o, ["a", "b"]);
+var { ['b']: renamed } = o, justA = __rest(o, ["b"]);
+var { 'b': renamed } = o, justA = __rest(o, ["b"]);
+var { b: { '0': n, '1': oooo } } = o, justA = __rest(o, ["b"]);
+let o2 = { c: 'terrible idea?', d: 'yes' };
+var { d: renamed } = o2, d = __rest(o2, ["d"]);
+let nestedrest;
+var { x } = nestedrest, _a = nestedrest.n1, { y } = _a, _b = _a.n2, { z } = _b, nr = __rest(_b.n3, []), restrest = __rest(nestedrest, ["x", "n1"]);
+let complex;
+var _c = complex.x, { ka } = _c, nested = __rest(_c, ["ka"]), { y: other } = complex, rest = __rest(complex, ["x", "y"]);
+(_d = complex.x, { ka } = _d, nested = __rest(_d, ["ka"]), { y: other } = complex, rest = __rest(complex, ["x", "y"]), complex);
+var _e = { x: 1, y: 2 }, { x } = _e, fresh = __rest(_e, ["x"]);
+(_f = { x: 1, y: 2 }, { x } = _f, fresh = __rest(_f, ["x"]), _f);
+class Removable {
+    set z(value) { }
+    get both() { return 12; }
+    set both(value) { }
+    m() { }
+}
+var removable = new Removable();
+var { removed } = removable, removableRest = __rest(removable, ["removed"]);
+var _d, _f;
diff --git a/tests/baselines/reference/objectRest.symbols b/tests/baselines/reference/objectRest.symbols
new file mode 100644
index 00000000000..427656248ee
--- /dev/null
+++ b/tests/baselines/reference/objectRest.symbols
@@ -0,0 +1,146 @@
+=== tests/cases/conformance/types/rest/objectRest.ts ===
+let o = { a: 1, b: 'no' }
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+>a : Symbol(a, Decl(objectRest.ts, 0, 9))
+>b : Symbol(b, Decl(objectRest.ts, 0, 15))
+
+var { ...clone } = o;
+>clone : Symbol(clone, Decl(objectRest.ts, 1, 5))
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+
+var { a, ...justB } = o;
+>a : Symbol(a, Decl(objectRest.ts, 2, 5), Decl(objectRest.ts, 3, 5))
+>justB : Symbol(justB, Decl(objectRest.ts, 2, 8))
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+
+var { a, b: renamed, ...empty } = o;
+>a : Symbol(a, Decl(objectRest.ts, 2, 5), Decl(objectRest.ts, 3, 5))
+>b : Symbol(b, Decl(objectRest.ts, 0, 15))
+>renamed : Symbol(renamed, Decl(objectRest.ts, 3, 8), Decl(objectRest.ts, 4, 5), Decl(objectRest.ts, 5, 5), Decl(objectRest.ts, 9, 5))
+>empty : Symbol(empty, Decl(objectRest.ts, 3, 20))
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+
+var { ['b']: renamed, ...justA } = o;
+>'b' : Symbol(renamed, Decl(objectRest.ts, 3, 8), Decl(objectRest.ts, 4, 5), Decl(objectRest.ts, 5, 5), Decl(objectRest.ts, 9, 5))
+>renamed : Symbol(renamed, Decl(objectRest.ts, 3, 8), Decl(objectRest.ts, 4, 5), Decl(objectRest.ts, 5, 5), Decl(objectRest.ts, 9, 5))
+>justA : Symbol(justA, Decl(objectRest.ts, 4, 21), Decl(objectRest.ts, 5, 19), Decl(objectRest.ts, 6, 31))
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+
+var { 'b': renamed, ...justA } = o;
+>renamed : Symbol(renamed, Decl(objectRest.ts, 3, 8), Decl(objectRest.ts, 4, 5), Decl(objectRest.ts, 5, 5), Decl(objectRest.ts, 9, 5))
+>justA : Symbol(justA, Decl(objectRest.ts, 4, 21), Decl(objectRest.ts, 5, 19), Decl(objectRest.ts, 6, 31))
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+
+var { b: { '0': n, '1': oooo }, ...justA } = o;
+>b : Symbol(b, Decl(objectRest.ts, 0, 15))
+>n : Symbol(n, Decl(objectRest.ts, 6, 10))
+>oooo : Symbol(oooo, Decl(objectRest.ts, 6, 18))
+>justA : Symbol(justA, Decl(objectRest.ts, 4, 21), Decl(objectRest.ts, 5, 19), Decl(objectRest.ts, 6, 31))
+>o : Symbol(o, Decl(objectRest.ts, 0, 3))
+
+let o2 = { c: 'terrible idea?', d: 'yes' };
+>o2 : Symbol(o2, Decl(objectRest.ts, 8, 3))
+>c : Symbol(c, Decl(objectRest.ts, 8, 10))
+>d : Symbol(d, Decl(objectRest.ts, 8, 31))
+
+var { d: renamed, ...d } = o2;
+>d : Symbol(d, Decl(objectRest.ts, 8, 31))
+>renamed : Symbol(renamed, Decl(objectRest.ts, 3, 8), Decl(objectRest.ts, 4, 5), Decl(objectRest.ts, 5, 5), Decl(objectRest.ts, 9, 5))
+>d : Symbol(d, Decl(objectRest.ts, 9, 17))
+>o2 : Symbol(o2, Decl(objectRest.ts, 8, 3))
+
+let nestedrest: { x: number, n1: { y: number, n2: { z: number, n3: { n4: number } } }, rest: number, restrest: number };
+>nestedrest : Symbol(nestedrest, Decl(objectRest.ts, 11, 3))
+>x : Symbol(x, Decl(objectRest.ts, 11, 17))
+>n1 : Symbol(n1, Decl(objectRest.ts, 11, 28))
+>y : Symbol(y, Decl(objectRest.ts, 11, 34))
+>n2 : Symbol(n2, Decl(objectRest.ts, 11, 45))
+>z : Symbol(z, Decl(objectRest.ts, 11, 51))
+>n3 : Symbol(n3, Decl(objectRest.ts, 11, 62))
+>n4 : Symbol(n4, Decl(objectRest.ts, 11, 68))
+>rest : Symbol(rest, Decl(objectRest.ts, 11, 86))
+>restrest : Symbol(restrest, Decl(objectRest.ts, 11, 100))
+
+var { x, n1: { y, n2: { z, n3: { ...nr } } }, ...restrest } = nestedrest;
+>x : Symbol(x, Decl(objectRest.ts, 12, 5), Decl(objectRest.ts, 17, 5))
+>n1 : Symbol(n1, Decl(objectRest.ts, 11, 28))
+>y : Symbol(y, Decl(objectRest.ts, 12, 14))
+>n2 : Symbol(n2, Decl(objectRest.ts, 11, 45))
+>z : Symbol(z, Decl(objectRest.ts, 12, 23))
+>n3 : Symbol(n3, Decl(objectRest.ts, 11, 62))
+>nr : Symbol(nr, Decl(objectRest.ts, 12, 32))
+>restrest : Symbol(restrest, Decl(objectRest.ts, 12, 45))
+>nestedrest : Symbol(nestedrest, Decl(objectRest.ts, 11, 3))
+
+let complex: { x: { ka, ki }, y: number };
+>complex : Symbol(complex, Decl(objectRest.ts, 14, 3))
+>x : Symbol(x, Decl(objectRest.ts, 14, 14))
+>ka : Symbol(ka, Decl(objectRest.ts, 14, 19))
+>ki : Symbol(ki, Decl(objectRest.ts, 14, 23))
+>y : Symbol(y, Decl(objectRest.ts, 14, 29))
+
+var { x: { ka, ...nested }, y: other, ...rest } = complex;
+>x : Symbol(x, Decl(objectRest.ts, 14, 14))
+>ka : Symbol(ka, Decl(objectRest.ts, 15, 10))
+>nested : Symbol(nested, Decl(objectRest.ts, 15, 14))
+>y : Symbol(y, Decl(objectRest.ts, 14, 29))
+>other : Symbol(other, Decl(objectRest.ts, 15, 27))
+>rest : Symbol(rest, Decl(objectRest.ts, 15, 37))
+>complex : Symbol(complex, Decl(objectRest.ts, 14, 3))
+
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+>x : Symbol(x, Decl(objectRest.ts, 16, 2))
+>ka : Symbol(ka, Decl(objectRest.ts, 16, 6))
+>y : Symbol(y, Decl(objectRest.ts, 16, 23))
+>other : Symbol(other, Decl(objectRest.ts, 15, 27))
+>complex : Symbol(complex, Decl(objectRest.ts, 14, 3))
+
+var { x, ...fresh } = { x: 1, y: 2 };
+>x : Symbol(x, Decl(objectRest.ts, 12, 5), Decl(objectRest.ts, 17, 5))
+>fresh : Symbol(fresh, Decl(objectRest.ts, 17, 8))
+>x : Symbol(x, Decl(objectRest.ts, 17, 23))
+>y : Symbol(y, Decl(objectRest.ts, 17, 29))
+
+({ x, ...fresh } = { x: 1, y: 2 });
+>x : Symbol(x, Decl(objectRest.ts, 18, 2))
+>x : Symbol(x, Decl(objectRest.ts, 18, 20))
+>y : Symbol(y, Decl(objectRest.ts, 18, 26))
+
+class Removable {
+>Removable : Symbol(Removable, Decl(objectRest.ts, 18, 35))
+
+    private x: number;
+>x : Symbol(Removable.x, Decl(objectRest.ts, 20, 17))
+
+    protected y: number;
+>y : Symbol(Removable.y, Decl(objectRest.ts, 21, 22))
+
+    set z(value: number) { }
+>z : Symbol(Removable.z, Decl(objectRest.ts, 22, 24))
+>value : Symbol(value, Decl(objectRest.ts, 23, 10))
+
+    get both(): number { return 12 }
+>both : Symbol(Removable.both, Decl(objectRest.ts, 23, 28), Decl(objectRest.ts, 24, 36))
+
+    set both(value: number) { }
+>both : Symbol(Removable.both, Decl(objectRest.ts, 23, 28), Decl(objectRest.ts, 24, 36))
+>value : Symbol(value, Decl(objectRest.ts, 25, 13))
+
+    m() { }
+>m : Symbol(Removable.m, Decl(objectRest.ts, 25, 31))
+
+    removed: string;
+>removed : Symbol(Removable.removed, Decl(objectRest.ts, 26, 11))
+
+    remainder: string;
+>remainder : Symbol(Removable.remainder, Decl(objectRest.ts, 27, 20))
+}
+var removable = new Removable();
+>removable : Symbol(removable, Decl(objectRest.ts, 30, 3))
+>Removable : Symbol(Removable, Decl(objectRest.ts, 18, 35))
+
+var { removed, ...removableRest } = removable;
+>removed : Symbol(removed, Decl(objectRest.ts, 31, 5))
+>removableRest : Symbol(removableRest, Decl(objectRest.ts, 31, 14))
+>removable : Symbol(removable, Decl(objectRest.ts, 30, 3))
+
diff --git a/tests/baselines/reference/objectRest.types b/tests/baselines/reference/objectRest.types
new file mode 100644
index 00000000000..95e378359c8
--- /dev/null
+++ b/tests/baselines/reference/objectRest.types
@@ -0,0 +1,170 @@
+=== tests/cases/conformance/types/rest/objectRest.ts ===
+let o = { a: 1, b: 'no' }
+>o : { a: number; b: string; }
+>{ a: 1, b: 'no' } : { a: number; b: string; }
+>a : number
+>1 : 1
+>b : string
+>'no' : "no"
+
+var { ...clone } = o;
+>clone : { a: number; b: string; }
+>o : { a: number; b: string; }
+
+var { a, ...justB } = o;
+>a : number
+>justB : { b: string; }
+>o : { a: number; b: string; }
+
+var { a, b: renamed, ...empty } = o;
+>a : number
+>b : any
+>renamed : string
+>empty : {}
+>o : { a: number; b: string; }
+
+var { ['b']: renamed, ...justA } = o;
+>'b' : "b"
+>renamed : string
+>justA : { a: number; }
+>o : { a: number; b: string; }
+
+var { 'b': renamed, ...justA } = o;
+>renamed : string
+>justA : { a: number; }
+>o : { a: number; b: string; }
+
+var { b: { '0': n, '1': oooo }, ...justA } = o;
+>b : any
+>n : string
+>oooo : string
+>justA : { a: number; }
+>o : { a: number; b: string; }
+
+let o2 = { c: 'terrible idea?', d: 'yes' };
+>o2 : { c: string; d: string; }
+>{ c: 'terrible idea?', d: 'yes' } : { c: string; d: string; }
+>c : string
+>'terrible idea?' : "terrible idea?"
+>d : string
+>'yes' : "yes"
+
+var { d: renamed, ...d } = o2;
+>d : any
+>renamed : string
+>d : { c: string; }
+>o2 : { c: string; d: string; }
+
+let nestedrest: { x: number, n1: { y: number, n2: { z: number, n3: { n4: number } } }, rest: number, restrest: number };
+>nestedrest : { x: number; n1: { y: number; n2: { z: number; n3: { n4: number; }; }; }; rest: number; restrest: number; }
+>x : number
+>n1 : { y: number; n2: { z: number; n3: { n4: number; }; }; }
+>y : number
+>n2 : { z: number; n3: { n4: number; }; }
+>z : number
+>n3 : { n4: number; }
+>n4 : number
+>rest : number
+>restrest : number
+
+var { x, n1: { y, n2: { z, n3: { ...nr } } }, ...restrest } = nestedrest;
+>x : number
+>n1 : any
+>y : number
+>n2 : any
+>z : number
+>n3 : any
+>nr : { n4: number; }
+>restrest : { rest: number; restrest: number; }
+>nestedrest : { x: number; n1: { y: number; n2: { z: number; n3: { n4: number; }; }; }; rest: number; restrest: number; }
+
+let complex: { x: { ka, ki }, y: number };
+>complex : { x: { ka: any; ki: any; }; y: number; }
+>x : { ka: any; ki: any; }
+>ka : any
+>ki : any
+>y : number
+
+var { x: { ka, ...nested }, y: other, ...rest } = complex;
+>x : any
+>ka : any
+>nested : { ki: any; }
+>y : any
+>other : number
+>rest : {}
+>complex : { x: { ka: any; ki: any; }; y: number; }
+
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+>({x: { ka, ...nested }, y: other, ...rest} = complex) : { x: { ka: any; ki: any; }; y: number; }
+>{x: { ka, ...nested }, y: other, ...rest} = complex : { x: { ka: any; ki: any; }; y: number; }
+>{x: { ka, ...nested }, y: other, ...rest} : { x: { ki: any; ka: any; }; y: number; }
+>x : { ki: any; ka: any; }
+>{ ka, ...nested } : { ki: any; ka: any; }
+>ka : any
+>nested : any
+>y : number
+>other : number
+>rest : any
+>complex : { x: { ka: any; ki: any; }; y: number; }
+
+var { x, ...fresh } = { x: 1, y: 2 };
+>x : number
+>fresh : { y: number; }
+>{ x: 1, y: 2 } : { x: number; y: number; }
+>x : number
+>1 : 1
+>y : number
+>2 : 2
+
+({ x, ...fresh } = { x: 1, y: 2 });
+>({ x, ...fresh } = { x: 1, y: 2 }) : { x: number; y: number; }
+>{ x, ...fresh } = { x: 1, y: 2 } : { x: number; y: number; }
+>{ x, ...fresh } : { y: number; x: number; }
+>x : number
+>fresh : any
+>{ x: 1, y: 2 } : { x: number; y: number; }
+>x : number
+>1 : 1
+>y : number
+>2 : 2
+
+class Removable {
+>Removable : Removable
+
+    private x: number;
+>x : number
+
+    protected y: number;
+>y : number
+
+    set z(value: number) { }
+>z : number
+>value : number
+
+    get both(): number { return 12 }
+>both : number
+>12 : 12
+
+    set both(value: number) { }
+>both : number
+>value : number
+
+    m() { }
+>m : () => void
+
+    removed: string;
+>removed : string
+
+    remainder: string;
+>remainder : string
+}
+var removable = new Removable();
+>removable : Removable
+>new Removable() : Removable
+>Removable : typeof Removable
+
+var { removed, ...removableRest } = removable;
+>removed : string
+>removableRest : { both: number; remainder: string; }
+>removable : Removable
+
diff --git a/tests/baselines/reference/objectRestAssignment.js b/tests/baselines/reference/objectRestAssignment.js
new file mode 100644
index 00000000000..41620d59b58
--- /dev/null
+++ b/tests/baselines/reference/objectRestAssignment.js
@@ -0,0 +1,35 @@
+//// [objectRestAssignment.ts]
+let ka: any;
+let nested: { ki };
+let other: number;
+let rest: { };
+let complex: { x: { ka, ki }, y: number };
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+
+// should be:
+let overEmit: { a: { ka: string, x: string }[], b: { z: string, ki: string, ku: string }, ke: string, ko: string };
+
+// var _g = overEmit.a, [_h, ...y] = _g, nested2 = __rest(_h, []), _j = overEmit.b, { z } = _j, c = __rest(_j, ["z"]), rest2 = __rest(overEmit, ["a", "b"]);
+var { a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit;
+({ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit);
+
+
+//// [objectRestAssignment.js]
+var __rest = (this && this.__rest) || function (s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && !e.indexOf(p))
+        t[p] = s[p];
+    return t;
+};
+let ka;
+let nested;
+let other;
+let rest;
+let complex;
+(_a = complex.x, { ka } = _a, nested = __rest(_a, ["ka"]), { y: other } = complex, rest = __rest(complex, ["x", "y"]), complex);
+// should be:
+let overEmit;
+// var _g = overEmit.a, [_h, ...y] = _g, nested2 = __rest(_h, []), _j = overEmit.b, { z } = _j, c = __rest(_j, ["z"]), rest2 = __rest(overEmit, ["a", "b"]);
+var _b = overEmit.a, [_c, ...y] = _b, nested2 = __rest(_c, []), _d = overEmit.b, { z } = _d, c = __rest(_d, ["z"]), rest2 = __rest(overEmit, ["a", "b"]);
+(_e = overEmit.a, [_f, ...y] = _e, nested2 = __rest(_f, []), _g = overEmit.b, { z } = _g, c = __rest(_g, ["z"]), rest2 = __rest(overEmit, ["a", "b"]), overEmit);
+var _a, _e, _f, _g;
diff --git a/tests/baselines/reference/objectRestAssignment.symbols b/tests/baselines/reference/objectRestAssignment.symbols
new file mode 100644
index 00000000000..4cb27e6e7ec
--- /dev/null
+++ b/tests/baselines/reference/objectRestAssignment.symbols
@@ -0,0 +1,59 @@
+=== tests/cases/conformance/types/rest/objectRestAssignment.ts ===
+let ka: any;
+>ka : Symbol(ka, Decl(objectRestAssignment.ts, 0, 3))
+
+let nested: { ki };
+>nested : Symbol(nested, Decl(objectRestAssignment.ts, 1, 3))
+>ki : Symbol(ki, Decl(objectRestAssignment.ts, 1, 13))
+
+let other: number;
+>other : Symbol(other, Decl(objectRestAssignment.ts, 2, 3))
+
+let rest: { };
+>rest : Symbol(rest, Decl(objectRestAssignment.ts, 3, 3))
+
+let complex: { x: { ka, ki }, y: number };
+>complex : Symbol(complex, Decl(objectRestAssignment.ts, 4, 3))
+>x : Symbol(x, Decl(objectRestAssignment.ts, 4, 14))
+>ka : Symbol(ka, Decl(objectRestAssignment.ts, 4, 19))
+>ki : Symbol(ki, Decl(objectRestAssignment.ts, 4, 23))
+>y : Symbol(y, Decl(objectRestAssignment.ts, 4, 29))
+
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+>x : Symbol(x, Decl(objectRestAssignment.ts, 5, 2))
+>ka : Symbol(ka, Decl(objectRestAssignment.ts, 5, 6))
+>y : Symbol(y, Decl(objectRestAssignment.ts, 5, 23))
+>other : Symbol(other, Decl(objectRestAssignment.ts, 2, 3))
+>complex : Symbol(complex, Decl(objectRestAssignment.ts, 4, 3))
+
+// should be:
+let overEmit: { a: { ka: string, x: string }[], b: { z: string, ki: string, ku: string }, ke: string, ko: string };
+>overEmit : Symbol(overEmit, Decl(objectRestAssignment.ts, 8, 3))
+>a : Symbol(a, Decl(objectRestAssignment.ts, 8, 15))
+>ka : Symbol(ka, Decl(objectRestAssignment.ts, 8, 20))
+>x : Symbol(x, Decl(objectRestAssignment.ts, 8, 32))
+>b : Symbol(b, Decl(objectRestAssignment.ts, 8, 47))
+>z : Symbol(z, Decl(objectRestAssignment.ts, 8, 52))
+>ki : Symbol(ki, Decl(objectRestAssignment.ts, 8, 63))
+>ku : Symbol(ku, Decl(objectRestAssignment.ts, 8, 75))
+>ke : Symbol(ke, Decl(objectRestAssignment.ts, 8, 89))
+>ko : Symbol(ko, Decl(objectRestAssignment.ts, 8, 101))
+
+// var _g = overEmit.a, [_h, ...y] = _g, nested2 = __rest(_h, []), _j = overEmit.b, { z } = _j, c = __rest(_j, ["z"]), rest2 = __rest(overEmit, ["a", "b"]);
+var { a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit;
+>a : Symbol(a, Decl(objectRestAssignment.ts, 8, 15))
+>nested2 : Symbol(nested2, Decl(objectRestAssignment.ts, 11, 11))
+>y : Symbol(y, Decl(objectRestAssignment.ts, 11, 25))
+>b : Symbol(b, Decl(objectRestAssignment.ts, 8, 47))
+>z : Symbol(z, Decl(objectRestAssignment.ts, 11, 37))
+>c : Symbol(c, Decl(objectRestAssignment.ts, 11, 40))
+>rest2 : Symbol(rest2, Decl(objectRestAssignment.ts, 11, 48))
+>overEmit : Symbol(overEmit, Decl(objectRestAssignment.ts, 8, 3))
+
+({ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit);
+>a : Symbol(a, Decl(objectRestAssignment.ts, 12, 2))
+>y : Symbol(y, Decl(objectRestAssignment.ts, 11, 25))
+>b : Symbol(b, Decl(objectRestAssignment.ts, 12, 29))
+>z : Symbol(z, Decl(objectRestAssignment.ts, 12, 34))
+>overEmit : Symbol(overEmit, Decl(objectRestAssignment.ts, 8, 3))
+
diff --git a/tests/baselines/reference/objectRestAssignment.types b/tests/baselines/reference/objectRestAssignment.types
new file mode 100644
index 00000000000..38aa00ce61d
--- /dev/null
+++ b/tests/baselines/reference/objectRestAssignment.types
@@ -0,0 +1,75 @@
+=== tests/cases/conformance/types/rest/objectRestAssignment.ts ===
+let ka: any;
+>ka : any
+
+let nested: { ki };
+>nested : { ki: any; }
+>ki : any
+
+let other: number;
+>other : number
+
+let rest: { };
+>rest : {}
+
+let complex: { x: { ka, ki }, y: number };
+>complex : { x: { ka: any; ki: any; }; y: number; }
+>x : { ka: any; ki: any; }
+>ka : any
+>ki : any
+>y : number
+
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+>({x: { ka, ...nested }, y: other, ...rest} = complex) : { x: { ka: any; ki: any; }; y: number; }
+>{x: { ka, ...nested }, y: other, ...rest} = complex : { x: { ka: any; ki: any; }; y: number; }
+>{x: { ka, ...nested }, y: other, ...rest} : { x: { ki: any; ka: any; }; y: number; }
+>x : { ki: any; ka: any; }
+>{ ka, ...nested } : { ki: any; ka: any; }
+>ka : any
+>nested : any
+>y : number
+>other : number
+>rest : any
+>complex : { x: { ka: any; ki: any; }; y: number; }
+
+// should be:
+let overEmit: { a: { ka: string, x: string }[], b: { z: string, ki: string, ku: string }, ke: string, ko: string };
+>overEmit : { a: { ka: string; x: string; }[]; b: { z: string; ki: string; ku: string; }; ke: string; ko: string; }
+>a : { ka: string; x: string; }[]
+>ka : string
+>x : string
+>b : { z: string; ki: string; ku: string; }
+>z : string
+>ki : string
+>ku : string
+>ke : string
+>ko : string
+
+// var _g = overEmit.a, [_h, ...y] = _g, nested2 = __rest(_h, []), _j = overEmit.b, { z } = _j, c = __rest(_j, ["z"]), rest2 = __rest(overEmit, ["a", "b"]);
+var { a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit;
+>a : any
+>nested2 : { ka: string; x: string; }
+>y : { ka: string; x: string; }[]
+>b : any
+>z : string
+>c : { ki: string; ku: string; }
+>rest2 : { ke: string; ko: string; }
+>overEmit : { a: { ka: string; x: string; }[]; b: { z: string; ki: string; ku: string; }; ke: string; ko: string; }
+
+({ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit);
+>({ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit) : { a: { ka: string; x: string; }[]; b: { z: string; ki: string; ku: string; }; ke: string; ko: string; }
+>{ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit : { a: { ka: string; x: string; }[]; b: { z: string; ki: string; ku: string; }; ke: string; ko: string; }
+>{ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } : { ke: string; ko: string; a: { ka: string; x: string; }[]; b: { ki: string; ku: string; z: string; }; }
+>a : { ka: string; x: string; }[]
+>[{ ...nested2 }, ...y] : { ka: string; x: string; }[]
+>{ ...nested2 } : { ka: string; x: string; }
+>nested2 : any
+>...y : { ka: string; x: string; }
+>y : { ka: string; x: string; }[]
+>b : { ki: string; ku: string; z: string; }
+>{ z, ...c } : { ki: string; ku: string; z: string; }
+>z : string
+>c : any
+>rest2 : any
+>overEmit : { a: { ka: string; x: string; }[]; b: { z: string; ki: string; ku: string; }; ke: string; ko: string; }
+
diff --git a/tests/baselines/reference/objectRestForOf.js b/tests/baselines/reference/objectRestForOf.js
new file mode 100644
index 00000000000..26ebd8f8229
--- /dev/null
+++ b/tests/baselines/reference/objectRestForOf.js
@@ -0,0 +1,45 @@
+//// [objectRestForOf.ts]
+let array: { x: number, y: string }[];
+for (let { x, ...restOf } of array) {
+    [x, restOf];
+}
+let xx: number;
+let rrestOff: { y: string };
+for ({ x: xx, ...rrestOff } of array ) {
+    [xx, rrestOff];
+}
+for (const norest of array.map(a => ({ ...a, x: 'a string' }))) {
+    [norest.x, norest.y];
+    // x is now a string. who knows why.
+}
+
+
+//// [objectRestForOf.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var __rest = (this && this.__rest) || function (s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && !e.indexOf(p))
+        t[p] = s[p];
+    return t;
+};
+let array;
+for (var array_1 of array) {
+    var { x } = array_1, restOf = __rest(array_1, ["x"]);
+    [x, restOf];
+}
+let xx;
+let rrestOff;
+for (var array_2 of array) {
+    ({ x: xx } = array_2, rrestOff = __rest(array_2, ["x"]));
+    [xx, rrestOff];
+}
+for (const norest of array.map(a => (__assign({}, a, { x: 'a string' })))) {
+    [norest.x, norest.y];
+}
diff --git a/tests/baselines/reference/objectRestForOf.symbols b/tests/baselines/reference/objectRestForOf.symbols
new file mode 100644
index 00000000000..ec0ccde740d
--- /dev/null
+++ b/tests/baselines/reference/objectRestForOf.symbols
@@ -0,0 +1,50 @@
+=== tests/cases/conformance/types/rest/objectRestForOf.ts ===
+let array: { x: number, y: string }[];
+>array : Symbol(array, Decl(objectRestForOf.ts, 0, 3))
+>x : Symbol(x, Decl(objectRestForOf.ts, 0, 12))
+>y : Symbol(y, Decl(objectRestForOf.ts, 0, 23))
+
+for (let { x, ...restOf } of array) {
+>x : Symbol(x, Decl(objectRestForOf.ts, 1, 10))
+>restOf : Symbol(restOf, Decl(objectRestForOf.ts, 1, 13))
+>array : Symbol(array, Decl(objectRestForOf.ts, 0, 3))
+
+    [x, restOf];
+>x : Symbol(x, Decl(objectRestForOf.ts, 1, 10))
+>restOf : Symbol(restOf, Decl(objectRestForOf.ts, 1, 13))
+}
+let xx: number;
+>xx : Symbol(xx, Decl(objectRestForOf.ts, 4, 3))
+
+let rrestOff: { y: string };
+>rrestOff : Symbol(rrestOff, Decl(objectRestForOf.ts, 5, 3))
+>y : Symbol(y, Decl(objectRestForOf.ts, 5, 15))
+
+for ({ x: xx, ...rrestOff } of array ) {
+>x : Symbol(x, Decl(objectRestForOf.ts, 6, 6))
+>xx : Symbol(xx, Decl(objectRestForOf.ts, 4, 3))
+>array : Symbol(array, Decl(objectRestForOf.ts, 0, 3))
+
+    [xx, rrestOff];
+>xx : Symbol(xx, Decl(objectRestForOf.ts, 4, 3))
+>rrestOff : Symbol(rrestOff, Decl(objectRestForOf.ts, 5, 3))
+}
+for (const norest of array.map(a => ({ ...a, x: 'a string' }))) {
+>norest : Symbol(norest, Decl(objectRestForOf.ts, 9, 10))
+>array.map : Symbol(Array.map, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>array : Symbol(array, Decl(objectRestForOf.ts, 0, 3))
+>map : Symbol(Array.map, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>a : Symbol(a, Decl(objectRestForOf.ts, 9, 31))
+>x : Symbol(x, Decl(objectRestForOf.ts, 9, 44))
+
+    [norest.x, norest.y];
+>norest.x : Symbol(x, Decl(objectRestForOf.ts, 9, 44))
+>norest : Symbol(norest, Decl(objectRestForOf.ts, 9, 10))
+>x : Symbol(x, Decl(objectRestForOf.ts, 9, 44))
+>norest.y : Symbol(y, Decl(objectRestForOf.ts, 0, 23))
+>norest : Symbol(norest, Decl(objectRestForOf.ts, 9, 10))
+>y : Symbol(y, Decl(objectRestForOf.ts, 0, 23))
+
+    // x is now a string. who knows why.
+}
+
diff --git a/tests/baselines/reference/objectRestForOf.types b/tests/baselines/reference/objectRestForOf.types
new file mode 100644
index 00000000000..e8c3b4a82ab
--- /dev/null
+++ b/tests/baselines/reference/objectRestForOf.types
@@ -0,0 +1,61 @@
+=== tests/cases/conformance/types/rest/objectRestForOf.ts ===
+let array: { x: number, y: string }[];
+>array : { x: number; y: string; }[]
+>x : number
+>y : string
+
+for (let { x, ...restOf } of array) {
+>x : number
+>restOf : { y: string; }
+>array : { x: number; y: string; }[]
+
+    [x, restOf];
+>[x, restOf] : (number | { y: string; })[]
+>x : number
+>restOf : { y: string; }
+}
+let xx: number;
+>xx : number
+
+let rrestOff: { y: string };
+>rrestOff : { y: string; }
+>y : string
+
+for ({ x: xx, ...rrestOff } of array ) {
+>{ x: xx, ...rrestOff } : { y: string; x: number; }
+>x : { x: number; y: string; }
+>xx : number
+>rrestOff : any
+>array : { x: number; y: string; }[]
+
+    [xx, rrestOff];
+>[xx, rrestOff] : (number | { y: string; })[]
+>xx : number
+>rrestOff : { y: string; }
+}
+for (const norest of array.map(a => ({ ...a, x: 'a string' }))) {
+>norest : { x: string; y: string; }
+>array.map(a => ({ ...a, x: 'a string' })) : { x: string; y: string; }[]
+>array.map : { <U>(this: [{ x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U, U, U, U]; <U>(this: [{ x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U, U, U]; <U>(this: [{ x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U, U]; <U>(this: [{ x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U]; <U>(callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): U[]; }
+>array : { x: number; y: string; }[]
+>map : { <U>(this: [{ x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U, U, U, U]; <U>(this: [{ x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U, U, U]; <U>(this: [{ x: number; y: string; }, { x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U, U]; <U>(this: [{ x: number; y: string; }, { x: number; y: string; }], callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): [U, U]; <U>(callbackfn: (value: { x: number; y: string; }, index: number, array: { x: number; y: string; }[]) => U, thisArg?: any): U[]; }
+>a => ({ ...a, x: 'a string' }) : (a: { x: number; y: string; }) => { x: string; y: string; }
+>a : { x: number; y: string; }
+>({ ...a, x: 'a string' }) : { x: string; y: string; }
+>{ ...a, x: 'a string' } : { x: string; y: string; }
+>a : any
+>x : string
+>'a string' : "a string"
+
+    [norest.x, norest.y];
+>[norest.x, norest.y] : string[]
+>norest.x : string
+>norest : { x: string; y: string; }
+>x : string
+>norest.y : string
+>norest : { x: string; y: string; }
+>y : string
+
+    // x is now a string. who knows why.
+}
+
diff --git a/tests/baselines/reference/objectRestNegative.errors.txt b/tests/baselines/reference/objectRestNegative.errors.txt
new file mode 100644
index 00000000000..b8144e3209b
--- /dev/null
+++ b/tests/baselines/reference/objectRestNegative.errors.txt
@@ -0,0 +1,27 @@
+tests/cases/conformance/types/rest/objectRestNegative.ts(2,10): error TS2462: A rest element must be last in a destructuring pattern
+tests/cases/conformance/types/rest/objectRestNegative.ts(3,31): error TS2462: A rest element must be last in a destructuring pattern
+tests/cases/conformance/types/rest/objectRestNegative.ts(6,17): error TS2700: Rest types may only be created from object types.
+tests/cases/conformance/types/rest/objectRestNegative.ts(11,9): error TS2701: An object rest element must be an identifier.
+
+
+==== tests/cases/conformance/types/rest/objectRestNegative.ts (4 errors) ====
+    let o = { a: 1, b: 'no' };
+    var { ...mustBeLast, a } = o;
+             ~~~~~~~~~~
+!!! error TS2462: A rest element must be last in a destructuring pattern
+    function stillMustBeLast({ ...mustBeLast, a }: { a: number, b: string }): void {
+                                  ~~~~~~~~~~
+!!! error TS2462: A rest element must be last in a destructuring pattern
+    }
+    function generic<T extends { x, y }>(t: T) {
+        let { x, ...rest } = t;
+                    ~~~~
+!!! error TS2700: Rest types may only be created from object types.
+        return rest;
+    }
+    
+    let rest: { b: string }
+    ({a, ...rest.b + rest.b} = o);
+            ~~~~~~~~~~~~~~~
+!!! error TS2701: An object rest element must be an identifier.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/objectRestNegative.js b/tests/baselines/reference/objectRestNegative.js
new file mode 100644
index 00000000000..8692850dbdd
--- /dev/null
+++ b/tests/baselines/reference/objectRestNegative.js
@@ -0,0 +1,32 @@
+//// [objectRestNegative.ts]
+let o = { a: 1, b: 'no' };
+var { ...mustBeLast, a } = o;
+function stillMustBeLast({ ...mustBeLast, a }: { a: number, b: string }): void {
+}
+function generic<T extends { x, y }>(t: T) {
+    let { x, ...rest } = t;
+    return rest;
+}
+
+let rest: { b: string }
+({a, ...rest.b + rest.b} = o);
+
+
+//// [objectRestNegative.js]
+var __rest = (this && this.__rest) || function (s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && !e.indexOf(p))
+        t[p] = s[p];
+    return t;
+};
+var o = { a: 1, b: 'no' };
+var mustBeLast = o.mustBeLast, a = o.a;
+function stillMustBeLast(_a) {
+    var mustBeLast = _a.mustBeLast, a = _a.a;
+}
+function generic(t) {
+    var x = t.x, rest = __rest(t, ["x"]);
+    return rest;
+}
+var rest;
+(a = o.a, o, o);
diff --git a/tests/baselines/reference/objectRestParameter.js b/tests/baselines/reference/objectRestParameter.js
new file mode 100644
index 00000000000..49434f24eec
--- /dev/null
+++ b/tests/baselines/reference/objectRestParameter.js
@@ -0,0 +1,28 @@
+//// [objectRestParameter.ts]
+function cloneAgain({ a, ...clone }: { a: number, b: string }): void {
+}
+
+declare function suddenly(f: (a: { x: { z, ka }, y: string }) => void);
+suddenly(({ x: a, ...rest }) => rest.y);
+suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka);
+
+
+
+//// [objectRestParameter.js]
+var __rest = (this && this.__rest) || function (s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && !e.indexOf(p))
+        t[p] = s[p];
+    return t;
+};
+function cloneAgain(_a) {
+    var { a } = _a, clone = __rest(_a, ["a"]);
+}
+suddenly((_a) => {
+    var { x: a } = _a, rest = __rest(_a, ["x"]);
+    return rest.y;
+});
+suddenly((_a = { x: { z: 1, ka: 1 }, y: 'noo' }) => {
+    var _b = _a.x, { z = 12 } = _b, nested = __rest(_b, ["z"]), rest = __rest(_a, ["x"]);
+    return rest.y + nested.ka;
+});
diff --git a/tests/baselines/reference/objectRestParameter.symbols b/tests/baselines/reference/objectRestParameter.symbols
new file mode 100644
index 00000000000..9569dc53d3a
--- /dev/null
+++ b/tests/baselines/reference/objectRestParameter.symbols
@@ -0,0 +1,45 @@
+=== tests/cases/conformance/types/rest/objectRestParameter.ts ===
+function cloneAgain({ a, ...clone }: { a: number, b: string }): void {
+>cloneAgain : Symbol(cloneAgain, Decl(objectRestParameter.ts, 0, 0))
+>a : Symbol(a, Decl(objectRestParameter.ts, 0, 21))
+>clone : Symbol(clone, Decl(objectRestParameter.ts, 0, 24))
+>a : Symbol(a, Decl(objectRestParameter.ts, 0, 38))
+>b : Symbol(b, Decl(objectRestParameter.ts, 0, 49))
+}
+
+declare function suddenly(f: (a: { x: { z, ka }, y: string }) => void);
+>suddenly : Symbol(suddenly, Decl(objectRestParameter.ts, 1, 1))
+>f : Symbol(f, Decl(objectRestParameter.ts, 3, 26))
+>a : Symbol(a, Decl(objectRestParameter.ts, 3, 30))
+>x : Symbol(x, Decl(objectRestParameter.ts, 3, 34))
+>z : Symbol(z, Decl(objectRestParameter.ts, 3, 39))
+>ka : Symbol(ka, Decl(objectRestParameter.ts, 3, 42))
+>y : Symbol(y, Decl(objectRestParameter.ts, 3, 48))
+
+suddenly(({ x: a, ...rest }) => rest.y);
+>suddenly : Symbol(suddenly, Decl(objectRestParameter.ts, 1, 1))
+>x : Symbol(x, Decl(objectRestParameter.ts, 3, 34))
+>a : Symbol(a, Decl(objectRestParameter.ts, 4, 11))
+>rest : Symbol(rest, Decl(objectRestParameter.ts, 4, 17))
+>rest.y : Symbol(y, Decl(objectRestParameter.ts, 3, 48))
+>rest : Symbol(rest, Decl(objectRestParameter.ts, 4, 17))
+>y : Symbol(y, Decl(objectRestParameter.ts, 3, 48))
+
+suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka);
+>suddenly : Symbol(suddenly, Decl(objectRestParameter.ts, 1, 1))
+>x : Symbol(x, Decl(objectRestParameter.ts, 3, 34))
+>z : Symbol(z, Decl(objectRestParameter.ts, 5, 16))
+>nested : Symbol(nested, Decl(objectRestParameter.ts, 5, 24))
+>rest : Symbol(rest, Decl(objectRestParameter.ts, 5, 37))
+>x : Symbol(x, Decl(objectRestParameter.ts, 5, 51))
+>z : Symbol(z, Decl(objectRestParameter.ts, 5, 56))
+>ka : Symbol(ka, Decl(objectRestParameter.ts, 5, 62))
+>y : Symbol(y, Decl(objectRestParameter.ts, 5, 71))
+>rest.y : Symbol(y, Decl(objectRestParameter.ts, 3, 48))
+>rest : Symbol(rest, Decl(objectRestParameter.ts, 5, 37))
+>y : Symbol(y, Decl(objectRestParameter.ts, 3, 48))
+>nested.ka : Symbol(ka, Decl(objectRestParameter.ts, 3, 42))
+>nested : Symbol(nested, Decl(objectRestParameter.ts, 5, 24))
+>ka : Symbol(ka, Decl(objectRestParameter.ts, 3, 42))
+
+
diff --git a/tests/baselines/reference/objectRestParameter.types b/tests/baselines/reference/objectRestParameter.types
new file mode 100644
index 00000000000..c634c9c5cd5
--- /dev/null
+++ b/tests/baselines/reference/objectRestParameter.types
@@ -0,0 +1,56 @@
+=== tests/cases/conformance/types/rest/objectRestParameter.ts ===
+function cloneAgain({ a, ...clone }: { a: number, b: string }): void {
+>cloneAgain : ({a, ...clone}: { a: number; b: string; }) => void
+>a : number
+>clone : { b: string; }
+>a : number
+>b : string
+}
+
+declare function suddenly(f: (a: { x: { z, ka }, y: string }) => void);
+>suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
+>f : (a: { x: { z: any; ka: any; }; y: string; }) => void
+>a : { x: { z: any; ka: any; }; y: string; }
+>x : { z: any; ka: any; }
+>z : any
+>ka : any
+>y : string
+
+suddenly(({ x: a, ...rest }) => rest.y);
+>suddenly(({ x: a, ...rest }) => rest.y) : any
+>suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
+>({ x: a, ...rest }) => rest.y : ({x: a, ...rest}: { x: { z: any; ka: any; }; y: string; }) => string
+>x : any
+>a : { z: any; ka: any; }
+>rest : { y: string; }
+>rest.y : string
+>rest : { y: string; }
+>y : string
+
+suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka);
+>suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka) : any
+>suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
+>({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka : ({x: {z, ...nested}, ...rest}?: { x: { z: any; ka: any; }; y: string; }) => string
+>x : any
+>z : any
+>12 : 12
+>nested : { ka: any; }
+>rest : { y: string; }
+>{ x: { z: 1, ka: 1 }, y: 'noo' } : { x: { z: number; ka: number; }; y: string; }
+>x : { z: number; ka: number; }
+>{ z: 1, ka: 1 } : { z: number; ka: number; }
+>z : number
+>1 : 1
+>ka : number
+>1 : 1
+>y : string
+>'noo' : "noo"
+>rest.y + nested.ka : string
+>rest.y : string
+>rest : { y: string; }
+>y : string
+>nested.ka : any
+>nested : { ka: any; }
+>ka : any
+
+
diff --git a/tests/baselines/reference/objectSpread.js b/tests/baselines/reference/objectSpread.js
new file mode 100644
index 00000000000..d1de48c5cab
--- /dev/null
+++ b/tests/baselines/reference/objectSpread.js
@@ -0,0 +1,151 @@
+//// [objectSpread.ts]
+let o = { a: 1, b: 'no' }
+let o2 = { b: 'yes', c: true }
+let swap = { a: 'yes', b: -1 };
+
+let addAfter: { a: number, b: string, c: boolean } =
+    { ...o, c: false }
+let addBefore: { a: number, b: string, c: boolean } =
+    { c: false, ...o }
+// Note: ignore still changes the order that properties are printed
+let ignore: { a: number, b: string } =
+    { b: 'ignored', ...o }
+let override: { a: number, b: string } =
+    { ...o, b: 'override' }
+let nested: { a: number, b: boolean, c: string } =
+    { ...{ a: 3, ...{ b: false, c: 'overriden' } }, c: 'whatever' }
+let combined: { a: number, b: string, c: boolean } =
+    { ...o, ...o2 }
+let combinedBefore: { a: number, b: string, c: boolean } =
+    { b: 'ok', ...o, ...o2 }
+let combinedMid: { a: number, b: string, c: boolean } =
+    { ...o, b: 'ok', ...o2 }
+let combinedAfter: { a: number, b: string, c: boolean } =
+    { ...o, ...o2, b: 'ok' }
+let combinedNested: { a: number, b: boolean, c: string, d: string } =
+    { ...{ a: 4, ...{ b: false, c: 'overriden' } }, d: 'actually new', ...{ a: 5, d: 'maybe new' } }
+let combinedNestedChangeType: { a: number, b: boolean, c: number } =
+    { ...{ a: 1, ...{ b: false, c: 'overriden' } }, c: -1 }
+let propertyNested: { a: { a: number, b: string } } =
+    { a: { ... o } }
+// accessors don't copy the descriptor
+// (which means that readonly getters become read/write properties)
+let op = { get a () { return 6 } };
+let getter: { a: number, c: number } =
+    { ...op, c: 7 }
+getter.a = 12;
+
+// functions result in { }
+let spreadFunc = { ...(function () { }) };
+
+// any results in any
+let anything: any;
+let spreadAny = { ...anything };
+
+// methods are not enumerable
+class C { p = 1; m() { } }
+let c: C = new C()
+let spreadC: { p: number } = { ...c }
+
+// own methods are enumerable
+let cplus: { p: number, plus(): void } = { ...c, plus() { return this.p + 1; } };
+cplus.plus();
+
+// new field's type conflicting with existing field is OK
+let changeTypeAfter: { a: string, b: string } =
+    { ...o, a: 'wrong type?' }
+let changeTypeBefore: { a: number, b: string } =
+    { a: 'wrong type?', ...o };
+let changeTypeBoth: { a: string, b: number } =
+    { ...o, ...swap };
+
+// optional
+let definiteBoolean: { sn: boolean };
+let definiteString: { sn: string };
+let optionalString: { sn?: string };
+let optionalNumber: { sn?: number };
+let optionalUnionStops: { sn: string | number | boolean } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+
+// computed property
+let computedFirst: { a: number, b: string, "before everything": number } =
+    { ['before everything']: 12, ...o, b: 'yes' }
+let computedMiddle: { a: number, b: string, c: boolean, "in the middle": number } =
+    { ...o, ['in the middle']: 13, b: 'maybe?', ...o2 }
+let computedAfter: { a: number, b: string, "at the end": number } =
+    { ...o, b: 'yeah', ['at the end']: 14 }
+// shortcut syntax
+let a = 12;
+let shortCutted: { a: number, b: string } = { ...o, a }
+
+
+
+//// [objectSpread.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var o = { a: 1, b: 'no' };
+var o2 = { b: 'yes', c: true };
+var swap = { a: 'yes', b: -1 };
+var addAfter = __assign({}, o, { c: false });
+var addBefore = __assign({ c: false }, o);
+// Note: ignore still changes the order that properties are printed
+var ignore = __assign({ b: 'ignored' }, o);
+var override = __assign({}, o, { b: 'override' });
+var nested = __assign({}, __assign({ a: 3 }, { b: false, c: 'overriden' }), { c: 'whatever' });
+var combined = __assign({}, o, o2);
+var combinedBefore = __assign({ b: 'ok' }, o, o2);
+var combinedMid = __assign({}, o, { b: 'ok' }, o2);
+var combinedAfter = __assign({}, o, o2, { b: 'ok' });
+var combinedNested = __assign({}, __assign({ a: 4 }, { b: false, c: 'overriden' }), { d: 'actually new' }, { a: 5, d: 'maybe new' });
+var combinedNestedChangeType = __assign({}, __assign({ a: 1 }, { b: false, c: 'overriden' }), { c: -1 });
+var propertyNested = __assign({ a: __assign({}, o) });
+// accessors don't copy the descriptor
+// (which means that readonly getters become read/write properties)
+var op = { get a() { return 6; } };
+var getter = __assign({}, op, { c: 7 });
+getter.a = 12;
+// functions result in { }
+var spreadFunc = __assign({}, (function () { }));
+// any results in any
+var anything;
+var spreadAny = __assign({}, anything);
+// methods are not enumerable
+var C = (function () {
+    function C() {
+        this.p = 1;
+    }
+    C.prototype.m = function () { };
+    return C;
+}());
+var c = new C();
+var spreadC = __assign({}, c);
+// own methods are enumerable
+var cplus = __assign({}, c, { plus: function () { return this.p + 1; } });
+cplus.plus();
+// new field's type conflicting with existing field is OK
+var changeTypeAfter = __assign({}, o, { a: 'wrong type?' });
+var changeTypeBefore = __assign({ a: 'wrong type?' }, o);
+var changeTypeBoth = __assign({}, o, swap);
+// optional
+var definiteBoolean;
+var definiteString;
+var optionalString;
+var optionalNumber;
+var optionalUnionStops = __assign({}, definiteBoolean, definiteString, optionalNumber);
+var optionalUnionDuplicates = __assign({}, definiteBoolean, definiteString, optionalString, optionalNumber);
+var allOptional = __assign({}, optionalString, optionalNumber);
+// computed property
+var computedFirst = __assign((_a = {}, _a['before everything'] = 12, _a), o, { b: 'yes' });
+var computedMiddle = __assign({}, o, (_b = {}, _b['in the middle'] = 13, _b.b = 'maybe?', _b), o2);
+var computedAfter = __assign({}, o, (_c = { b: 'yeah' }, _c['at the end'] = 14, _c));
+// shortcut syntax
+var a = 12;
+var shortCutted = __assign({}, o, { a: a });
+var _a, _b, _c;
diff --git a/tests/baselines/reference/objectSpread.symbols b/tests/baselines/reference/objectSpread.symbols
new file mode 100644
index 00000000000..9946b313f52
--- /dev/null
+++ b/tests/baselines/reference/objectSpread.symbols
@@ -0,0 +1,284 @@
+=== tests/cases/conformance/types/spread/objectSpread.ts ===
+let o = { a: 1, b: 'no' }
+>o : Symbol(o, Decl(objectSpread.ts, 0, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 0, 9))
+>b : Symbol(b, Decl(objectSpread.ts, 0, 15))
+
+let o2 = { b: 'yes', c: true }
+>o2 : Symbol(o2, Decl(objectSpread.ts, 1, 3))
+>b : Symbol(b, Decl(objectSpread.ts, 1, 10))
+>c : Symbol(c, Decl(objectSpread.ts, 1, 20))
+
+let swap = { a: 'yes', b: -1 };
+>swap : Symbol(swap, Decl(objectSpread.ts, 2, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 2, 12))
+>b : Symbol(b, Decl(objectSpread.ts, 2, 22))
+
+let addAfter: { a: number, b: string, c: boolean } =
+>addAfter : Symbol(addAfter, Decl(objectSpread.ts, 4, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 4, 15))
+>b : Symbol(b, Decl(objectSpread.ts, 4, 26))
+>c : Symbol(c, Decl(objectSpread.ts, 4, 37))
+
+    { ...o, c: false }
+>c : Symbol(c, Decl(objectSpread.ts, 5, 11))
+
+let addBefore: { a: number, b: string, c: boolean } =
+>addBefore : Symbol(addBefore, Decl(objectSpread.ts, 6, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 6, 16))
+>b : Symbol(b, Decl(objectSpread.ts, 6, 27))
+>c : Symbol(c, Decl(objectSpread.ts, 6, 38))
+
+    { c: false, ...o }
+>c : Symbol(c, Decl(objectSpread.ts, 7, 5))
+
+// Note: ignore still changes the order that properties are printed
+let ignore: { a: number, b: string } =
+>ignore : Symbol(ignore, Decl(objectSpread.ts, 9, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 9, 13))
+>b : Symbol(b, Decl(objectSpread.ts, 9, 24))
+
+    { b: 'ignored', ...o }
+>b : Symbol(b, Decl(objectSpread.ts, 10, 5))
+
+let override: { a: number, b: string } =
+>override : Symbol(override, Decl(objectSpread.ts, 11, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 11, 15))
+>b : Symbol(b, Decl(objectSpread.ts, 11, 26))
+
+    { ...o, b: 'override' }
+>b : Symbol(b, Decl(objectSpread.ts, 12, 11))
+
+let nested: { a: number, b: boolean, c: string } =
+>nested : Symbol(nested, Decl(objectSpread.ts, 13, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 13, 13))
+>b : Symbol(b, Decl(objectSpread.ts, 13, 24))
+>c : Symbol(c, Decl(objectSpread.ts, 13, 36))
+
+    { ...{ a: 3, ...{ b: false, c: 'overriden' } }, c: 'whatever' }
+>a : Symbol(a, Decl(objectSpread.ts, 14, 10))
+>b : Symbol(b, Decl(objectSpread.ts, 14, 21))
+>c : Symbol(c, Decl(objectSpread.ts, 14, 31))
+>c : Symbol(c, Decl(objectSpread.ts, 14, 51))
+
+let combined: { a: number, b: string, c: boolean } =
+>combined : Symbol(combined, Decl(objectSpread.ts, 15, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 15, 15))
+>b : Symbol(b, Decl(objectSpread.ts, 15, 26))
+>c : Symbol(c, Decl(objectSpread.ts, 15, 37))
+
+    { ...o, ...o2 }
+let combinedBefore: { a: number, b: string, c: boolean } =
+>combinedBefore : Symbol(combinedBefore, Decl(objectSpread.ts, 17, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 17, 21))
+>b : Symbol(b, Decl(objectSpread.ts, 17, 32))
+>c : Symbol(c, Decl(objectSpread.ts, 17, 43))
+
+    { b: 'ok', ...o, ...o2 }
+>b : Symbol(b, Decl(objectSpread.ts, 18, 5))
+
+let combinedMid: { a: number, b: string, c: boolean } =
+>combinedMid : Symbol(combinedMid, Decl(objectSpread.ts, 19, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 19, 18))
+>b : Symbol(b, Decl(objectSpread.ts, 19, 29))
+>c : Symbol(c, Decl(objectSpread.ts, 19, 40))
+
+    { ...o, b: 'ok', ...o2 }
+>b : Symbol(b, Decl(objectSpread.ts, 20, 11))
+
+let combinedAfter: { a: number, b: string, c: boolean } =
+>combinedAfter : Symbol(combinedAfter, Decl(objectSpread.ts, 21, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 21, 20))
+>b : Symbol(b, Decl(objectSpread.ts, 21, 31))
+>c : Symbol(c, Decl(objectSpread.ts, 21, 42))
+
+    { ...o, ...o2, b: 'ok' }
+>b : Symbol(b, Decl(objectSpread.ts, 22, 18))
+
+let combinedNested: { a: number, b: boolean, c: string, d: string } =
+>combinedNested : Symbol(combinedNested, Decl(objectSpread.ts, 23, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 23, 21))
+>b : Symbol(b, Decl(objectSpread.ts, 23, 32))
+>c : Symbol(c, Decl(objectSpread.ts, 23, 44))
+>d : Symbol(d, Decl(objectSpread.ts, 23, 55))
+
+    { ...{ a: 4, ...{ b: false, c: 'overriden' } }, d: 'actually new', ...{ a: 5, d: 'maybe new' } }
+>a : Symbol(a, Decl(objectSpread.ts, 24, 10))
+>b : Symbol(b, Decl(objectSpread.ts, 24, 21))
+>c : Symbol(c, Decl(objectSpread.ts, 24, 31))
+>d : Symbol(d, Decl(objectSpread.ts, 24, 51))
+>a : Symbol(a, Decl(objectSpread.ts, 24, 75))
+>d : Symbol(d, Decl(objectSpread.ts, 24, 81))
+
+let combinedNestedChangeType: { a: number, b: boolean, c: number } =
+>combinedNestedChangeType : Symbol(combinedNestedChangeType, Decl(objectSpread.ts, 25, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 25, 31))
+>b : Symbol(b, Decl(objectSpread.ts, 25, 42))
+>c : Symbol(c, Decl(objectSpread.ts, 25, 54))
+
+    { ...{ a: 1, ...{ b: false, c: 'overriden' } }, c: -1 }
+>a : Symbol(a, Decl(objectSpread.ts, 26, 10))
+>b : Symbol(b, Decl(objectSpread.ts, 26, 21))
+>c : Symbol(c, Decl(objectSpread.ts, 26, 31))
+>c : Symbol(c, Decl(objectSpread.ts, 26, 51))
+
+let propertyNested: { a: { a: number, b: string } } =
+>propertyNested : Symbol(propertyNested, Decl(objectSpread.ts, 27, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 27, 21))
+>a : Symbol(a, Decl(objectSpread.ts, 27, 26))
+>b : Symbol(b, Decl(objectSpread.ts, 27, 37))
+
+    { a: { ... o } }
+>a : Symbol(a, Decl(objectSpread.ts, 28, 5))
+
+// accessors don't copy the descriptor
+// (which means that readonly getters become read/write properties)
+let op = { get a () { return 6 } };
+>op : Symbol(op, Decl(objectSpread.ts, 31, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 31, 10))
+
+let getter: { a: number, c: number } =
+>getter : Symbol(getter, Decl(objectSpread.ts, 32, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 32, 13))
+>c : Symbol(c, Decl(objectSpread.ts, 32, 24))
+
+    { ...op, c: 7 }
+>c : Symbol(c, Decl(objectSpread.ts, 33, 12))
+
+getter.a = 12;
+>getter.a : Symbol(a, Decl(objectSpread.ts, 32, 13))
+>getter : Symbol(getter, Decl(objectSpread.ts, 32, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 32, 13))
+
+// functions result in { }
+let spreadFunc = { ...(function () { }) };
+>spreadFunc : Symbol(spreadFunc, Decl(objectSpread.ts, 37, 3))
+
+// any results in any
+let anything: any;
+>anything : Symbol(anything, Decl(objectSpread.ts, 40, 3))
+
+let spreadAny = { ...anything };
+>spreadAny : Symbol(spreadAny, Decl(objectSpread.ts, 41, 3))
+
+// methods are not enumerable
+class C { p = 1; m() { } }
+>C : Symbol(C, Decl(objectSpread.ts, 41, 32))
+>p : Symbol(C.p, Decl(objectSpread.ts, 44, 9))
+>m : Symbol(C.m, Decl(objectSpread.ts, 44, 16))
+
+let c: C = new C()
+>c : Symbol(c, Decl(objectSpread.ts, 45, 3))
+>C : Symbol(C, Decl(objectSpread.ts, 41, 32))
+>C : Symbol(C, Decl(objectSpread.ts, 41, 32))
+
+let spreadC: { p: number } = { ...c }
+>spreadC : Symbol(spreadC, Decl(objectSpread.ts, 46, 3))
+>p : Symbol(p, Decl(objectSpread.ts, 46, 14))
+
+// own methods are enumerable
+let cplus: { p: number, plus(): void } = { ...c, plus() { return this.p + 1; } };
+>cplus : Symbol(cplus, Decl(objectSpread.ts, 49, 3))
+>p : Symbol(p, Decl(objectSpread.ts, 49, 12))
+>plus : Symbol(plus, Decl(objectSpread.ts, 49, 23))
+>plus : Symbol(plus, Decl(objectSpread.ts, 49, 48))
+>this : Symbol(__object, Decl(objectSpread.ts, 41, 15))
+
+cplus.plus();
+>cplus.plus : Symbol(plus, Decl(objectSpread.ts, 49, 23))
+>cplus : Symbol(cplus, Decl(objectSpread.ts, 49, 3))
+>plus : Symbol(plus, Decl(objectSpread.ts, 49, 23))
+
+// new field's type conflicting with existing field is OK
+let changeTypeAfter: { a: string, b: string } =
+>changeTypeAfter : Symbol(changeTypeAfter, Decl(objectSpread.ts, 53, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 53, 22))
+>b : Symbol(b, Decl(objectSpread.ts, 53, 33))
+
+    { ...o, a: 'wrong type?' }
+>a : Symbol(a, Decl(objectSpread.ts, 54, 11))
+
+let changeTypeBefore: { a: number, b: string } =
+>changeTypeBefore : Symbol(changeTypeBefore, Decl(objectSpread.ts, 55, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 55, 23))
+>b : Symbol(b, Decl(objectSpread.ts, 55, 34))
+
+    { a: 'wrong type?', ...o };
+>a : Symbol(a, Decl(objectSpread.ts, 56, 5))
+
+let changeTypeBoth: { a: string, b: number } =
+>changeTypeBoth : Symbol(changeTypeBoth, Decl(objectSpread.ts, 57, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 57, 21))
+>b : Symbol(b, Decl(objectSpread.ts, 57, 32))
+
+    { ...o, ...swap };
+
+// optional
+let definiteBoolean: { sn: boolean };
+>definiteBoolean : Symbol(definiteBoolean, Decl(objectSpread.ts, 61, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 61, 22))
+
+let definiteString: { sn: string };
+>definiteString : Symbol(definiteString, Decl(objectSpread.ts, 62, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 62, 21))
+
+let optionalString: { sn?: string };
+>optionalString : Symbol(optionalString, Decl(objectSpread.ts, 63, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 63, 21))
+
+let optionalNumber: { sn?: number };
+>optionalNumber : Symbol(optionalNumber, Decl(objectSpread.ts, 64, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 64, 21))
+
+let optionalUnionStops: { sn: string | number | boolean } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+>optionalUnionStops : Symbol(optionalUnionStops, Decl(objectSpread.ts, 65, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 65, 25))
+
+let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+>optionalUnionDuplicates : Symbol(optionalUnionDuplicates, Decl(objectSpread.ts, 66, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 66, 30))
+
+let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+>allOptional : Symbol(allOptional, Decl(objectSpread.ts, 67, 3))
+>sn : Symbol(sn, Decl(objectSpread.ts, 67, 18))
+
+// computed property
+let computedFirst: { a: number, b: string, "before everything": number } =
+>computedFirst : Symbol(computedFirst, Decl(objectSpread.ts, 70, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 70, 20))
+>b : Symbol(b, Decl(objectSpread.ts, 70, 31))
+
+    { ['before everything']: 12, ...o, b: 'yes' }
+>'before everything' : Symbol(['before everything'], Decl(objectSpread.ts, 71, 5))
+>b : Symbol(b, Decl(objectSpread.ts, 71, 38))
+
+let computedMiddle: { a: number, b: string, c: boolean, "in the middle": number } =
+>computedMiddle : Symbol(computedMiddle, Decl(objectSpread.ts, 72, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 72, 21))
+>b : Symbol(b, Decl(objectSpread.ts, 72, 32))
+>c : Symbol(c, Decl(objectSpread.ts, 72, 43))
+
+    { ...o, ['in the middle']: 13, b: 'maybe?', ...o2 }
+>'in the middle' : Symbol(['in the middle'], Decl(objectSpread.ts, 73, 11))
+>b : Symbol(b, Decl(objectSpread.ts, 73, 34))
+
+let computedAfter: { a: number, b: string, "at the end": number } =
+>computedAfter : Symbol(computedAfter, Decl(objectSpread.ts, 74, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 74, 20))
+>b : Symbol(b, Decl(objectSpread.ts, 74, 31))
+
+    { ...o, b: 'yeah', ['at the end']: 14 }
+>b : Symbol(b, Decl(objectSpread.ts, 75, 11))
+>'at the end' : Symbol(['at the end'], Decl(objectSpread.ts, 75, 22))
+
+// shortcut syntax
+let a = 12;
+>a : Symbol(a, Decl(objectSpread.ts, 77, 3))
+
+let shortCutted: { a: number, b: string } = { ...o, a }
+>shortCutted : Symbol(shortCutted, Decl(objectSpread.ts, 78, 3))
+>a : Symbol(a, Decl(objectSpread.ts, 78, 18))
+>b : Symbol(b, Decl(objectSpread.ts, 78, 29))
+>a : Symbol(a, Decl(objectSpread.ts, 78, 51))
+
+
diff --git a/tests/baselines/reference/objectSpread.types b/tests/baselines/reference/objectSpread.types
new file mode 100644
index 00000000000..a1c70720d12
--- /dev/null
+++ b/tests/baselines/reference/objectSpread.types
@@ -0,0 +1,410 @@
+=== tests/cases/conformance/types/spread/objectSpread.ts ===
+let o = { a: 1, b: 'no' }
+>o : { a: number; b: string; }
+>{ a: 1, b: 'no' } : { a: number; b: string; }
+>a : number
+>1 : 1
+>b : string
+>'no' : "no"
+
+let o2 = { b: 'yes', c: true }
+>o2 : { b: string; c: boolean; }
+>{ b: 'yes', c: true } : { b: string; c: boolean; }
+>b : string
+>'yes' : "yes"
+>c : boolean
+>true : true
+
+let swap = { a: 'yes', b: -1 };
+>swap : { a: string; b: number; }
+>{ a: 'yes', b: -1 } : { a: string; b: number; }
+>a : string
+>'yes' : "yes"
+>b : number
+>-1 : -1
+>1 : 1
+
+let addAfter: { a: number, b: string, c: boolean } =
+>addAfter : { a: number; b: string; c: boolean; }
+>a : number
+>b : string
+>c : boolean
+
+    { ...o, c: false }
+>{ ...o, c: false } : { c: false; a: number; b: string; }
+>o : any
+>c : boolean
+>false : false
+
+let addBefore: { a: number, b: string, c: boolean } =
+>addBefore : { a: number; b: string; c: boolean; }
+>a : number
+>b : string
+>c : boolean
+
+    { c: false, ...o }
+>{ c: false, ...o } : { a: number; b: string; c: false; }
+>c : boolean
+>false : false
+>o : any
+
+// Note: ignore still changes the order that properties are printed
+let ignore: { a: number, b: string } =
+>ignore : { a: number; b: string; }
+>a : number
+>b : string
+
+    { b: 'ignored', ...o }
+>{ b: 'ignored', ...o } : { a: number; b: string; }
+>b : string
+>'ignored' : "ignored"
+>o : any
+
+let override: { a: number, b: string } =
+>override : { a: number; b: string; }
+>a : number
+>b : string
+
+    { ...o, b: 'override' }
+>{ ...o, b: 'override' } : { b: string; a: number; }
+>o : any
+>b : string
+>'override' : "override"
+
+let nested: { a: number, b: boolean, c: string } =
+>nested : { a: number; b: boolean; c: string; }
+>a : number
+>b : boolean
+>c : string
+
+    { ...{ a: 3, ...{ b: false, c: 'overriden' } }, c: 'whatever' }
+>{ ...{ a: 3, ...{ b: false, c: 'overriden' } }, c: 'whatever' } : { c: string; b: boolean; a: number; }
+>{ a: 3, ...{ b: false, c: 'overriden' } } : { b: boolean; c: string; a: number; }
+>a : number
+>3 : 3
+>{ b: false, c: 'overriden' } : { b: boolean; c: string; }
+>b : boolean
+>false : false
+>c : string
+>'overriden' : "overriden"
+>c : string
+>'whatever' : "whatever"
+
+let combined: { a: number, b: string, c: boolean } =
+>combined : { a: number; b: string; c: boolean; }
+>a : number
+>b : string
+>c : boolean
+
+    { ...o, ...o2 }
+>{ ...o, ...o2 } : { b: string; c: boolean; a: number; }
+>o : any
+>o2 : any
+
+let combinedBefore: { a: number, b: string, c: boolean } =
+>combinedBefore : { a: number; b: string; c: boolean; }
+>a : number
+>b : string
+>c : boolean
+
+    { b: 'ok', ...o, ...o2 }
+>{ b: 'ok', ...o, ...o2 } : { b: string; c: boolean; a: number; }
+>b : string
+>'ok' : "ok"
+>o : any
+>o2 : any
+
+let combinedMid: { a: number, b: string, c: boolean } =
+>combinedMid : { a: number; b: string; c: boolean; }
+>a : number
+>b : string
+>c : boolean
+
+    { ...o, b: 'ok', ...o2 }
+>{ ...o, b: 'ok', ...o2 } : { b: string; c: boolean; a: number; }
+>o : any
+>b : string
+>'ok' : "ok"
+>o2 : any
+
+let combinedAfter: { a: number, b: string, c: boolean } =
+>combinedAfter : { a: number; b: string; c: boolean; }
+>a : number
+>b : string
+>c : boolean
+
+    { ...o, ...o2, b: 'ok' }
+>{ ...o, ...o2, b: 'ok' } : { b: string; c: boolean; a: number; }
+>o : any
+>o2 : any
+>b : string
+>'ok' : "ok"
+
+let combinedNested: { a: number, b: boolean, c: string, d: string } =
+>combinedNested : { a: number; b: boolean; c: string; d: string; }
+>a : number
+>b : boolean
+>c : string
+>d : string
+
+    { ...{ a: 4, ...{ b: false, c: 'overriden' } }, d: 'actually new', ...{ a: 5, d: 'maybe new' } }
+>{ ...{ a: 4, ...{ b: false, c: 'overriden' } }, d: 'actually new', ...{ a: 5, d: 'maybe new' } } : { a: number; d: string; b: boolean; c: string; }
+>{ a: 4, ...{ b: false, c: 'overriden' } } : { b: boolean; c: string; a: number; }
+>a : number
+>4 : 4
+>{ b: false, c: 'overriden' } : { b: boolean; c: string; }
+>b : boolean
+>false : false
+>c : string
+>'overriden' : "overriden"
+>d : string
+>'actually new' : "actually new"
+>{ a: 5, d: 'maybe new' } : { a: number; d: string; }
+>a : number
+>5 : 5
+>d : string
+>'maybe new' : "maybe new"
+
+let combinedNestedChangeType: { a: number, b: boolean, c: number } =
+>combinedNestedChangeType : { a: number; b: boolean; c: number; }
+>a : number
+>b : boolean
+>c : number
+
+    { ...{ a: 1, ...{ b: false, c: 'overriden' } }, c: -1 }
+>{ ...{ a: 1, ...{ b: false, c: 'overriden' } }, c: -1 } : { c: number; b: boolean; a: number; }
+>{ a: 1, ...{ b: false, c: 'overriden' } } : { b: boolean; c: string; a: number; }
+>a : number
+>1 : 1
+>{ b: false, c: 'overriden' } : { b: boolean; c: string; }
+>b : boolean
+>false : false
+>c : string
+>'overriden' : "overriden"
+>c : number
+>-1 : -1
+>1 : 1
+
+let propertyNested: { a: { a: number, b: string } } =
+>propertyNested : { a: { a: number; b: string; }; }
+>a : { a: number; b: string; }
+>a : number
+>b : string
+
+    { a: { ... o } }
+>{ a: { ... o } } : { a: { a: number; b: string; }; }
+>a : { a: number; b: string; }
+>{ ... o } : { a: number; b: string; }
+>o : any
+
+// accessors don't copy the descriptor
+// (which means that readonly getters become read/write properties)
+let op = { get a () { return 6 } };
+>op : { readonly a: number; }
+>{ get a () { return 6 } } : { readonly a: number; }
+>a : number
+>6 : 6
+
+let getter: { a: number, c: number } =
+>getter : { a: number; c: number; }
+>a : number
+>c : number
+
+    { ...op, c: 7 }
+>{ ...op, c: 7 } : { c: number; readonly a: number; }
+>op : any
+>c : number
+>7 : 7
+
+getter.a = 12;
+>getter.a = 12 : 12
+>getter.a : number
+>getter : { a: number; c: number; }
+>a : number
+>12 : 12
+
+// functions result in { }
+let spreadFunc = { ...(function () { }) };
+>spreadFunc : {}
+>{ ...(function () { }) } : {}
+>(function () { }) : () => void
+>function () { } : () => void
+
+// any results in any
+let anything: any;
+>anything : any
+
+let spreadAny = { ...anything };
+>spreadAny : any
+>{ ...anything } : any
+>anything : any
+
+// methods are not enumerable
+class C { p = 1; m() { } }
+>C : C
+>p : number
+>1 : 1
+>m : () => void
+
+let c: C = new C()
+>c : C
+>C : C
+>new C() : C
+>C : typeof C
+
+let spreadC: { p: number } = { ...c }
+>spreadC : { p: number; }
+>p : number
+>{ ...c } : { p: number; }
+>c : any
+
+// own methods are enumerable
+let cplus: { p: number, plus(): void } = { ...c, plus() { return this.p + 1; } };
+>cplus : { p: number; plus(): void; }
+>p : number
+>plus : () => void
+>{ ...c, plus() { return this.p + 1; } } : { plus(): any; p: number; }
+>c : any
+>plus : () => any
+>this.p + 1 : any
+>this.p : any
+>this : any
+>p : any
+>1 : 1
+
+cplus.plus();
+>cplus.plus() : void
+>cplus.plus : () => void
+>cplus : { p: number; plus(): void; }
+>plus : () => void
+
+// new field's type conflicting with existing field is OK
+let changeTypeAfter: { a: string, b: string } =
+>changeTypeAfter : { a: string; b: string; }
+>a : string
+>b : string
+
+    { ...o, a: 'wrong type?' }
+>{ ...o, a: 'wrong type?' } : { a: string; b: string; }
+>o : any
+>a : string
+>'wrong type?' : "wrong type?"
+
+let changeTypeBefore: { a: number, b: string } =
+>changeTypeBefore : { a: number; b: string; }
+>a : number
+>b : string
+
+    { a: 'wrong type?', ...o };
+>{ a: 'wrong type?', ...o } : { a: number; b: string; }
+>a : string
+>'wrong type?' : "wrong type?"
+>o : any
+
+let changeTypeBoth: { a: string, b: number } =
+>changeTypeBoth : { a: string; b: number; }
+>a : string
+>b : number
+
+    { ...o, ...swap };
+>{ ...o, ...swap } : { a: string; b: number; }
+>o : any
+>swap : any
+
+// optional
+let definiteBoolean: { sn: boolean };
+>definiteBoolean : { sn: boolean; }
+>sn : boolean
+
+let definiteString: { sn: string };
+>definiteString : { sn: string; }
+>sn : string
+
+let optionalString: { sn?: string };
+>optionalString : { sn?: string; }
+>sn : string
+
+let optionalNumber: { sn?: number };
+>optionalNumber : { sn?: number; }
+>sn : number
+
+let optionalUnionStops: { sn: string | number | boolean } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+>optionalUnionStops : { sn: string | number | boolean; }
+>sn : string | number | boolean
+>{ ...definiteBoolean, ...definiteString, ...optionalNumber } : { sn: string | number; }
+>definiteBoolean : any
+>definiteString : any
+>optionalNumber : any
+
+let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+>optionalUnionDuplicates : { sn: string | number; }
+>sn : string | number
+>{ ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber } : { sn: string | number; }
+>definiteBoolean : any
+>definiteString : any
+>optionalString : any
+>optionalNumber : any
+
+let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+>allOptional : { sn?: string | number; }
+>sn : string | number
+>{ ...optionalString, ...optionalNumber } : { sn?: string | number; }
+>optionalString : any
+>optionalNumber : any
+
+// computed property
+let computedFirst: { a: number, b: string, "before everything": number } =
+>computedFirst : { a: number; b: string; "before everything": number; }
+>a : number
+>b : string
+
+    { ['before everything']: 12, ...o, b: 'yes' }
+>{ ['before everything']: 12, ...o, b: 'yes' } : { b: string; a: number; ['before everything']: number; }
+>'before everything' : "before everything"
+>12 : 12
+>o : any
+>b : string
+>'yes' : "yes"
+
+let computedMiddle: { a: number, b: string, c: boolean, "in the middle": number } =
+>computedMiddle : { a: number; b: string; c: boolean; "in the middle": number; }
+>a : number
+>b : string
+>c : boolean
+
+    { ...o, ['in the middle']: 13, b: 'maybe?', ...o2 }
+>{ ...o, ['in the middle']: 13, b: 'maybe?', ...o2 } : { b: string; c: boolean; ['in the middle']: number; a: number; }
+>o : any
+>'in the middle' : "in the middle"
+>13 : 13
+>b : string
+>'maybe?' : "maybe?"
+>o2 : any
+
+let computedAfter: { a: number, b: string, "at the end": number } =
+>computedAfter : { a: number; b: string; "at the end": number; }
+>a : number
+>b : string
+
+    { ...o, b: 'yeah', ['at the end']: 14 }
+>{ ...o, b: 'yeah', ['at the end']: 14 } : { b: string; ['at the end']: number; a: number; }
+>o : any
+>b : string
+>'yeah' : "yeah"
+>'at the end' : "at the end"
+>14 : 14
+
+// shortcut syntax
+let a = 12;
+>a : number
+>12 : 12
+
+let shortCutted: { a: number, b: string } = { ...o, a }
+>shortCutted : { a: number; b: string; }
+>a : number
+>b : string
+>{ ...o, a } : { a: number; b: string; }
+>o : any
+>a : number
+
+
diff --git a/tests/baselines/reference/objectSpreadIndexSignature.js b/tests/baselines/reference/objectSpreadIndexSignature.js
new file mode 100644
index 00000000000..22e92e6a844
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadIndexSignature.js
@@ -0,0 +1,36 @@
+//// [objectSpreadIndexSignature.ts]
+interface Indexed {
+    [n: string]: number;
+    a: number;
+}
+interface Indexed2 {
+    [n: string]: boolean;
+    c: boolean;
+}
+let indexed: Indexed;
+let indexed2: Indexed2;
+let i = { ...indexed, b: 11 };
+// only indexed has indexer, so i[101]: any
+i[101];
+let ii = { ...indexed, ...indexed2 };
+// both have indexer, so i[1001]: number | boolean
+ii[1001];
+
+
+//// [objectSpreadIndexSignature.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var indexed;
+var indexed2;
+var i = __assign({}, indexed, { b: 11 });
+// only indexed has indexer, so i[101]: any
+i[101];
+var ii = __assign({}, indexed, indexed2);
+// both have indexer, so i[1001]: number | boolean
+ii[1001];
diff --git a/tests/baselines/reference/objectSpreadIndexSignature.symbols b/tests/baselines/reference/objectSpreadIndexSignature.symbols
new file mode 100644
index 00000000000..c51e7f4532f
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadIndexSignature.symbols
@@ -0,0 +1,42 @@
+=== tests/cases/conformance/types/spread/objectSpreadIndexSignature.ts ===
+interface Indexed {
+>Indexed : Symbol(Indexed, Decl(objectSpreadIndexSignature.ts, 0, 0))
+
+    [n: string]: number;
+>n : Symbol(n, Decl(objectSpreadIndexSignature.ts, 1, 5))
+
+    a: number;
+>a : Symbol(Indexed.a, Decl(objectSpreadIndexSignature.ts, 1, 24))
+}
+interface Indexed2 {
+>Indexed2 : Symbol(Indexed2, Decl(objectSpreadIndexSignature.ts, 3, 1))
+
+    [n: string]: boolean;
+>n : Symbol(n, Decl(objectSpreadIndexSignature.ts, 5, 5))
+
+    c: boolean;
+>c : Symbol(Indexed2.c, Decl(objectSpreadIndexSignature.ts, 5, 25))
+}
+let indexed: Indexed;
+>indexed : Symbol(indexed, Decl(objectSpreadIndexSignature.ts, 8, 3))
+>Indexed : Symbol(Indexed, Decl(objectSpreadIndexSignature.ts, 0, 0))
+
+let indexed2: Indexed2;
+>indexed2 : Symbol(indexed2, Decl(objectSpreadIndexSignature.ts, 9, 3))
+>Indexed2 : Symbol(Indexed2, Decl(objectSpreadIndexSignature.ts, 3, 1))
+
+let i = { ...indexed, b: 11 };
+>i : Symbol(i, Decl(objectSpreadIndexSignature.ts, 10, 3))
+>b : Symbol(b, Decl(objectSpreadIndexSignature.ts, 10, 21))
+
+// only indexed has indexer, so i[101]: any
+i[101];
+>i : Symbol(i, Decl(objectSpreadIndexSignature.ts, 10, 3))
+
+let ii = { ...indexed, ...indexed2 };
+>ii : Symbol(ii, Decl(objectSpreadIndexSignature.ts, 13, 3))
+
+// both have indexer, so i[1001]: number | boolean
+ii[1001];
+>ii : Symbol(ii, Decl(objectSpreadIndexSignature.ts, 13, 3))
+
diff --git a/tests/baselines/reference/objectSpreadIndexSignature.types b/tests/baselines/reference/objectSpreadIndexSignature.types
new file mode 100644
index 00000000000..79a515e7374
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadIndexSignature.types
@@ -0,0 +1,52 @@
+=== tests/cases/conformance/types/spread/objectSpreadIndexSignature.ts ===
+interface Indexed {
+>Indexed : Indexed
+
+    [n: string]: number;
+>n : string
+
+    a: number;
+>a : number
+}
+interface Indexed2 {
+>Indexed2 : Indexed2
+
+    [n: string]: boolean;
+>n : string
+
+    c: boolean;
+>c : boolean
+}
+let indexed: Indexed;
+>indexed : Indexed
+>Indexed : Indexed
+
+let indexed2: Indexed2;
+>indexed2 : Indexed2
+>Indexed2 : Indexed2
+
+let i = { ...indexed, b: 11 };
+>i : { b: number; a: number; }
+>{ ...indexed, b: 11 } : { b: number; a: number; }
+>indexed : any
+>b : number
+>11 : 11
+
+// only indexed has indexer, so i[101]: any
+i[101];
+>i[101] : any
+>i : { b: number; a: number; }
+>101 : 101
+
+let ii = { ...indexed, ...indexed2 };
+>ii : { [x: string]: number | boolean; c: boolean; a: number; }
+>{ ...indexed, ...indexed2 } : { [x: string]: number | boolean; c: boolean; a: number; }
+>indexed : any
+>indexed2 : any
+
+// both have indexer, so i[1001]: number | boolean
+ii[1001];
+>ii[1001] : number | boolean
+>ii : { [x: string]: number | boolean; c: boolean; a: number; }
+>1001 : 1001
+
diff --git a/tests/baselines/reference/objectSpreadInference.js b/tests/baselines/reference/objectSpreadInference.js
new file mode 100644
index 00000000000..77930e56511
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadInference.js
@@ -0,0 +1,43 @@
+//// [objectSpreadInference.ts]
+interface Result<T,U,V> {
+    t: T;
+    u: U;
+    v: V;
+}
+declare function infer<T,U,V>(tuv: { ...T, ...U, a: V }): { t: T, u: U, v: V };
+declare function infer2<T,U,V>(utv: { ...U, a: V, ...T }): { t: T, u: U, v: V };
+function generic<W, X, Y>(w: W, x: X, y: Y) {
+    // should infer { t: {}, u: {}, v: {} } because there is no trailing type parameter
+    return infer({ ...w, ...x, a: y, b: "different type" });
+}
+let b: { b: number };
+let c: { c: number };
+// can only infer { t: {}, u: {}, v: {} }
+let i1 = infer({ ...b, ...c, a: 12 });
+// can only infer { t: {}, u: {}, v: {} }
+let i2 = infer2({ ...b, ...c, a: 12 });
+// can only infer { t: {}, u: {}, v: {} }
+let i3 = generic(b, c, { a: 12 });
+
+
+//// [objectSpreadInference.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+function generic(w, x, y) {
+    // should infer { t: {}, u: {}, v: {} } because there is no trailing type parameter
+    return infer(__assign({}, w, x, { a: y, b: "different type" }));
+}
+var b;
+var c;
+// can only infer { t: {}, u: {}, v: {} }
+var i1 = infer(__assign({}, b, c, { a: 12 }));
+// can only infer { t: {}, u: {}, v: {} }
+var i2 = infer2(__assign({}, b, c, { a: 12 }));
+// can only infer { t: {}, u: {}, v: {} }
+var i3 = generic(b, c, { a: 12 });
diff --git a/tests/baselines/reference/objectSpreadInference.symbols b/tests/baselines/reference/objectSpreadInference.symbols
new file mode 100644
index 00000000000..ddecc4d7e5d
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadInference.symbols
@@ -0,0 +1,100 @@
+=== tests/cases/conformance/types/spread/objectSpreadInference.ts ===
+interface Result<T,U,V> {
+>Result : Symbol(Result, Decl(objectSpreadInference.ts, 0, 0))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 0, 17))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 0, 19))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 0, 21))
+
+    t: T;
+>t : Symbol(Result.t, Decl(objectSpreadInference.ts, 0, 25))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 0, 17))
+
+    u: U;
+>u : Symbol(Result.u, Decl(objectSpreadInference.ts, 1, 9))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 0, 19))
+
+    v: V;
+>v : Symbol(Result.v, Decl(objectSpreadInference.ts, 2, 9))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 0, 21))
+}
+declare function infer<T,U,V>(tuv: { ...T, ...U, a: V }): { t: T, u: U, v: V };
+>infer : Symbol(infer, Decl(objectSpreadInference.ts, 4, 1))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 5, 23))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 5, 25))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 5, 27))
+>tuv : Symbol(tuv, Decl(objectSpreadInference.ts, 5, 30))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 5, 23))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 5, 25))
+>a : Symbol(a, Decl(objectSpreadInference.ts, 5, 48))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 5, 27))
+>t : Symbol(t, Decl(objectSpreadInference.ts, 5, 59))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 5, 23))
+>u : Symbol(u, Decl(objectSpreadInference.ts, 5, 65))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 5, 25))
+>v : Symbol(v, Decl(objectSpreadInference.ts, 5, 71))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 5, 27))
+
+declare function infer2<T,U,V>(utv: { ...U, a: V, ...T }): { t: T, u: U, v: V };
+>infer2 : Symbol(infer2, Decl(objectSpreadInference.ts, 5, 79))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 6, 24))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 6, 26))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 6, 28))
+>utv : Symbol(utv, Decl(objectSpreadInference.ts, 6, 31))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 6, 26))
+>a : Symbol(a, Decl(objectSpreadInference.ts, 6, 43))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 6, 28))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 6, 24))
+>t : Symbol(t, Decl(objectSpreadInference.ts, 6, 60))
+>T : Symbol(T, Decl(objectSpreadInference.ts, 6, 24))
+>u : Symbol(u, Decl(objectSpreadInference.ts, 6, 66))
+>U : Symbol(U, Decl(objectSpreadInference.ts, 6, 26))
+>v : Symbol(v, Decl(objectSpreadInference.ts, 6, 72))
+>V : Symbol(V, Decl(objectSpreadInference.ts, 6, 28))
+
+function generic<W, X, Y>(w: W, x: X, y: Y) {
+>generic : Symbol(generic, Decl(objectSpreadInference.ts, 6, 80))
+>W : Symbol(W, Decl(objectSpreadInference.ts, 7, 17))
+>X : Symbol(X, Decl(objectSpreadInference.ts, 7, 19))
+>Y : Symbol(Y, Decl(objectSpreadInference.ts, 7, 22))
+>w : Symbol(w, Decl(objectSpreadInference.ts, 7, 26))
+>W : Symbol(W, Decl(objectSpreadInference.ts, 7, 17))
+>x : Symbol(x, Decl(objectSpreadInference.ts, 7, 31))
+>X : Symbol(X, Decl(objectSpreadInference.ts, 7, 19))
+>y : Symbol(y, Decl(objectSpreadInference.ts, 7, 37))
+>Y : Symbol(Y, Decl(objectSpreadInference.ts, 7, 22))
+
+    // should infer { t: {}, u: {}, v: {} } because there is no trailing type parameter
+    return infer({ ...w, ...x, a: y, b: "different type" });
+>infer : Symbol(infer, Decl(objectSpreadInference.ts, 4, 1))
+>a : Symbol(a, Decl(objectSpreadInference.ts, 9, 30))
+>y : Symbol(y, Decl(objectSpreadInference.ts, 7, 37))
+>b : Symbol(b, Decl(objectSpreadInference.ts, 9, 36))
+}
+let b: { b: number };
+>b : Symbol(b, Decl(objectSpreadInference.ts, 11, 3))
+>b : Symbol(b, Decl(objectSpreadInference.ts, 11, 8))
+
+let c: { c: number };
+>c : Symbol(c, Decl(objectSpreadInference.ts, 12, 3))
+>c : Symbol(c, Decl(objectSpreadInference.ts, 12, 8))
+
+// can only infer { t: {}, u: {}, v: {} }
+let i1 = infer({ ...b, ...c, a: 12 });
+>i1 : Symbol(i1, Decl(objectSpreadInference.ts, 14, 3))
+>infer : Symbol(infer, Decl(objectSpreadInference.ts, 4, 1))
+>a : Symbol(a, Decl(objectSpreadInference.ts, 14, 28))
+
+// can only infer { t: {}, u: {}, v: {} }
+let i2 = infer2({ ...b, ...c, a: 12 });
+>i2 : Symbol(i2, Decl(objectSpreadInference.ts, 16, 3))
+>infer2 : Symbol(infer2, Decl(objectSpreadInference.ts, 5, 79))
+>a : Symbol(a, Decl(objectSpreadInference.ts, 16, 29))
+
+// can only infer { t: {}, u: {}, v: {} }
+let i3 = generic(b, c, { a: 12 });
+>i3 : Symbol(i3, Decl(objectSpreadInference.ts, 18, 3))
+>generic : Symbol(generic, Decl(objectSpreadInference.ts, 6, 80))
+>b : Symbol(b, Decl(objectSpreadInference.ts, 11, 3))
+>c : Symbol(c, Decl(objectSpreadInference.ts, 12, 3))
+>a : Symbol(a, Decl(objectSpreadInference.ts, 18, 24))
+
diff --git a/tests/baselines/reference/objectSpreadInference.types b/tests/baselines/reference/objectSpreadInference.types
new file mode 100644
index 00000000000..3e71e29b83c
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadInference.types
@@ -0,0 +1,118 @@
+=== tests/cases/conformance/types/spread/objectSpreadInference.ts ===
+interface Result<T,U,V> {
+>Result : Result<T, U, V>
+>T : T
+>U : U
+>V : V
+
+    t: T;
+>t : T
+>T : T
+
+    u: U;
+>u : U
+>U : U
+
+    v: V;
+>v : V
+>V : V
+}
+declare function infer<T,U,V>(tuv: { ...T, ...U, a: V }): { t: T, u: U, v: V };
+>infer : <T, U, V>(tuv: { ...T; ...U; a: V; }) => { t: T; u: U; v: V; }
+>T : T
+>U : U
+>V : V
+>tuv : { ...T; ...U; a: V; }
+>T : T
+>U : U
+>a : V
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+declare function infer2<T,U,V>(utv: { ...U, a: V, ...T }): { t: T, u: U, v: V };
+>infer2 : <T, U, V>(utv: { ...U; a: V; ...T }) => { t: T; u: U; v: V; }
+>T : T
+>U : U
+>V : V
+>utv : { ...U; a: V; ...T }
+>U : U
+>a : V
+>V : V
+>T : T
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+function generic<W, X, Y>(w: W, x: X, y: Y) {
+>generic : <W, X, Y>(w: W, x: X, y: Y) => { t: {}; u: {}; v: {}; }
+>W : W
+>X : X
+>Y : Y
+>w : W
+>W : W
+>x : X
+>X : X
+>y : Y
+>Y : Y
+
+    // should infer { t: {}, u: {}, v: {} } because there is no trailing type parameter
+    return infer({ ...w, ...x, a: y, b: "different type" });
+>infer({ ...w, ...x, a: y, b: "different type" }) : { t: {}; u: {}; v: {}; }
+>infer : <T, U, V>(tuv: { ...T; ...U; a: V; }) => { t: T; u: U; v: V; }
+>{ ...w, ...x, a: y, b: "different type" } : { ...W; ...X; a: Y; b: string; }
+>w : any
+>x : any
+>a : Y
+>y : Y
+>b : string
+>"different type" : "different type"
+}
+let b: { b: number };
+>b : { b: number; }
+>b : number
+
+let c: { c: number };
+>c : { c: number; }
+>c : number
+
+// can only infer { t: {}, u: {}, v: {} }
+let i1 = infer({ ...b, ...c, a: 12 });
+>i1 : { t: {}; u: {}; v: {}; }
+>infer({ ...b, ...c, a: 12 }) : { t: {}; u: {}; v: {}; }
+>infer : <T, U, V>(tuv: { ...T; ...U; a: V; }) => { t: T; u: U; v: V; }
+>{ ...b, ...c, a: 12 } : { a: number; c: number; b: number; }
+>b : any
+>c : any
+>a : number
+>12 : 12
+
+// can only infer { t: {}, u: {}, v: {} }
+let i2 = infer2({ ...b, ...c, a: 12 });
+>i2 : { t: {}; u: {}; v: {}; }
+>infer2({ ...b, ...c, a: 12 }) : { t: {}; u: {}; v: {}; }
+>infer2 : <T, U, V>(utv: { ...U; a: V; ...T }) => { t: T; u: U; v: V; }
+>{ ...b, ...c, a: 12 } : { a: number; c: number; b: number; }
+>b : any
+>c : any
+>a : number
+>12 : 12
+
+// can only infer { t: {}, u: {}, v: {} }
+let i3 = generic(b, c, { a: 12 });
+>i3 : { t: {}; u: {}; v: {}; }
+>generic(b, c, { a: 12 }) : { t: {}; u: {}; v: {}; }
+>generic : <W, X, Y>(w: W, x: X, y: Y) => { t: {}; u: {}; v: {}; }
+>b : { b: number; }
+>c : { c: number; }
+>{ a: 12 } : { a: number; }
+>a : number
+>12 : 12
+
diff --git a/tests/baselines/reference/objectSpreadIntersection.js b/tests/baselines/reference/objectSpreadIntersection.js
new file mode 100644
index 00000000000..2ec6ad35413
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadIntersection.js
@@ -0,0 +1,77 @@
+//// [objectSpreadIntersection.ts]
+function iteratedUnionIntersection<T, U, V>(t: T, u: U, v: V): void {
+    let tu: T | U;
+    let uv: U & V;
+    let result = { ...tu, ...uv, id: 'foo' };
+    let assignable: { ...(T | U), ...(U & V), id: string } = result;
+}
+// concrete types work
+interface A1 { a: number }
+interface A2 { a: string }
+interface B1 { b: number }
+interface B2 { b: string }
+let a12: A1 & A2;
+let b12: B1 & B2;
+let result = { ...a12, ...b12 };
+let sn: number & string = result.a;
+sn = result.b;
+let assignable: { ...(A1 & A2), ...(B1 & B2) } = result;
+
+function tripleIntersection<T, U, V>(t: T, u: U, v: V): void {
+    let tuv: T & U & V;
+    let result = { ...tuv, id: 'bar' };
+    let assignable: { ...(T & U & V), id: string } = result;
+}
+function iteratedDoubleIntersection<T, U, V>(t: T, u: U, v: V): void {
+    let tu: T & U;
+    let uv: U & V;
+    let result = { ...tu, ...uv, id: 'baz' };
+    let assignable: { ...(T & U), ...(U & V), id: string } = result;
+}
+function iteratedIntersectionUnion<T, U, V>(t: T, u: U, v: V): void {
+    let tu: T & U;
+    let uv: U | V;
+    let result = { ...tu, ...uv, id: 'qux' };
+    let assignable: { ...(T & U), ...(U | V), id: string } = result;
+}
+
+
+
+//// [objectSpreadIntersection.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+function iteratedUnionIntersection(t, u, v) {
+    var tu;
+    var uv;
+    var result = __assign({}, tu, uv, { id: 'foo' });
+    var assignable = result;
+}
+var a12;
+var b12;
+var result = __assign({}, a12, b12);
+var sn = result.a;
+sn = result.b;
+var assignable = result;
+function tripleIntersection(t, u, v) {
+    var tuv;
+    var result = __assign({}, tuv, { id: 'bar' });
+    var assignable = result;
+}
+function iteratedDoubleIntersection(t, u, v) {
+    var tu;
+    var uv;
+    var result = __assign({}, tu, uv, { id: 'baz' });
+    var assignable = result;
+}
+function iteratedIntersectionUnion(t, u, v) {
+    var tu;
+    var uv;
+    var result = __assign({}, tu, uv, { id: 'qux' });
+    var assignable = result;
+}
diff --git a/tests/baselines/reference/objectSpreadIntersection.symbols b/tests/baselines/reference/objectSpreadIntersection.symbols
new file mode 100644
index 00000000000..bc63cb11348
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadIntersection.symbols
@@ -0,0 +1,188 @@
+=== tests/cases/conformance/types/spread/objectSpreadIntersection.ts ===
+function iteratedUnionIntersection<T, U, V>(t: T, u: U, v: V): void {
+>iteratedUnionIntersection : Symbol(iteratedUnionIntersection, Decl(objectSpreadIntersection.ts, 0, 0))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 0, 35))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 0, 37))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 0, 40))
+>t : Symbol(t, Decl(objectSpreadIntersection.ts, 0, 44))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 0, 35))
+>u : Symbol(u, Decl(objectSpreadIntersection.ts, 0, 49))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 0, 37))
+>v : Symbol(v, Decl(objectSpreadIntersection.ts, 0, 55))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 0, 40))
+
+    let tu: T | U;
+>tu : Symbol(tu, Decl(objectSpreadIntersection.ts, 1, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 0, 35))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 0, 37))
+
+    let uv: U & V;
+>uv : Symbol(uv, Decl(objectSpreadIntersection.ts, 2, 7))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 0, 37))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 0, 40))
+
+    let result = { ...tu, ...uv, id: 'foo' };
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 3, 7))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 3, 32))
+
+    let assignable: { ...(T | U), ...(U & V), id: string } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadIntersection.ts, 4, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 0, 35))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 0, 37))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 0, 37))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 0, 40))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 4, 45))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 3, 7))
+}
+// concrete types work
+interface A1 { a: number }
+>A1 : Symbol(A1, Decl(objectSpreadIntersection.ts, 5, 1))
+>a : Symbol(A1.a, Decl(objectSpreadIntersection.ts, 7, 14))
+
+interface A2 { a: string }
+>A2 : Symbol(A2, Decl(objectSpreadIntersection.ts, 7, 26))
+>a : Symbol(A2.a, Decl(objectSpreadIntersection.ts, 8, 14))
+
+interface B1 { b: number }
+>B1 : Symbol(B1, Decl(objectSpreadIntersection.ts, 8, 26))
+>b : Symbol(B1.b, Decl(objectSpreadIntersection.ts, 9, 14))
+
+interface B2 { b: string }
+>B2 : Symbol(B2, Decl(objectSpreadIntersection.ts, 9, 26))
+>b : Symbol(B2.b, Decl(objectSpreadIntersection.ts, 10, 14))
+
+let a12: A1 & A2;
+>a12 : Symbol(a12, Decl(objectSpreadIntersection.ts, 11, 3))
+>A1 : Symbol(A1, Decl(objectSpreadIntersection.ts, 5, 1))
+>A2 : Symbol(A2, Decl(objectSpreadIntersection.ts, 7, 26))
+
+let b12: B1 & B2;
+>b12 : Symbol(b12, Decl(objectSpreadIntersection.ts, 12, 3))
+>B1 : Symbol(B1, Decl(objectSpreadIntersection.ts, 8, 26))
+>B2 : Symbol(B2, Decl(objectSpreadIntersection.ts, 9, 26))
+
+let result = { ...a12, ...b12 };
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 13, 3))
+
+let sn: number & string = result.a;
+>sn : Symbol(sn, Decl(objectSpreadIntersection.ts, 14, 3))
+>result.a : Symbol(a, Decl(objectSpreadIntersection.ts, 7, 14), Decl(objectSpreadIntersection.ts, 8, 14))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 13, 3))
+>a : Symbol(a, Decl(objectSpreadIntersection.ts, 7, 14), Decl(objectSpreadIntersection.ts, 8, 14))
+
+sn = result.b;
+>sn : Symbol(sn, Decl(objectSpreadIntersection.ts, 14, 3))
+>result.b : Symbol(b, Decl(objectSpreadIntersection.ts, 9, 14), Decl(objectSpreadIntersection.ts, 10, 14))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 13, 3))
+>b : Symbol(b, Decl(objectSpreadIntersection.ts, 9, 14), Decl(objectSpreadIntersection.ts, 10, 14))
+
+let assignable: { ...(A1 & A2), ...(B1 & B2) } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadIntersection.ts, 16, 3))
+>A1 : Symbol(A1, Decl(objectSpreadIntersection.ts, 5, 1))
+>A2 : Symbol(A2, Decl(objectSpreadIntersection.ts, 7, 26))
+>B1 : Symbol(B1, Decl(objectSpreadIntersection.ts, 8, 26))
+>B2 : Symbol(B2, Decl(objectSpreadIntersection.ts, 9, 26))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 13, 3))
+
+function tripleIntersection<T, U, V>(t: T, u: U, v: V): void {
+>tripleIntersection : Symbol(tripleIntersection, Decl(objectSpreadIntersection.ts, 16, 56))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 18, 28))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 18, 30))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 18, 33))
+>t : Symbol(t, Decl(objectSpreadIntersection.ts, 18, 37))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 18, 28))
+>u : Symbol(u, Decl(objectSpreadIntersection.ts, 18, 42))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 18, 30))
+>v : Symbol(v, Decl(objectSpreadIntersection.ts, 18, 48))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 18, 33))
+
+    let tuv: T & U & V;
+>tuv : Symbol(tuv, Decl(objectSpreadIntersection.ts, 19, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 18, 28))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 18, 30))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 18, 33))
+
+    let result = { ...tuv, id: 'bar' };
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 20, 7))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 20, 26))
+
+    let assignable: { ...(T & U & V), id: string } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadIntersection.ts, 21, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 18, 28))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 18, 30))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 18, 33))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 21, 37))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 20, 7))
+}
+function iteratedDoubleIntersection<T, U, V>(t: T, u: U, v: V): void {
+>iteratedDoubleIntersection : Symbol(iteratedDoubleIntersection, Decl(objectSpreadIntersection.ts, 22, 1))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 23, 36))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 23, 38))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 23, 41))
+>t : Symbol(t, Decl(objectSpreadIntersection.ts, 23, 45))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 23, 36))
+>u : Symbol(u, Decl(objectSpreadIntersection.ts, 23, 50))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 23, 38))
+>v : Symbol(v, Decl(objectSpreadIntersection.ts, 23, 56))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 23, 41))
+
+    let tu: T & U;
+>tu : Symbol(tu, Decl(objectSpreadIntersection.ts, 24, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 23, 36))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 23, 38))
+
+    let uv: U & V;
+>uv : Symbol(uv, Decl(objectSpreadIntersection.ts, 25, 7))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 23, 38))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 23, 41))
+
+    let result = { ...tu, ...uv, id: 'baz' };
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 26, 7))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 26, 32))
+
+    let assignable: { ...(T & U), ...(U & V), id: string } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadIntersection.ts, 27, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 23, 36))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 23, 38))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 23, 38))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 23, 41))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 27, 45))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 26, 7))
+}
+function iteratedIntersectionUnion<T, U, V>(t: T, u: U, v: V): void {
+>iteratedIntersectionUnion : Symbol(iteratedIntersectionUnion, Decl(objectSpreadIntersection.ts, 28, 1))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 29, 35))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 29, 37))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 29, 40))
+>t : Symbol(t, Decl(objectSpreadIntersection.ts, 29, 44))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 29, 35))
+>u : Symbol(u, Decl(objectSpreadIntersection.ts, 29, 49))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 29, 37))
+>v : Symbol(v, Decl(objectSpreadIntersection.ts, 29, 55))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 29, 40))
+
+    let tu: T & U;
+>tu : Symbol(tu, Decl(objectSpreadIntersection.ts, 30, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 29, 35))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 29, 37))
+
+    let uv: U | V;
+>uv : Symbol(uv, Decl(objectSpreadIntersection.ts, 31, 7))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 29, 37))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 29, 40))
+
+    let result = { ...tu, ...uv, id: 'qux' };
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 32, 7))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 32, 32))
+
+    let assignable: { ...(T & U), ...(U | V), id: string } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadIntersection.ts, 33, 7))
+>T : Symbol(T, Decl(objectSpreadIntersection.ts, 29, 35))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 29, 37))
+>U : Symbol(U, Decl(objectSpreadIntersection.ts, 29, 37))
+>V : Symbol(V, Decl(objectSpreadIntersection.ts, 29, 40))
+>id : Symbol(id, Decl(objectSpreadIntersection.ts, 33, 45))
+>result : Symbol(result, Decl(objectSpreadIntersection.ts, 32, 7))
+}
+
+
diff --git a/tests/baselines/reference/objectSpreadIntersection.types b/tests/baselines/reference/objectSpreadIntersection.types
new file mode 100644
index 00000000000..e6a7b7c19ee
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadIntersection.types
@@ -0,0 +1,207 @@
+=== tests/cases/conformance/types/spread/objectSpreadIntersection.ts ===
+function iteratedUnionIntersection<T, U, V>(t: T, u: U, v: V): void {
+>iteratedUnionIntersection : <T, U, V>(t: T, u: U, v: V) => void
+>T : T
+>U : U
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+    let tu: T | U;
+>tu : T | U
+>T : T
+>U : U
+
+    let uv: U & V;
+>uv : U & V
+>U : U
+>V : V
+
+    let result = { ...tu, ...uv, id: 'foo' };
+>result : { ...T; ...U & V; id: string; } | { ...U; ...U & V; id: string; }
+>{ ...tu, ...uv, id: 'foo' } : { ...T; ...U & V; id: string; } | { ...U; ...U & V; id: string; }
+>tu : any
+>uv : any
+>id : string
+>'foo' : "foo"
+
+    let assignable: { ...(T | U), ...(U & V), id: string } = result;
+>assignable : { ...T; ...U & V; id: string; } | { ...U; ...U & V; id: string; }
+>T : T
+>U : U
+>U : U
+>V : V
+>id : string
+>result : { ...T; ...U & V; id: string; } | { ...U; ...U & V; id: string; }
+}
+// concrete types work
+interface A1 { a: number }
+>A1 : A1
+>a : number
+
+interface A2 { a: string }
+>A2 : A2
+>a : string
+
+interface B1 { b: number }
+>B1 : B1
+>b : number
+
+interface B2 { b: string }
+>B2 : B2
+>b : string
+
+let a12: A1 & A2;
+>a12 : A1 & A2
+>A1 : A1
+>A2 : A2
+
+let b12: B1 & B2;
+>b12 : B1 & B2
+>B1 : B1
+>B2 : B2
+
+let result = { ...a12, ...b12 };
+>result : { b: number & string; a: number & string; }
+>{ ...a12, ...b12 } : { b: number & string; a: number & string; }
+>a12 : any
+>b12 : any
+
+let sn: number & string = result.a;
+>sn : number & string
+>result.a : number & string
+>result : { b: number & string; a: number & string; }
+>a : number & string
+
+sn = result.b;
+>sn = result.b : number & string
+>sn : number & string
+>result.b : number & string
+>result : { b: number & string; a: number & string; }
+>b : number & string
+
+let assignable: { ...(A1 & A2), ...(B1 & B2) } = result;
+>assignable : { b: number & string; a: number & string; }
+>A1 : A1
+>A2 : A2
+>B1 : B1
+>B2 : B2
+>result : { b: number & string; a: number & string; }
+
+function tripleIntersection<T, U, V>(t: T, u: U, v: V): void {
+>tripleIntersection : <T, U, V>(t: T, u: U, v: V) => void
+>T : T
+>U : U
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+    let tuv: T & U & V;
+>tuv : T & U & V
+>T : T
+>U : U
+>V : V
+
+    let result = { ...tuv, id: 'bar' };
+>result : { ...T & U & V; id: string; }
+>{ ...tuv, id: 'bar' } : { ...T & U & V; id: string; }
+>tuv : any
+>id : string
+>'bar' : "bar"
+
+    let assignable: { ...(T & U & V), id: string } = result;
+>assignable : { ...T & U & V; id: string; }
+>T : T
+>U : U
+>V : V
+>id : string
+>result : { ...T & U & V; id: string; }
+}
+function iteratedDoubleIntersection<T, U, V>(t: T, u: U, v: V): void {
+>iteratedDoubleIntersection : <T, U, V>(t: T, u: U, v: V) => void
+>T : T
+>U : U
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+    let tu: T & U;
+>tu : T & U
+>T : T
+>U : U
+
+    let uv: U & V;
+>uv : U & V
+>U : U
+>V : V
+
+    let result = { ...tu, ...uv, id: 'baz' };
+>result : { ...T & U; ...U & V; id: string; }
+>{ ...tu, ...uv, id: 'baz' } : { ...T & U; ...U & V; id: string; }
+>tu : any
+>uv : any
+>id : string
+>'baz' : "baz"
+
+    let assignable: { ...(T & U), ...(U & V), id: string } = result;
+>assignable : { ...T & U; ...U & V; id: string; }
+>T : T
+>U : U
+>U : U
+>V : V
+>id : string
+>result : { ...T & U; ...U & V; id: string; }
+}
+function iteratedIntersectionUnion<T, U, V>(t: T, u: U, v: V): void {
+>iteratedIntersectionUnion : <T, U, V>(t: T, u: U, v: V) => void
+>T : T
+>U : U
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+    let tu: T & U;
+>tu : T & U
+>T : T
+>U : U
+
+    let uv: U | V;
+>uv : U | V
+>U : U
+>V : V
+
+    let result = { ...tu, ...uv, id: 'qux' };
+>result : { ...T & U; ...U; id: string; } | { ...T & U; ...V; id: string; }
+>{ ...tu, ...uv, id: 'qux' } : { ...T & U; ...U; id: string; } | { ...T & U; ...V; id: string; }
+>tu : any
+>uv : any
+>id : string
+>'qux' : "qux"
+
+    let assignable: { ...(T & U), ...(U | V), id: string } = result;
+>assignable : { ...T & U; ...U; id: string; } | { ...T & U; ...V; id: string; }
+>T : T
+>U : U
+>U : U
+>V : V
+>id : string
+>result : { ...T & U; ...U; id: string; } | { ...T & U; ...V; id: string; }
+}
+
+
diff --git a/tests/baselines/reference/objectSpreadNegative.errors.txt b/tests/baselines/reference/objectSpreadNegative.errors.txt
new file mode 100644
index 00000000000..dc6a356708f
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNegative.errors.txt
@@ -0,0 +1,131 @@
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(13,21): error TS2339: Property 'x' does not exist on type '{}'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(16,5): error TS2322: Type '{ sn?: string | number; }' is not assignable to type '{ sn: string | number; }'.
+  Property 'sn' is optional in type '{ sn?: string | number; }' but required in type '{ sn: string | number; }'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(23,1): error TS2322: Type '{ s: string; }' is not assignable to type '{ s: string; b: boolean; }'.
+  Property 'b' is missing in type '{ s: string; }'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(25,1): error TS2322: Type '{ b: boolean; }' is not assignable to type '{ s: string; b: boolean; }'.
+  Property 's' is missing in type '{ b: boolean; }'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(28,36): error TS2300: Duplicate identifier 'b'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(28,53): error TS2300: Duplicate identifier 'b'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(32,20): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(33,24): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(34,19): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(35,19): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(37,20): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(39,19): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(44,1): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '{}' has no compatible call signatures.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(48,12): error TS2339: Property 'b' does not exist on type '{}'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(54,9): error TS2339: Property 'm' does not exist on type '{ p: number; }'.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(58,14): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegative.ts(61,14): error TS2698: Spread types may only be created from object types.
+
+
+==== tests/cases/conformance/types/spread/objectSpreadNegative.ts (17 errors) ====
+    let o = { a: 1, b: 'no' }
+    
+    /// private propagates
+    class PrivateOptionalX {
+        private x?: number;
+    }
+    class PublicX {
+        public x: number;
+    }
+    let publicX: PublicX;
+    let privateOptionalX: PrivateOptionalX;
+    let o2 = { ...publicX, ...privateOptionalX };
+    let sn: number = o2.x; // error, x is private
+                        ~
+!!! error TS2339: Property 'x' does not exist on type '{}'.
+    let optionalString: { sn?: string };
+    let optionalNumber: { sn?: number };
+    let allOptional: { sn: string | number } = { ...optionalString, ...optionalNumber };
+        ~~~~~~~~~~~
+!!! error TS2322: Type '{ sn?: string | number; }' is not assignable to type '{ sn: string | number; }'.
+!!! error TS2322:   Property 'sn' is optional in type '{ sn?: string | number; }' but required in type '{ sn: string | number; }'.
+    // error, 'sn' is optional in source, required in target
+    
+    // assignability as target
+    interface Bool { b: boolean };
+    interface Str { s: string };
+    let spread = { ...{ b: true }, ...{s: "foo" } };
+    spread = { s: "foo" };  // error, missing 'b'
+    ~~~~~~
+!!! error TS2322: Type '{ s: string; }' is not assignable to type '{ s: string; b: boolean; }'.
+!!! error TS2322:   Property 'b' is missing in type '{ s: string; }'.
+    let b = { b: false };
+    spread = b; // error, missing 's'
+    ~~~~~~
+!!! error TS2322: Type '{ b: boolean; }' is not assignable to type '{ s: string; b: boolean; }'.
+!!! error TS2322:   Property 's' is missing in type '{ b: boolean; }'.
+    
+    // literal repeats are not allowed, but spread repeats are fine
+    let duplicated = { b: 'bad', ...o, b: 'bad', ...o2, b: 'bad' }
+                                       ~
+!!! error TS2300: Duplicate identifier 'b'.
+                                                        ~
+!!! error TS2300: Duplicate identifier 'b'.
+    let duplicatedSpread = { ...o, ...o }
+    
+    // null, undefined and primitives are not allowed
+    let spreadNull = { ...null };
+                       ~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    let spreadUndefind = { ...undefined };
+                           ~~~~~~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    let spreadNum = { ...12 };
+                      ~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    let spreadSum = { ...1 + 1 };
+                      ~~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    spreadSum.toFixed(); // error, no methods from number
+    let spreadBool = { ...false };
+                       ~~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    spreadBool.valueOf(); // error, what were you thinking?
+    let spreadStr = { ...'foo' };
+                      ~~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    spreadStr.length; // error, no 'length'
+    spreadStr.charAt(1); // error, no methods either
+    // functions are skipped
+    let spreadFunc = { ...function () { } }
+    spreadFunc(); // error, no call signature
+    ~~~~~~~~~~~~
+!!! error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '{}' has no compatible call signatures.
+    
+    // write-only properties get skipped
+    let setterOnly = { ...{ set b (bad: number) { } } };
+    setterOnly.b = 12; // error, 'b' does not exist
+               ~
+!!! error TS2339: Property 'b' does not exist on type '{}'.
+    
+    // methods are skipped because they aren't enumerable
+    class C { p = 1; m() { } }
+    let c: C = new C()
+    let spreadC = { ...c }
+    spreadC.m(); // error 'm' is not in '{ ... c }'
+            ~
+!!! error TS2339: Property 'm' does not exist on type '{ p: number; }'.
+    
+    // generics
+    function f<T, U>(t: T, u: U) {
+        return { ...t, ...u, id: 'id' };
+                 ~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    }
+    function override<U>(initial: U, override: U): U {
+        return { ...initial, ...override };
+                 ~~~~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+    }
+    let exclusive: { id: string, a: number, b: string, c: string, d: boolean } =
+        f({ a: 1, b: 'yes' }, { c: 'no', d: false })
+    let overlap: { id: string, a: number, b: string } =
+        f({ a: 1 }, { a: 2, b: 'extra' })
+    let overlapConflict: { id:string, a: string } =
+        f({ a: 1 }, { a: 'mismatch' })
+    let overwriteId: { id: string, a: number, c: number, d: string } =
+        f({ a: 1, id: true }, { c: 1, d: 'no' })
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/objectSpreadNegative.js b/tests/baselines/reference/objectSpreadNegative.js
new file mode 100644
index 00000000000..6287f4559a7
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNegative.js
@@ -0,0 +1,149 @@
+//// [objectSpreadNegative.ts]
+let o = { a: 1, b: 'no' }
+
+/// private propagates
+class PrivateOptionalX {
+    private x?: number;
+}
+class PublicX {
+    public x: number;
+}
+let publicX: PublicX;
+let privateOptionalX: PrivateOptionalX;
+let o2 = { ...publicX, ...privateOptionalX };
+let sn: number = o2.x; // error, x is private
+let optionalString: { sn?: string };
+let optionalNumber: { sn?: number };
+let allOptional: { sn: string | number } = { ...optionalString, ...optionalNumber };
+// error, 'sn' is optional in source, required in target
+
+// assignability as target
+interface Bool { b: boolean };
+interface Str { s: string };
+let spread = { ...{ b: true }, ...{s: "foo" } };
+spread = { s: "foo" };  // error, missing 'b'
+let b = { b: false };
+spread = b; // error, missing 's'
+
+// literal repeats are not allowed, but spread repeats are fine
+let duplicated = { b: 'bad', ...o, b: 'bad', ...o2, b: 'bad' }
+let duplicatedSpread = { ...o, ...o }
+
+// null, undefined and primitives are not allowed
+let spreadNull = { ...null };
+let spreadUndefind = { ...undefined };
+let spreadNum = { ...12 };
+let spreadSum = { ...1 + 1 };
+spreadSum.toFixed(); // error, no methods from number
+let spreadBool = { ...false };
+spreadBool.valueOf(); // error, what were you thinking?
+let spreadStr = { ...'foo' };
+spreadStr.length; // error, no 'length'
+spreadStr.charAt(1); // error, no methods either
+// functions are skipped
+let spreadFunc = { ...function () { } }
+spreadFunc(); // error, no call signature
+
+// write-only properties get skipped
+let setterOnly = { ...{ set b (bad: number) { } } };
+setterOnly.b = 12; // error, 'b' does not exist
+
+// methods are skipped because they aren't enumerable
+class C { p = 1; m() { } }
+let c: C = new C()
+let spreadC = { ...c }
+spreadC.m(); // error 'm' is not in '{ ... c }'
+
+// generics
+function f<T, U>(t: T, u: U) {
+    return { ...t, ...u, id: 'id' };
+}
+function override<U>(initial: U, override: U): U {
+    return { ...initial, ...override };
+}
+let exclusive: { id: string, a: number, b: string, c: string, d: boolean } =
+    f({ a: 1, b: 'yes' }, { c: 'no', d: false })
+let overlap: { id: string, a: number, b: string } =
+    f({ a: 1 }, { a: 2, b: 'extra' })
+let overlapConflict: { id:string, a: string } =
+    f({ a: 1 }, { a: 'mismatch' })
+let overwriteId: { id: string, a: number, c: number, d: string } =
+    f({ a: 1, id: true }, { c: 1, d: 'no' })
+
+
+//// [objectSpreadNegative.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var o = { a: 1, b: 'no' };
+/// private propagates
+var PrivateOptionalX = (function () {
+    function PrivateOptionalX() {
+    }
+    return PrivateOptionalX;
+}());
+var PublicX = (function () {
+    function PublicX() {
+    }
+    return PublicX;
+}());
+var publicX;
+var privateOptionalX;
+var o2 = __assign({}, publicX, privateOptionalX);
+var sn = o2.x; // error, x is private
+var optionalString;
+var optionalNumber;
+var allOptional = __assign({}, optionalString, optionalNumber);
+;
+;
+var spread = __assign({ b: true }, { s: "foo" });
+spread = { s: "foo" }; // error, missing 'b'
+var b = { b: false };
+spread = b; // error, missing 's'
+// literal repeats are not allowed, but spread repeats are fine
+var duplicated = __assign({ b: 'bad' }, o, { b: 'bad' }, o2, { b: 'bad' });
+var duplicatedSpread = __assign({}, o, o);
+// null, undefined and primitives are not allowed
+var spreadNull = __assign({}, null);
+var spreadUndefind = __assign({}, undefined);
+var spreadNum = __assign({}, 12);
+var spreadSum = __assign({}, 1 + 1);
+spreadSum.toFixed(); // error, no methods from number
+var spreadBool = __assign({}, false);
+spreadBool.valueOf(); // error, what were you thinking?
+var spreadStr = __assign({}, 'foo');
+spreadStr.length; // error, no 'length'
+spreadStr.charAt(1); // error, no methods either
+// functions are skipped
+var spreadFunc = __assign({}, function () { });
+spreadFunc(); // error, no call signature
+// write-only properties get skipped
+var setterOnly = __assign({ set b(bad) { } });
+setterOnly.b = 12; // error, 'b' does not exist
+// methods are skipped because they aren't enumerable
+var C = (function () {
+    function C() {
+        this.p = 1;
+    }
+    C.prototype.m = function () { };
+    return C;
+}());
+var c = new C();
+var spreadC = __assign({}, c);
+spreadC.m(); // error 'm' is not in '{ ... c }'
+// generics
+function f(t, u) {
+    return __assign({}, t, u, { id: 'id' });
+}
+function override(initial, override) {
+    return __assign({}, initial, override);
+}
+var exclusive = f({ a: 1, b: 'yes' }, { c: 'no', d: false });
+var overlap = f({ a: 1 }, { a: 2, b: 'extra' });
+var overlapConflict = f({ a: 1 }, { a: 'mismatch' });
+var overwriteId = f({ a: 1, id: true }, { c: 1, d: 'no' });
diff --git a/tests/baselines/reference/objectSpreadNegativeParse.errors.txt b/tests/baselines/reference/objectSpreadNegativeParse.errors.txt
new file mode 100644
index 00000000000..b37200c4f02
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNegativeParse.errors.txt
@@ -0,0 +1,38 @@
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(1,15): error TS2304: Cannot find name 'o'.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(1,18): error TS1109: Expression expected.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(2,12): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(2,15): error TS1109: Expression expected.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(2,16): error TS2304: Cannot find name 'o'.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(3,15): error TS2304: Cannot find name 'matchMedia'.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(3,28): error TS1005: ',' expected.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(3,31): error TS1128: Declaration or statement expected.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(4,16): error TS2304: Cannot find name 'get'.
+tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(4,20): error TS1005: ',' expected.
+
+
+==== tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts (10 errors) ====
+    let o7 = { ...o? };
+                  ~
+!!! error TS2304: Cannot find name 'o'.
+                     ~
+!!! error TS1109: Expression expected.
+    let o8 = { ...*o };
+               ~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+                  ~
+!!! error TS1109: Expression expected.
+                   ~
+!!! error TS2304: Cannot find name 'o'.
+    let o9 = { ...matchMedia() { }};
+                  ~~~~~~~~~~
+!!! error TS2304: Cannot find name 'matchMedia'.
+                               ~
+!!! error TS1005: ',' expected.
+                                  ~
+!!! error TS1128: Declaration or statement expected.
+    let o10 = { ...get x() { return 12; }};
+                   ~~~
+!!! error TS2304: Cannot find name 'get'.
+                       ~
+!!! error TS1005: ',' expected.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/objectSpreadNegativeParse.js b/tests/baselines/reference/objectSpreadNegativeParse.js
new file mode 100644
index 00000000000..297c56c3e62
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNegativeParse.js
@@ -0,0 +1,21 @@
+//// [objectSpreadNegativeParse.ts]
+let o7 = { ...o? };
+let o8 = { ...*o };
+let o9 = { ...matchMedia() { }};
+let o10 = { ...get x() { return 12; }};
+
+
+//// [objectSpreadNegativeParse.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var o7 = __assign({}, o ?  : );
+var o8 = __assign({},  * o);
+var o9 = __assign({}, matchMedia()), _a = void 0;
+;
+var o10 = __assign({}, get, { x: function () { return 12; } });
diff --git a/tests/baselines/reference/objectSpreadNoTransform.js b/tests/baselines/reference/objectSpreadNoTransform.js
new file mode 100644
index 00000000000..3442d086409
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNoTransform.js
@@ -0,0 +1,14 @@
+//// [objectSpreadNoTransform.ts]
+const y = { a: 'yes', b: 'no' };
+const o = { x: 1, ...y };
+var b;
+var rest;
+({ b, ...rest } = o);
+
+
+//// [objectSpreadNoTransform.js]
+const y = { a: 'yes', b: 'no' };
+const o = { x: 1, ...y };
+var b;
+var rest;
+({ b, ...rest } = o);
diff --git a/tests/baselines/reference/objectSpreadNoTransform.symbols b/tests/baselines/reference/objectSpreadNoTransform.symbols
new file mode 100644
index 00000000000..d7dac11a530
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNoTransform.symbols
@@ -0,0 +1,20 @@
+=== tests/cases/conformance/types/spread/objectSpreadNoTransform.ts ===
+const y = { a: 'yes', b: 'no' };
+>y : Symbol(y, Decl(objectSpreadNoTransform.ts, 0, 5))
+>a : Symbol(a, Decl(objectSpreadNoTransform.ts, 0, 11))
+>b : Symbol(b, Decl(objectSpreadNoTransform.ts, 0, 21))
+
+const o = { x: 1, ...y };
+>o : Symbol(o, Decl(objectSpreadNoTransform.ts, 1, 5))
+>x : Symbol(x, Decl(objectSpreadNoTransform.ts, 1, 11))
+
+var b;
+>b : Symbol(b, Decl(objectSpreadNoTransform.ts, 2, 3))
+
+var rest;
+>rest : Symbol(rest, Decl(objectSpreadNoTransform.ts, 3, 3))
+
+({ b, ...rest } = o);
+>b : Symbol(b, Decl(objectSpreadNoTransform.ts, 4, 2))
+>o : Symbol(o, Decl(objectSpreadNoTransform.ts, 1, 5))
+
diff --git a/tests/baselines/reference/objectSpreadNoTransform.types b/tests/baselines/reference/objectSpreadNoTransform.types
new file mode 100644
index 00000000000..0a6c867e8fe
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadNoTransform.types
@@ -0,0 +1,30 @@
+=== tests/cases/conformance/types/spread/objectSpreadNoTransform.ts ===
+const y = { a: 'yes', b: 'no' };
+>y : { a: string; b: string; }
+>{ a: 'yes', b: 'no' } : { a: string; b: string; }
+>a : string
+>'yes' : "yes"
+>b : string
+>'no' : "no"
+
+const o = { x: 1, ...y };
+>o : { a: string; b: string; x: number; }
+>{ x: 1, ...y } : { a: string; b: string; x: number; }
+>x : number
+>1 : 1
+>y : any
+
+var b;
+>b : any
+
+var rest;
+>rest : any
+
+({ b, ...rest } = o);
+>({ b, ...rest } = o) : { a: string; b: string; x: number; }
+>{ b, ...rest } = o : { a: string; b: string; x: number; }
+>{ b, ...rest } : any
+>b : any
+>rest : any
+>o : { a: string; b: string; x: number; }
+
diff --git a/tests/baselines/reference/objectSpreadScenarios.js b/tests/baselines/reference/objectSpreadScenarios.js
new file mode 100644
index 00000000000..96ac98d2d35
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadScenarios.js
@@ -0,0 +1,45 @@
+//// [objectSpreadScenarios.ts]
+interface A1 { a: boolean }
+interface B1 { b: number };
+function override<U>(initial: U, override: U): { ...U, ...U } {
+    return { ...initial, ...override };
+}
+function update<U>(this: { u: { ...U } }, override: U): void {
+    this.u = { ...this.u, ...override };
+}
+function mixin<T, U>(one: T, two: U): { ...T, ...U } {
+    return { ...one, ...two };
+}
+let a1: A1 = { a: true };
+let b1: B1 = { b: 101 };
+a1 = override(a1, { a: false });
+let host = { u: a1, update };
+host.update({ a: false });
+let mixed = mixin(a1, b1);
+
+
+//// [objectSpreadScenarios.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+;
+function override(initial, override) {
+    return __assign({}, initial, override);
+}
+function update(override) {
+    this.u = __assign({}, this.u, override);
+}
+function mixin(one, two) {
+    return __assign({}, one, two);
+}
+var a1 = { a: true };
+var b1 = { b: 101 };
+a1 = override(a1, { a: false });
+var host = { u: a1, update: update };
+host.update({ a: false });
+var mixed = mixin(a1, b1);
diff --git a/tests/baselines/reference/objectSpreadScenarios.symbols b/tests/baselines/reference/objectSpreadScenarios.symbols
new file mode 100644
index 00000000000..cf1e1833ac9
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadScenarios.symbols
@@ -0,0 +1,85 @@
+=== tests/cases/conformance/types/spread/objectSpreadScenarios.ts ===
+interface A1 { a: boolean }
+>A1 : Symbol(A1, Decl(objectSpreadScenarios.ts, 0, 0))
+>a : Symbol(A1.a, Decl(objectSpreadScenarios.ts, 0, 14))
+
+interface B1 { b: number };
+>B1 : Symbol(B1, Decl(objectSpreadScenarios.ts, 0, 27))
+>b : Symbol(B1.b, Decl(objectSpreadScenarios.ts, 1, 14))
+
+function override<U>(initial: U, override: U): { ...U, ...U } {
+>override : Symbol(override, Decl(objectSpreadScenarios.ts, 1, 27))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 2, 18))
+>initial : Symbol(initial, Decl(objectSpreadScenarios.ts, 2, 21))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 2, 18))
+>override : Symbol(override, Decl(objectSpreadScenarios.ts, 2, 32))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 2, 18))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 2, 18))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 2, 18))
+
+    return { ...initial, ...override };
+}
+function update<U>(this: { u: { ...U } }, override: U): void {
+>update : Symbol(update, Decl(objectSpreadScenarios.ts, 4, 1))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 5, 16))
+>this : Symbol(this, Decl(objectSpreadScenarios.ts, 5, 19))
+>u : Symbol(u, Decl(objectSpreadScenarios.ts, 5, 26))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 5, 16))
+>override : Symbol(override, Decl(objectSpreadScenarios.ts, 5, 41))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 5, 16))
+
+    this.u = { ...this.u, ...override };
+>this.u : Symbol(u, Decl(objectSpreadScenarios.ts, 5, 26))
+>this : Symbol(this, Decl(objectSpreadScenarios.ts, 5, 19))
+>u : Symbol(u, Decl(objectSpreadScenarios.ts, 5, 26))
+>this.u : Symbol(u, Decl(objectSpreadScenarios.ts, 5, 26))
+>this : Symbol(this, Decl(objectSpreadScenarios.ts, 5, 19))
+>u : Symbol(u, Decl(objectSpreadScenarios.ts, 5, 26))
+}
+function mixin<T, U>(one: T, two: U): { ...T, ...U } {
+>mixin : Symbol(mixin, Decl(objectSpreadScenarios.ts, 7, 1))
+>T : Symbol(T, Decl(objectSpreadScenarios.ts, 8, 15))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 8, 17))
+>one : Symbol(one, Decl(objectSpreadScenarios.ts, 8, 21))
+>T : Symbol(T, Decl(objectSpreadScenarios.ts, 8, 15))
+>two : Symbol(two, Decl(objectSpreadScenarios.ts, 8, 28))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 8, 17))
+>T : Symbol(T, Decl(objectSpreadScenarios.ts, 8, 15))
+>U : Symbol(U, Decl(objectSpreadScenarios.ts, 8, 17))
+
+    return { ...one, ...two };
+}
+let a1: A1 = { a: true };
+>a1 : Symbol(a1, Decl(objectSpreadScenarios.ts, 11, 3))
+>A1 : Symbol(A1, Decl(objectSpreadScenarios.ts, 0, 0))
+>a : Symbol(a, Decl(objectSpreadScenarios.ts, 11, 14))
+
+let b1: B1 = { b: 101 };
+>b1 : Symbol(b1, Decl(objectSpreadScenarios.ts, 12, 3))
+>B1 : Symbol(B1, Decl(objectSpreadScenarios.ts, 0, 27))
+>b : Symbol(b, Decl(objectSpreadScenarios.ts, 12, 14))
+
+a1 = override(a1, { a: false });
+>a1 : Symbol(a1, Decl(objectSpreadScenarios.ts, 11, 3))
+>override : Symbol(override, Decl(objectSpreadScenarios.ts, 1, 27))
+>a1 : Symbol(a1, Decl(objectSpreadScenarios.ts, 11, 3))
+>a : Symbol(a, Decl(objectSpreadScenarios.ts, 13, 19))
+
+let host = { u: a1, update };
+>host : Symbol(host, Decl(objectSpreadScenarios.ts, 14, 3))
+>u : Symbol(u, Decl(objectSpreadScenarios.ts, 14, 12))
+>a1 : Symbol(a1, Decl(objectSpreadScenarios.ts, 11, 3))
+>update : Symbol(update, Decl(objectSpreadScenarios.ts, 14, 19))
+
+host.update({ a: false });
+>host.update : Symbol(update, Decl(objectSpreadScenarios.ts, 14, 19))
+>host : Symbol(host, Decl(objectSpreadScenarios.ts, 14, 3))
+>update : Symbol(update, Decl(objectSpreadScenarios.ts, 14, 19))
+>a : Symbol(a, Decl(objectSpreadScenarios.ts, 15, 13))
+
+let mixed = mixin(a1, b1);
+>mixed : Symbol(mixed, Decl(objectSpreadScenarios.ts, 16, 3))
+>mixin : Symbol(mixin, Decl(objectSpreadScenarios.ts, 7, 1))
+>a1 : Symbol(a1, Decl(objectSpreadScenarios.ts, 11, 3))
+>b1 : Symbol(b1, Decl(objectSpreadScenarios.ts, 12, 3))
+
diff --git a/tests/baselines/reference/objectSpreadScenarios.types b/tests/baselines/reference/objectSpreadScenarios.types
new file mode 100644
index 00000000000..2d1aa47bd50
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadScenarios.types
@@ -0,0 +1,107 @@
+=== tests/cases/conformance/types/spread/objectSpreadScenarios.ts ===
+interface A1 { a: boolean }
+>A1 : A1
+>a : boolean
+
+interface B1 { b: number };
+>B1 : B1
+>b : number
+
+function override<U>(initial: U, override: U): { ...U, ...U } {
+>override : <U>(initial: U, override: U) => { ...U }
+>U : U
+>initial : U
+>U : U
+>override : U
+>U : U
+>U : U
+>U : U
+
+    return { ...initial, ...override };
+>{ ...initial, ...override } : { ...U }
+>initial : any
+>override : any
+}
+function update<U>(this: { u: { ...U } }, override: U): void {
+>update : <U>(this: { u: { ...U }; }, override: U) => void
+>U : U
+>this : { u: { ...U }; }
+>u : { ...U }
+>U : U
+>override : U
+>U : U
+
+    this.u = { ...this.u, ...override };
+>this.u = { ...this.u, ...override } : { ...U }
+>this.u : { ...U }
+>this : { u: { ...U }; }
+>u : { ...U }
+>{ ...this.u, ...override } : { ...U }
+>this.u : { ...U }
+>this : { u: { ...U }; }
+>u : { ...U }
+>override : any
+}
+function mixin<T, U>(one: T, two: U): { ...T, ...U } {
+>mixin : <T, U>(one: T, two: U) => { ...T; ...U }
+>T : T
+>U : U
+>one : T
+>T : T
+>two : U
+>U : U
+>T : T
+>U : U
+
+    return { ...one, ...two };
+>{ ...one, ...two } : { ...T; ...U }
+>one : any
+>two : any
+}
+let a1: A1 = { a: true };
+>a1 : A1
+>A1 : A1
+>{ a: true } : { a: true; }
+>a : boolean
+>true : true
+
+let b1: B1 = { b: 101 };
+>b1 : B1
+>B1 : B1
+>{ b: 101 } : { b: number; }
+>b : number
+>101 : 101
+
+a1 = override(a1, { a: false });
+>a1 = override(a1, { a: false }) : { a: boolean; }
+>a1 : A1
+>override(a1, { a: false }) : { a: boolean; }
+>override : <U>(initial: U, override: U) => { ...U }
+>a1 : A1
+>{ a: false } : { a: false; }
+>a : boolean
+>false : false
+
+let host = { u: a1, update };
+>host : { u: A1; update: <U>(this: { u: { ...U }; }, override: U) => void; }
+>{ u: a1, update } : { u: A1; update: <U>(this: { u: { ...U }; }, override: U) => void; }
+>u : A1
+>a1 : A1
+>update : <U>(this: { u: { ...U }; }, override: U) => void
+
+host.update({ a: false });
+>host.update({ a: false }) : void
+>host.update : <U>(this: { u: { ...U }; }, override: U) => void
+>host : { u: A1; update: <U>(this: { u: { ...U }; }, override: U) => void; }
+>update : <U>(this: { u: { ...U }; }, override: U) => void
+>{ a: false } : { a: false; }
+>a : boolean
+>false : false
+
+let mixed = mixin(a1, b1);
+>mixed : { b: number; a: boolean; }
+>mixin(a1, b1) : { b: number; a: boolean; }
+>mixin : <T, U>(one: T, two: U) => { ...T; ...U }
+>a1 : A1
+>b1 : B1
+
diff --git a/tests/baselines/reference/objectSpreadStrictNull.js b/tests/baselines/reference/objectSpreadStrictNull.js
new file mode 100644
index 00000000000..84604d728cd
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadStrictNull.js
@@ -0,0 +1,43 @@
+//// [objectSpreadStrictNull.ts]
+
+function f(
+    definiteBoolean: { sn: boolean },
+    definiteString: { sn: string },
+    optionalString: { sn?: string },
+    optionalNumber: { sn?: number },
+    undefinedString: { sn: string | undefined },
+    undefinedNumber: { sn: number | undefined }) {
+    // optional
+    let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+    let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+    let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+
+    // undefined
+    let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
+    let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
+    let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
+
+    let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
+}
+
+
+//// [objectSpreadStrictNull.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+function f(definiteBoolean, definiteString, optionalString, optionalNumber, undefinedString, undefinedNumber) {
+    // optional
+    var optionalUnionStops = __assign({}, definiteBoolean, definiteString, optionalNumber);
+    var optionalUnionDuplicates = __assign({}, definiteBoolean, definiteString, optionalString, optionalNumber);
+    var allOptional = __assign({}, optionalString, optionalNumber);
+    // undefined
+    var undefinedUnionStops = __assign({}, definiteBoolean, definiteString, undefinedNumber);
+    var undefinedUnionDuplicates = __assign({}, definiteBoolean, definiteString, undefinedString, undefinedNumber);
+    var allUndefined = __assign({}, undefinedString, undefinedNumber);
+    var undefinedWithOptionalContinues = __assign({}, definiteBoolean, undefinedString, optionalNumber);
+}
diff --git a/tests/baselines/reference/objectSpreadStrictNull.symbols b/tests/baselines/reference/objectSpreadStrictNull.symbols
new file mode 100644
index 00000000000..85def473ce4
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadStrictNull.symbols
@@ -0,0 +1,60 @@
+=== tests/cases/conformance/types/spread/objectSpreadStrictNull.ts ===
+
+function f(
+>f : Symbol(f, Decl(objectSpreadStrictNull.ts, 0, 0))
+
+    definiteBoolean: { sn: boolean },
+>definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 1, 11))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 2, 22))
+
+    definiteString: { sn: string },
+>definiteString : Symbol(definiteString, Decl(objectSpreadStrictNull.ts, 2, 37))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 3, 21))
+
+    optionalString: { sn?: string },
+>optionalString : Symbol(optionalString, Decl(objectSpreadStrictNull.ts, 3, 35))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 4, 21))
+
+    optionalNumber: { sn?: number },
+>optionalNumber : Symbol(optionalNumber, Decl(objectSpreadStrictNull.ts, 4, 36))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 5, 21))
+
+    undefinedString: { sn: string | undefined },
+>undefinedString : Symbol(undefinedString, Decl(objectSpreadStrictNull.ts, 5, 36))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 6, 22))
+
+    undefinedNumber: { sn: number | undefined }) {
+>undefinedNumber : Symbol(undefinedNumber, Decl(objectSpreadStrictNull.ts, 6, 48))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 7, 22))
+
+    // optional
+    let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+>optionalUnionStops : Symbol(optionalUnionStops, Decl(objectSpreadStrictNull.ts, 9, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 9, 29))
+
+    let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+>optionalUnionDuplicates : Symbol(optionalUnionDuplicates, Decl(objectSpreadStrictNull.ts, 10, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 10, 34))
+
+    let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+>allOptional : Symbol(allOptional, Decl(objectSpreadStrictNull.ts, 11, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 11, 22))
+
+    // undefined
+    let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
+>undefinedUnionStops : Symbol(undefinedUnionStops, Decl(objectSpreadStrictNull.ts, 14, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 14, 30))
+
+    let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
+>undefinedUnionDuplicates : Symbol(undefinedUnionDuplicates, Decl(objectSpreadStrictNull.ts, 15, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 15, 35))
+
+    let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
+>allUndefined : Symbol(allUndefined, Decl(objectSpreadStrictNull.ts, 16, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 16, 23))
+
+    let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
+>undefinedWithOptionalContinues : Symbol(undefinedWithOptionalContinues, Decl(objectSpreadStrictNull.ts, 18, 7))
+>sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 18, 41))
+}
+
diff --git a/tests/baselines/reference/objectSpreadStrictNull.types b/tests/baselines/reference/objectSpreadStrictNull.types
new file mode 100644
index 00000000000..a91295b2bca
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadStrictNull.types
@@ -0,0 +1,88 @@
+=== tests/cases/conformance/types/spread/objectSpreadStrictNull.ts ===
+
+function f(
+>f : (definiteBoolean: { sn: boolean; }, definiteString: { sn: string; }, optionalString: { sn?: string | undefined; }, optionalNumber: { sn?: number | undefined; }, undefinedString: { sn: string | undefined; }, undefinedNumber: { sn: number | undefined; }) => void
+
+    definiteBoolean: { sn: boolean },
+>definiteBoolean : { sn: boolean; }
+>sn : boolean
+
+    definiteString: { sn: string },
+>definiteString : { sn: string; }
+>sn : string
+
+    optionalString: { sn?: string },
+>optionalString : { sn?: string | undefined; }
+>sn : string | undefined
+
+    optionalNumber: { sn?: number },
+>optionalNumber : { sn?: number | undefined; }
+>sn : number | undefined
+
+    undefinedString: { sn: string | undefined },
+>undefinedString : { sn: string | undefined; }
+>sn : string | undefined
+
+    undefinedNumber: { sn: number | undefined }) {
+>undefinedNumber : { sn: number | undefined; }
+>sn : number | undefined
+
+    // optional
+    let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+>optionalUnionStops : { sn: string | number; }
+>sn : string | number
+>{ ...definiteBoolean, ...definiteString, ...optionalNumber } : { sn: string | number; }
+>definiteBoolean : any
+>definiteString : any
+>optionalNumber : any
+
+    let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+>optionalUnionDuplicates : { sn: string | number; }
+>sn : string | number
+>{ ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber } : { sn: string | number; }
+>definiteBoolean : any
+>definiteString : any
+>optionalString : any
+>optionalNumber : any
+
+    let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+>allOptional : { sn?: string | number | undefined; }
+>sn : string | number | undefined
+>{ ...optionalString, ...optionalNumber } : { sn?: string | number | undefined; }
+>optionalString : any
+>optionalNumber : any
+
+    // undefined
+    let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
+>undefinedUnionStops : { sn: string | number; }
+>sn : string | number
+>{ ...definiteBoolean, ...definiteString, ...undefinedNumber } : { sn: string | number; }
+>definiteBoolean : any
+>definiteString : any
+>undefinedNumber : any
+
+    let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
+>undefinedUnionDuplicates : { sn: string | number; }
+>sn : string | number
+>{ ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber } : { sn: string | number; }
+>definiteBoolean : any
+>definiteString : any
+>undefinedString : any
+>undefinedNumber : any
+
+    let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
+>allUndefined : { sn: string | number | undefined; }
+>sn : string | number | undefined
+>{ ...undefinedString, ...undefinedNumber } : { sn: string | number | undefined; }
+>undefinedString : any
+>undefinedNumber : any
+
+    let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
+>undefinedWithOptionalContinues : { sn: string | number | boolean; }
+>sn : string | number | boolean
+>{ ...definiteBoolean, ...undefinedString, ...optionalNumber } : { sn: string | number | boolean; }
+>definiteBoolean : any
+>undefinedString : any
+>optionalNumber : any
+}
+
diff --git a/tests/baselines/reference/objectSpreadUnion.js b/tests/baselines/reference/objectSpreadUnion.js
new file mode 100644
index 00000000000..b3a114c7722
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadUnion.js
@@ -0,0 +1,52 @@
+//// [objectSpreadUnion.ts]
+// concrete types work
+interface A1 { a: number }
+interface A2 { a: string }
+let a12: A1 | A2;
+let result = { ...a12 };
+let sn: number | string = result.a;
+let assignable: { ...(A1 | A2) } = result;
+
+function tripleUnion<T, U, V>(t: T, u: U, v: V): void {
+    let tuv: T | U | V;
+    let result = { ...tuv, id: 'foo' };
+    let expected: { ...T, id: string } | { ...U, id: string } | { ...V, id: string } = result;
+    let assignable: { ...(T | U | V), id: string } = result;
+}
+function iteratedDoubleUnion<T, U, V>(t: T, u: U, v: V): void {
+    let tu: T | U;
+    let uv: U | V;
+    let result = { ...tu, ...uv, id: 'bar' };
+    let expected: { ...T, ...U, id: string } | { ...T, ...V, id: string } | { ...U, id: string } | { ...U, ...V, id: string };
+    let assignable: { ...(T | U), ...(U | V), id: string } = result;
+}
+
+
+
+
+//// [objectSpreadUnion.js]
+var __assign = (this && this.__assign) || Object.assign || function(t) {
+    for (var s, i = 1, n = arguments.length; i < n; i++) {
+        s = arguments[i];
+        for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+            t[p] = s[p];
+    }
+    return t;
+};
+var a12;
+var result = __assign({}, a12);
+var sn = result.a;
+var assignable = result;
+function tripleUnion(t, u, v) {
+    var tuv;
+    var result = __assign({}, tuv, { id: 'foo' });
+    var expected = result;
+    var assignable = result;
+}
+function iteratedDoubleUnion(t, u, v) {
+    var tu;
+    var uv;
+    var result = __assign({}, tu, uv, { id: 'bar' });
+    var expected;
+    var assignable = result;
+}
diff --git a/tests/baselines/reference/objectSpreadUnion.symbols b/tests/baselines/reference/objectSpreadUnion.symbols
new file mode 100644
index 00000000000..d630fde518b
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadUnion.symbols
@@ -0,0 +1,122 @@
+=== tests/cases/conformance/types/spread/objectSpreadUnion.ts ===
+// concrete types work
+interface A1 { a: number }
+>A1 : Symbol(A1, Decl(objectSpreadUnion.ts, 0, 0))
+>a : Symbol(A1.a, Decl(objectSpreadUnion.ts, 1, 14))
+
+interface A2 { a: string }
+>A2 : Symbol(A2, Decl(objectSpreadUnion.ts, 1, 26))
+>a : Symbol(A2.a, Decl(objectSpreadUnion.ts, 2, 14))
+
+let a12: A1 | A2;
+>a12 : Symbol(a12, Decl(objectSpreadUnion.ts, 3, 3))
+>A1 : Symbol(A1, Decl(objectSpreadUnion.ts, 0, 0))
+>A2 : Symbol(A2, Decl(objectSpreadUnion.ts, 1, 26))
+
+let result = { ...a12 };
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 4, 3))
+
+let sn: number | string = result.a;
+>sn : Symbol(sn, Decl(objectSpreadUnion.ts, 5, 3))
+>result.a : Symbol(a, Decl(objectSpreadUnion.ts, 1, 14), Decl(objectSpreadUnion.ts, 2, 14))
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 4, 3))
+>a : Symbol(a, Decl(objectSpreadUnion.ts, 1, 14), Decl(objectSpreadUnion.ts, 2, 14))
+
+let assignable: { ...(A1 | A2) } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadUnion.ts, 6, 3))
+>A1 : Symbol(A1, Decl(objectSpreadUnion.ts, 0, 0))
+>A2 : Symbol(A2, Decl(objectSpreadUnion.ts, 1, 26))
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 4, 3))
+
+function tripleUnion<T, U, V>(t: T, u: U, v: V): void {
+>tripleUnion : Symbol(tripleUnion, Decl(objectSpreadUnion.ts, 6, 42))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 8, 21))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 8, 23))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 8, 26))
+>t : Symbol(t, Decl(objectSpreadUnion.ts, 8, 30))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 8, 21))
+>u : Symbol(u, Decl(objectSpreadUnion.ts, 8, 35))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 8, 23))
+>v : Symbol(v, Decl(objectSpreadUnion.ts, 8, 41))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 8, 26))
+
+    let tuv: T | U | V;
+>tuv : Symbol(tuv, Decl(objectSpreadUnion.ts, 9, 7))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 8, 21))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 8, 23))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 8, 26))
+
+    let result = { ...tuv, id: 'foo' };
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 10, 7))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 10, 26))
+
+    let expected: { ...T, id: string } | { ...U, id: string } | { ...V, id: string } = result;
+>expected : Symbol(expected, Decl(objectSpreadUnion.ts, 11, 7))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 8, 21))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 11, 25))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 8, 23))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 11, 48))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 8, 26))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 11, 71))
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 10, 7))
+
+    let assignable: { ...(T | U | V), id: string } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadUnion.ts, 12, 7))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 8, 21))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 8, 23))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 8, 26))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 12, 37))
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 10, 7))
+}
+function iteratedDoubleUnion<T, U, V>(t: T, u: U, v: V): void {
+>iteratedDoubleUnion : Symbol(iteratedDoubleUnion, Decl(objectSpreadUnion.ts, 13, 1))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 14, 29))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 14, 34))
+>t : Symbol(t, Decl(objectSpreadUnion.ts, 14, 38))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 14, 29))
+>u : Symbol(u, Decl(objectSpreadUnion.ts, 14, 43))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>v : Symbol(v, Decl(objectSpreadUnion.ts, 14, 49))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 14, 34))
+
+    let tu: T | U;
+>tu : Symbol(tu, Decl(objectSpreadUnion.ts, 15, 7))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 14, 29))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+
+    let uv: U | V;
+>uv : Symbol(uv, Decl(objectSpreadUnion.ts, 16, 7))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 14, 34))
+
+    let result = { ...tu, ...uv, id: 'bar' };
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 17, 7))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 17, 32))
+
+    let expected: { ...T, ...U, id: string } | { ...T, ...V, id: string } | { ...U, id: string } | { ...U, ...V, id: string };
+>expected : Symbol(expected, Decl(objectSpreadUnion.ts, 18, 7))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 14, 29))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 18, 31))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 14, 29))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 14, 34))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 18, 60))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 18, 83))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 14, 34))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 18, 112))
+
+    let assignable: { ...(T | U), ...(U | V), id: string } = result;
+>assignable : Symbol(assignable, Decl(objectSpreadUnion.ts, 19, 7))
+>T : Symbol(T, Decl(objectSpreadUnion.ts, 14, 29))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>U : Symbol(U, Decl(objectSpreadUnion.ts, 14, 31))
+>V : Symbol(V, Decl(objectSpreadUnion.ts, 14, 34))
+>id : Symbol(id, Decl(objectSpreadUnion.ts, 19, 45))
+>result : Symbol(result, Decl(objectSpreadUnion.ts, 17, 7))
+}
+
+
+
diff --git a/tests/baselines/reference/objectSpreadUnion.types b/tests/baselines/reference/objectSpreadUnion.types
new file mode 100644
index 00000000000..20633295acb
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadUnion.types
@@ -0,0 +1,131 @@
+=== tests/cases/conformance/types/spread/objectSpreadUnion.ts ===
+// concrete types work
+interface A1 { a: number }
+>A1 : A1
+>a : number
+
+interface A2 { a: string }
+>A2 : A2
+>a : string
+
+let a12: A1 | A2;
+>a12 : A1 | A2
+>A1 : A1
+>A2 : A2
+
+let result = { ...a12 };
+>result : { a: number; } | { a: string; }
+>{ ...a12 } : { a: number; } | { a: string; }
+>a12 : any
+
+let sn: number | string = result.a;
+>sn : string | number
+>result.a : string | number
+>result : { a: number; } | { a: string; }
+>a : string | number
+
+let assignable: { ...(A1 | A2) } = result;
+>assignable : { a: number; } | { a: string; }
+>A1 : A1
+>A2 : A2
+>result : { a: number; } | { a: string; }
+
+function tripleUnion<T, U, V>(t: T, u: U, v: V): void {
+>tripleUnion : <T, U, V>(t: T, u: U, v: V) => void
+>T : T
+>U : U
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+    let tuv: T | U | V;
+>tuv : T | U | V
+>T : T
+>U : U
+>V : V
+
+    let result = { ...tuv, id: 'foo' };
+>result : { ...T; id: string; } | { ...U; id: string; } | { ...V; id: string; }
+>{ ...tuv, id: 'foo' } : { ...T; id: string; } | { ...U; id: string; } | { ...V; id: string; }
+>tuv : any
+>id : string
+>'foo' : "foo"
+
+    let expected: { ...T, id: string } | { ...U, id: string } | { ...V, id: string } = result;
+>expected : { ...T; id: string; } | { ...U; id: string; } | { ...V; id: string; }
+>T : T
+>id : string
+>U : U
+>id : string
+>V : V
+>id : string
+>result : { ...T; id: string; } | { ...U; id: string; } | { ...V; id: string; }
+
+    let assignable: { ...(T | U | V), id: string } = result;
+>assignable : { ...T; id: string; } | { ...U; id: string; } | { ...V; id: string; }
+>T : T
+>U : U
+>V : V
+>id : string
+>result : { ...T; id: string; } | { ...U; id: string; } | { ...V; id: string; }
+}
+function iteratedDoubleUnion<T, U, V>(t: T, u: U, v: V): void {
+>iteratedDoubleUnion : <T, U, V>(t: T, u: U, v: V) => void
+>T : T
+>U : U
+>V : V
+>t : T
+>T : T
+>u : U
+>U : U
+>v : V
+>V : V
+
+    let tu: T | U;
+>tu : T | U
+>T : T
+>U : U
+
+    let uv: U | V;
+>uv : U | V
+>U : U
+>V : V
+
+    let result = { ...tu, ...uv, id: 'bar' };
+>result : { ...U; id: string; } | { ...T; ...U; id: string; } | { ...T; ...V; id: string; } | { ...U; ...V; id: string; }
+>{ ...tu, ...uv, id: 'bar' } : { ...U; id: string; } | { ...T; ...U; id: string; } | { ...T; ...V; id: string; } | { ...U; ...V; id: string; }
+>tu : any
+>uv : any
+>id : string
+>'bar' : "bar"
+
+    let expected: { ...T, ...U, id: string } | { ...T, ...V, id: string } | { ...U, id: string } | { ...U, ...V, id: string };
+>expected : { ...T; ...U; id: string; } | { ...T; ...V; id: string; } | { ...U; id: string; } | { ...U; ...V; id: string; }
+>T : T
+>U : U
+>id : string
+>T : T
+>V : V
+>id : string
+>U : U
+>id : string
+>U : U
+>V : V
+>id : string
+
+    let assignable: { ...(T | U), ...(U | V), id: string } = result;
+>assignable : { ...U; id: string; } | { ...T; ...U; id: string; } | { ...T; ...V; id: string; } | { ...U; ...V; id: string; }
+>T : T
+>U : U
+>U : U
+>V : V
+>id : string
+>result : { ...U; id: string; } | { ...T; ...U; id: string; } | { ...T; ...V; id: string; } | { ...U; ...V; id: string; }
+}
+
+
+
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
index ab7210d7d02..f468d864eef 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
@@ -33,12 +33,8 @@
     "File 'c:/root/folder2/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/file4.ts' does not exist.",
     "File 'c:/root/node_modules/file4.tsx' does not exist.",
@@ -47,12 +43,8 @@
     "File 'c:/root/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' does not exist.",
     "File 'c:/node_modules/file4.tsx' does not exist.",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
index ab7210d7d02..f468d864eef 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
@@ -33,12 +33,8 @@
     "File 'c:/root/folder2/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/file4.ts' does not exist.",
     "File 'c:/root/node_modules/file4.tsx' does not exist.",
@@ -47,12 +43,8 @@
     "File 'c:/root/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' does not exist.",
     "File 'c:/node_modules/file4.tsx' does not exist.",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
index 2efeefa24e5..92a98a1067c 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
@@ -75,12 +75,8 @@
     "File 'c:/root/folder1/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/folder1/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/folder1/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/folder1/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/folder1/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/folder1/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/file4.ts' does not exist.",
     "File 'c:/root/node_modules/file4.tsx' does not exist.",
@@ -89,12 +85,8 @@
     "File 'c:/root/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' exist - use it as a name resolution result.",
     "Resolving real path for 'c:/node_modules/file4.ts', result 'c:/node_modules/file4.ts'",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
index 48633c85e3b..cc33d8d1c37 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
@@ -51,12 +51,8 @@
     "File 'c:/root/src/node_modules/module3/index.ts' does not exist.",
     "File 'c:/root/src/node_modules/module3/index.tsx' does not exist.",
     "File 'c:/root/src/node_modules/module3/index.d.ts' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3.ts' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3.tsx' does not exist.",
     "File 'c:/root/src/node_modules/@types/module3.d.ts' does not exist.",
     "File 'c:/root/src/node_modules/@types/module3/package.json' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3/index.ts' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3/index.tsx' does not exist.",
     "File 'c:/root/src/node_modules/@types/module3/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/module3.ts' does not exist.",
     "File 'c:/root/node_modules/module3.tsx' does not exist.",
@@ -65,12 +61,8 @@
     "File 'c:/root/node_modules/module3/index.ts' does not exist.",
     "File 'c:/root/node_modules/module3/index.tsx' does not exist.",
     "File 'c:/root/node_modules/module3/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/module3.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/module3.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/module3.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/module3/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/module3/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/module3/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/module3/index.d.ts' does not exist.",
     "File 'c:/node_modules/module3.ts' does not exist.",
     "File 'c:/node_modules/module3.tsx' does not exist.",
diff --git a/tests/baselines/reference/restElementMustBeLast.errors.txt b/tests/baselines/reference/restElementMustBeLast.errors.txt
index 269d984bc00..5eb5a4cd208 100644
--- a/tests/baselines/reference/restElementMustBeLast.errors.txt
+++ b/tests/baselines/reference/restElementMustBeLast.errors.txt
@@ -1,12 +1,12 @@
-tests/cases/conformance/es6/destructuring/restElementMustBeLast.ts(1,9): error TS2462: A rest element must be last in an array destructuring pattern
-tests/cases/conformance/es6/destructuring/restElementMustBeLast.ts(2,2): error TS2462: A rest element must be last in an array destructuring pattern
+tests/cases/conformance/types/rest/restElementMustBeLast.ts(1,9): error TS2462: A rest element must be last in a destructuring pattern
+tests/cases/conformance/types/rest/restElementMustBeLast.ts(2,2): error TS2462: A rest element must be last in a destructuring pattern
 
 
-==== tests/cases/conformance/es6/destructuring/restElementMustBeLast.ts (2 errors) ====
+==== tests/cases/conformance/types/rest/restElementMustBeLast.ts (2 errors) ====
     var [...a, x] = [1, 2, 3];  // Error, rest must be last element
             ~
-!!! error TS2462: A rest element must be last in an array destructuring pattern
+!!! error TS2462: A rest element must be last in a destructuring pattern
     [...a, x] = [1, 2, 3];      // Error, rest must be last element
      ~~~~
-!!! error TS2462: A rest element must be last in an array destructuring pattern
+!!! error TS2462: A rest element must be last in a destructuring pattern
     
\ No newline at end of file
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js b/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js
index 9f7a70699bd..8355d61d9c3 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js
+++ b/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js
@@ -194,13 +194,13 @@ for (_b = getRobot(), _c = _b.name, nameA = _c === void 0 ? "noName" : _c, _b, i
 for (_d = { name: "trimmer", skill: "trimming" }, _e = _d.name, nameA = _e === void 0 ? "noName" : _e, _d, i = 0; i < 1; i++) {
     console.log(nameA);
 }
-for (_f = multiRobot.skills, _g = _f === void 0 ? { primary: "none", secondary: "none" } : _f, _h = _g.primary, primaryA = _h === void 0 ? "primary" : _h, _j = _g.secondary, secondaryA = _j === void 0 ? "secondary" : _j, multiRobot, i = 0; i < 1; i++) {
+for (_f = multiRobot.skills, _g = _f === void 0 ? { primary: "none", secondary: "none" } : _f, _h = _g.primary, primaryA = _h === void 0 ? "primary" : _h, _j = _g.secondary, secondaryA = _j === void 0 ? "secondary" : _j, multiRobot, multiRobot, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_k = getMultiRobot(), _l = _k.skills, _m = _l === void 0 ? { primary: "none", secondary: "none" } : _l, _o = _m.primary, primaryA = _o === void 0 ? "primary" : _o, _p = _m.secondary, secondaryA = _p === void 0 ? "secondary" : _p, _k, i = 0; i < 1; i++) {
+for (_k = getMultiRobot(), (_l = _k.skills, _m = _l === void 0 ? { primary: "none", secondary: "none" } : _l, _o = _m.primary, primaryA = _o === void 0 ? "primary" : _o, _p = _m.secondary, secondaryA = _p === void 0 ? "secondary" : _p, _k), _k, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_q = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _r = _q.skills, _s = _r === void 0 ? { primary: "none", secondary: "none" } : _r, _t = _s.primary, primaryA = _t === void 0 ? "primary" : _t, _u = _s.secondary, secondaryA = _u === void 0 ? "secondary" : _u, _q,
+for (_q = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_r = _q.skills, _s = _r === void 0 ? { primary: "none", secondary: "none" } : _r, _t = _s.primary, primaryA = _t === void 0 ? "primary" : _t, _u = _s.secondary, secondaryA = _u === void 0 ? "secondary" : _u, _q), _q,
     i = 0; i < 1; i++) {
     console.log(primaryA);
 }
@@ -213,13 +213,13 @@ for (_w = getRobot(), _x = _w.name, name = _x === void 0 ? "noName" : _x, _w, i
 for (_y = { name: "trimmer", skill: "trimming" }, _z = _y.name, name = _z === void 0 ? "noName" : _z, _y, i = 0; i < 1; i++) {
     console.log(nameA);
 }
-for (_0 = multiRobot.skills, _1 = _0 === void 0 ? { primary: "none", secondary: "none" } : _0, _2 = _1.primary, primary = _2 === void 0 ? "primary" : _2, _3 = _1.secondary, secondary = _3 === void 0 ? "secondary" : _3, multiRobot, i = 0; i < 1; i++) {
+for (_0 = multiRobot.skills, _1 = _0 === void 0 ? { primary: "none", secondary: "none" } : _0, _2 = _1.primary, primary = _2 === void 0 ? "primary" : _2, _3 = _1.secondary, secondary = _3 === void 0 ? "secondary" : _3, multiRobot, multiRobot, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_4 = getMultiRobot(), _5 = _4.skills, _6 = _5 === void 0 ? { primary: "none", secondary: "none" } : _5, _7 = _6.primary, primary = _7 === void 0 ? "primary" : _7, _8 = _6.secondary, secondary = _8 === void 0 ? "secondary" : _8, _4, i = 0; i < 1; i++) {
+for (_4 = getMultiRobot(), (_5 = _4.skills, _6 = _5 === void 0 ? { primary: "none", secondary: "none" } : _5, _7 = _6.primary, primary = _7 === void 0 ? "primary" : _7, _8 = _6.secondary, secondary = _8 === void 0 ? "secondary" : _8, _4), _4, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_9 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _10 = _9.skills, _11 = _10 === void 0 ? { primary: "none", secondary: "none" } : _10, _12 = _11.primary, primary = _12 === void 0 ? "primary" : _12, _13 = _11.secondary, secondary = _13 === void 0 ? "secondary" : _13, _9,
+for (_9 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_10 = _9.skills, _11 = _10 === void 0 ? { primary: "none", secondary: "none" } : _10, _12 = _11.primary, primary = _12 === void 0 ? "primary" : _12, _13 = _11.secondary, secondary = _13 === void 0 ? "secondary" : _13, _9), _9,
     i = 0; i < 1; i++) {
     console.log(primaryA);
 }
@@ -232,13 +232,13 @@ for (_16 = getRobot(), _17 = _16.name, nameA = _17 === void 0 ? "noName" : _17,
 for (_19 = { name: "trimmer", skill: "trimming" }, _20 = _19.name, nameA = _20 === void 0 ? "noName" : _20, _21 = _19.skill, skillA = _21 === void 0 ? "skill" : _21, _19, i = 0; i < 1; i++) {
     console.log(nameA);
 }
-for (_22 = multiRobot.name, nameA = _22 === void 0 ? "noName" : _22, _23 = multiRobot.skills, _24 = _23 === void 0 ? { primary: "none", secondary: "none" } : _23, _25 = _24.primary, primaryA = _25 === void 0 ? "primary" : _25, _26 = _24.secondary, secondaryA = _26 === void 0 ? "secondary" : _26, multiRobot, i = 0; i < 1; i++) {
+for (_22 = multiRobot.name, nameA = _22 === void 0 ? "noName" : _22, _23 = multiRobot.skills, _24 = _23 === void 0 ? { primary: "none", secondary: "none" } : _23, _25 = _24.primary, primaryA = _25 === void 0 ? "primary" : _25, _26 = _24.secondary, secondaryA = _26 === void 0 ? "secondary" : _26, multiRobot, multiRobot, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_27 = getMultiRobot(), _28 = _27.name, nameA = _28 === void 0 ? "noName" : _28, _29 = _27.skills, _30 = _29 === void 0 ? { primary: "none", secondary: "none" } : _29, _31 = _30.primary, primaryA = _31 === void 0 ? "primary" : _31, _32 = _30.secondary, secondaryA = _32 === void 0 ? "secondary" : _32, _27, i = 0; i < 1; i++) {
+for (_27 = getMultiRobot(), (_28 = _27.name, nameA = _28 === void 0 ? "noName" : _28, _29 = _27.skills, _30 = _29 === void 0 ? { primary: "none", secondary: "none" } : _29, _31 = _30.primary, primaryA = _31 === void 0 ? "primary" : _31, _32 = _30.secondary, secondaryA = _32 === void 0 ? "secondary" : _32, _27), _27, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_33 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _34 = _33.name, nameA = _34 === void 0 ? "noName" : _34, _35 = _33.skills, _36 = _35 === void 0 ? { primary: "none", secondary: "none" } : _35, _37 = _36.primary, primaryA = _37 === void 0 ? "primary" : _37, _38 = _36.secondary, secondaryA = _38 === void 0 ? "secondary" : _38, _33,
+for (_33 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_34 = _33.name, nameA = _34 === void 0 ? "noName" : _34, _35 = _33.skills, _36 = _35 === void 0 ? { primary: "none", secondary: "none" } : _35, _37 = _36.primary, primaryA = _37 === void 0 ? "primary" : _37, _38 = _36.secondary, secondaryA = _38 === void 0 ? "secondary" : _38, _33), _33,
     i = 0; i < 1; i++) {
     console.log(primaryA);
 }
@@ -251,15 +251,16 @@ for (_41 = getRobot(), _42 = _41.name, name = _42 === void 0 ? "noName" : _42, _
 for (_44 = { name: "trimmer", skill: "trimming" }, _45 = _44.name, name = _45 === void 0 ? "noName" : _45, _46 = _44.skill, skill = _46 === void 0 ? "skill" : _46, _44, i = 0; i < 1; i++) {
     console.log(nameA);
 }
-for (_47 = multiRobot.name, name = _47 === void 0 ? "noName" : _47, _48 = multiRobot.skills, _49 = _48 === void 0 ? { primary: "none", secondary: "none" } : _48, _50 = _49.primary, primary = _50 === void 0 ? "primary" : _50, _51 = _49.secondary, secondary = _51 === void 0 ? "secondary" : _51, multiRobot, i = 0; i < 1; i++) {
+for (_47 = multiRobot.name, name = _47 === void 0 ? "noName" : _47, _48 = multiRobot.skills, _49 = _48 === void 0 ? { primary: "none", secondary: "none" } : _48, _50 = _49.primary, primary = _50 === void 0 ? "primary" : _50, _51 = _49.secondary, secondary = _51 === void 0 ? "secondary" : _51, multiRobot, multiRobot, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_52 = getMultiRobot(), _53 = _52.name, name = _53 === void 0 ? "noName" : _53, _54 = _52.skills, _55 = _54 === void 0 ? { primary: "none", secondary: "none" } : _54, _56 = _55.primary, primary = _56 === void 0 ? "primary" : _56, _57 = _55.secondary, secondary = _57 === void 0 ? "secondary" : _57, _52, i = 0; i < 1; i++) {
+for (_52 = getMultiRobot(), (_53 = _52.name, name = _53 === void 0 ? "noName" : _53, _54 = _52.skills, _55 = _54 === void 0 ? { primary: "none", secondary: "none" } : _54, _56 = _55.primary, primary = _56 === void 0 ? "primary" : _56, _57 = _55.secondary, secondary = _57 === void 0 ? "secondary" : _57, _52), _52, i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-for (_58 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _59 = _58.name, name = _59 === void 0 ? "noName" : _59, _60 = _58.skills, _61 = _60 === void 0 ? { primary: "none", secondary: "none" } : _60, _62 = _61.primary, primary = _62 === void 0 ? "primary" : _62, _63 = _61.secondary, secondary = _63 === void 0 ? "secondary" : _63, _58,
+for (_58 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_59 = _58.name, name = _59 === void 0 ? "noName" : _59, _60 = _58.skills, _61 = _60 === void 0 ? { primary: "none", secondary: "none" } : _60, _62 = _61.primary, primary = _62 === void 0 ? "primary" : _62, _63 = _61.secondary, secondary = _63 === void 0 ? "secondary" : _63, _58), _58,
     i = 0; i < 1; i++) {
     console.log(primaryA);
 }
-var _a, _b, _c, _d, _e, _f, _g, _h, _j, _k, _l, _m, _o, _p, _q, _r, _s, _t, _u, _v, _w, _x, _y, _z, _0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, _61, _62, _63;
+var _k, _q, _4, _9, _27, _33, _52, _58;
+var _a, _b, _c, _d, _e, _f, _g, _h, _j, _l, _m, _o, _p, _r, _s, _t, _u, _v, _w, _x, _y, _z, _0, _1, _2, _3, _5, _6, _7, _8, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _28, _29, _30, _31, _32, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _53, _54, _55, _56, _57, _59, _60, _61, _62, _63;
 //# sourceMappingURL=sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map b/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map
index dd248e89944..56f8aa0f607 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map
+++ b/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map
@@ -1,2 +1,2 @@
 //// [sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map]
-{"version":3,"file":"sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js","sourceRoot":"","sources":["sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.ts"],"names":[],"mappings":"AAgBA,IAAI,KAAK,GAAU,EAAE,IAAI,EAAE,OAAO,EAAE,KAAK,EAAE,QAAQ,EAAE,CAAC;AACtD,IAAI,UAAU,GAAe,EAAE,IAAI,EAAE,OAAO,EAAE,MAAM,EAAE,EAAE,OAAO,EAAE,QAAQ,EAAE,SAAS,EAAE,MAAM,EAAE,EAAE,CAAC;AACjG;IACI,MAAM,CAAC,KAAK,CAAC;AACjB,CAAC;AACD;IACI,MAAM,CAAC,UAAU,CAAC;AACtB,CAAC;AAED,IAAI,KAAa,EAAE,QAAgB,EAAE,UAAkB,EAAE,CAAS,EAAE,MAAc,CAAC;AACnF,IAAI,IAAY,EAAE,OAAe,EAAE,SAAiB,EAAE,KAAa,CAAC;AAEpE,GAAG,CAAC,CAAE,eAAsB,EAAtB,qCAAsB,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACxD,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,eAAsC,EAArC,YAAsB,EAAtB,qCAAsB,MAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAC7D,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,2CAAyE,EAAxE,YAAsB,EAAtB,qCAAsB,MAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChG,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,sBAG0C,EAH1C,gEAG0C,EAFtC,eAA6B,EAA7B,yCAA6B,EAC7B,iBAAmC,EAAnC,6CAAmC,EAEvC,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,oBAKc,EAJf,cAG0C,EAH1C,gEAG0C,EAFtC,eAA6B,EAA7B,yCAA6B,EAC7B,iBAAmC,EAAnC,6CAAmC,MAEtB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,8EAKoF,EAJrF,cAG0C,EAH1C,gEAG0C,EAFtC,eAA6B,EAA7B,yCAA6B,EAC7B,iBAAmC,EAAnC,6CAAmC;IAGvC,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AAED,GAAG,CAAC,CAAG,eAAe,EAAf,oCAAe,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAClD,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,eAAgC,EAA9B,YAAe,EAAf,oCAAe,MAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACvD,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,2CAAmE,EAAjE,YAAe,EAAf,oCAAe,MAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAC1F,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,sBAG0C,EAH1C,gEAG0C,EAFtC,eAAmB,EAAnB,wCAAmB,EACnB,iBAAuB,EAAvB,4CAAuB,EAE3B,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,oBAKc,EAJf,cAG0C,EAH1C,gEAG0C,EAFtC,eAAmB,EAAnB,wCAAmB,EACnB,iBAAuB,EAAvB,4CAAuB,MAEV,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,8EAKoF,EAJrF,eAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB;IAG3B,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AAGD,GAAG,CAAC,CAAE,gBAAsB,EAAtB,uCAAsB,EAAE,iBAAuB,EAAvB,uCAAuB,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACjF,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,gBAA+D,EAA9D,cAAsB,EAAtB,uCAAsB,EAAE,eAAuB,EAAvB,uCAAuB,OAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACtF,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,4CAAkG,EAAjG,cAAsB,EAAtB,uCAAsB,EAAE,eAAuB,EAAvB,uCAAuB,OAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACzH,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,qBAAsB,EAAtB,uCAAsB,EACtB,uBAG0C,EAH1C,mEAG0C,EAFtC,iBAA6B,EAA7B,2CAA6B,EAC7B,mBAAmC,EAAnC,+CAAmC,EAEvC,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,qBAMc,EALf,cAAsB,EAAtB,uCAAsB,EACtB,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAA6B,EAA7B,2CAA6B,EAC7B,mBAAmC,EAAnC,+CAAmC,OAEtB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,+EAMoF,EALrF,cAAsB,EAAtB,uCAAsB,EACtB,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAA6B,EAA7B,2CAA6B,EAC7B,mBAAmC,EAAnC,+CAAmC;IAGvC,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AAED,GAAG,CAAC,CAAG,gBAAe,EAAf,sCAAe,EAAE,iBAAe,EAAf,sCAAe,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACnE,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,gBAAiD,EAA/C,cAAe,EAAf,sCAAe,EAAE,eAAe,EAAf,sCAAe,OAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACxE,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,4CAAoF,EAAlF,cAAe,EAAf,sCAAe,EAAE,eAAe,EAAf,sCAAe,OAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAC3G,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,qBAAe,EAAf,sCAAe,EACf,uBAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB,EAE3B,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,qBAMc,EALf,cAAe,EAAf,sCAAe,EACf,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB,OAEV,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,+EAMoF,EALrF,cAAe,EAAf,sCAAe,EACf,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB;IAG3B,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC"}
\ No newline at end of file
+{"version":3,"file":"sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js","sourceRoot":"","sources":["sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.ts"],"names":[],"mappings":"AAgBA,IAAI,KAAK,GAAU,EAAE,IAAI,EAAE,OAAO,EAAE,KAAK,EAAE,QAAQ,EAAE,CAAC;AACtD,IAAI,UAAU,GAAe,EAAE,IAAI,EAAE,OAAO,EAAE,MAAM,EAAE,EAAE,OAAO,EAAE,QAAQ,EAAE,SAAS,EAAE,MAAM,EAAE,EAAE,CAAC;AACjG;IACI,MAAM,CAAC,KAAK,CAAC;AACjB,CAAC;AACD;IACI,MAAM,CAAC,UAAU,CAAC;AACtB,CAAC;AAED,IAAI,KAAa,EAAE,QAAgB,EAAE,UAAkB,EAAE,CAAS,EAAE,MAAc,CAAC;AACnF,IAAI,IAAY,EAAE,OAAe,EAAE,SAAiB,EAAE,KAAa,CAAC;AAEpE,GAAG,CAAC,CAAE,eAAsB,EAAtB,qCAAsB,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACxD,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,eAAsC,EAArC,YAAsB,EAAtB,qCAAsB,MAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAC7D,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,2CAAyE,EAAxE,YAAsB,EAAtB,qCAAsB,MAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChG,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,sBAG0C,EAH1C,gEAG0C,EAFtC,eAA6B,EAA7B,yCAA6B,EAC7B,iBAAmC,EAAnC,6CAAmC,EAEvC,UAAU,EAAV,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,oBAKc,GAJf,cAG0C,EAH1C,gEAG0C,EAFtC,eAA6B,EAA7B,yCAA6B,EAC7B,iBAAmC,EAAnC,6CAAmC,WAEtB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,8EAKoF,GAJrF,cAG0C,EAH1C,gEAG0C,EAFtC,eAA6B,EAA7B,yCAA6B,EAC7B,iBAAmC,EAAnC,6CAAmC;IAGvC,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AAED,GAAG,CAAC,CAAG,eAAe,EAAf,oCAAe,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAClD,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,eAAgC,EAA9B,YAAe,EAAf,oCAAe,MAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACvD,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,2CAAmE,EAAjE,YAAe,EAAf,oCAAe,MAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAC1F,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,sBAG0C,EAH1C,gEAG0C,EAFtC,eAAmB,EAAnB,wCAAmB,EACnB,iBAAuB,EAAvB,4CAAuB,EAE3B,UAAU,EAAV,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,oBAKc,GAJf,cAG0C,EAH1C,gEAG0C,EAFtC,eAAmB,EAAnB,wCAAmB,EACnB,iBAAuB,EAAvB,4CAAuB,WAEV,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,8EAKoF,GAJrF,eAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB;IAG3B,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AAGD,GAAG,CAAC,CAAE,gBAAsB,EAAtB,uCAAsB,EAAE,iBAAuB,EAAvB,uCAAuB,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACjF,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,gBAA+D,EAA9D,cAAsB,EAAtB,uCAAsB,EAAE,eAAuB,EAAvB,uCAAuB,OAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACtF,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,4CAAkG,EAAjG,cAAsB,EAAtB,uCAAsB,EAAE,eAAuB,EAAvB,uCAAuB,OAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACzH,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,qBAAsB,EAAtB,uCAAsB,EACtB,uBAG0C,EAH1C,mEAG0C,EAFtC,iBAA6B,EAA7B,2CAA6B,EAC7B,mBAAmC,EAAnC,+CAAmC,EAEvC,UAAU,EAAV,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,qBAMc,GALf,cAAsB,EAAtB,uCAAsB,EACtB,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAA6B,EAA7B,2CAA6B,EAC7B,mBAAmC,EAAnC,+CAAmC,aAEtB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,+EAMoF,GALrF,cAAsB,EAAtB,uCAAsB,EACtB,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAA6B,EAA7B,2CAA6B,EAC7B,mBAAmC,EAAnC,+CAAmC;IAGvC,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AAED,GAAG,CAAC,CAAG,gBAAe,EAAf,sCAAe,EAAE,iBAAe,EAAf,sCAAe,EAAK,KAAK,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACnE,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,gBAAiD,EAA/C,cAAe,EAAf,sCAAe,EAAE,eAAe,EAAf,sCAAe,OAAiB,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACxE,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CAAC,4CAAoF,EAAlF,cAAe,EAAf,sCAAe,EAAE,eAAe,EAAf,sCAAe,OAAoD,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAC3G,OAAO,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;AACvB,CAAC;AACD,GAAG,CAAC,CACA,qBAAe,EAAf,sCAAe,EACf,uBAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB,EAE3B,UAAU,EAAV,UAAU,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IAChC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,qBAMc,GALf,cAAe,EAAf,sCAAe,EACf,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB,aAEV,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACrC,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC;AACD,GAAG,CAAC,CAAC,+EAMoF,GALrF,cAAe,EAAf,sCAAe,EACf,gBAG0C,EAH1C,mEAG0C,EAFtC,iBAAmB,EAAnB,0CAAmB,EACnB,mBAAuB,EAAvB,8CAAuB;IAG3B,CAAC,GAAG,CAAC,EAAE,CAAC,GAAG,CAAC,EAAE,CAAC,EAAE,EAAE,CAAC;IACpB,OAAO,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC;AAC1B,CAAC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.sourcemap.txt b/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.sourcemap.txt
index 97271e8f3d0..9e0e92d4a68 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.sourcemap.txt
+++ b/tests/baselines/reference/sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.sourcemap.txt
@@ -594,14 +594,14 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(19, 1) Source(37, 1) + SourceIndex(0)
 2 >Emitted(19, 2) Source(37, 2) + SourceIndex(0)
 ---
->>>for (_f = multiRobot.skills, _g = _f === void 0 ? { primary: "none", secondary: "none" } : _f, _h = _g.primary, primaryA = _h === void 0 ? "primary" : _h, _j = _g.secondary, secondaryA = _j === void 0 ? "secondary" : _j, multiRobot, i = 0; i < 1; i++) {
+>>>for (_f = multiRobot.skills, _g = _f === void 0 ? { primary: "none", secondary: "none" } : _f, _h = _g.primary, primaryA = _h === void 0 ? "primary" : _h, _j = _g.secondary, secondaryA = _j === void 0 ? "secondary" : _j, multiRobot, multiRobot, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
@@ -620,18 +620,20 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 16>                                                                                                                                                                                                                           ^^
 17>                                                                                                                                                                                                                             ^^^^^^^^^^
 18>                                                                                                                                                                                                                                       ^^
-19>                                                                                                                                                                                                                                         ^
-20>                                                                                                                                                                                                                                          ^^^
-21>                                                                                                                                                                                                                                             ^
-22>                                                                                                                                                                                                                                              ^^
-23>                                                                                                                                                                                                                                                ^
-24>                                                                                                                                                                                                                                                 ^^^
-25>                                                                                                                                                                                                                                                    ^
-26>                                                                                                                                                                                                                                                     ^^
-27>                                                                                                                                                                                                                                                       ^
-28>                                                                                                                                                                                                                                                        ^^
-29>                                                                                                                                                                                                                                                          ^^
-30>                                                                                                                                                                                                                                                            ^
+19>                                                                                                                                                                                                                                         ^^^^^^^^^^
+20>                                                                                                                                                                                                                                                   ^^
+21>                                                                                                                                                                                                                                                     ^
+22>                                                                                                                                                                                                                                                      ^^^
+23>                                                                                                                                                                                                                                                         ^
+24>                                                                                                                                                                                                                                                          ^^
+25>                                                                                                                                                                                                                                                            ^
+26>                                                                                                                                                                                                                                                             ^^^
+27>                                                                                                                                                                                                                                                                ^
+28>                                                                                                                                                                                                                                                                 ^^
+29>                                                                                                                                                                                                                                                                   ^
+30>                                                                                                                                                                                                                                                                    ^^
+31>                                                                                                                                                                                                                                                                      ^^
+32>                                                                                                                                                                                                                                                                        ^
 1->
   >
 2 >for
@@ -660,19 +662,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >                                                                                                                                                                                                                               } = { primary: "none", secondary: "none" }
   >                                                                                                                                                                                                                           } = 
 17>                                                                                                                                                                                                                             multiRobot
-18>                                                                                                                                                                                                                                       , 
-19>                                                                                                                                                                                                                                         i
-20>                                                                                                                                                                                                                                           = 
-21>                                                                                                                                                                                                                                             0
-22>                                                                                                                                                                                                                                              ; 
-23>                                                                                                                                                                                                                                                i
-24>                                                                                                                                                                                                                                                  < 
-25>                                                                                                                                                                                                                                                    1
-26>                                                                                                                                                                                                                                                     ; 
-27>                                                                                                                                                                                                                                                       i
-28>                                                                                                                                                                                                                                                        ++
-29>                                                                                                                                                                                                                                                          ) 
-30>                                                                                                                                                                                                                                                            {
+18>                                                                                                                                                                                                                                       
+19>                                                                                                                                                                                                                                         multiRobot
+20>                                                                                                                                                                                                                                                   , 
+21>                                                                                                                                                                                                                                                     i
+22>                                                                                                                                                                                                                                                       = 
+23>                                                                                                                                                                                                                                                         0
+24>                                                                                                                                                                                                                                                          ; 
+25>                                                                                                                                                                                                                                                            i
+26>                                                                                                                                                                                                                                                              < 
+27>                                                                                                                                                                                                                                                                1
+28>                                                                                                                                                                                                                                                                 ; 
+29>                                                                                                                                                                                                                                                                   i
+30>                                                                                                                                                                                                                                                                    ++
+31>                                                                                                                                                                                                                                                                      ) 
+32>                                                                                                                                                                                                                                                                        {
 1->Emitted(20, 1) Source(38, 1) + SourceIndex(0)
 2 >Emitted(20, 4) Source(38, 4) + SourceIndex(0)
 3 >Emitted(20, 5) Source(38, 5) + SourceIndex(0)
@@ -690,19 +694,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 15>Emitted(20, 220) Source(41, 44) + SourceIndex(0)
 16>Emitted(20, 222) Source(43, 5) + SourceIndex(0)
 17>Emitted(20, 232) Source(43, 15) + SourceIndex(0)
-18>Emitted(20, 234) Source(43, 17) + SourceIndex(0)
-19>Emitted(20, 235) Source(43, 18) + SourceIndex(0)
-20>Emitted(20, 238) Source(43, 21) + SourceIndex(0)
-21>Emitted(20, 239) Source(43, 22) + SourceIndex(0)
-22>Emitted(20, 241) Source(43, 24) + SourceIndex(0)
-23>Emitted(20, 242) Source(43, 25) + SourceIndex(0)
-24>Emitted(20, 245) Source(43, 28) + SourceIndex(0)
-25>Emitted(20, 246) Source(43, 29) + SourceIndex(0)
-26>Emitted(20, 248) Source(43, 31) + SourceIndex(0)
-27>Emitted(20, 249) Source(43, 32) + SourceIndex(0)
-28>Emitted(20, 251) Source(43, 34) + SourceIndex(0)
-29>Emitted(20, 253) Source(43, 36) + SourceIndex(0)
-30>Emitted(20, 254) Source(43, 37) + SourceIndex(0)
+18>Emitted(20, 234) Source(43, 5) + SourceIndex(0)
+19>Emitted(20, 244) Source(43, 15) + SourceIndex(0)
+20>Emitted(20, 246) Source(43, 17) + SourceIndex(0)
+21>Emitted(20, 247) Source(43, 18) + SourceIndex(0)
+22>Emitted(20, 250) Source(43, 21) + SourceIndex(0)
+23>Emitted(20, 251) Source(43, 22) + SourceIndex(0)
+24>Emitted(20, 253) Source(43, 24) + SourceIndex(0)
+25>Emitted(20, 254) Source(43, 25) + SourceIndex(0)
+26>Emitted(20, 257) Source(43, 28) + SourceIndex(0)
+27>Emitted(20, 258) Source(43, 29) + SourceIndex(0)
+28>Emitted(20, 260) Source(43, 31) + SourceIndex(0)
+29>Emitted(20, 261) Source(43, 32) + SourceIndex(0)
+30>Emitted(20, 263) Source(43, 34) + SourceIndex(0)
+31>Emitted(20, 265) Source(43, 36) + SourceIndex(0)
+32>Emitted(20, 266) Source(43, 37) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -734,44 +740,44 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(22, 1) Source(45, 1) + SourceIndex(0)
 2 >Emitted(22, 2) Source(45, 2) + SourceIndex(0)
 ---
->>>for (_k = getMultiRobot(), _l = _k.skills, _m = _l === void 0 ? { primary: "none", secondary: "none" } : _l, _o = _m.primary, primaryA = _o === void 0 ? "primary" : _o, _p = _m.secondary, secondaryA = _p === void 0 ? "secondary" : _p, _k, i = 0; i < 1; i++) {
+>>>for (_k = getMultiRobot(), (_l = _k.skills, _m = _l === void 0 ? { primary: "none", secondary: "none" } : _l, _o = _m.primary, primaryA = _o === void 0 ? "primary" : _o, _p = _m.secondary, secondaryA = _p === void 0 ? "secondary" : _p, _k), _k, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^
-6 >                         ^^
-7 >                           ^^^^^^^^^^^^^^
-8 >                                         ^^
-9 >                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                                           ^^
-11>                                                                                                             ^^^^^^^^^^^^^^^
-12>                                                                                                                            ^^
-13>                                                                                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                       ^^
-15>                                                                                                                                                                         ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                          ^^
-17>                                                                                                                                                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18>                                                                                                                                                                                                                                         ^^^^^^
-19>                                                                                                                                                                                                                                               ^
-20>                                                                                                                                                                                                                                                ^^^
-21>                                                                                                                                                                                                                                                   ^
-22>                                                                                                                                                                                                                                                    ^^
-23>                                                                                                                                                                                                                                                      ^
-24>                                                                                                                                                                                                                                                       ^^^
-25>                                                                                                                                                                                                                                                          ^
-26>                                                                                                                                                                                                                                                           ^^
-27>                                                                                                                                                                                                                                                             ^
-28>                                                                                                                                                                                                                                                              ^^
-29>                                                                                                                                                                                                                                                                ^^
-30>                                                                                                                                                                                                                                                                  ^
+6 >                         ^^^
+7 >                            ^^^^^^^^^^^^^^
+8 >                                          ^^
+9 >                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                                            ^^
+11>                                                                                                              ^^^^^^^^^^^^^^^
+12>                                                                                                                             ^^
+13>                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                        ^^
+15>                                                                                                                                                                          ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                           ^^
+17>                                                                                                                                                                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+18>                                                                                                                                                                                                                                          ^^^^^^^^^^^
+19>                                                                                                                                                                                                                                                     ^
+20>                                                                                                                                                                                                                                                      ^^^
+21>                                                                                                                                                                                                                                                         ^
+22>                                                                                                                                                                                                                                                          ^^
+23>                                                                                                                                                                                                                                                            ^
+24>                                                                                                                                                                                                                                                             ^^^
+25>                                                                                                                                                                                                                                                                ^
+26>                                                                                                                                                                                                                                                                 ^^
+27>                                                                                                                                                                                                                                                                   ^
+28>                                                                                                                                                                                                                                                                    ^^
+29>                                                                                                                                                                                                                                                                      ^^
+30>                                                                                                                                                                                                                                                                        ^
 1->
   >
 2 >for
@@ -784,69 +790,69 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = getMultiRobot()
 6 >                         
-7 >                           skills: {
-  >                                   primary: primaryA = "primary",
-  >                                   secondary: secondaryA = "secondary"
-  >                               } = { primary: "none", secondary: "none" }
-8 >                                         
-9 >                                           skills: {
-  >                                                   primary: primaryA = "primary",
-  >                                                   secondary: secondaryA = "secondary"
-  >                                               } = { primary: "none", secondary: "none" }
-10>                                                                                                           
-11>                                                                                                             primary: primaryA = "primary"
-12>                                                                                                                            
-13>                                                                                                                              primary: primaryA = "primary"
-14>                                                                                                                                                                       ,
-  >                                                                                                                                                                               
-15>                                                                                                                                                                         secondary: secondaryA = "secondary"
-16>                                                                                                                                                                                          
-17>                                                                                                                                                                                            secondary: secondaryA = "secondary"
-18>                                                                                                                                                                                                                                         
-  >                                                                                                                                                                                                                                             } = { primary: "none", secondary: "none" }
-  >                                                                                                                                                                                                                                         } = getMultiRobot(), 
-19>                                                                                                                                                                                                                                               i
-20>                                                                                                                                                                                                                                                 = 
-21>                                                                                                                                                                                                                                                   0
-22>                                                                                                                                                                                                                                                    ; 
-23>                                                                                                                                                                                                                                                      i
-24>                                                                                                                                                                                                                                                        < 
-25>                                                                                                                                                                                                                                                          1
-26>                                                                                                                                                                                                                                                           ; 
-27>                                                                                                                                                                                                                                                             i
-28>                                                                                                                                                                                                                                                              ++
-29>                                                                                                                                                                                                                                                                ) 
-30>                                                                                                                                                                                                                                                                  {
+7 >                            skills: {
+  >                                    primary: primaryA = "primary",
+  >                                    secondary: secondaryA = "secondary"
+  >                                } = { primary: "none", secondary: "none" }
+8 >                                          
+9 >                                            skills: {
+  >                                                    primary: primaryA = "primary",
+  >                                                    secondary: secondaryA = "secondary"
+  >                                                } = { primary: "none", secondary: "none" }
+10>                                                                                                            
+11>                                                                                                              primary: primaryA = "primary"
+12>                                                                                                                             
+13>                                                                                                                               primary: primaryA = "primary"
+14>                                                                                                                                                                        ,
+  >                                                                                                                                                                                
+15>                                                                                                                                                                          secondary: secondaryA = "secondary"
+16>                                                                                                                                                                                           
+17>                                                                                                                                                                                             secondary: secondaryA = "secondary"
+18>                                                                                                                                                                                                                                          
+  >                                                                                                                                                                                                                                              } = { primary: "none", secondary: "none" }
+  >                                                                                                                                                                                                                                          } = getMultiRobot(), 
+19>                                                                                                                                                                                                                                                     i
+20>                                                                                                                                                                                                                                                       = 
+21>                                                                                                                                                                                                                                                         0
+22>                                                                                                                                                                                                                                                          ; 
+23>                                                                                                                                                                                                                                                            i
+24>                                                                                                                                                                                                                                                              < 
+25>                                                                                                                                                                                                                                                                1
+26>                                                                                                                                                                                                                                                                 ; 
+27>                                                                                                                                                                                                                                                                   i
+28>                                                                                                                                                                                                                                                                    ++
+29>                                                                                                                                                                                                                                                                      ) 
+30>                                                                                                                                                                                                                                                                        {
 1->Emitted(23, 1) Source(46, 1) + SourceIndex(0)
 2 >Emitted(23, 4) Source(46, 4) + SourceIndex(0)
 3 >Emitted(23, 5) Source(46, 5) + SourceIndex(0)
 4 >Emitted(23, 6) Source(46, 6) + SourceIndex(0)
 5 >Emitted(23, 26) Source(51, 20) + SourceIndex(0)
-6 >Emitted(23, 28) Source(47, 5) + SourceIndex(0)
-7 >Emitted(23, 42) Source(50, 47) + SourceIndex(0)
-8 >Emitted(23, 44) Source(47, 5) + SourceIndex(0)
-9 >Emitted(23, 108) Source(50, 47) + SourceIndex(0)
-10>Emitted(23, 110) Source(48, 9) + SourceIndex(0)
-11>Emitted(23, 125) Source(48, 38) + SourceIndex(0)
-12>Emitted(23, 127) Source(48, 9) + SourceIndex(0)
-13>Emitted(23, 168) Source(48, 38) + SourceIndex(0)
-14>Emitted(23, 170) Source(49, 9) + SourceIndex(0)
-15>Emitted(23, 187) Source(49, 44) + SourceIndex(0)
-16>Emitted(23, 189) Source(49, 9) + SourceIndex(0)
-17>Emitted(23, 234) Source(49, 44) + SourceIndex(0)
-18>Emitted(23, 240) Source(51, 22) + SourceIndex(0)
-19>Emitted(23, 241) Source(51, 23) + SourceIndex(0)
-20>Emitted(23, 244) Source(51, 26) + SourceIndex(0)
-21>Emitted(23, 245) Source(51, 27) + SourceIndex(0)
-22>Emitted(23, 247) Source(51, 29) + SourceIndex(0)
-23>Emitted(23, 248) Source(51, 30) + SourceIndex(0)
-24>Emitted(23, 251) Source(51, 33) + SourceIndex(0)
-25>Emitted(23, 252) Source(51, 34) + SourceIndex(0)
-26>Emitted(23, 254) Source(51, 36) + SourceIndex(0)
-27>Emitted(23, 255) Source(51, 37) + SourceIndex(0)
-28>Emitted(23, 257) Source(51, 39) + SourceIndex(0)
-29>Emitted(23, 259) Source(51, 41) + SourceIndex(0)
-30>Emitted(23, 260) Source(51, 42) + SourceIndex(0)
+6 >Emitted(23, 29) Source(47, 5) + SourceIndex(0)
+7 >Emitted(23, 43) Source(50, 47) + SourceIndex(0)
+8 >Emitted(23, 45) Source(47, 5) + SourceIndex(0)
+9 >Emitted(23, 109) Source(50, 47) + SourceIndex(0)
+10>Emitted(23, 111) Source(48, 9) + SourceIndex(0)
+11>Emitted(23, 126) Source(48, 38) + SourceIndex(0)
+12>Emitted(23, 128) Source(48, 9) + SourceIndex(0)
+13>Emitted(23, 169) Source(48, 38) + SourceIndex(0)
+14>Emitted(23, 171) Source(49, 9) + SourceIndex(0)
+15>Emitted(23, 188) Source(49, 44) + SourceIndex(0)
+16>Emitted(23, 190) Source(49, 9) + SourceIndex(0)
+17>Emitted(23, 235) Source(49, 44) + SourceIndex(0)
+18>Emitted(23, 246) Source(51, 22) + SourceIndex(0)
+19>Emitted(23, 247) Source(51, 23) + SourceIndex(0)
+20>Emitted(23, 250) Source(51, 26) + SourceIndex(0)
+21>Emitted(23, 251) Source(51, 27) + SourceIndex(0)
+22>Emitted(23, 253) Source(51, 29) + SourceIndex(0)
+23>Emitted(23, 254) Source(51, 30) + SourceIndex(0)
+24>Emitted(23, 257) Source(51, 33) + SourceIndex(0)
+25>Emitted(23, 258) Source(51, 34) + SourceIndex(0)
+26>Emitted(23, 260) Source(51, 36) + SourceIndex(0)
+27>Emitted(23, 261) Source(51, 37) + SourceIndex(0)
+28>Emitted(23, 263) Source(51, 39) + SourceIndex(0)
+29>Emitted(23, 265) Source(51, 41) + SourceIndex(0)
+30>Emitted(23, 266) Source(51, 42) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -878,31 +884,31 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(25, 1) Source(53, 1) + SourceIndex(0)
 2 >Emitted(25, 2) Source(53, 2) + SourceIndex(0)
 ---
->>>for (_q = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _r = _q.skills, _s = _r === void 0 ? { primary: "none", secondary: "none" } : _r, _t = _s.primary, primaryA = _t === void 0 ? "primary" : _t, _u = _s.secondary, secondaryA = _u === void 0 ? "secondary" : _u, _q,
+>>>for (_q = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_r = _q.skills, _s = _r === void 0 ? { primary: "none", secondary: "none" } : _r, _t = _s.primary, primaryA = _t === void 0 ? "primary" : _t, _u = _s.secondary, secondaryA = _u === void 0 ? "secondary" : _u, _q), _q,
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-6 >                                                                                   ^^
-7 >                                                                                     ^^^^^^^^^^^^^^
-8 >                                                                                                   ^^
-9 >                                                                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                                                                                                     ^^
-11>                                                                                                                                                                       ^^^^^^^^^^^^^^^
-12>                                                                                                                                                                                      ^^
-13>                                                                                                                                                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                                                                                 ^^
-15>                                                                                                                                                                                                                                   ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                                                                                    ^^
-17>                                                                                                                                                                                                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+6 >                                                                                   ^^^
+7 >                                                                                      ^^^^^^^^^^^^^^
+8 >                                                                                                    ^^
+9 >                                                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                                                                                                      ^^
+11>                                                                                                                                                                        ^^^^^^^^^^^^^^^
+12>                                                                                                                                                                                       ^^
+13>                                                                                                                                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                                                                                  ^^
+15>                                                                                                                                                                                                                                    ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                                                                                     ^^
+17>                                                                                                                                                                                                                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->
   >
 2 >for
@@ -915,41 +921,41 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = <MultiRobot>{ name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }
 6 >                                                                                   
-7 >                                                                                     skills: {
-  >                                                                                             primary: primaryA = "primary",
-  >                                                                                             secondary: secondaryA = "secondary"
-  >                                                                                         } = { primary: "none", secondary: "none" }
-8 >                                                                                                   
-9 >                                                                                                     skills: {
-  >                                                                                                             primary: primaryA = "primary",
-  >                                                                                                             secondary: secondaryA = "secondary"
-  >                                                                                                         } = { primary: "none", secondary: "none" }
-10>                                                                                                                                                                     
-11>                                                                                                                                                                       primary: primaryA = "primary"
-12>                                                                                                                                                                                      
-13>                                                                                                                                                                                        primary: primaryA = "primary"
-14>                                                                                                                                                                                                                                 ,
-  >                                                                                                                                                                                                                                         
-15>                                                                                                                                                                                                                                   secondary: secondaryA = "secondary"
-16>                                                                                                                                                                                                                                                    
-17>                                                                                                                                                                                                                                                      secondary: secondaryA = "secondary"
+7 >                                                                                      skills: {
+  >                                                                                              primary: primaryA = "primary",
+  >                                                                                              secondary: secondaryA = "secondary"
+  >                                                                                          } = { primary: "none", secondary: "none" }
+8 >                                                                                                    
+9 >                                                                                                      skills: {
+  >                                                                                                              primary: primaryA = "primary",
+  >                                                                                                              secondary: secondaryA = "secondary"
+  >                                                                                                          } = { primary: "none", secondary: "none" }
+10>                                                                                                                                                                      
+11>                                                                                                                                                                        primary: primaryA = "primary"
+12>                                                                                                                                                                                       
+13>                                                                                                                                                                                         primary: primaryA = "primary"
+14>                                                                                                                                                                                                                                  ,
+  >                                                                                                                                                                                                                                          
+15>                                                                                                                                                                                                                                    secondary: secondaryA = "secondary"
+16>                                                                                                                                                                                                                                                     
+17>                                                                                                                                                                                                                                                       secondary: secondaryA = "secondary"
 1->Emitted(26, 1) Source(54, 1) + SourceIndex(0)
 2 >Emitted(26, 4) Source(54, 4) + SourceIndex(0)
 3 >Emitted(26, 5) Source(54, 5) + SourceIndex(0)
 4 >Emitted(26, 6) Source(54, 6) + SourceIndex(0)
 5 >Emitted(26, 84) Source(59, 90) + SourceIndex(0)
-6 >Emitted(26, 86) Source(55, 5) + SourceIndex(0)
-7 >Emitted(26, 100) Source(58, 47) + SourceIndex(0)
-8 >Emitted(26, 102) Source(55, 5) + SourceIndex(0)
-9 >Emitted(26, 166) Source(58, 47) + SourceIndex(0)
-10>Emitted(26, 168) Source(56, 9) + SourceIndex(0)
-11>Emitted(26, 183) Source(56, 38) + SourceIndex(0)
-12>Emitted(26, 185) Source(56, 9) + SourceIndex(0)
-13>Emitted(26, 226) Source(56, 38) + SourceIndex(0)
-14>Emitted(26, 228) Source(57, 9) + SourceIndex(0)
-15>Emitted(26, 245) Source(57, 44) + SourceIndex(0)
-16>Emitted(26, 247) Source(57, 9) + SourceIndex(0)
-17>Emitted(26, 292) Source(57, 44) + SourceIndex(0)
+6 >Emitted(26, 87) Source(55, 5) + SourceIndex(0)
+7 >Emitted(26, 101) Source(58, 47) + SourceIndex(0)
+8 >Emitted(26, 103) Source(55, 5) + SourceIndex(0)
+9 >Emitted(26, 167) Source(58, 47) + SourceIndex(0)
+10>Emitted(26, 169) Source(56, 9) + SourceIndex(0)
+11>Emitted(26, 184) Source(56, 38) + SourceIndex(0)
+12>Emitted(26, 186) Source(56, 9) + SourceIndex(0)
+13>Emitted(26, 227) Source(56, 38) + SourceIndex(0)
+14>Emitted(26, 229) Source(57, 9) + SourceIndex(0)
+15>Emitted(26, 246) Source(57, 44) + SourceIndex(0)
+16>Emitted(26, 248) Source(57, 9) + SourceIndex(0)
+17>Emitted(26, 293) Source(57, 44) + SourceIndex(0)
 ---
 >>>    i = 0; i < 1; i++) {
 1 >^^^^
@@ -1345,14 +1351,14 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(38, 1) Source(72, 1) + SourceIndex(0)
 2 >Emitted(38, 2) Source(72, 2) + SourceIndex(0)
 ---
->>>for (_0 = multiRobot.skills, _1 = _0 === void 0 ? { primary: "none", secondary: "none" } : _0, _2 = _1.primary, primary = _2 === void 0 ? "primary" : _2, _3 = _1.secondary, secondary = _3 === void 0 ? "secondary" : _3, multiRobot, i = 0; i < 1; i++) {
+>>>for (_0 = multiRobot.skills, _1 = _0 === void 0 ? { primary: "none", secondary: "none" } : _0, _2 = _1.primary, primary = _2 === void 0 ? "primary" : _2, _3 = _1.secondary, secondary = _3 === void 0 ? "secondary" : _3, multiRobot, multiRobot, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
@@ -1371,18 +1377,20 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 16>                                                                                                                                                                                                                         ^^
 17>                                                                                                                                                                                                                           ^^^^^^^^^^
 18>                                                                                                                                                                                                                                     ^^
-19>                                                                                                                                                                                                                                       ^
-20>                                                                                                                                                                                                                                        ^^^
-21>                                                                                                                                                                                                                                           ^
-22>                                                                                                                                                                                                                                            ^^
-23>                                                                                                                                                                                                                                              ^
-24>                                                                                                                                                                                                                                               ^^^
-25>                                                                                                                                                                                                                                                  ^
-26>                                                                                                                                                                                                                                                   ^^
-27>                                                                                                                                                                                                                                                     ^
-28>                                                                                                                                                                                                                                                      ^^
-29>                                                                                                                                                                                                                                                        ^^
-30>                                                                                                                                                                                                                                                          ^
+19>                                                                                                                                                                                                                                       ^^^^^^^^^^
+20>                                                                                                                                                                                                                                                 ^^
+21>                                                                                                                                                                                                                                                   ^
+22>                                                                                                                                                                                                                                                    ^^^
+23>                                                                                                                                                                                                                                                       ^
+24>                                                                                                                                                                                                                                                        ^^
+25>                                                                                                                                                                                                                                                          ^
+26>                                                                                                                                                                                                                                                           ^^^
+27>                                                                                                                                                                                                                                                              ^
+28>                                                                                                                                                                                                                                                               ^^
+29>                                                                                                                                                                                                                                                                 ^
+30>                                                                                                                                                                                                                                                                  ^^
+31>                                                                                                                                                                                                                                                                    ^^
+32>                                                                                                                                                                                                                                                                      ^
 1->
   >
 2 >for
@@ -1411,19 +1419,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >                                                                                                                                                                                                                             } = { primary: "none", secondary: "none" }
   >                                                                                                                                                                                                                         } = 
 17>                                                                                                                                                                                                                           multiRobot
-18>                                                                                                                                                                                                                                     , 
-19>                                                                                                                                                                                                                                       i
-20>                                                                                                                                                                                                                                         = 
-21>                                                                                                                                                                                                                                           0
-22>                                                                                                                                                                                                                                            ; 
-23>                                                                                                                                                                                                                                              i
-24>                                                                                                                                                                                                                                                < 
-25>                                                                                                                                                                                                                                                  1
-26>                                                                                                                                                                                                                                                   ; 
-27>                                                                                                                                                                                                                                                     i
-28>                                                                                                                                                                                                                                                      ++
-29>                                                                                                                                                                                                                                                        ) 
-30>                                                                                                                                                                                                                                                          {
+18>                                                                                                                                                                                                                                     
+19>                                                                                                                                                                                                                                       multiRobot
+20>                                                                                                                                                                                                                                                 , 
+21>                                                                                                                                                                                                                                                   i
+22>                                                                                                                                                                                                                                                     = 
+23>                                                                                                                                                                                                                                                       0
+24>                                                                                                                                                                                                                                                        ; 
+25>                                                                                                                                                                                                                                                          i
+26>                                                                                                                                                                                                                                                            < 
+27>                                                                                                                                                                                                                                                              1
+28>                                                                                                                                                                                                                                                               ; 
+29>                                                                                                                                                                                                                                                                 i
+30>                                                                                                                                                                                                                                                                  ++
+31>                                                                                                                                                                                                                                                                    ) 
+32>                                                                                                                                                                                                                                                                      {
 1->Emitted(39, 1) Source(73, 1) + SourceIndex(0)
 2 >Emitted(39, 4) Source(73, 4) + SourceIndex(0)
 3 >Emitted(39, 5) Source(73, 5) + SourceIndex(0)
@@ -1441,19 +1451,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 15>Emitted(39, 218) Source(76, 32) + SourceIndex(0)
 16>Emitted(39, 220) Source(78, 5) + SourceIndex(0)
 17>Emitted(39, 230) Source(78, 15) + SourceIndex(0)
-18>Emitted(39, 232) Source(78, 17) + SourceIndex(0)
-19>Emitted(39, 233) Source(78, 18) + SourceIndex(0)
-20>Emitted(39, 236) Source(78, 21) + SourceIndex(0)
-21>Emitted(39, 237) Source(78, 22) + SourceIndex(0)
-22>Emitted(39, 239) Source(78, 24) + SourceIndex(0)
-23>Emitted(39, 240) Source(78, 25) + SourceIndex(0)
-24>Emitted(39, 243) Source(78, 28) + SourceIndex(0)
-25>Emitted(39, 244) Source(78, 29) + SourceIndex(0)
-26>Emitted(39, 246) Source(78, 31) + SourceIndex(0)
-27>Emitted(39, 247) Source(78, 32) + SourceIndex(0)
-28>Emitted(39, 249) Source(78, 34) + SourceIndex(0)
-29>Emitted(39, 251) Source(78, 36) + SourceIndex(0)
-30>Emitted(39, 252) Source(78, 37) + SourceIndex(0)
+18>Emitted(39, 232) Source(78, 5) + SourceIndex(0)
+19>Emitted(39, 242) Source(78, 15) + SourceIndex(0)
+20>Emitted(39, 244) Source(78, 17) + SourceIndex(0)
+21>Emitted(39, 245) Source(78, 18) + SourceIndex(0)
+22>Emitted(39, 248) Source(78, 21) + SourceIndex(0)
+23>Emitted(39, 249) Source(78, 22) + SourceIndex(0)
+24>Emitted(39, 251) Source(78, 24) + SourceIndex(0)
+25>Emitted(39, 252) Source(78, 25) + SourceIndex(0)
+26>Emitted(39, 255) Source(78, 28) + SourceIndex(0)
+27>Emitted(39, 256) Source(78, 29) + SourceIndex(0)
+28>Emitted(39, 258) Source(78, 31) + SourceIndex(0)
+29>Emitted(39, 259) Source(78, 32) + SourceIndex(0)
+30>Emitted(39, 261) Source(78, 34) + SourceIndex(0)
+31>Emitted(39, 263) Source(78, 36) + SourceIndex(0)
+32>Emitted(39, 264) Source(78, 37) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -1485,44 +1497,44 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(41, 1) Source(80, 1) + SourceIndex(0)
 2 >Emitted(41, 2) Source(80, 2) + SourceIndex(0)
 ---
->>>for (_4 = getMultiRobot(), _5 = _4.skills, _6 = _5 === void 0 ? { primary: "none", secondary: "none" } : _5, _7 = _6.primary, primary = _7 === void 0 ? "primary" : _7, _8 = _6.secondary, secondary = _8 === void 0 ? "secondary" : _8, _4, i = 0; i < 1; i++) {
+>>>for (_4 = getMultiRobot(), (_5 = _4.skills, _6 = _5 === void 0 ? { primary: "none", secondary: "none" } : _5, _7 = _6.primary, primary = _7 === void 0 ? "primary" : _7, _8 = _6.secondary, secondary = _8 === void 0 ? "secondary" : _8, _4), _4, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^
-6 >                         ^^
-7 >                           ^^^^^^^^^^^^^^
-8 >                                         ^^
-9 >                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                                           ^^
-11>                                                                                                             ^^^^^^^^^^^^^^^
-12>                                                                                                                            ^^
-13>                                                                                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                      ^^
-15>                                                                                                                                                                        ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                         ^^
-17>                                                                                                                                                                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18>                                                                                                                                                                                                                                       ^^^^^^
-19>                                                                                                                                                                                                                                             ^
-20>                                                                                                                                                                                                                                              ^^^
-21>                                                                                                                                                                                                                                                 ^
-22>                                                                                                                                                                                                                                                  ^^
-23>                                                                                                                                                                                                                                                    ^
-24>                                                                                                                                                                                                                                                     ^^^
-25>                                                                                                                                                                                                                                                        ^
-26>                                                                                                                                                                                                                                                         ^^
-27>                                                                                                                                                                                                                                                           ^
-28>                                                                                                                                                                                                                                                            ^^
-29>                                                                                                                                                                                                                                                              ^^
-30>                                                                                                                                                                                                                                                                ^
+6 >                         ^^^
+7 >                            ^^^^^^^^^^^^^^
+8 >                                          ^^
+9 >                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                                            ^^
+11>                                                                                                              ^^^^^^^^^^^^^^^
+12>                                                                                                                             ^^
+13>                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                       ^^
+15>                                                                                                                                                                         ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                          ^^
+17>                                                                                                                                                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+18>                                                                                                                                                                                                                                        ^^^^^^^^^^^
+19>                                                                                                                                                                                                                                                   ^
+20>                                                                                                                                                                                                                                                    ^^^
+21>                                                                                                                                                                                                                                                       ^
+22>                                                                                                                                                                                                                                                        ^^
+23>                                                                                                                                                                                                                                                          ^
+24>                                                                                                                                                                                                                                                           ^^^
+25>                                                                                                                                                                                                                                                              ^
+26>                                                                                                                                                                                                                                                               ^^
+27>                                                                                                                                                                                                                                                                 ^
+28>                                                                                                                                                                                                                                                                  ^^
+29>                                                                                                                                                                                                                                                                    ^^
+30>                                                                                                                                                                                                                                                                      ^
 1->
   >
 2 >for
@@ -1535,69 +1547,69 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = getMultiRobot()
 6 >                         
-7 >                           skills: {
-  >                                   primary = "primary",
-  >                                   secondary = "secondary"
-  >                               } = { primary: "none", secondary: "none" }
-8 >                                         
-9 >                                           skills: {
-  >                                                   primary = "primary",
-  >                                                   secondary = "secondary"
-  >                                               } = { primary: "none", secondary: "none" }
-10>                                                                                                           
-11>                                                                                                             primary = "primary"
-12>                                                                                                                            
-13>                                                                                                                              primary = "primary"
-14>                                                                                                                                                                      ,
-  >                                                                                                                                                                              
-15>                                                                                                                                                                        secondary = "secondary"
-16>                                                                                                                                                                                         
-17>                                                                                                                                                                                           secondary = "secondary"
-18>                                                                                                                                                                                                                                       
-  >                                                                                                                                                                                                                                           } = { primary: "none", secondary: "none" }
-  >                                                                                                                                                                                                                                       } = getMultiRobot(), 
-19>                                                                                                                                                                                                                                             i
-20>                                                                                                                                                                                                                                               = 
-21>                                                                                                                                                                                                                                                 0
-22>                                                                                                                                                                                                                                                  ; 
-23>                                                                                                                                                                                                                                                    i
-24>                                                                                                                                                                                                                                                      < 
-25>                                                                                                                                                                                                                                                        1
-26>                                                                                                                                                                                                                                                         ; 
-27>                                                                                                                                                                                                                                                           i
-28>                                                                                                                                                                                                                                                            ++
-29>                                                                                                                                                                                                                                                              ) 
-30>                                                                                                                                                                                                                                                                {
+7 >                            skills: {
+  >                                    primary = "primary",
+  >                                    secondary = "secondary"
+  >                                } = { primary: "none", secondary: "none" }
+8 >                                          
+9 >                                            skills: {
+  >                                                    primary = "primary",
+  >                                                    secondary = "secondary"
+  >                                                } = { primary: "none", secondary: "none" }
+10>                                                                                                            
+11>                                                                                                              primary = "primary"
+12>                                                                                                                             
+13>                                                                                                                               primary = "primary"
+14>                                                                                                                                                                       ,
+  >                                                                                                                                                                               
+15>                                                                                                                                                                         secondary = "secondary"
+16>                                                                                                                                                                                          
+17>                                                                                                                                                                                            secondary = "secondary"
+18>                                                                                                                                                                                                                                        
+  >                                                                                                                                                                                                                                            } = { primary: "none", secondary: "none" }
+  >                                                                                                                                                                                                                                        } = getMultiRobot(), 
+19>                                                                                                                                                                                                                                                   i
+20>                                                                                                                                                                                                                                                     = 
+21>                                                                                                                                                                                                                                                       0
+22>                                                                                                                                                                                                                                                        ; 
+23>                                                                                                                                                                                                                                                          i
+24>                                                                                                                                                                                                                                                            < 
+25>                                                                                                                                                                                                                                                              1
+26>                                                                                                                                                                                                                                                               ; 
+27>                                                                                                                                                                                                                                                                 i
+28>                                                                                                                                                                                                                                                                  ++
+29>                                                                                                                                                                                                                                                                    ) 
+30>                                                                                                                                                                                                                                                                      {
 1->Emitted(42, 1) Source(81, 1) + SourceIndex(0)
 2 >Emitted(42, 4) Source(81, 4) + SourceIndex(0)
 3 >Emitted(42, 5) Source(81, 5) + SourceIndex(0)
 4 >Emitted(42, 6) Source(81, 6) + SourceIndex(0)
 5 >Emitted(42, 26) Source(86, 20) + SourceIndex(0)
-6 >Emitted(42, 28) Source(82, 5) + SourceIndex(0)
-7 >Emitted(42, 42) Source(85, 47) + SourceIndex(0)
-8 >Emitted(42, 44) Source(82, 5) + SourceIndex(0)
-9 >Emitted(42, 108) Source(85, 47) + SourceIndex(0)
-10>Emitted(42, 110) Source(83, 9) + SourceIndex(0)
-11>Emitted(42, 125) Source(83, 28) + SourceIndex(0)
-12>Emitted(42, 127) Source(83, 9) + SourceIndex(0)
-13>Emitted(42, 167) Source(83, 28) + SourceIndex(0)
-14>Emitted(42, 169) Source(84, 9) + SourceIndex(0)
-15>Emitted(42, 186) Source(84, 32) + SourceIndex(0)
-16>Emitted(42, 188) Source(84, 9) + SourceIndex(0)
-17>Emitted(42, 232) Source(84, 32) + SourceIndex(0)
-18>Emitted(42, 238) Source(86, 22) + SourceIndex(0)
-19>Emitted(42, 239) Source(86, 23) + SourceIndex(0)
-20>Emitted(42, 242) Source(86, 26) + SourceIndex(0)
-21>Emitted(42, 243) Source(86, 27) + SourceIndex(0)
-22>Emitted(42, 245) Source(86, 29) + SourceIndex(0)
-23>Emitted(42, 246) Source(86, 30) + SourceIndex(0)
-24>Emitted(42, 249) Source(86, 33) + SourceIndex(0)
-25>Emitted(42, 250) Source(86, 34) + SourceIndex(0)
-26>Emitted(42, 252) Source(86, 36) + SourceIndex(0)
-27>Emitted(42, 253) Source(86, 37) + SourceIndex(0)
-28>Emitted(42, 255) Source(86, 39) + SourceIndex(0)
-29>Emitted(42, 257) Source(86, 41) + SourceIndex(0)
-30>Emitted(42, 258) Source(86, 42) + SourceIndex(0)
+6 >Emitted(42, 29) Source(82, 5) + SourceIndex(0)
+7 >Emitted(42, 43) Source(85, 47) + SourceIndex(0)
+8 >Emitted(42, 45) Source(82, 5) + SourceIndex(0)
+9 >Emitted(42, 109) Source(85, 47) + SourceIndex(0)
+10>Emitted(42, 111) Source(83, 9) + SourceIndex(0)
+11>Emitted(42, 126) Source(83, 28) + SourceIndex(0)
+12>Emitted(42, 128) Source(83, 9) + SourceIndex(0)
+13>Emitted(42, 168) Source(83, 28) + SourceIndex(0)
+14>Emitted(42, 170) Source(84, 9) + SourceIndex(0)
+15>Emitted(42, 187) Source(84, 32) + SourceIndex(0)
+16>Emitted(42, 189) Source(84, 9) + SourceIndex(0)
+17>Emitted(42, 233) Source(84, 32) + SourceIndex(0)
+18>Emitted(42, 244) Source(86, 22) + SourceIndex(0)
+19>Emitted(42, 245) Source(86, 23) + SourceIndex(0)
+20>Emitted(42, 248) Source(86, 26) + SourceIndex(0)
+21>Emitted(42, 249) Source(86, 27) + SourceIndex(0)
+22>Emitted(42, 251) Source(86, 29) + SourceIndex(0)
+23>Emitted(42, 252) Source(86, 30) + SourceIndex(0)
+24>Emitted(42, 255) Source(86, 33) + SourceIndex(0)
+25>Emitted(42, 256) Source(86, 34) + SourceIndex(0)
+26>Emitted(42, 258) Source(86, 36) + SourceIndex(0)
+27>Emitted(42, 259) Source(86, 37) + SourceIndex(0)
+28>Emitted(42, 261) Source(86, 39) + SourceIndex(0)
+29>Emitted(42, 263) Source(86, 41) + SourceIndex(0)
+30>Emitted(42, 264) Source(86, 42) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -1629,31 +1641,31 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(44, 1) Source(88, 1) + SourceIndex(0)
 2 >Emitted(44, 2) Source(88, 2) + SourceIndex(0)
 ---
->>>for (_9 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _10 = _9.skills, _11 = _10 === void 0 ? { primary: "none", secondary: "none" } : _10, _12 = _11.primary, primary = _12 === void 0 ? "primary" : _12, _13 = _11.secondary, secondary = _13 === void 0 ? "secondary" : _13, _9,
+>>>for (_9 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_10 = _9.skills, _11 = _10 === void 0 ? { primary: "none", secondary: "none" } : _10, _12 = _11.primary, primary = _12 === void 0 ? "primary" : _12, _13 = _11.secondary, secondary = _13 === void 0 ? "secondary" : _13, _9), _9,
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-6 >                                                                                   ^^
-7 >                                                                                     ^^^^^^^^^^^^^^^
-8 >                                                                                                    ^^
-9 >                                                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                                                                                                         ^^
-11>                                                                                                                                                                           ^^^^^^^^^^^^^^^^^
-12>                                                                                                                                                                                            ^^
-13>                                                                                                                                                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                                                                                        ^^
-15>                                                                                                                                                                                                                                          ^^^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                                                                                             ^^
-17>                                                                                                                                                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+6 >                                                                                   ^^^
+7 >                                                                                      ^^^^^^^^^^^^^^^
+8 >                                                                                                     ^^
+9 >                                                                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                                                                                                          ^^
+11>                                                                                                                                                                            ^^^^^^^^^^^^^^^^^
+12>                                                                                                                                                                                             ^^
+13>                                                                                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                                                                                         ^^
+15>                                                                                                                                                                                                                                           ^^^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                                                                                              ^^
+17>                                                                                                                                                                                                                                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->
   >
 2 >for
@@ -1666,41 +1678,41 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = <MultiRobot>{ name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }
 6 >                                                                                   
-7 >                                                                                     skills: {
-  >                                                                                             primary = "primary",
-  >                                                                                             secondary = "secondary"
-  >                                                                                         } = { primary: "none", secondary: "none" }
-8 >                                                                                                    
-9 >                                                                                                      skills: {
-  >                                                                                                              primary = "primary",
-  >                                                                                                              secondary = "secondary"
-  >                                                                                                          } = { primary: "none", secondary: "none" }
-10>                                                                                                                                                                         
-11>                                                                                                                                                                           primary = "primary"
-12>                                                                                                                                                                                            
-13>                                                                                                                                                                                              primary = "primary"
-14>                                                                                                                                                                                                                                        ,
-  >                                                                                                                                                                                                                                                
-15>                                                                                                                                                                                                                                          secondary = "secondary"
-16>                                                                                                                                                                                                                                                             
-17>                                                                                                                                                                                                                                                               secondary = "secondary"
+7 >                                                                                      skills: {
+  >                                                                                              primary = "primary",
+  >                                                                                              secondary = "secondary"
+  >                                                                                          } = { primary: "none", secondary: "none" }
+8 >                                                                                                     
+9 >                                                                                                       skills: {
+  >                                                                                                               primary = "primary",
+  >                                                                                                               secondary = "secondary"
+  >                                                                                                           } = { primary: "none", secondary: "none" }
+10>                                                                                                                                                                          
+11>                                                                                                                                                                            primary = "primary"
+12>                                                                                                                                                                                             
+13>                                                                                                                                                                                               primary = "primary"
+14>                                                                                                                                                                                                                                         ,
+  >                                                                                                                                                                                                                                                 
+15>                                                                                                                                                                                                                                           secondary = "secondary"
+16>                                                                                                                                                                                                                                                              
+17>                                                                                                                                                                                                                                                                secondary = "secondary"
 1->Emitted(45, 1) Source(89, 1) + SourceIndex(0)
 2 >Emitted(45, 4) Source(89, 4) + SourceIndex(0)
 3 >Emitted(45, 5) Source(89, 5) + SourceIndex(0)
 4 >Emitted(45, 6) Source(89, 6) + SourceIndex(0)
 5 >Emitted(45, 84) Source(94, 90) + SourceIndex(0)
-6 >Emitted(45, 86) Source(90, 5) + SourceIndex(0)
-7 >Emitted(45, 101) Source(93, 47) + SourceIndex(0)
-8 >Emitted(45, 103) Source(90, 5) + SourceIndex(0)
-9 >Emitted(45, 170) Source(93, 47) + SourceIndex(0)
-10>Emitted(45, 172) Source(91, 9) + SourceIndex(0)
-11>Emitted(45, 189) Source(91, 28) + SourceIndex(0)
-12>Emitted(45, 191) Source(91, 9) + SourceIndex(0)
-13>Emitted(45, 233) Source(91, 28) + SourceIndex(0)
-14>Emitted(45, 235) Source(92, 9) + SourceIndex(0)
-15>Emitted(45, 254) Source(92, 32) + SourceIndex(0)
-16>Emitted(45, 256) Source(92, 9) + SourceIndex(0)
-17>Emitted(45, 302) Source(92, 32) + SourceIndex(0)
+6 >Emitted(45, 87) Source(90, 5) + SourceIndex(0)
+7 >Emitted(45, 102) Source(93, 47) + SourceIndex(0)
+8 >Emitted(45, 104) Source(90, 5) + SourceIndex(0)
+9 >Emitted(45, 171) Source(93, 47) + SourceIndex(0)
+10>Emitted(45, 173) Source(91, 9) + SourceIndex(0)
+11>Emitted(45, 190) Source(91, 28) + SourceIndex(0)
+12>Emitted(45, 192) Source(91, 9) + SourceIndex(0)
+13>Emitted(45, 234) Source(91, 28) + SourceIndex(0)
+14>Emitted(45, 236) Source(92, 9) + SourceIndex(0)
+15>Emitted(45, 255) Source(92, 32) + SourceIndex(0)
+16>Emitted(45, 257) Source(92, 9) + SourceIndex(0)
+17>Emitted(45, 303) Source(92, 32) + SourceIndex(0)
 ---
 >>>    i = 0; i < 1; i++) {
 1 >^^^^
@@ -2133,14 +2145,14 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(57, 1) Source(108, 1) + SourceIndex(0)
 2 >Emitted(57, 2) Source(108, 2) + SourceIndex(0)
 ---
->>>for (_22 = multiRobot.name, nameA = _22 === void 0 ? "noName" : _22, _23 = multiRobot.skills, _24 = _23 === void 0 ? { primary: "none", secondary: "none" } : _23, _25 = _24.primary, primaryA = _25 === void 0 ? "primary" : _25, _26 = _24.secondary, secondaryA = _26 === void 0 ? "secondary" : _26, multiRobot, i = 0; i < 1; i++) {
+>>>for (_22 = multiRobot.name, nameA = _22 === void 0 ? "noName" : _22, _23 = multiRobot.skills, _24 = _23 === void 0 ? { primary: "none", secondary: "none" } : _23, _25 = _24.primary, primaryA = _25 === void 0 ? "primary" : _25, _26 = _24.secondary, secondaryA = _26 === void 0 ? "secondary" : _26, multiRobot, multiRobot, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
@@ -2163,18 +2175,20 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 20>                                                                                                                                                                                                                                                                                                       ^^
 21>                                                                                                                                                                                                                                                                                                         ^^^^^^^^^^
 22>                                                                                                                                                                                                                                                                                                                   ^^
-23>                                                                                                                                                                                                                                                                                                                     ^
-24>                                                                                                                                                                                                                                                                                                                      ^^^
-25>                                                                                                                                                                                                                                                                                                                         ^
-26>                                                                                                                                                                                                                                                                                                                          ^^
-27>                                                                                                                                                                                                                                                                                                                            ^
-28>                                                                                                                                                                                                                                                                                                                             ^^^
-29>                                                                                                                                                                                                                                                                                                                                ^
-30>                                                                                                                                                                                                                                                                                                                                 ^^
-31>                                                                                                                                                                                                                                                                                                                                   ^
-32>                                                                                                                                                                                                                                                                                                                                    ^^
-33>                                                                                                                                                                                                                                                                                                                                      ^^
-34>                                                                                                                                                                                                                                                                                                                                        ^
+23>                                                                                                                                                                                                                                                                                                                     ^^^^^^^^^^
+24>                                                                                                                                                                                                                                                                                                                               ^^
+25>                                                                                                                                                                                                                                                                                                                                 ^
+26>                                                                                                                                                                                                                                                                                                                                  ^^^
+27>                                                                                                                                                                                                                                                                                                                                     ^
+28>                                                                                                                                                                                                                                                                                                                                      ^^
+29>                                                                                                                                                                                                                                                                                                                                        ^
+30>                                                                                                                                                                                                                                                                                                                                         ^^^
+31>                                                                                                                                                                                                                                                                                                                                            ^
+32>                                                                                                                                                                                                                                                                                                                                             ^^
+33>                                                                                                                                                                                                                                                                                                                                               ^
+34>                                                                                                                                                                                                                                                                                                                                                ^^
+35>                                                                                                                                                                                                                                                                                                                                                  ^^
+36>                                                                                                                                                                                                                                                                                                                                                    ^
 1->
   >
 2 >for
@@ -2208,19 +2222,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >                                                                                                                                                                                                                                                                                                           } = { primary: "none", secondary: "none" }
   >                                                                                                                                                                                                                                                                                                       } = 
 21>                                                                                                                                                                                                                                                                                                         multiRobot
-22>                                                                                                                                                                                                                                                                                                                   , 
-23>                                                                                                                                                                                                                                                                                                                     i
-24>                                                                                                                                                                                                                                                                                                                       = 
-25>                                                                                                                                                                                                                                                                                                                         0
-26>                                                                                                                                                                                                                                                                                                                          ; 
-27>                                                                                                                                                                                                                                                                                                                            i
-28>                                                                                                                                                                                                                                                                                                                              < 
-29>                                                                                                                                                                                                                                                                                                                                1
-30>                                                                                                                                                                                                                                                                                                                                 ; 
-31>                                                                                                                                                                                                                                                                                                                                   i
-32>                                                                                                                                                                                                                                                                                                                                    ++
-33>                                                                                                                                                                                                                                                                                                                                      ) 
-34>                                                                                                                                                                                                                                                                                                                                        {
+22>                                                                                                                                                                                                                                                                                                                   
+23>                                                                                                                                                                                                                                                                                                                     multiRobot
+24>                                                                                                                                                                                                                                                                                                                               , 
+25>                                                                                                                                                                                                                                                                                                                                 i
+26>                                                                                                                                                                                                                                                                                                                                   = 
+27>                                                                                                                                                                                                                                                                                                                                     0
+28>                                                                                                                                                                                                                                                                                                                                      ; 
+29>                                                                                                                                                                                                                                                                                                                                        i
+30>                                                                                                                                                                                                                                                                                                                                          < 
+31>                                                                                                                                                                                                                                                                                                                                            1
+32>                                                                                                                                                                                                                                                                                                                                             ; 
+33>                                                                                                                                                                                                                                                                                                                                               i
+34>                                                                                                                                                                                                                                                                                                                                                ++
+35>                                                                                                                                                                                                                                                                                                                                                  ) 
+36>                                                                                                                                                                                                                                                                                                                                                    {
 1->Emitted(58, 1) Source(109, 1) + SourceIndex(0)
 2 >Emitted(58, 4) Source(109, 4) + SourceIndex(0)
 3 >Emitted(58, 5) Source(109, 5) + SourceIndex(0)
@@ -2242,19 +2258,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 19>Emitted(58, 296) Source(113, 44) + SourceIndex(0)
 20>Emitted(58, 298) Source(115, 5) + SourceIndex(0)
 21>Emitted(58, 308) Source(115, 15) + SourceIndex(0)
-22>Emitted(58, 310) Source(115, 17) + SourceIndex(0)
-23>Emitted(58, 311) Source(115, 18) + SourceIndex(0)
-24>Emitted(58, 314) Source(115, 21) + SourceIndex(0)
-25>Emitted(58, 315) Source(115, 22) + SourceIndex(0)
-26>Emitted(58, 317) Source(115, 24) + SourceIndex(0)
-27>Emitted(58, 318) Source(115, 25) + SourceIndex(0)
-28>Emitted(58, 321) Source(115, 28) + SourceIndex(0)
-29>Emitted(58, 322) Source(115, 29) + SourceIndex(0)
-30>Emitted(58, 324) Source(115, 31) + SourceIndex(0)
-31>Emitted(58, 325) Source(115, 32) + SourceIndex(0)
-32>Emitted(58, 327) Source(115, 34) + SourceIndex(0)
-33>Emitted(58, 329) Source(115, 36) + SourceIndex(0)
-34>Emitted(58, 330) Source(115, 37) + SourceIndex(0)
+22>Emitted(58, 310) Source(115, 5) + SourceIndex(0)
+23>Emitted(58, 320) Source(115, 15) + SourceIndex(0)
+24>Emitted(58, 322) Source(115, 17) + SourceIndex(0)
+25>Emitted(58, 323) Source(115, 18) + SourceIndex(0)
+26>Emitted(58, 326) Source(115, 21) + SourceIndex(0)
+27>Emitted(58, 327) Source(115, 22) + SourceIndex(0)
+28>Emitted(58, 329) Source(115, 24) + SourceIndex(0)
+29>Emitted(58, 330) Source(115, 25) + SourceIndex(0)
+30>Emitted(58, 333) Source(115, 28) + SourceIndex(0)
+31>Emitted(58, 334) Source(115, 29) + SourceIndex(0)
+32>Emitted(58, 336) Source(115, 31) + SourceIndex(0)
+33>Emitted(58, 337) Source(115, 32) + SourceIndex(0)
+34>Emitted(58, 339) Source(115, 34) + SourceIndex(0)
+35>Emitted(58, 341) Source(115, 36) + SourceIndex(0)
+36>Emitted(58, 342) Source(115, 37) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -2286,48 +2304,48 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(60, 1) Source(117, 1) + SourceIndex(0)
 2 >Emitted(60, 2) Source(117, 2) + SourceIndex(0)
 ---
->>>for (_27 = getMultiRobot(), _28 = _27.name, nameA = _28 === void 0 ? "noName" : _28, _29 = _27.skills, _30 = _29 === void 0 ? { primary: "none", secondary: "none" } : _29, _31 = _30.primary, primaryA = _31 === void 0 ? "primary" : _31, _32 = _30.secondary, secondaryA = _32 === void 0 ? "secondary" : _32, _27, i = 0; i < 1; i++) {
+>>>for (_27 = getMultiRobot(), (_28 = _27.name, nameA = _28 === void 0 ? "noName" : _28, _29 = _27.skills, _30 = _29 === void 0 ? { primary: "none", secondary: "none" } : _29, _31 = _30.primary, primaryA = _31 === void 0 ? "primary" : _31, _32 = _30.secondary, secondaryA = _32 === void 0 ? "secondary" : _32, _27), _27, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^^
-6 >                          ^^
-7 >                            ^^^^^^^^^^^^^^
-8 >                                          ^^
-9 >                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                   ^^
-11>                                                                                     ^^^^^^^^^^^^^^^^
-12>                                                                                                     ^^
-13>                                                                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                          ^^
-15>                                                                                                                                                                            ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                             ^^
-17>                                                                                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18>                                                                                                                                                                                                                                          ^^
-19>                                                                                                                                                                                                                                            ^^^^^^^^^^^^^^^^^^^
-20>                                                                                                                                                                                                                                                               ^^
-21>                                                                                                                                                                                                                                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-22>                                                                                                                                                                                                                                                                                                                ^^^^^^^
-23>                                                                                                                                                                                                                                                                                                                       ^
-24>                                                                                                                                                                                                                                                                                                                        ^^^
-25>                                                                                                                                                                                                                                                                                                                           ^
-26>                                                                                                                                                                                                                                                                                                                            ^^
-27>                                                                                                                                                                                                                                                                                                                              ^
-28>                                                                                                                                                                                                                                                                                                                               ^^^
-29>                                                                                                                                                                                                                                                                                                                                  ^
-30>                                                                                                                                                                                                                                                                                                                                   ^^
-31>                                                                                                                                                                                                                                                                                                                                     ^
-32>                                                                                                                                                                                                                                                                                                                                      ^^
-33>                                                                                                                                                                                                                                                                                                                                        ^^
-34>                                                                                                                                                                                                                                                                                                                                          ^
+6 >                          ^^^
+7 >                             ^^^^^^^^^^^^^^
+8 >                                           ^^
+9 >                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                    ^^
+11>                                                                                      ^^^^^^^^^^^^^^^^
+12>                                                                                                      ^^
+13>                                                                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                           ^^
+15>                                                                                                                                                                             ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                              ^^
+17>                                                                                                                                                                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+18>                                                                                                                                                                                                                                           ^^
+19>                                                                                                                                                                                                                                             ^^^^^^^^^^^^^^^^^^^
+20>                                                                                                                                                                                                                                                                ^^
+21>                                                                                                                                                                                                                                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+22>                                                                                                                                                                                                                                                                                                                 ^^^^^^^^^^^^^
+23>                                                                                                                                                                                                                                                                                                                              ^
+24>                                                                                                                                                                                                                                                                                                                               ^^^
+25>                                                                                                                                                                                                                                                                                                                                  ^
+26>                                                                                                                                                                                                                                                                                                                                   ^^
+27>                                                                                                                                                                                                                                                                                                                                     ^
+28>                                                                                                                                                                                                                                                                                                                                      ^^^
+29>                                                                                                                                                                                                                                                                                                                                         ^
+30>                                                                                                                                                                                                                                                                                                                                          ^^
+31>                                                                                                                                                                                                                                                                                                                                            ^
+32>                                                                                                                                                                                                                                                                                                                                             ^^
+33>                                                                                                                                                                                                                                                                                                                                               ^^
+34>                                                                                                                                                                                                                                                                                                                                                 ^
 1->
   >
 2 >for
@@ -2341,78 +2359,78 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = getMultiRobot()
 6 >                          
-7 >                            name: nameA = "noName"
-8 >                                          
-9 >                                            name: nameA = "noName"
-10>                                                                                   ,
-  >                                                                                       
-11>                                                                                     skills: {
-  >                                                                                             primary: primaryA = "primary",
-  >                                                                                             secondary: secondaryA = "secondary"
-  >                                                                                         } = { primary: "none", secondary: "none" }
-12>                                                                                                     
-13>                                                                                                       skills: {
-  >                                                                                                               primary: primaryA = "primary",
-  >                                                                                                               secondary: secondaryA = "secondary"
-  >                                                                                                           } = { primary: "none", secondary: "none" }
-14>                                                                                                                                                                          
-15>                                                                                                                                                                            primary: primaryA = "primary"
-16>                                                                                                                                                                                             
-17>                                                                                                                                                                                               primary: primaryA = "primary"
-18>                                                                                                                                                                                                                                          ,
-  >                                                                                                                                                                                                                                                  
-19>                                                                                                                                                                                                                                            secondary: secondaryA = "secondary"
-20>                                                                                                                                                                                                                                                               
-21>                                                                                                                                                                                                                                                                 secondary: secondaryA = "secondary"
-22>                                                                                                                                                                                                                                                                                                                
-  >                                                                                                                                                                                                                                                                                                                    } = { primary: "none", secondary: "none" }
-  >                                                                                                                                                                                                                                                                                                                } = getMultiRobot(), 
-23>                                                                                                                                                                                                                                                                                                                       i
-24>                                                                                                                                                                                                                                                                                                                         = 
-25>                                                                                                                                                                                                                                                                                                                           0
-26>                                                                                                                                                                                                                                                                                                                            ; 
-27>                                                                                                                                                                                                                                                                                                                              i
-28>                                                                                                                                                                                                                                                                                                                                < 
-29>                                                                                                                                                                                                                                                                                                                                  1
-30>                                                                                                                                                                                                                                                                                                                                   ; 
-31>                                                                                                                                                                                                                                                                                                                                     i
-32>                                                                                                                                                                                                                                                                                                                                      ++
-33>                                                                                                                                                                                                                                                                                                                                        ) 
-34>                                                                                                                                                                                                                                                                                                                                          {
+7 >                             name: nameA = "noName"
+8 >                                           
+9 >                                             name: nameA = "noName"
+10>                                                                                    ,
+  >                                                                                        
+11>                                                                                      skills: {
+  >                                                                                              primary: primaryA = "primary",
+  >                                                                                              secondary: secondaryA = "secondary"
+  >                                                                                          } = { primary: "none", secondary: "none" }
+12>                                                                                                      
+13>                                                                                                        skills: {
+  >                                                                                                                primary: primaryA = "primary",
+  >                                                                                                                secondary: secondaryA = "secondary"
+  >                                                                                                            } = { primary: "none", secondary: "none" }
+14>                                                                                                                                                                           
+15>                                                                                                                                                                             primary: primaryA = "primary"
+16>                                                                                                                                                                                              
+17>                                                                                                                                                                                                primary: primaryA = "primary"
+18>                                                                                                                                                                                                                                           ,
+  >                                                                                                                                                                                                                                                   
+19>                                                                                                                                                                                                                                             secondary: secondaryA = "secondary"
+20>                                                                                                                                                                                                                                                                
+21>                                                                                                                                                                                                                                                                  secondary: secondaryA = "secondary"
+22>                                                                                                                                                                                                                                                                                                                 
+  >                                                                                                                                                                                                                                                                                                                     } = { primary: "none", secondary: "none" }
+  >                                                                                                                                                                                                                                                                                                                 } = getMultiRobot(), 
+23>                                                                                                                                                                                                                                                                                                                              i
+24>                                                                                                                                                                                                                                                                                                                                = 
+25>                                                                                                                                                                                                                                                                                                                                  0
+26>                                                                                                                                                                                                                                                                                                                                   ; 
+27>                                                                                                                                                                                                                                                                                                                                     i
+28>                                                                                                                                                                                                                                                                                                                                       < 
+29>                                                                                                                                                                                                                                                                                                                                         1
+30>                                                                                                                                                                                                                                                                                                                                          ; 
+31>                                                                                                                                                                                                                                                                                                                                            i
+32>                                                                                                                                                                                                                                                                                                                                             ++
+33>                                                                                                                                                                                                                                                                                                                                               ) 
+34>                                                                                                                                                                                                                                                                                                                                                 {
 1->Emitted(61, 1) Source(118, 1) + SourceIndex(0)
 2 >Emitted(61, 4) Source(118, 4) + SourceIndex(0)
 3 >Emitted(61, 5) Source(118, 5) + SourceIndex(0)
 4 >Emitted(61, 6) Source(118, 6) + SourceIndex(0)
 5 >Emitted(61, 27) Source(124, 20) + SourceIndex(0)
-6 >Emitted(61, 29) Source(119, 5) + SourceIndex(0)
-7 >Emitted(61, 43) Source(119, 27) + SourceIndex(0)
-8 >Emitted(61, 45) Source(119, 5) + SourceIndex(0)
-9 >Emitted(61, 84) Source(119, 27) + SourceIndex(0)
-10>Emitted(61, 86) Source(120, 5) + SourceIndex(0)
-11>Emitted(61, 102) Source(123, 47) + SourceIndex(0)
-12>Emitted(61, 104) Source(120, 5) + SourceIndex(0)
-13>Emitted(61, 171) Source(123, 47) + SourceIndex(0)
-14>Emitted(61, 173) Source(121, 9) + SourceIndex(0)
-15>Emitted(61, 190) Source(121, 38) + SourceIndex(0)
-16>Emitted(61, 192) Source(121, 9) + SourceIndex(0)
-17>Emitted(61, 235) Source(121, 38) + SourceIndex(0)
-18>Emitted(61, 237) Source(122, 9) + SourceIndex(0)
-19>Emitted(61, 256) Source(122, 44) + SourceIndex(0)
-20>Emitted(61, 258) Source(122, 9) + SourceIndex(0)
-21>Emitted(61, 305) Source(122, 44) + SourceIndex(0)
-22>Emitted(61, 312) Source(124, 22) + SourceIndex(0)
-23>Emitted(61, 313) Source(124, 23) + SourceIndex(0)
-24>Emitted(61, 316) Source(124, 26) + SourceIndex(0)
-25>Emitted(61, 317) Source(124, 27) + SourceIndex(0)
-26>Emitted(61, 319) Source(124, 29) + SourceIndex(0)
-27>Emitted(61, 320) Source(124, 30) + SourceIndex(0)
-28>Emitted(61, 323) Source(124, 33) + SourceIndex(0)
-29>Emitted(61, 324) Source(124, 34) + SourceIndex(0)
-30>Emitted(61, 326) Source(124, 36) + SourceIndex(0)
-31>Emitted(61, 327) Source(124, 37) + SourceIndex(0)
-32>Emitted(61, 329) Source(124, 39) + SourceIndex(0)
-33>Emitted(61, 331) Source(124, 41) + SourceIndex(0)
-34>Emitted(61, 332) Source(124, 42) + SourceIndex(0)
+6 >Emitted(61, 30) Source(119, 5) + SourceIndex(0)
+7 >Emitted(61, 44) Source(119, 27) + SourceIndex(0)
+8 >Emitted(61, 46) Source(119, 5) + SourceIndex(0)
+9 >Emitted(61, 85) Source(119, 27) + SourceIndex(0)
+10>Emitted(61, 87) Source(120, 5) + SourceIndex(0)
+11>Emitted(61, 103) Source(123, 47) + SourceIndex(0)
+12>Emitted(61, 105) Source(120, 5) + SourceIndex(0)
+13>Emitted(61, 172) Source(123, 47) + SourceIndex(0)
+14>Emitted(61, 174) Source(121, 9) + SourceIndex(0)
+15>Emitted(61, 191) Source(121, 38) + SourceIndex(0)
+16>Emitted(61, 193) Source(121, 9) + SourceIndex(0)
+17>Emitted(61, 236) Source(121, 38) + SourceIndex(0)
+18>Emitted(61, 238) Source(122, 9) + SourceIndex(0)
+19>Emitted(61, 257) Source(122, 44) + SourceIndex(0)
+20>Emitted(61, 259) Source(122, 9) + SourceIndex(0)
+21>Emitted(61, 306) Source(122, 44) + SourceIndex(0)
+22>Emitted(61, 319) Source(124, 22) + SourceIndex(0)
+23>Emitted(61, 320) Source(124, 23) + SourceIndex(0)
+24>Emitted(61, 323) Source(124, 26) + SourceIndex(0)
+25>Emitted(61, 324) Source(124, 27) + SourceIndex(0)
+26>Emitted(61, 326) Source(124, 29) + SourceIndex(0)
+27>Emitted(61, 327) Source(124, 30) + SourceIndex(0)
+28>Emitted(61, 330) Source(124, 33) + SourceIndex(0)
+29>Emitted(61, 331) Source(124, 34) + SourceIndex(0)
+30>Emitted(61, 333) Source(124, 36) + SourceIndex(0)
+31>Emitted(61, 334) Source(124, 37) + SourceIndex(0)
+32>Emitted(61, 336) Source(124, 39) + SourceIndex(0)
+33>Emitted(61, 338) Source(124, 41) + SourceIndex(0)
+34>Emitted(61, 339) Source(124, 42) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -2444,35 +2462,35 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(63, 1) Source(126, 1) + SourceIndex(0)
 2 >Emitted(63, 2) Source(126, 2) + SourceIndex(0)
 ---
->>>for (_33 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _34 = _33.name, nameA = _34 === void 0 ? "noName" : _34, _35 = _33.skills, _36 = _35 === void 0 ? { primary: "none", secondary: "none" } : _35, _37 = _36.primary, primaryA = _37 === void 0 ? "primary" : _37, _38 = _36.secondary, secondaryA = _38 === void 0 ? "secondary" : _38, _33,
+>>>for (_33 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_34 = _33.name, nameA = _34 === void 0 ? "noName" : _34, _35 = _33.skills, _36 = _35 === void 0 ? { primary: "none", secondary: "none" } : _35, _37 = _36.primary, primaryA = _37 === void 0 ? "primary" : _37, _38 = _36.secondary, secondaryA = _38 === void 0 ? "secondary" : _38, _33), _33,
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-6 >                                                                                    ^^
-7 >                                                                                      ^^^^^^^^^^^^^^
-8 >                                                                                                    ^^
-9 >                                                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                                                                             ^^
-11>                                                                                                                                               ^^^^^^^^^^^^^^^^
-12>                                                                                                                                                               ^^
-13>                                                                                                                                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                                                                                    ^^
-15>                                                                                                                                                                                                                                      ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                                                                                       ^^
-17>                                                                                                                                                                                                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18>                                                                                                                                                                                                                                                                                                    ^^
-19>                                                                                                                                                                                                                                                                                                      ^^^^^^^^^^^^^^^^^^^
-20>                                                                                                                                                                                                                                                                                                                         ^^
-21>                                                                                                                                                                                                                                                                                                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+6 >                                                                                    ^^^
+7 >                                                                                       ^^^^^^^^^^^^^^
+8 >                                                                                                     ^^
+9 >                                                                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                                                                              ^^
+11>                                                                                                                                                ^^^^^^^^^^^^^^^^
+12>                                                                                                                                                                ^^
+13>                                                                                                                                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                                                                                     ^^
+15>                                                                                                                                                                                                                                       ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                                                                                        ^^
+17>                                                                                                                                                                                                                                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+18>                                                                                                                                                                                                                                                                                                     ^^
+19>                                                                                                                                                                                                                                                                                                       ^^^^^^^^^^^^^^^^^^^
+20>                                                                                                                                                                                                                                                                                                                          ^^
+21>                                                                                                                                                                                                                                                                                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->
   >
 2 >for
@@ -2486,50 +2504,50 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = <MultiRobot>{ name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }
 6 >                                                                                    
-7 >                                                                                      name: nameA = "noName"
-8 >                                                                                                    
-9 >                                                                                                      name: nameA = "noName"
-10>                                                                                                                                             ,
-  >                                                                                                                                                 
-11>                                                                                                                                               skills: {
-  >                                                                                                                                                       primary: primaryA = "primary",
-  >                                                                                                                                                       secondary: secondaryA = "secondary"
-  >                                                                                                                                                   } = { primary: "none", secondary: "none" }
-12>                                                                                                                                                               
-13>                                                                                                                                                                 skills: {
-  >                                                                                                                                                                         primary: primaryA = "primary",
-  >                                                                                                                                                                         secondary: secondaryA = "secondary"
-  >                                                                                                                                                                     } = { primary: "none", secondary: "none" }
-14>                                                                                                                                                                                                                                    
-15>                                                                                                                                                                                                                                      primary: primaryA = "primary"
-16>                                                                                                                                                                                                                                                       
-17>                                                                                                                                                                                                                                                         primary: primaryA = "primary"
-18>                                                                                                                                                                                                                                                                                                    ,
-  >                                                                                                                                                                                                                                                                                                            
-19>                                                                                                                                                                                                                                                                                                      secondary: secondaryA = "secondary"
-20>                                                                                                                                                                                                                                                                                                                         
-21>                                                                                                                                                                                                                                                                                                                           secondary: secondaryA = "secondary"
+7 >                                                                                       name: nameA = "noName"
+8 >                                                                                                     
+9 >                                                                                                       name: nameA = "noName"
+10>                                                                                                                                              ,
+  >                                                                                                                                                  
+11>                                                                                                                                                skills: {
+  >                                                                                                                                                        primary: primaryA = "primary",
+  >                                                                                                                                                        secondary: secondaryA = "secondary"
+  >                                                                                                                                                    } = { primary: "none", secondary: "none" }
+12>                                                                                                                                                                
+13>                                                                                                                                                                  skills: {
+  >                                                                                                                                                                          primary: primaryA = "primary",
+  >                                                                                                                                                                          secondary: secondaryA = "secondary"
+  >                                                                                                                                                                      } = { primary: "none", secondary: "none" }
+14>                                                                                                                                                                                                                                     
+15>                                                                                                                                                                                                                                       primary: primaryA = "primary"
+16>                                                                                                                                                                                                                                                        
+17>                                                                                                                                                                                                                                                          primary: primaryA = "primary"
+18>                                                                                                                                                                                                                                                                                                     ,
+  >                                                                                                                                                                                                                                                                                                             
+19>                                                                                                                                                                                                                                                                                                       secondary: secondaryA = "secondary"
+20>                                                                                                                                                                                                                                                                                                                          
+21>                                                                                                                                                                                                                                                                                                                            secondary: secondaryA = "secondary"
 1->Emitted(64, 1) Source(127, 1) + SourceIndex(0)
 2 >Emitted(64, 4) Source(127, 4) + SourceIndex(0)
 3 >Emitted(64, 5) Source(127, 5) + SourceIndex(0)
 4 >Emitted(64, 6) Source(127, 6) + SourceIndex(0)
 5 >Emitted(64, 85) Source(133, 90) + SourceIndex(0)
-6 >Emitted(64, 87) Source(128, 5) + SourceIndex(0)
-7 >Emitted(64, 101) Source(128, 27) + SourceIndex(0)
-8 >Emitted(64, 103) Source(128, 5) + SourceIndex(0)
-9 >Emitted(64, 142) Source(128, 27) + SourceIndex(0)
-10>Emitted(64, 144) Source(129, 5) + SourceIndex(0)
-11>Emitted(64, 160) Source(132, 47) + SourceIndex(0)
-12>Emitted(64, 162) Source(129, 5) + SourceIndex(0)
-13>Emitted(64, 229) Source(132, 47) + SourceIndex(0)
-14>Emitted(64, 231) Source(130, 9) + SourceIndex(0)
-15>Emitted(64, 248) Source(130, 38) + SourceIndex(0)
-16>Emitted(64, 250) Source(130, 9) + SourceIndex(0)
-17>Emitted(64, 293) Source(130, 38) + SourceIndex(0)
-18>Emitted(64, 295) Source(131, 9) + SourceIndex(0)
-19>Emitted(64, 314) Source(131, 44) + SourceIndex(0)
-20>Emitted(64, 316) Source(131, 9) + SourceIndex(0)
-21>Emitted(64, 363) Source(131, 44) + SourceIndex(0)
+6 >Emitted(64, 88) Source(128, 5) + SourceIndex(0)
+7 >Emitted(64, 102) Source(128, 27) + SourceIndex(0)
+8 >Emitted(64, 104) Source(128, 5) + SourceIndex(0)
+9 >Emitted(64, 143) Source(128, 27) + SourceIndex(0)
+10>Emitted(64, 145) Source(129, 5) + SourceIndex(0)
+11>Emitted(64, 161) Source(132, 47) + SourceIndex(0)
+12>Emitted(64, 163) Source(129, 5) + SourceIndex(0)
+13>Emitted(64, 230) Source(132, 47) + SourceIndex(0)
+14>Emitted(64, 232) Source(130, 9) + SourceIndex(0)
+15>Emitted(64, 249) Source(130, 38) + SourceIndex(0)
+16>Emitted(64, 251) Source(130, 9) + SourceIndex(0)
+17>Emitted(64, 294) Source(130, 38) + SourceIndex(0)
+18>Emitted(64, 296) Source(131, 9) + SourceIndex(0)
+19>Emitted(64, 315) Source(131, 44) + SourceIndex(0)
+20>Emitted(64, 317) Source(131, 9) + SourceIndex(0)
+21>Emitted(64, 364) Source(131, 44) + SourceIndex(0)
 ---
 >>>    i = 0; i < 1; i++) {
 1 >^^^^
@@ -2961,14 +2979,14 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(76, 1) Source(146, 1) + SourceIndex(0)
 2 >Emitted(76, 2) Source(146, 2) + SourceIndex(0)
 ---
->>>for (_47 = multiRobot.name, name = _47 === void 0 ? "noName" : _47, _48 = multiRobot.skills, _49 = _48 === void 0 ? { primary: "none", secondary: "none" } : _48, _50 = _49.primary, primary = _50 === void 0 ? "primary" : _50, _51 = _49.secondary, secondary = _51 === void 0 ? "secondary" : _51, multiRobot, i = 0; i < 1; i++) {
+>>>for (_47 = multiRobot.name, name = _47 === void 0 ? "noName" : _47, _48 = multiRobot.skills, _49 = _48 === void 0 ? { primary: "none", secondary: "none" } : _48, _50 = _49.primary, primary = _50 === void 0 ? "primary" : _50, _51 = _49.secondary, secondary = _51 === void 0 ? "secondary" : _51, multiRobot, multiRobot, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
@@ -2991,18 +3009,20 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 20>                                                                                                                                                                                                                                                                                                    ^^
 21>                                                                                                                                                                                                                                                                                                      ^^^^^^^^^^
 22>                                                                                                                                                                                                                                                                                                                ^^
-23>                                                                                                                                                                                                                                                                                                                  ^
-24>                                                                                                                                                                                                                                                                                                                   ^^^
-25>                                                                                                                                                                                                                                                                                                                      ^
-26>                                                                                                                                                                                                                                                                                                                       ^^
-27>                                                                                                                                                                                                                                                                                                                         ^
-28>                                                                                                                                                                                                                                                                                                                          ^^^
-29>                                                                                                                                                                                                                                                                                                                             ^
-30>                                                                                                                                                                                                                                                                                                                              ^^
-31>                                                                                                                                                                                                                                                                                                                                ^
-32>                                                                                                                                                                                                                                                                                                                                 ^^
-33>                                                                                                                                                                                                                                                                                                                                   ^^
-34>                                                                                                                                                                                                                                                                                                                                     ^
+23>                                                                                                                                                                                                                                                                                                                  ^^^^^^^^^^
+24>                                                                                                                                                                                                                                                                                                                            ^^
+25>                                                                                                                                                                                                                                                                                                                              ^
+26>                                                                                                                                                                                                                                                                                                                               ^^^
+27>                                                                                                                                                                                                                                                                                                                                  ^
+28>                                                                                                                                                                                                                                                                                                                                   ^^
+29>                                                                                                                                                                                                                                                                                                                                     ^
+30>                                                                                                                                                                                                                                                                                                                                      ^^^
+31>                                                                                                                                                                                                                                                                                                                                         ^
+32>                                                                                                                                                                                                                                                                                                                                          ^^
+33>                                                                                                                                                                                                                                                                                                                                            ^
+34>                                                                                                                                                                                                                                                                                                                                             ^^
+35>                                                                                                                                                                                                                                                                                                                                               ^^
+36>                                                                                                                                                                                                                                                                                                                                                 ^
 1->
   >
 2 >for
@@ -3036,19 +3056,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >                                                                                                                                                                                                                                                                                                        } = { primary: "none", secondary: "none" }
   >                                                                                                                                                                                                                                                                                                    } = 
 21>                                                                                                                                                                                                                                                                                                      multiRobot
-22>                                                                                                                                                                                                                                                                                                                , 
-23>                                                                                                                                                                                                                                                                                                                  i
-24>                                                                                                                                                                                                                                                                                                                    = 
-25>                                                                                                                                                                                                                                                                                                                      0
-26>                                                                                                                                                                                                                                                                                                                       ; 
-27>                                                                                                                                                                                                                                                                                                                         i
-28>                                                                                                                                                                                                                                                                                                                           < 
-29>                                                                                                                                                                                                                                                                                                                             1
-30>                                                                                                                                                                                                                                                                                                                              ; 
-31>                                                                                                                                                                                                                                                                                                                                i
-32>                                                                                                                                                                                                                                                                                                                                 ++
-33>                                                                                                                                                                                                                                                                                                                                   ) 
-34>                                                                                                                                                                                                                                                                                                                                     {
+22>                                                                                                                                                                                                                                                                                                                
+23>                                                                                                                                                                                                                                                                                                                  multiRobot
+24>                                                                                                                                                                                                                                                                                                                            , 
+25>                                                                                                                                                                                                                                                                                                                              i
+26>                                                                                                                                                                                                                                                                                                                                = 
+27>                                                                                                                                                                                                                                                                                                                                  0
+28>                                                                                                                                                                                                                                                                                                                                   ; 
+29>                                                                                                                                                                                                                                                                                                                                     i
+30>                                                                                                                                                                                                                                                                                                                                       < 
+31>                                                                                                                                                                                                                                                                                                                                         1
+32>                                                                                                                                                                                                                                                                                                                                          ; 
+33>                                                                                                                                                                                                                                                                                                                                            i
+34>                                                                                                                                                                                                                                                                                                                                             ++
+35>                                                                                                                                                                                                                                                                                                                                               ) 
+36>                                                                                                                                                                                                                                                                                                                                                 {
 1->Emitted(77, 1) Source(147, 1) + SourceIndex(0)
 2 >Emitted(77, 4) Source(147, 4) + SourceIndex(0)
 3 >Emitted(77, 5) Source(147, 5) + SourceIndex(0)
@@ -3070,19 +3092,21 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 19>Emitted(77, 293) Source(151, 32) + SourceIndex(0)
 20>Emitted(77, 295) Source(153, 5) + SourceIndex(0)
 21>Emitted(77, 305) Source(153, 15) + SourceIndex(0)
-22>Emitted(77, 307) Source(153, 17) + SourceIndex(0)
-23>Emitted(77, 308) Source(153, 18) + SourceIndex(0)
-24>Emitted(77, 311) Source(153, 21) + SourceIndex(0)
-25>Emitted(77, 312) Source(153, 22) + SourceIndex(0)
-26>Emitted(77, 314) Source(153, 24) + SourceIndex(0)
-27>Emitted(77, 315) Source(153, 25) + SourceIndex(0)
-28>Emitted(77, 318) Source(153, 28) + SourceIndex(0)
-29>Emitted(77, 319) Source(153, 29) + SourceIndex(0)
-30>Emitted(77, 321) Source(153, 31) + SourceIndex(0)
-31>Emitted(77, 322) Source(153, 32) + SourceIndex(0)
-32>Emitted(77, 324) Source(153, 34) + SourceIndex(0)
-33>Emitted(77, 326) Source(153, 36) + SourceIndex(0)
-34>Emitted(77, 327) Source(153, 37) + SourceIndex(0)
+22>Emitted(77, 307) Source(153, 5) + SourceIndex(0)
+23>Emitted(77, 317) Source(153, 15) + SourceIndex(0)
+24>Emitted(77, 319) Source(153, 17) + SourceIndex(0)
+25>Emitted(77, 320) Source(153, 18) + SourceIndex(0)
+26>Emitted(77, 323) Source(153, 21) + SourceIndex(0)
+27>Emitted(77, 324) Source(153, 22) + SourceIndex(0)
+28>Emitted(77, 326) Source(153, 24) + SourceIndex(0)
+29>Emitted(77, 327) Source(153, 25) + SourceIndex(0)
+30>Emitted(77, 330) Source(153, 28) + SourceIndex(0)
+31>Emitted(77, 331) Source(153, 29) + SourceIndex(0)
+32>Emitted(77, 333) Source(153, 31) + SourceIndex(0)
+33>Emitted(77, 334) Source(153, 32) + SourceIndex(0)
+34>Emitted(77, 336) Source(153, 34) + SourceIndex(0)
+35>Emitted(77, 338) Source(153, 36) + SourceIndex(0)
+36>Emitted(77, 339) Source(153, 37) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -3114,48 +3138,48 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(79, 1) Source(155, 1) + SourceIndex(0)
 2 >Emitted(79, 2) Source(155, 2) + SourceIndex(0)
 ---
->>>for (_52 = getMultiRobot(), _53 = _52.name, name = _53 === void 0 ? "noName" : _53, _54 = _52.skills, _55 = _54 === void 0 ? { primary: "none", secondary: "none" } : _54, _56 = _55.primary, primary = _56 === void 0 ? "primary" : _56, _57 = _55.secondary, secondary = _57 === void 0 ? "secondary" : _57, _52, i = 0; i < 1; i++) {
+>>>for (_52 = getMultiRobot(), (_53 = _52.name, name = _53 === void 0 ? "noName" : _53, _54 = _52.skills, _55 = _54 === void 0 ? { primary: "none", secondary: "none" } : _54, _56 = _55.primary, primary = _56 === void 0 ? "primary" : _56, _57 = _55.secondary, secondary = _57 === void 0 ? "secondary" : _57, _52), _52, i = 0; i < 1; i++) {
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^^
-6 >                          ^^
-7 >                            ^^^^^^^^^^^^^^
-8 >                                          ^^
-9 >                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                  ^^
-11>                                                                                    ^^^^^^^^^^^^^^^^
-12>                                                                                                    ^^
-13>                                                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                         ^^
-15>                                                                                                                                                                           ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                            ^^
-17>                                                                                                                                                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18>                                                                                                                                                                                                                                        ^^
-19>                                                                                                                                                                                                                                          ^^^^^^^^^^^^^^^^^^^
-20>                                                                                                                                                                                                                                                             ^^
-21>                                                                                                                                                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-22>                                                                                                                                                                                                                                                                                                             ^^^^^^^
-23>                                                                                                                                                                                                                                                                                                                    ^
-24>                                                                                                                                                                                                                                                                                                                     ^^^
-25>                                                                                                                                                                                                                                                                                                                        ^
-26>                                                                                                                                                                                                                                                                                                                         ^^
-27>                                                                                                                                                                                                                                                                                                                           ^
-28>                                                                                                                                                                                                                                                                                                                            ^^^
-29>                                                                                                                                                                                                                                                                                                                               ^
-30>                                                                                                                                                                                                                                                                                                                                ^^
-31>                                                                                                                                                                                                                                                                                                                                  ^
-32>                                                                                                                                                                                                                                                                                                                                   ^^
-33>                                                                                                                                                                                                                                                                                                                                     ^^
-34>                                                                                                                                                                                                                                                                                                                                       ^
+6 >                          ^^^
+7 >                             ^^^^^^^^^^^^^^
+8 >                                           ^^
+9 >                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                   ^^
+11>                                                                                     ^^^^^^^^^^^^^^^^
+12>                                                                                                     ^^
+13>                                                                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                          ^^
+15>                                                                                                                                                                            ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                             ^^
+17>                                                                                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+18>                                                                                                                                                                                                                                         ^^
+19>                                                                                                                                                                                                                                           ^^^^^^^^^^^^^^^^^^^
+20>                                                                                                                                                                                                                                                              ^^
+21>                                                                                                                                                                                                                                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+22>                                                                                                                                                                                                                                                                                                              ^^^^^^^^^^^^^
+23>                                                                                                                                                                                                                                                                                                                           ^
+24>                                                                                                                                                                                                                                                                                                                            ^^^
+25>                                                                                                                                                                                                                                                                                                                               ^
+26>                                                                                                                                                                                                                                                                                                                                ^^
+27>                                                                                                                                                                                                                                                                                                                                  ^
+28>                                                                                                                                                                                                                                                                                                                                   ^^^
+29>                                                                                                                                                                                                                                                                                                                                      ^
+30>                                                                                                                                                                                                                                                                                                                                       ^^
+31>                                                                                                                                                                                                                                                                                                                                         ^
+32>                                                                                                                                                                                                                                                                                                                                          ^^
+33>                                                                                                                                                                                                                                                                                                                                            ^^
+34>                                                                                                                                                                                                                                                                                                                                              ^
 1->
   >
 2 >for
@@ -3169,78 +3193,78 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = getMultiRobot()
 6 >                          
-7 >                            name = "noName"
-8 >                                          
-9 >                                            name = "noName"
-10>                                                                                  ,
-  >                                                                                      
-11>                                                                                    skills: {
-  >                                                                                            primary = "primary",
-  >                                                                                            secondary = "secondary"
-  >                                                                                        } = { primary: "none", secondary: "none" }
-12>                                                                                                    
-13>                                                                                                      skills: {
-  >                                                                                                              primary = "primary",
-  >                                                                                                              secondary = "secondary"
-  >                                                                                                          } = { primary: "none", secondary: "none" }
-14>                                                                                                                                                                         
-15>                                                                                                                                                                           primary = "primary"
-16>                                                                                                                                                                                            
-17>                                                                                                                                                                                              primary = "primary"
-18>                                                                                                                                                                                                                                        ,
-  >                                                                                                                                                                                                                                                
-19>                                                                                                                                                                                                                                          secondary = "secondary"
-20>                                                                                                                                                                                                                                                             
-21>                                                                                                                                                                                                                                                               secondary = "secondary"
-22>                                                                                                                                                                                                                                                                                                             
-  >                                                                                                                                                                                                                                                                                                                 } = { primary: "none", secondary: "none" }
-  >                                                                                                                                                                                                                                                                                                             } = getMultiRobot(), 
-23>                                                                                                                                                                                                                                                                                                                    i
-24>                                                                                                                                                                                                                                                                                                                      = 
-25>                                                                                                                                                                                                                                                                                                                        0
-26>                                                                                                                                                                                                                                                                                                                         ; 
-27>                                                                                                                                                                                                                                                                                                                           i
-28>                                                                                                                                                                                                                                                                                                                             < 
-29>                                                                                                                                                                                                                                                                                                                               1
-30>                                                                                                                                                                                                                                                                                                                                ; 
-31>                                                                                                                                                                                                                                                                                                                                  i
-32>                                                                                                                                                                                                                                                                                                                                   ++
-33>                                                                                                                                                                                                                                                                                                                                     ) 
-34>                                                                                                                                                                                                                                                                                                                                       {
+7 >                             name = "noName"
+8 >                                           
+9 >                                             name = "noName"
+10>                                                                                   ,
+  >                                                                                       
+11>                                                                                     skills: {
+  >                                                                                             primary = "primary",
+  >                                                                                             secondary = "secondary"
+  >                                                                                         } = { primary: "none", secondary: "none" }
+12>                                                                                                     
+13>                                                                                                       skills: {
+  >                                                                                                               primary = "primary",
+  >                                                                                                               secondary = "secondary"
+  >                                                                                                           } = { primary: "none", secondary: "none" }
+14>                                                                                                                                                                          
+15>                                                                                                                                                                            primary = "primary"
+16>                                                                                                                                                                                             
+17>                                                                                                                                                                                               primary = "primary"
+18>                                                                                                                                                                                                                                         ,
+  >                                                                                                                                                                                                                                                 
+19>                                                                                                                                                                                                                                           secondary = "secondary"
+20>                                                                                                                                                                                                                                                              
+21>                                                                                                                                                                                                                                                                secondary = "secondary"
+22>                                                                                                                                                                                                                                                                                                              
+  >                                                                                                                                                                                                                                                                                                                  } = { primary: "none", secondary: "none" }
+  >                                                                                                                                                                                                                                                                                                              } = getMultiRobot(), 
+23>                                                                                                                                                                                                                                                                                                                           i
+24>                                                                                                                                                                                                                                                                                                                             = 
+25>                                                                                                                                                                                                                                                                                                                               0
+26>                                                                                                                                                                                                                                                                                                                                ; 
+27>                                                                                                                                                                                                                                                                                                                                  i
+28>                                                                                                                                                                                                                                                                                                                                    < 
+29>                                                                                                                                                                                                                                                                                                                                      1
+30>                                                                                                                                                                                                                                                                                                                                       ; 
+31>                                                                                                                                                                                                                                                                                                                                         i
+32>                                                                                                                                                                                                                                                                                                                                          ++
+33>                                                                                                                                                                                                                                                                                                                                            ) 
+34>                                                                                                                                                                                                                                                                                                                                              {
 1->Emitted(80, 1) Source(156, 1) + SourceIndex(0)
 2 >Emitted(80, 4) Source(156, 4) + SourceIndex(0)
 3 >Emitted(80, 5) Source(156, 5) + SourceIndex(0)
 4 >Emitted(80, 6) Source(156, 6) + SourceIndex(0)
 5 >Emitted(80, 27) Source(162, 20) + SourceIndex(0)
-6 >Emitted(80, 29) Source(157, 5) + SourceIndex(0)
-7 >Emitted(80, 43) Source(157, 20) + SourceIndex(0)
-8 >Emitted(80, 45) Source(157, 5) + SourceIndex(0)
-9 >Emitted(80, 83) Source(157, 20) + SourceIndex(0)
-10>Emitted(80, 85) Source(158, 5) + SourceIndex(0)
-11>Emitted(80, 101) Source(161, 47) + SourceIndex(0)
-12>Emitted(80, 103) Source(158, 5) + SourceIndex(0)
-13>Emitted(80, 170) Source(161, 47) + SourceIndex(0)
-14>Emitted(80, 172) Source(159, 9) + SourceIndex(0)
-15>Emitted(80, 189) Source(159, 28) + SourceIndex(0)
-16>Emitted(80, 191) Source(159, 9) + SourceIndex(0)
-17>Emitted(80, 233) Source(159, 28) + SourceIndex(0)
-18>Emitted(80, 235) Source(160, 9) + SourceIndex(0)
-19>Emitted(80, 254) Source(160, 32) + SourceIndex(0)
-20>Emitted(80, 256) Source(160, 9) + SourceIndex(0)
-21>Emitted(80, 302) Source(160, 32) + SourceIndex(0)
-22>Emitted(80, 309) Source(162, 22) + SourceIndex(0)
-23>Emitted(80, 310) Source(162, 23) + SourceIndex(0)
-24>Emitted(80, 313) Source(162, 26) + SourceIndex(0)
-25>Emitted(80, 314) Source(162, 27) + SourceIndex(0)
-26>Emitted(80, 316) Source(162, 29) + SourceIndex(0)
-27>Emitted(80, 317) Source(162, 30) + SourceIndex(0)
-28>Emitted(80, 320) Source(162, 33) + SourceIndex(0)
-29>Emitted(80, 321) Source(162, 34) + SourceIndex(0)
-30>Emitted(80, 323) Source(162, 36) + SourceIndex(0)
-31>Emitted(80, 324) Source(162, 37) + SourceIndex(0)
-32>Emitted(80, 326) Source(162, 39) + SourceIndex(0)
-33>Emitted(80, 328) Source(162, 41) + SourceIndex(0)
-34>Emitted(80, 329) Source(162, 42) + SourceIndex(0)
+6 >Emitted(80, 30) Source(157, 5) + SourceIndex(0)
+7 >Emitted(80, 44) Source(157, 20) + SourceIndex(0)
+8 >Emitted(80, 46) Source(157, 5) + SourceIndex(0)
+9 >Emitted(80, 84) Source(157, 20) + SourceIndex(0)
+10>Emitted(80, 86) Source(158, 5) + SourceIndex(0)
+11>Emitted(80, 102) Source(161, 47) + SourceIndex(0)
+12>Emitted(80, 104) Source(158, 5) + SourceIndex(0)
+13>Emitted(80, 171) Source(161, 47) + SourceIndex(0)
+14>Emitted(80, 173) Source(159, 9) + SourceIndex(0)
+15>Emitted(80, 190) Source(159, 28) + SourceIndex(0)
+16>Emitted(80, 192) Source(159, 9) + SourceIndex(0)
+17>Emitted(80, 234) Source(159, 28) + SourceIndex(0)
+18>Emitted(80, 236) Source(160, 9) + SourceIndex(0)
+19>Emitted(80, 255) Source(160, 32) + SourceIndex(0)
+20>Emitted(80, 257) Source(160, 9) + SourceIndex(0)
+21>Emitted(80, 303) Source(160, 32) + SourceIndex(0)
+22>Emitted(80, 316) Source(162, 22) + SourceIndex(0)
+23>Emitted(80, 317) Source(162, 23) + SourceIndex(0)
+24>Emitted(80, 320) Source(162, 26) + SourceIndex(0)
+25>Emitted(80, 321) Source(162, 27) + SourceIndex(0)
+26>Emitted(80, 323) Source(162, 29) + SourceIndex(0)
+27>Emitted(80, 324) Source(162, 30) + SourceIndex(0)
+28>Emitted(80, 327) Source(162, 33) + SourceIndex(0)
+29>Emitted(80, 328) Source(162, 34) + SourceIndex(0)
+30>Emitted(80, 330) Source(162, 36) + SourceIndex(0)
+31>Emitted(80, 331) Source(162, 37) + SourceIndex(0)
+32>Emitted(80, 333) Source(162, 39) + SourceIndex(0)
+33>Emitted(80, 335) Source(162, 41) + SourceIndex(0)
+34>Emitted(80, 336) Source(162, 42) + SourceIndex(0)
 ---
 >>>    console.log(primaryA);
 1 >^^^^
@@ -3272,35 +3296,35 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(82, 1) Source(164, 1) + SourceIndex(0)
 2 >Emitted(82, 2) Source(164, 2) + SourceIndex(0)
 ---
->>>for (_58 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, _59 = _58.name, name = _59 === void 0 ? "noName" : _59, _60 = _58.skills, _61 = _60 === void 0 ? { primary: "none", secondary: "none" } : _60, _62 = _61.primary, primary = _62 === void 0 ? "primary" : _62, _63 = _61.secondary, secondary = _63 === void 0 ? "secondary" : _63, _58,
+>>>for (_58 = { name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }, (_59 = _58.name, name = _59 === void 0 ? "noName" : _59, _60 = _58.skills, _61 = _60 === void 0 ? { primary: "none", secondary: "none" } : _60, _62 = _61.primary, primary = _62 === void 0 ? "primary" : _62, _63 = _61.secondary, secondary = _63 === void 0 ? "secondary" : _63, _58), _58,
 1->
 2 >^^^
 3 >   ^
 4 >    ^
 5 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-6 >                                                                                    ^^
-7 >                                                                                      ^^^^^^^^^^^^^^
-8 >                                                                                                    ^^
-9 >                                                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10>                                                                                                                                            ^^
-11>                                                                                                                                              ^^^^^^^^^^^^^^^^
-12>                                                                                                                                                              ^^
-13>                                                                                                                                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-14>                                                                                                                                                                                                                                   ^^
-15>                                                                                                                                                                                                                                     ^^^^^^^^^^^^^^^^^
-16>                                                                                                                                                                                                                                                      ^^
-17>                                                                                                                                                                                                                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18>                                                                                                                                                                                                                                                                                                  ^^
-19>                                                                                                                                                                                                                                                                                                    ^^^^^^^^^^^^^^^^^^^
-20>                                                                                                                                                                                                                                                                                                                       ^^
-21>                                                                                                                                                                                                                                                                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+6 >                                                                                    ^^^
+7 >                                                                                       ^^^^^^^^^^^^^^
+8 >                                                                                                     ^^
+9 >                                                                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+10>                                                                                                                                             ^^
+11>                                                                                                                                               ^^^^^^^^^^^^^^^^
+12>                                                                                                                                                               ^^
+13>                                                                                                                                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+14>                                                                                                                                                                                                                                    ^^
+15>                                                                                                                                                                                                                                      ^^^^^^^^^^^^^^^^^
+16>                                                                                                                                                                                                                                                       ^^
+17>                                                                                                                                                                                                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+18>                                                                                                                                                                                                                                                                                                   ^^
+19>                                                                                                                                                                                                                                                                                                     ^^^^^^^^^^^^^^^^^^^
+20>                                                                                                                                                                                                                                                                                                                        ^^
+21>                                                                                                                                                                                                                                                                                                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->
   >
 2 >for
@@ -3314,50 +3338,50 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
   >         } = { primary: "none", secondary: "none" }
   >     } = <MultiRobot>{ name: "trimmer", skills: { primary: "trimming", secondary: "edging" } }
 6 >                                                                                    
-7 >                                                                                      name = "noName"
-8 >                                                                                                    
-9 >                                                                                                      name = "noName"
-10>                                                                                                                                            ,
-  >                                                                                                                                                
-11>                                                                                                                                              skills: {
-  >                                                                                                                                                      primary = "primary",
-  >                                                                                                                                                      secondary = "secondary"
-  >                                                                                                                                                  } = { primary: "none", secondary: "none" }
-12>                                                                                                                                                              
-13>                                                                                                                                                                skills: {
-  >                                                                                                                                                                        primary = "primary",
-  >                                                                                                                                                                        secondary = "secondary"
-  >                                                                                                                                                                    } = { primary: "none", secondary: "none" }
-14>                                                                                                                                                                                                                                   
-15>                                                                                                                                                                                                                                     primary = "primary"
-16>                                                                                                                                                                                                                                                      
-17>                                                                                                                                                                                                                                                        primary = "primary"
-18>                                                                                                                                                                                                                                                                                                  ,
-  >                                                                                                                                                                                                                                                                                                          
-19>                                                                                                                                                                                                                                                                                                    secondary = "secondary"
-20>                                                                                                                                                                                                                                                                                                                       
-21>                                                                                                                                                                                                                                                                                                                         secondary = "secondary"
+7 >                                                                                       name = "noName"
+8 >                                                                                                     
+9 >                                                                                                       name = "noName"
+10>                                                                                                                                             ,
+  >                                                                                                                                                 
+11>                                                                                                                                               skills: {
+  >                                                                                                                                                       primary = "primary",
+  >                                                                                                                                                       secondary = "secondary"
+  >                                                                                                                                                   } = { primary: "none", secondary: "none" }
+12>                                                                                                                                                               
+13>                                                                                                                                                                 skills: {
+  >                                                                                                                                                                         primary = "primary",
+  >                                                                                                                                                                         secondary = "secondary"
+  >                                                                                                                                                                     } = { primary: "none", secondary: "none" }
+14>                                                                                                                                                                                                                                    
+15>                                                                                                                                                                                                                                      primary = "primary"
+16>                                                                                                                                                                                                                                                       
+17>                                                                                                                                                                                                                                                         primary = "primary"
+18>                                                                                                                                                                                                                                                                                                   ,
+  >                                                                                                                                                                                                                                                                                                           
+19>                                                                                                                                                                                                                                                                                                     secondary = "secondary"
+20>                                                                                                                                                                                                                                                                                                                        
+21>                                                                                                                                                                                                                                                                                                                          secondary = "secondary"
 1->Emitted(83, 1) Source(165, 1) + SourceIndex(0)
 2 >Emitted(83, 4) Source(165, 4) + SourceIndex(0)
 3 >Emitted(83, 5) Source(165, 5) + SourceIndex(0)
 4 >Emitted(83, 6) Source(165, 6) + SourceIndex(0)
 5 >Emitted(83, 85) Source(171, 90) + SourceIndex(0)
-6 >Emitted(83, 87) Source(166, 5) + SourceIndex(0)
-7 >Emitted(83, 101) Source(166, 20) + SourceIndex(0)
-8 >Emitted(83, 103) Source(166, 5) + SourceIndex(0)
-9 >Emitted(83, 141) Source(166, 20) + SourceIndex(0)
-10>Emitted(83, 143) Source(167, 5) + SourceIndex(0)
-11>Emitted(83, 159) Source(170, 47) + SourceIndex(0)
-12>Emitted(83, 161) Source(167, 5) + SourceIndex(0)
-13>Emitted(83, 228) Source(170, 47) + SourceIndex(0)
-14>Emitted(83, 230) Source(168, 9) + SourceIndex(0)
-15>Emitted(83, 247) Source(168, 28) + SourceIndex(0)
-16>Emitted(83, 249) Source(168, 9) + SourceIndex(0)
-17>Emitted(83, 291) Source(168, 28) + SourceIndex(0)
-18>Emitted(83, 293) Source(169, 9) + SourceIndex(0)
-19>Emitted(83, 312) Source(169, 32) + SourceIndex(0)
-20>Emitted(83, 314) Source(169, 9) + SourceIndex(0)
-21>Emitted(83, 360) Source(169, 32) + SourceIndex(0)
+6 >Emitted(83, 88) Source(166, 5) + SourceIndex(0)
+7 >Emitted(83, 102) Source(166, 20) + SourceIndex(0)
+8 >Emitted(83, 104) Source(166, 5) + SourceIndex(0)
+9 >Emitted(83, 142) Source(166, 20) + SourceIndex(0)
+10>Emitted(83, 144) Source(167, 5) + SourceIndex(0)
+11>Emitted(83, 160) Source(170, 47) + SourceIndex(0)
+12>Emitted(83, 162) Source(167, 5) + SourceIndex(0)
+13>Emitted(83, 229) Source(170, 47) + SourceIndex(0)
+14>Emitted(83, 231) Source(168, 9) + SourceIndex(0)
+15>Emitted(83, 248) Source(168, 28) + SourceIndex(0)
+16>Emitted(83, 250) Source(168, 9) + SourceIndex(0)
+17>Emitted(83, 292) Source(168, 28) + SourceIndex(0)
+18>Emitted(83, 294) Source(169, 9) + SourceIndex(0)
+19>Emitted(83, 313) Source(169, 32) + SourceIndex(0)
+20>Emitted(83, 315) Source(169, 9) + SourceIndex(0)
+21>Emitted(83, 361) Source(169, 32) + SourceIndex(0)
 ---
 >>>    i = 0; i < 1; i++) {
 1 >^^^^
@@ -3434,12 +3458,13 @@ sourceFile:sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2
 >>>}
 1 >
 2 >^
-3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+3 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >
 2 >}
 1 >Emitted(86, 1) Source(174, 1) + SourceIndex(0)
 2 >Emitted(86, 2) Source(174, 2) + SourceIndex(0)
 ---
->>>var _a, _b, _c, _d, _e, _f, _g, _h, _j, _k, _l, _m, _o, _p, _q, _r, _s, _t, _u, _v, _w, _x, _y, _z, _0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, _61, _62, _63;
+>>>var _k, _q, _4, _9, _27, _33, _52, _58;
+>>>var _a, _b, _c, _d, _e, _f, _g, _h, _j, _l, _m, _o, _p, _r, _s, _t, _u, _v, _w, _x, _y, _z, _0, _1, _2, _3, _5, _6, _7, _8, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _28, _29, _30, _31, _32, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _53, _54, _55, _56, _57, _59, _60, _61, _62, _63;
 >>>//# sourceMappingURL=sourceMapValidationDestructuringForObjectBindingPatternDefaultValues2.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/switchAssignmentCompat.errors.txt b/tests/baselines/reference/switchAssignmentCompat.errors.txt
index 46c89fa5b52..747a1035b68 100644
--- a/tests/baselines/reference/switchAssignmentCompat.errors.txt
+++ b/tests/baselines/reference/switchAssignmentCompat.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type '0'.
+tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
 
 
 ==== tests/cases/compiler/switchAssignmentCompat.ts (1 errors) ====
@@ -7,6 +7,6 @@ tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof
     switch (0) {
         case Foo: break; // Error expected
              ~~~
-!!! error TS2678: Type 'typeof Foo' is not comparable to type '0'.
+!!! error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
     }
     
\ No newline at end of file
diff --git a/tests/baselines/reference/switchCaseCircularRefeference.errors.txt b/tests/baselines/reference/switchCaseCircularRefeference.errors.txt
index 9ee571de468..bc576f8e723 100644
--- a/tests/baselines/reference/switchCaseCircularRefeference.errors.txt
+++ b/tests/baselines/reference/switchCaseCircularRefeference.errors.txt
@@ -1,6 +1,5 @@
-tests/cases/compiler/switchCaseCircularRefeference.ts(5,10): error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
-  Type '{ a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
-    Type '{ a: "C"; e: any; }' is not comparable to type '"C"'.
+tests/cases/compiler/switchCaseCircularRefeference.ts(5,10): error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type 'string'.
+  Type '{ a: "C"; e: any; }' is not comparable to type 'string'.
 
 
 ==== tests/cases/compiler/switchCaseCircularRefeference.ts (1 errors) ====
@@ -10,9 +9,8 @@ tests/cases/compiler/switchCaseCircularRefeference.ts(5,10): error TS2678: Type
         switch (x.a) {
         case x:
              ~
-!!! error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
-!!! error TS2678:   Type '{ a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
-!!! error TS2678:     Type '{ a: "C"; e: any; }' is not comparable to type '"C"'.
+!!! error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type 'string'.
+!!! error TS2678:   Type '{ a: "C"; e: any; }' is not comparable to type 'string'.
             break;
         }
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt b/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
index 3ea12e2460f..7a5fd12182e 100644
--- a/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
+++ b/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type '0'.
+tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
 tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(5,10): error TS2678: Type '"sss"' is not comparable to type '0'.
 tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(6,10): error TS2678: Type '123' is not comparable to type '0'.
 tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2678: Type 'true' is not comparable to type '0'.
@@ -10,11 +10,11 @@ tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2678: T
     switch (0) {
         case Foo: break;    // Error
              ~~~
-!!! error TS2678: Type 'typeof Foo' is not comparable to type '0'.
+!!! error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
         case "sss": break;  // Error
              ~~~~~
 !!! error TS2678: Type '"sss"' is not comparable to type '0'.
-        case 123: break;    // No Error
+        case 123: break;    // Error
              ~~~
 !!! error TS2678: Type '123' is not comparable to type '0'.
         case true: break;   // Error
@@ -30,4 +30,5 @@ tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2678: T
         case "sss": break;
         case 123: break;
         case true: break;
-    }
\ No newline at end of file
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/switchCasesExpressionTypeMismatch.js b/tests/baselines/reference/switchCasesExpressionTypeMismatch.js
index ba929691d25..43a43224579 100644
--- a/tests/baselines/reference/switchCasesExpressionTypeMismatch.js
+++ b/tests/baselines/reference/switchCasesExpressionTypeMismatch.js
@@ -4,7 +4,7 @@ class Foo { }
 switch (0) {
     case Foo: break;    // Error
     case "sss": break;  // Error
-    case 123: break;    // No Error
+    case 123: break;    // Error
     case true: break;   // Error
 }
 
@@ -16,7 +16,8 @@ switch (s) {
     case "sss": break;
     case 123: break;
     case true: break;
-}
+}
+
 
 //// [switchCasesExpressionTypeMismatch.js]
 var Foo = (function () {
@@ -27,7 +28,7 @@ var Foo = (function () {
 switch (0) {
     case Foo: break; // Error
     case "sss": break; // Error
-    case 123: break; // No Error
+    case 123: break; // Error
     case true: break; // Error
 }
 var s = 0;
diff --git a/tests/baselines/reference/switchComparableCompatForBrands.js b/tests/baselines/reference/switchComparableCompatForBrands.js
new file mode 100644
index 00000000000..316edfc9c31
--- /dev/null
+++ b/tests/baselines/reference/switchComparableCompatForBrands.js
@@ -0,0 +1,29 @@
+//// [switchComparableCompatForBrands.ts]
+class MyBrand
+{
+    private _a: number;
+}
+
+function test(strInput: string & MyBrand) {
+    switch(strInput)
+    {
+        case "a":
+        return 1;
+    }
+    return 0;
+}
+
+
+//// [switchComparableCompatForBrands.js]
+var MyBrand = (function () {
+    function MyBrand() {
+    }
+    return MyBrand;
+}());
+function test(strInput) {
+    switch (strInput) {
+        case "a":
+            return 1;
+    }
+    return 0;
+}
diff --git a/tests/baselines/reference/switchComparableCompatForBrands.symbols b/tests/baselines/reference/switchComparableCompatForBrands.symbols
new file mode 100644
index 00000000000..adf6a5174ad
--- /dev/null
+++ b/tests/baselines/reference/switchComparableCompatForBrands.symbols
@@ -0,0 +1,22 @@
+=== tests/cases/compiler/switchComparableCompatForBrands.ts ===
+class MyBrand
+>MyBrand : Symbol(MyBrand, Decl(switchComparableCompatForBrands.ts, 0, 0))
+{
+    private _a: number;
+>_a : Symbol(MyBrand._a, Decl(switchComparableCompatForBrands.ts, 1, 1))
+}
+
+function test(strInput: string & MyBrand) {
+>test : Symbol(test, Decl(switchComparableCompatForBrands.ts, 3, 1))
+>strInput : Symbol(strInput, Decl(switchComparableCompatForBrands.ts, 5, 14))
+>MyBrand : Symbol(MyBrand, Decl(switchComparableCompatForBrands.ts, 0, 0))
+
+    switch(strInput)
+>strInput : Symbol(strInput, Decl(switchComparableCompatForBrands.ts, 5, 14))
+    {
+        case "a":
+        return 1;
+    }
+    return 0;
+}
+
diff --git a/tests/baselines/reference/switchComparableCompatForBrands.types b/tests/baselines/reference/switchComparableCompatForBrands.types
new file mode 100644
index 00000000000..5e479ee29dc
--- /dev/null
+++ b/tests/baselines/reference/switchComparableCompatForBrands.types
@@ -0,0 +1,26 @@
+=== tests/cases/compiler/switchComparableCompatForBrands.ts ===
+class MyBrand
+>MyBrand : MyBrand
+{
+    private _a: number;
+>_a : number
+}
+
+function test(strInput: string & MyBrand) {
+>test : (strInput: string & MyBrand) => 1 | 0
+>strInput : string & MyBrand
+>MyBrand : MyBrand
+
+    switch(strInput)
+>strInput : string & MyBrand
+    {
+        case "a":
+>"a" : "a"
+
+        return 1;
+>1 : 1
+    }
+    return 0;
+>0 : 0
+}
+
diff --git a/tests/baselines/reference/transpile/Supports setting jsxFactory.js b/tests/baselines/reference/transpile/Supports setting jsxFactory.js
new file mode 100644
index 00000000000..8d91090453b
--- /dev/null
+++ b/tests/baselines/reference/transpile/Supports setting jsxFactory.js	
@@ -0,0 +1,3 @@
+"use strict";
+x;
+//# sourceMappingURL=input.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json b/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json
index eec78e40192..2befbbde729 100644
--- a/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json
+++ b/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json
@@ -9,12 +9,8 @@
     "File '/foo/bar/node_modules/xyz/index.ts' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/foo/bar/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/xyz/index.d.ts' does not exist.",
     "File '/foo/node_modules/xyz.ts' does not exist.",
     "File '/foo/node_modules/xyz.tsx' does not exist.",
@@ -23,12 +19,8 @@
     "File '/foo/node_modules/xyz/index.ts' does not exist.",
     "File '/foo/node_modules/xyz/index.tsx' does not exist.",
     "File '/foo/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/foo/node_modules/@types/xyz.ts' does not exist.",
-    "File '/foo/node_modules/@types/xyz.tsx' does not exist.",
     "File '/foo/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/foo/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/foo/node_modules/@types/xyz/index.d.ts' does not exist.",
     "File '/node_modules/xyz.ts' does not exist.",
     "File '/node_modules/xyz.tsx' does not exist.",
@@ -37,12 +29,8 @@
     "File '/node_modules/xyz/index.ts' does not exist.",
     "File '/node_modules/xyz/index.tsx' does not exist.",
     "File '/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/node_modules/@types/xyz.ts' does not exist.",
-    "File '/node_modules/@types/xyz.tsx' does not exist.",
     "File '/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/node_modules/@types/xyz/index.d.ts' does not exist.",
     "Loading module 'xyz' from 'node_modules' folder.",
     "File '/foo/bar/node_modules/xyz.js' does not exist.",
@@ -50,31 +38,16 @@
     "File '/foo/bar/node_modules/xyz/package.json' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.js' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.jsx' does not exist.",
     "File '/foo/node_modules/xyz.js' does not exist.",
     "File '/foo/node_modules/xyz.jsx' does not exist.",
     "File '/foo/node_modules/xyz/package.json' does not exist.",
     "File '/foo/node_modules/xyz/index.js' does not exist.",
     "File '/foo/node_modules/xyz/index.jsx' does not exist.",
-    "File '/foo/node_modules/@types/xyz.js' does not exist.",
-    "File '/foo/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/foo/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.jsx' does not exist.",
     "File '/node_modules/xyz.js' does not exist.",
     "File '/node_modules/xyz.jsx' does not exist.",
     "File '/node_modules/xyz/package.json' does not exist.",
     "File '/node_modules/xyz/index.js' does not exist.",
     "File '/node_modules/xyz/index.jsx' does not exist.",
-    "File '/node_modules/@types/xyz.js' does not exist.",
-    "File '/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/node_modules/@types/xyz/index.jsx' does not exist.",
     "======== Module name 'xyz' was not resolved. ========",
     "======== Resolving module 'pdq' from '/foo/bar/a.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -86,12 +59,8 @@
     "File '/foo/bar/node_modules/pdq/index.ts' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.d.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/pdq.d.ts' does not exist.",
     "File '/foo/bar/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/pdq/index.d.ts' does not exist.",
     "File '/foo/node_modules/pdq.ts' does not exist.",
     "File '/foo/node_modules/pdq.tsx' does not exist.",
@@ -100,12 +69,8 @@
     "File '/foo/node_modules/pdq/index.ts' does not exist.",
     "File '/foo/node_modules/pdq/index.tsx' does not exist.",
     "File '/foo/node_modules/pdq/index.d.ts' does not exist.",
-    "File '/foo/node_modules/@types/pdq.ts' does not exist.",
-    "File '/foo/node_modules/@types/pdq.tsx' does not exist.",
     "File '/foo/node_modules/@types/pdq.d.ts' does not exist.",
     "File '/foo/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.ts' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.tsx' does not exist.",
     "File '/foo/node_modules/@types/pdq/index.d.ts' does not exist.",
     "File '/node_modules/pdq.ts' does not exist.",
     "File '/node_modules/pdq.tsx' does not exist.",
@@ -114,12 +79,8 @@
     "File '/node_modules/pdq/index.ts' does not exist.",
     "File '/node_modules/pdq/index.tsx' does not exist.",
     "File '/node_modules/pdq/index.d.ts' does not exist.",
-    "File '/node_modules/@types/pdq.ts' does not exist.",
-    "File '/node_modules/@types/pdq.tsx' does not exist.",
     "File '/node_modules/@types/pdq.d.ts' does not exist.",
     "File '/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/node_modules/@types/pdq/index.ts' does not exist.",
-    "File '/node_modules/@types/pdq/index.tsx' does not exist.",
     "File '/node_modules/@types/pdq/index.d.ts' does not exist.",
     "Loading module 'pdq' from 'node_modules' folder.",
     "File '/foo/bar/node_modules/pdq.js' does not exist.",
@@ -127,31 +88,16 @@
     "File '/foo/bar/node_modules/pdq/package.json' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.js' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.jsx' does not exist.",
     "File '/foo/node_modules/pdq.js' does not exist.",
     "File '/foo/node_modules/pdq.jsx' does not exist.",
     "File '/foo/node_modules/pdq/package.json' does not exist.",
     "File '/foo/node_modules/pdq/index.js' does not exist.",
     "File '/foo/node_modules/pdq/index.jsx' does not exist.",
-    "File '/foo/node_modules/@types/pdq.js' does not exist.",
-    "File '/foo/node_modules/@types/pdq.jsx' does not exist.",
-    "File '/foo/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.js' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.jsx' does not exist.",
     "File '/node_modules/pdq.js' does not exist.",
     "File '/node_modules/pdq.jsx' does not exist.",
     "File '/node_modules/pdq/package.json' does not exist.",
     "File '/node_modules/pdq/index.js' does not exist.",
     "File '/node_modules/pdq/index.jsx' does not exist.",
-    "File '/node_modules/@types/pdq.js' does not exist.",
-    "File '/node_modules/@types/pdq.jsx' does not exist.",
-    "File '/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/node_modules/@types/pdq/index.js' does not exist.",
-    "File '/node_modules/@types/pdq/index.jsx' does not exist.",
     "======== Module name 'pdq' was not resolved. ========",
     "======== Resolving module 'abc' from '/foo/bar/a.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -163,12 +109,8 @@
     "File '/foo/bar/node_modules/abc/index.ts' does not exist.",
     "File '/foo/bar/node_modules/abc/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/abc/index.d.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/abc.d.ts' does not exist.",
     "File '/foo/bar/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/abc/index.d.ts' does not exist.",
     "File '/foo/node_modules/abc.ts' does not exist.",
     "File '/foo/node_modules/abc.tsx' does not exist.",
@@ -177,12 +119,8 @@
     "File '/foo/node_modules/abc/index.ts' does not exist.",
     "File '/foo/node_modules/abc/index.tsx' does not exist.",
     "File '/foo/node_modules/abc/index.d.ts' does not exist.",
-    "File '/foo/node_modules/@types/abc.ts' does not exist.",
-    "File '/foo/node_modules/@types/abc.tsx' does not exist.",
     "File '/foo/node_modules/@types/abc.d.ts' does not exist.",
     "File '/foo/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.ts' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.tsx' does not exist.",
     "File '/foo/node_modules/@types/abc/index.d.ts' does not exist.",
     "File '/node_modules/abc.ts' does not exist.",
     "File '/node_modules/abc.tsx' does not exist.",
@@ -191,12 +129,8 @@
     "File '/node_modules/abc/index.ts' does not exist.",
     "File '/node_modules/abc/index.tsx' does not exist.",
     "File '/node_modules/abc/index.d.ts' does not exist.",
-    "File '/node_modules/@types/abc.ts' does not exist.",
-    "File '/node_modules/@types/abc.tsx' does not exist.",
     "File '/node_modules/@types/abc.d.ts' does not exist.",
     "File '/node_modules/@types/abc/package.json' does not exist.",
-    "File '/node_modules/@types/abc/index.ts' does not exist.",
-    "File '/node_modules/@types/abc/index.tsx' does not exist.",
     "File '/node_modules/@types/abc/index.d.ts' does not exist.",
     "Loading module 'abc' from 'node_modules' folder.",
     "File '/foo/bar/node_modules/abc.js' does not exist.",
@@ -204,31 +138,16 @@
     "File '/foo/bar/node_modules/abc/package.json' does not exist.",
     "File '/foo/bar/node_modules/abc/index.js' does not exist.",
     "File '/foo/bar/node_modules/abc/index.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.jsx' does not exist.",
     "File '/foo/node_modules/abc.js' does not exist.",
     "File '/foo/node_modules/abc.jsx' does not exist.",
     "File '/foo/node_modules/abc/package.json' does not exist.",
     "File '/foo/node_modules/abc/index.js' does not exist.",
     "File '/foo/node_modules/abc/index.jsx' does not exist.",
-    "File '/foo/node_modules/@types/abc.js' does not exist.",
-    "File '/foo/node_modules/@types/abc.jsx' does not exist.",
-    "File '/foo/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.js' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.jsx' does not exist.",
     "File '/node_modules/abc.js' does not exist.",
     "File '/node_modules/abc.jsx' does not exist.",
     "File '/node_modules/abc/package.json' does not exist.",
     "File '/node_modules/abc/index.js' does not exist.",
     "File '/node_modules/abc/index.jsx' does not exist.",
-    "File '/node_modules/@types/abc.js' does not exist.",
-    "File '/node_modules/@types/abc.jsx' does not exist.",
-    "File '/node_modules/@types/abc/package.json' does not exist.",
-    "File '/node_modules/@types/abc/index.js' does not exist.",
-    "File '/node_modules/@types/abc/index.jsx' does not exist.",
     "======== Module name 'abc' was not resolved. ========",
     "======== Resolving type reference directive 'grumpy', containing file '/src/__inferred type names__.ts', root directory '/foo/node_modules/@types,/node_modules/@types'. ========",
     "Resolving with primary search path '/foo/node_modules/@types, /node_modules/@types'",
diff --git a/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json b/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json
index 4bb62bc255a..421c47d30ec 100644
--- a/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json
+++ b/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json
@@ -9,12 +9,8 @@
     "File '/src/node_modules/xyz/index.ts' does not exist.",
     "File '/src/node_modules/xyz/index.tsx' does not exist.",
     "File '/src/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/src/node_modules/@types/xyz.ts' does not exist.",
-    "File '/src/node_modules/@types/xyz.tsx' does not exist.",
     "File '/src/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/src/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/src/node_modules/@types/xyz/index.d.ts' does not exist.",
     "File '/node_modules/xyz.ts' does not exist.",
     "File '/node_modules/xyz.tsx' does not exist.",
@@ -23,12 +19,8 @@
     "File '/node_modules/xyz/index.ts' does not exist.",
     "File '/node_modules/xyz/index.tsx' does not exist.",
     "File '/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/node_modules/@types/xyz.ts' does not exist.",
-    "File '/node_modules/@types/xyz.tsx' does not exist.",
     "File '/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/node_modules/@types/xyz/index.d.ts' does not exist.",
     "Loading module 'xyz' from 'node_modules' folder.",
     "File '/src/node_modules/xyz.js' does not exist.",
@@ -36,21 +28,11 @@
     "File '/src/node_modules/xyz/package.json' does not exist.",
     "File '/src/node_modules/xyz/index.js' does not exist.",
     "File '/src/node_modules/xyz/index.jsx' does not exist.",
-    "File '/src/node_modules/@types/xyz.js' does not exist.",
-    "File '/src/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/src/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.jsx' does not exist.",
     "File '/node_modules/xyz.js' does not exist.",
     "File '/node_modules/xyz.jsx' does not exist.",
     "File '/node_modules/xyz/package.json' does not exist.",
     "File '/node_modules/xyz/index.js' does not exist.",
     "File '/node_modules/xyz/index.jsx' does not exist.",
-    "File '/node_modules/@types/xyz.js' does not exist.",
-    "File '/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/node_modules/@types/xyz/index.jsx' does not exist.",
     "======== Module name 'xyz' was not resolved. ========",
     "======== Resolving type reference directive 'foo', containing file '/src/__inferred type names__.ts', root directory '/node_modules/@types'. ========",
     "Resolving with primary search path '/node_modules/@types'",
diff --git a/tests/baselines/reference/typingsLookup4.trace.json b/tests/baselines/reference/typingsLookup4.trace.json
index bb9d94f43b5..d1c29b1f11b 100644
--- a/tests/baselines/reference/typingsLookup4.trace.json
+++ b/tests/baselines/reference/typingsLookup4.trace.json
@@ -9,8 +9,6 @@
     "File '/node_modules/jquery/index.ts' does not exist.",
     "File '/node_modules/jquery/index.tsx' does not exist.",
     "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/jquery.ts' does not exist.",
-    "File '/node_modules/@types/jquery.tsx' does not exist.",
     "File '/node_modules/@types/jquery.d.ts' does not exist.",
     "Found 'package.json' at '/node_modules/@types/jquery/package.json'.",
     "'package.json' has 'typings' field 'jquery.d.ts' that references '/node_modules/@types/jquery/jquery.d.ts'.",
@@ -27,8 +25,6 @@
     "File '/node_modules/kquery/index.ts' does not exist.",
     "File '/node_modules/kquery/index.tsx' does not exist.",
     "File '/node_modules/kquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/kquery.ts' does not exist.",
-    "File '/node_modules/@types/kquery.tsx' does not exist.",
     "File '/node_modules/@types/kquery.d.ts' does not exist.",
     "Found 'package.json' at '/node_modules/@types/kquery/package.json'.",
     "'package.json' has 'typings' field 'kquery' that references '/node_modules/@types/kquery/kquery'.",
@@ -48,8 +44,6 @@
     "File '/node_modules/lquery/index.ts' does not exist.",
     "File '/node_modules/lquery/index.tsx' does not exist.",
     "File '/node_modules/lquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/lquery.ts' does not exist.",
-    "File '/node_modules/@types/lquery.tsx' does not exist.",
     "File '/node_modules/@types/lquery.d.ts' does not exist.",
     "Found 'package.json' at '/node_modules/@types/lquery/package.json'.",
     "'package.json' has 'typings' field 'lquery' that references '/node_modules/@types/lquery/lquery'.",
diff --git a/tests/baselines/reference/typingsLookupAmd.trace.json b/tests/baselines/reference/typingsLookupAmd.trace.json
index 496166926a8..843f16fe8c6 100644
--- a/tests/baselines/reference/typingsLookupAmd.trace.json
+++ b/tests/baselines/reference/typingsLookupAmd.trace.json
@@ -10,19 +10,11 @@
     "File '/b.ts' does not exist.",
     "File '/b.tsx' does not exist.",
     "File '/b.d.ts' does not exist.",
-    "File '/x/y/node_modules/@types/b.ts' does not exist.",
-    "File '/x/y/node_modules/@types/b.tsx' does not exist.",
     "File '/x/y/node_modules/@types/b.d.ts' does not exist.",
     "File '/x/y/node_modules/@types/b/package.json' does not exist.",
-    "File '/x/y/node_modules/@types/b/index.ts' does not exist.",
-    "File '/x/y/node_modules/@types/b/index.tsx' does not exist.",
     "File '/x/y/node_modules/@types/b/index.d.ts' does not exist.",
-    "File '/x/node_modules/@types/b.ts' does not exist.",
-    "File '/x/node_modules/@types/b.tsx' does not exist.",
     "File '/x/node_modules/@types/b.d.ts' does not exist.",
     "File '/x/node_modules/@types/b/package.json' does not exist.",
-    "File '/x/node_modules/@types/b/index.ts' does not exist.",
-    "File '/x/node_modules/@types/b/index.tsx' does not exist.",
     "File '/x/node_modules/@types/b/index.d.ts' exist - use it as a name resolution result.",
     "======== Module name 'b' was successfully resolved to '/x/node_modules/@types/b/index.d.ts'. ========",
     "======== Resolving module 'a' from '/x/node_modules/@types/b/index.d.ts'. ========",
@@ -42,33 +34,17 @@
     "File '/a.ts' does not exist.",
     "File '/a.tsx' does not exist.",
     "File '/a.d.ts' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a.ts' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a.tsx' does not exist.",
     "File '/x/node_modules/@types/b/node_modules/@types/a.d.ts' does not exist.",
     "File '/x/node_modules/@types/b/node_modules/@types/a/package.json' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a/index.ts' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a/index.tsx' does not exist.",
     "File '/x/node_modules/@types/b/node_modules/@types/a/index.d.ts' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a.ts' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a.tsx' does not exist.",
     "File '/x/node_modules/@types/node_modules/@types/a.d.ts' does not exist.",
     "File '/x/node_modules/@types/node_modules/@types/a/package.json' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a/index.ts' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a/index.tsx' does not exist.",
     "File '/x/node_modules/@types/node_modules/@types/a/index.d.ts' does not exist.",
-    "File '/x/node_modules/@types/a.ts' does not exist.",
-    "File '/x/node_modules/@types/a.tsx' does not exist.",
     "File '/x/node_modules/@types/a.d.ts' does not exist.",
     "File '/x/node_modules/@types/a/package.json' does not exist.",
-    "File '/x/node_modules/@types/a/index.ts' does not exist.",
-    "File '/x/node_modules/@types/a/index.tsx' does not exist.",
     "File '/x/node_modules/@types/a/index.d.ts' does not exist.",
-    "File '/node_modules/@types/a.ts' does not exist.",
-    "File '/node_modules/@types/a.tsx' does not exist.",
     "File '/node_modules/@types/a.d.ts' does not exist.",
     "File '/node_modules/@types/a/package.json' does not exist.",
-    "File '/node_modules/@types/a/index.ts' does not exist.",
-    "File '/node_modules/@types/a/index.tsx' does not exist.",
     "File '/node_modules/@types/a/index.d.ts' exist - use it as a name resolution result.",
     "======== Module name 'a' was successfully resolved to '/node_modules/@types/a/index.d.ts'. ========",
     "======== Resolving type reference directive 'a', containing file '/__inferred type names__.ts', root directory '/node_modules/@types'. ========",
diff --git a/tests/cases/compiler/alwaysStrictModule3.ts b/tests/cases/compiler/alwaysStrictModule3.ts
new file mode 100644
index 00000000000..adb93cede36
--- /dev/null
+++ b/tests/cases/compiler/alwaysStrictModule3.ts
@@ -0,0 +1,5 @@
+// @alwaysStrict: true
+// @module: es2015
+
+// module ES2015
+export const a = 1;
\ No newline at end of file
diff --git a/tests/cases/compiler/alwaysStrictModule4.ts b/tests/cases/compiler/alwaysStrictModule4.ts
new file mode 100644
index 00000000000..f731e6dd734
--- /dev/null
+++ b/tests/cases/compiler/alwaysStrictModule4.ts
@@ -0,0 +1,5 @@
+// @alwaysStrict: true
+// @module: commonjs
+
+// Module commonjs
+export const a = 1
\ No newline at end of file
diff --git a/tests/cases/compiler/alwaysStrictModule5.ts b/tests/cases/compiler/alwaysStrictModule5.ts
new file mode 100644
index 00000000000..d1ac5288370
--- /dev/null
+++ b/tests/cases/compiler/alwaysStrictModule5.ts
@@ -0,0 +1,5 @@
+// @alwaysStrict: true
+// @target: es6
+
+// Targeting ES6
+export const a = 1; 
\ No newline at end of file
diff --git a/tests/cases/compiler/alwaysStrictModule6.ts b/tests/cases/compiler/alwaysStrictModule6.ts
new file mode 100644
index 00000000000..064ece1a4e1
--- /dev/null
+++ b/tests/cases/compiler/alwaysStrictModule6.ts
@@ -0,0 +1,5 @@
+// @alwaysStrict: true
+// @target: es5
+
+// Targeting ES5
+export const a = 1; 
\ No newline at end of file
diff --git a/tests/cases/compiler/commonSourceDirectory.ts b/tests/cases/compiler/commonSourceDirectory.ts
new file mode 100644
index 00000000000..9baa27431a3
--- /dev/null
+++ b/tests/cases/compiler/commonSourceDirectory.ts
@@ -0,0 +1,30 @@
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+// @noImplicitReferences: true
+// @moduleResolution: node
+// @fullEmitPaths: true
+
+// @filename: /node_modules/foo/index.ts
+export const x = 0;
+
+// @filename: /types/bar.d.ts
+declare module "bar" {
+    export const y = 0;
+}
+
+// @filename: /app/index.ts
+/// <reference path="../types/bar.d.ts"/>
+import { x } from "foo";
+import { y } from "bar";
+x + y;
+
+// @filename: /app/tsconfig.json
+{
+    "compilerOptions": {
+        "outDir": "bin",
+        "typeRoots": ["../types"],
+        "sourceMap": true,
+        "mapRoot": "myMapRoot",
+        "sourceRoot": "mySourceRoot",
+        "declaration": true
+    }
+}
diff --git a/tests/cases/compiler/commonSourceDirectory_dts.ts b/tests/cases/compiler/commonSourceDirectory_dts.ts
new file mode 100644
index 00000000000..3a3dfea1772
--- /dev/null
+++ b/tests/cases/compiler/commonSourceDirectory_dts.ts
@@ -0,0 +1,22 @@
+// Test that importing a file from `node_modules` does not affect calculation of the common source directory.
+// @noImplicitReferences: true
+// @moduleResolution: node
+// @fullEmitPaths: true
+
+// @filename: /app/lib/bar.d.ts
+declare const y: number;
+
+// @filename: /app/src/index.ts
+/// <reference path="../lib/bar.d.ts" />
+export const x = y;
+
+// @filename: /app/tsconfig.json
+{
+    "compilerOptions": {
+        "outDir": "bin",
+        "sourceMap": true,
+        "mapRoot": "myMapRoot",
+        "sourceRoot": "mySourceRoot",
+        "declaration": true
+    }
+}
diff --git a/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters2.ts b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters2.ts
new file mode 100644
index 00000000000..de94ad4998d
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters2.ts
@@ -0,0 +1,6 @@
+// @declaration: true
+
+export type Bar<X, Y, Z> = () => [X, Y, Z];
+export type Baz<M, N> = Bar<M, string, N>;
+export type Baa<Y> = Baz<boolean, Y>;
+export const y = (x: Baa<number>) => 1
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters3.ts b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters3.ts
new file mode 100644
index 00000000000..6c7d4799abc
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters3.ts
@@ -0,0 +1,8 @@
+// @declaration: true
+
+type Foo<T> = {
+    foo<U>(): Foo<U>
+};
+function bar() {
+    return {} as Foo<number>;
+}
diff --git a/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters4.ts b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters4.ts
new file mode 100644
index 00000000000..42bb8097997
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters4.ts
@@ -0,0 +1,10 @@
+// @declaration: true
+
+type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>
+};
+type SubFoo<R> = Foo<string, R>;
+
+function foo() {
+    return {} as SubFoo<number>;
+}
diff --git a/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters5.ts b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters5.ts
new file mode 100644
index 00000000000..b6334e76337
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters5.ts
@@ -0,0 +1,10 @@
+// @declaration: true
+
+type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>
+};
+export type SubFoo<R> = Foo<string, R>;
+
+function foo() {
+    return {} as SubFoo<number>;
+}
diff --git a/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters6.ts b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters6.ts
new file mode 100644
index 00000000000..9b313027021
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters6.ts
@@ -0,0 +1,10 @@
+// @declaration: true
+
+type Foo<T, Y> = {
+    foo<U, J>(): Foo<U, J>
+};
+type SubFoo<R, S> = Foo<S, R>;
+
+function foo() {
+    return {} as SubFoo<number, string>;
+}
diff --git a/tests/cases/compiler/decoratorInJsFile.ts b/tests/cases/compiler/decoratorInJsFile.ts
new file mode 100644
index 00000000000..611be319209
--- /dev/null
+++ b/tests/cases/compiler/decoratorInJsFile.ts
@@ -0,0 +1,12 @@
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @allowjs: true
+// @noEmit: true
+
+// @filename: a.js
+@SomeDecorator
+class SomeClass {
+    foo(x: number) {
+
+    }
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/decoratorInJsFile1.ts b/tests/cases/compiler/decoratorInJsFile1.ts
new file mode 100644
index 00000000000..6bbe38cb835
--- /dev/null
+++ b/tests/cases/compiler/decoratorInJsFile1.ts
@@ -0,0 +1,10 @@
+// @allowjs: true
+// @noEmit: true
+
+// @filename: a.js
+@SomeDecorator
+class SomeClass {
+    foo(x: number) {
+
+    }
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/importHelpersNoHelpers.ts b/tests/cases/compiler/importHelpersNoHelpers.ts
index 82428552548..4ab48aba7df 100644
--- a/tests/cases/compiler/importHelpersNoHelpers.ts
+++ b/tests/cases/compiler/importHelpersNoHelpers.ts
@@ -16,6 +16,10 @@ class C {
     }
 }
 
+const o = { a: 1 };
+const y = { ...o };
+const { ...x } = y;
+
 // @filename: script.ts
 class A { }
 class B extends A { }
@@ -29,4 +33,4 @@ class C {
 }
 
 // @filename: tslib.d.ts
-export {}
\ No newline at end of file
+export {}
diff --git a/tests/cases/compiler/incompatibleAssignmentOfIdenticallyNamedTypes.ts b/tests/cases/compiler/incompatibleAssignmentOfIdenticallyNamedTypes.ts
new file mode 100644
index 00000000000..493feef1fd7
--- /dev/null
+++ b/tests/cases/compiler/incompatibleAssignmentOfIdenticallyNamedTypes.ts
@@ -0,0 +1,8 @@
+interface T { }
+declare const a: T;
+class Foo<T> {
+    x: T;
+    fn() {
+        this.x = a;
+    }
+}
diff --git a/tests/cases/compiler/jsFileCompilationAbstractModifier.ts b/tests/cases/compiler/jsFileCompilationAbstractModifier.ts
new file mode 100644
index 00000000000..ebd021e05a1
--- /dev/null
+++ b/tests/cases/compiler/jsFileCompilationAbstractModifier.ts
@@ -0,0 +1,5 @@
+// @allowJs: true
+// @filename: a.js
+abstract class c {
+    abstract x;
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/jsFileCompilationConstModifier.ts b/tests/cases/compiler/jsFileCompilationConstModifier.ts
new file mode 100644
index 00000000000..4ffa62bb6a2
--- /dev/null
+++ b/tests/cases/compiler/jsFileCompilationConstModifier.ts
@@ -0,0 +1,4 @@
+// @allowJs: true
+// @filename: a.js
+// @noEmit: true
+const c = 10;
\ No newline at end of file
diff --git a/tests/cases/compiler/jsxFactoryAndReactNamespace.ts b/tests/cases/compiler/jsxFactoryAndReactNamespace.ts
new file mode 100644
index 00000000000..2bdc954da3a
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryAndReactNamespace.ts
@@ -0,0 +1,54 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@reactNamespace: Element
+//@jsxFactory: Element.createElement
+
+// @filename: Element.ts
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+// @filename: test.tsx
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/jsxFactoryIdentifier.ts b/tests/cases/compiler/jsxFactoryIdentifier.ts
new file mode 100644
index 00000000000..88caf27482e
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryIdentifier.ts
@@ -0,0 +1,54 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: createElement
+//@sourcemap: true
+
+// @filename: Element.ts
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+// @filename: test.tsx
+import { Element} from './Element';
+let createElement = Element.createElement;
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/jsxFactoryIdentifierAsParameter.ts b/tests/cases/compiler/jsxFactoryIdentifierAsParameter.ts
new file mode 100644
index 00000000000..bd92a473428
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryIdentifierAsParameter.ts
@@ -0,0 +1,18 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: createElement
+//@sourcemap: true
+
+// @filename: test.tsx
+declare module JSX {
+    interface IntrinsicElements {
+        [s: string]: any;
+    }
+}
+
+export class AppComponent {
+    render(createElement) {
+        return <div />;
+    }
+}
diff --git a/tests/cases/compiler/jsxFactoryIdentifierWithAbsentParameter.ts b/tests/cases/compiler/jsxFactoryIdentifierWithAbsentParameter.ts
new file mode 100644
index 00000000000..49e485a1085
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryIdentifierWithAbsentParameter.ts
@@ -0,0 +1,18 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: createElement
+//@sourcemap: true
+
+// @filename: test.tsx
+declare module JSX {
+    interface IntrinsicElements {
+        [s: string]: any;
+    }
+}
+
+export class AppComponent {
+    render() {
+        return <div />;
+    }
+}
diff --git a/tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName.ts b/tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName.ts
new file mode 100644
index 00000000000..6f7c584d232
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName.ts
@@ -0,0 +1,53 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: Element.createElement=
+
+// @filename: Element.ts
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+// @filename: test.tsx
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName2.ts b/tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName2.ts
new file mode 100644
index 00000000000..610063f7d34
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryNotIdentifierOrQualifiedName2.ts
@@ -0,0 +1,53 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: id1 id2
+
+// @filename: Element.ts
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+// @filename: test.tsx
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/jsxFactoryQualifiedName.ts b/tests/cases/compiler/jsxFactoryQualifiedName.ts
new file mode 100644
index 00000000000..769b7cd566d
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryQualifiedName.ts
@@ -0,0 +1,54 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: Element.createElement
+//@sourcemap: true
+
+// @filename: Element.ts
+declare namespace JSX {
+    interface Element {
+        name: string;
+        isIntrinsic: boolean;
+        isCustomElement: boolean;
+        toString(renderId?: number): string;
+        bindDOM(renderId?: number): number;
+        resetComponent(): void;
+        instantiateComponents(renderId?: number): number;
+        props: any;
+    }
+}
+export namespace Element {
+    export function isElement(el: any): el is JSX.Element {
+        return el.markAsChildOfRootElement !== undefined;
+    }
+
+    export function createElement(args: any[]) {
+
+        return {
+        }
+    }
+}
+
+export let createElement = Element.createElement;
+
+function toCamelCase(text: string): string {
+    return text[0].toLowerCase() + text.substring(1);
+}
+
+// @filename: test.tsx
+import { Element} from './Element';
+
+let c: {
+	a?: {
+		b: string
+	}
+};
+
+class A {
+	view() {
+		return [
+			<meta content="helloworld"></meta>,
+			<meta content={c.a!.b}></meta>
+		];
+	}
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/jsxFactoryQualifiedNameResolutionError.ts b/tests/cases/compiler/jsxFactoryQualifiedNameResolutionError.ts
new file mode 100644
index 00000000000..a8996245138
--- /dev/null
+++ b/tests/cases/compiler/jsxFactoryQualifiedNameResolutionError.ts
@@ -0,0 +1,18 @@
+//@jsx: react
+//@target: es6
+//@module: commonjs
+//@jsxFactory: MyElement.createElement
+//@sourcemap: true
+
+// @filename: test.tsx
+declare module JSX {
+    interface IntrinsicElements {
+        [s: string]: any;
+    }
+}
+
+export class AppComponent {
+    render(createElement) {
+        return <div />;
+    }
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/switchCasesExpressionTypeMismatch.ts b/tests/cases/compiler/switchCasesExpressionTypeMismatch.ts
index 4de01ebba17..ee547705b84 100644
--- a/tests/cases/compiler/switchCasesExpressionTypeMismatch.ts
+++ b/tests/cases/compiler/switchCasesExpressionTypeMismatch.ts
@@ -3,7 +3,7 @@ class Foo { }
 switch (0) {
     case Foo: break;    // Error
     case "sss": break;  // Error
-    case 123: break;    // No Error
+    case 123: break;    // Error
     case true: break;   // Error
 }
 
@@ -15,4 +15,4 @@ switch (s) {
     case "sss": break;
     case 123: break;
     case true: break;
-}
\ No newline at end of file
+}
diff --git a/tests/cases/compiler/switchComparableCompatForBrands.ts b/tests/cases/compiler/switchComparableCompatForBrands.ts
new file mode 100644
index 00000000000..4b90db40e1d
--- /dev/null
+++ b/tests/cases/compiler/switchComparableCompatForBrands.ts
@@ -0,0 +1,13 @@
+class MyBrand
+{
+    private _a: number;
+}
+
+function test(strInput: string & MyBrand) {
+    switch(strInput)
+    {
+        case "a":
+        return 1;
+    }
+    return 0;
+}
diff --git a/tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts b/tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts
index 2b3192bc9a2..1e2bc1e68b4 100644
--- a/tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts
+++ b/tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts
@@ -3,8 +3,5 @@ var {h?} = { h?: 1 };
 var {i}: string | number = { i: 2 };
 var {i1}: string | number| {} = { i1: 2 };
 var { f2: {f21} = { f212: "string" } }: any = undefined;
-var { ...d1 } = {
-    a: 1, b: 1, d1: 9, e: 10
-}
 var {1} = { 1 };
-var {"prop"} = { "prop": 1 };
\ No newline at end of file
+var {"prop"} = { "prop": 1 };
diff --git a/tests/cases/conformance/externalModules/globalAugmentationModuleResolution.ts b/tests/cases/conformance/externalModules/globalAugmentationModuleResolution.ts
new file mode 100644
index 00000000000..4d87ffcab13
--- /dev/null
+++ b/tests/cases/conformance/externalModules/globalAugmentationModuleResolution.ts
@@ -0,0 +1,8 @@
+// @traceResolution: true
+
+// @fileName: a.ts
+export { };
+
+declare global {
+  var x: number;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/types/rest/objectRest.ts b/tests/cases/conformance/types/rest/objectRest.ts
new file mode 100644
index 00000000000..f1a77b1c129
--- /dev/null
+++ b/tests/cases/conformance/types/rest/objectRest.ts
@@ -0,0 +1,33 @@
+// @target: es2015
+let o = { a: 1, b: 'no' }
+var { ...clone } = o;
+var { a, ...justB } = o;
+var { a, b: renamed, ...empty } = o;
+var { ['b']: renamed, ...justA } = o;
+var { 'b': renamed, ...justA } = o;
+var { b: { '0': n, '1': oooo }, ...justA } = o;
+
+let o2 = { c: 'terrible idea?', d: 'yes' };
+var { d: renamed, ...d } = o2;
+
+let nestedrest: { x: number, n1: { y: number, n2: { z: number, n3: { n4: number } } }, rest: number, restrest: number };
+var { x, n1: { y, n2: { z, n3: { ...nr } } }, ...restrest } = nestedrest;
+
+let complex: { x: { ka, ki }, y: number };
+var { x: { ka, ...nested }, y: other, ...rest } = complex;
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+var { x, ...fresh } = { x: 1, y: 2 };
+({ x, ...fresh } = { x: 1, y: 2 });
+
+class Removable {
+    private x: number;
+    protected y: number;
+    set z(value: number) { }
+    get both(): number { return 12 }
+    set both(value: number) { }
+    m() { }
+    removed: string;
+    remainder: string;
+}
+var removable = new Removable();
+var { removed, ...removableRest } = removable;
diff --git a/tests/cases/conformance/types/rest/objectRestAssignment.ts b/tests/cases/conformance/types/rest/objectRestAssignment.ts
new file mode 100644
index 00000000000..dedc99b1f71
--- /dev/null
+++ b/tests/cases/conformance/types/rest/objectRestAssignment.ts
@@ -0,0 +1,14 @@
+// @target: es2015
+let ka: any;
+let nested: { ki };
+let other: number;
+let rest: { };
+let complex: { x: { ka, ki }, y: number };
+({x: { ka, ...nested }, y: other, ...rest} = complex);
+
+// should be:
+let overEmit: { a: { ka: string, x: string }[], b: { z: string, ki: string, ku: string }, ke: string, ko: string };
+
+// var _g = overEmit.a, [_h, ...y] = _g, nested2 = __rest(_h, []), _j = overEmit.b, { z } = _j, c = __rest(_j, ["z"]), rest2 = __rest(overEmit, ["a", "b"]);
+var { a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit;
+({ a: [{ ...nested2 }, ...y], b: { z, ...c }, ...rest2 } = overEmit);
diff --git a/tests/cases/conformance/types/rest/objectRestForOf.ts b/tests/cases/conformance/types/rest/objectRestForOf.ts
new file mode 100644
index 00000000000..4f675b1f15b
--- /dev/null
+++ b/tests/cases/conformance/types/rest/objectRestForOf.ts
@@ -0,0 +1,14 @@
+// @target: es2015
+let array: { x: number, y: string }[];
+for (let { x, ...restOf } of array) {
+    [x, restOf];
+}
+let xx: number;
+let rrestOff: { y: string };
+for ({ x: xx, ...rrestOff } of array ) {
+    [xx, rrestOff];
+}
+for (const norest of array.map(a => ({ ...a, x: 'a string' }))) {
+    [norest.x, norest.y];
+    // x is now a string. who knows why.
+}
diff --git a/tests/cases/conformance/types/rest/objectRestNegative.ts b/tests/cases/conformance/types/rest/objectRestNegative.ts
new file mode 100644
index 00000000000..75cbe9a55e4
--- /dev/null
+++ b/tests/cases/conformance/types/rest/objectRestNegative.ts
@@ -0,0 +1,11 @@
+let o = { a: 1, b: 'no' };
+var { ...mustBeLast, a } = o;
+function stillMustBeLast({ ...mustBeLast, a }: { a: number, b: string }): void {
+}
+function generic<T extends { x, y }>(t: T) {
+    let { x, ...rest } = t;
+    return rest;
+}
+
+let rest: { b: string }
+({a, ...rest.b + rest.b} = o);
diff --git a/tests/cases/conformance/types/rest/objectRestParameter.ts b/tests/cases/conformance/types/rest/objectRestParameter.ts
new file mode 100644
index 00000000000..5b47442f047
--- /dev/null
+++ b/tests/cases/conformance/types/rest/objectRestParameter.ts
@@ -0,0 +1,8 @@
+// @target: es2015
+function cloneAgain({ a, ...clone }: { a: number, b: string }): void {
+}
+
+declare function suddenly(f: (a: { x: { z, ka }, y: string }) => void);
+suddenly(({ x: a, ...rest }) => rest.y);
+suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka);
+
diff --git a/tests/cases/conformance/es6/destructuring/restElementMustBeLast.ts b/tests/cases/conformance/types/rest/restElementMustBeLast.ts
similarity index 100%
rename from tests/cases/conformance/es6/destructuring/restElementMustBeLast.ts
rename to tests/cases/conformance/types/rest/restElementMustBeLast.ts
diff --git a/tests/cases/conformance/types/spread/objectSpread.ts b/tests/cases/conformance/types/spread/objectSpread.ts
new file mode 100644
index 00000000000..ebf2bdb2ade
--- /dev/null
+++ b/tests/cases/conformance/types/spread/objectSpread.ts
@@ -0,0 +1,81 @@
+// @target: es5
+let o = { a: 1, b: 'no' }
+let o2 = { b: 'yes', c: true }
+let swap = { a: 'yes', b: -1 };
+
+let addAfter: { a: number, b: string, c: boolean } =
+    { ...o, c: false }
+let addBefore: { a: number, b: string, c: boolean } =
+    { c: false, ...o }
+// Note: ignore still changes the order that properties are printed
+let ignore: { a: number, b: string } =
+    { b: 'ignored', ...o }
+let override: { a: number, b: string } =
+    { ...o, b: 'override' }
+let nested: { a: number, b: boolean, c: string } =
+    { ...{ a: 3, ...{ b: false, c: 'overriden' } }, c: 'whatever' }
+let combined: { a: number, b: string, c: boolean } =
+    { ...o, ...o2 }
+let combinedBefore: { a: number, b: string, c: boolean } =
+    { b: 'ok', ...o, ...o2 }
+let combinedMid: { a: number, b: string, c: boolean } =
+    { ...o, b: 'ok', ...o2 }
+let combinedAfter: { a: number, b: string, c: boolean } =
+    { ...o, ...o2, b: 'ok' }
+let combinedNested: { a: number, b: boolean, c: string, d: string } =
+    { ...{ a: 4, ...{ b: false, c: 'overriden' } }, d: 'actually new', ...{ a: 5, d: 'maybe new' } }
+let combinedNestedChangeType: { a: number, b: boolean, c: number } =
+    { ...{ a: 1, ...{ b: false, c: 'overriden' } }, c: -1 }
+let propertyNested: { a: { a: number, b: string } } =
+    { a: { ... o } }
+// accessors don't copy the descriptor
+// (which means that readonly getters become read/write properties)
+let op = { get a () { return 6 } };
+let getter: { a: number, c: number } =
+    { ...op, c: 7 }
+getter.a = 12;
+
+// functions result in { }
+let spreadFunc = { ...(function () { }) };
+
+// any results in any
+let anything: any;
+let spreadAny = { ...anything };
+
+// methods are not enumerable
+class C { p = 1; m() { } }
+let c: C = new C()
+let spreadC: { p: number } = { ...c }
+
+// own methods are enumerable
+let cplus: { p: number, plus(): void } = { ...c, plus() { return this.p + 1; } };
+cplus.plus();
+
+// new field's type conflicting with existing field is OK
+let changeTypeAfter: { a: string, b: string } =
+    { ...o, a: 'wrong type?' }
+let changeTypeBefore: { a: number, b: string } =
+    { a: 'wrong type?', ...o };
+let changeTypeBoth: { a: string, b: number } =
+    { ...o, ...swap };
+
+// optional
+let definiteBoolean: { sn: boolean };
+let definiteString: { sn: string };
+let optionalString: { sn?: string };
+let optionalNumber: { sn?: number };
+let optionalUnionStops: { sn: string | number | boolean } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+
+// computed property
+let computedFirst: { a: number, b: string, "before everything": number } =
+    { ['before everything']: 12, ...o, b: 'yes' }
+let computedMiddle: { a: number, b: string, c: boolean, "in the middle": number } =
+    { ...o, ['in the middle']: 13, b: 'maybe?', ...o2 }
+let computedAfter: { a: number, b: string, "at the end": number } =
+    { ...o, b: 'yeah', ['at the end']: 14 }
+// shortcut syntax
+let a = 12;
+let shortCutted: { a: number, b: string } = { ...o, a }
+
diff --git a/tests/cases/conformance/types/spread/objectSpreadIndexSignature.ts b/tests/cases/conformance/types/spread/objectSpreadIndexSignature.ts
new file mode 100644
index 00000000000..ae46f2547d5
--- /dev/null
+++ b/tests/cases/conformance/types/spread/objectSpreadIndexSignature.ts
@@ -0,0 +1,16 @@
+interface Indexed {
+    [n: string]: number;
+    a: number;
+}
+interface Indexed2 {
+    [n: string]: boolean;
+    c: boolean;
+}
+let indexed: Indexed;
+let indexed2: Indexed2;
+let i = { ...indexed, b: 11 };
+// only indexed has indexer, so i[101]: any
+i[101];
+let ii = { ...indexed, ...indexed2 };
+// both have indexer, so i[1001]: number | boolean
+ii[1001];
diff --git a/tests/cases/conformance/types/spread/objectSpreadNegative.ts b/tests/cases/conformance/types/spread/objectSpreadNegative.ts
new file mode 100644
index 00000000000..3cd819d0613
--- /dev/null
+++ b/tests/cases/conformance/types/spread/objectSpreadNegative.ts
@@ -0,0 +1,71 @@
+// @target: es5
+let o = { a: 1, b: 'no' }
+
+/// private propagates
+class PrivateOptionalX {
+    private x?: number;
+}
+class PublicX {
+    public x: number;
+}
+let publicX: PublicX;
+let privateOptionalX: PrivateOptionalX;
+let o2 = { ...publicX, ...privateOptionalX };
+let sn: number = o2.x; // error, x is private
+let optionalString: { sn?: string };
+let optionalNumber: { sn?: number };
+let allOptional: { sn: string | number } = { ...optionalString, ...optionalNumber };
+// error, 'sn' is optional in source, required in target
+
+// assignability as target
+interface Bool { b: boolean };
+interface Str { s: string };
+let spread = { ...{ b: true }, ...{s: "foo" } };
+spread = { s: "foo" };  // error, missing 'b'
+let b = { b: false };
+spread = b; // error, missing 's'
+
+// literal repeats are not allowed, but spread repeats are fine
+let duplicated = { b: 'bad', ...o, b: 'bad', ...o2, b: 'bad' }
+let duplicatedSpread = { ...o, ...o }
+
+// null, undefined and primitives are not allowed
+let spreadNull = { ...null };
+let spreadUndefind = { ...undefined };
+let spreadNum = { ...12 };
+let spreadSum = { ...1 + 1 };
+spreadSum.toFixed(); // error, no methods from number
+let spreadBool = { ...false };
+spreadBool.valueOf(); // error, what were you thinking?
+let spreadStr = { ...'foo' };
+spreadStr.length; // error, no 'length'
+spreadStr.charAt(1); // error, no methods either
+// functions are skipped
+let spreadFunc = { ...function () { } }
+spreadFunc(); // error, no call signature
+
+// write-only properties get skipped
+let setterOnly = { ...{ set b (bad: number) { } } };
+setterOnly.b = 12; // error, 'b' does not exist
+
+// methods are skipped because they aren't enumerable
+class C { p = 1; m() { } }
+let c: C = new C()
+let spreadC = { ...c }
+spreadC.m(); // error 'm' is not in '{ ... c }'
+
+// generics
+function f<T, U>(t: T, u: U) {
+    return { ...t, ...u, id: 'id' };
+}
+function override<U>(initial: U, override: U): U {
+    return { ...initial, ...override };
+}
+let exclusive: { id: string, a: number, b: string, c: string, d: boolean } =
+    f({ a: 1, b: 'yes' }, { c: 'no', d: false })
+let overlap: { id: string, a: number, b: string } =
+    f({ a: 1 }, { a: 2, b: 'extra' })
+let overlapConflict: { id:string, a: string } =
+    f({ a: 1 }, { a: 'mismatch' })
+let overwriteId: { id: string, a: number, c: number, d: string } =
+    f({ a: 1, id: true }, { c: 1, d: 'no' })
diff --git a/tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts b/tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts
new file mode 100644
index 00000000000..47fd787ec9a
--- /dev/null
+++ b/tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts
@@ -0,0 +1,4 @@
+let o7 = { ...o? };
+let o8 = { ...*o };
+let o9 = { ...matchMedia() { }};
+let o10 = { ...get x() { return 12; }};
diff --git a/tests/cases/conformance/types/spread/objectSpreadNoTransform.ts b/tests/cases/conformance/types/spread/objectSpreadNoTransform.ts
new file mode 100644
index 00000000000..36c75e70887
--- /dev/null
+++ b/tests/cases/conformance/types/spread/objectSpreadNoTransform.ts
@@ -0,0 +1,6 @@
+// @target: esnext
+const y = { a: 'yes', b: 'no' };
+const o = { x: 1, ...y };
+var b;
+var rest;
+({ b, ...rest } = o);
diff --git a/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts b/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts
new file mode 100644
index 00000000000..087d47df26c
--- /dev/null
+++ b/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts
@@ -0,0 +1,21 @@
+// @strictNullChecks: true
+
+function f(
+    definiteBoolean: { sn: boolean },
+    definiteString: { sn: string },
+    optionalString: { sn?: string },
+    optionalNumber: { sn?: number },
+    undefinedString: { sn: string | undefined },
+    undefinedNumber: { sn: number | undefined }) {
+    // optional
+    let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+    let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+    let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+
+    // undefined
+    let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
+    let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
+    let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
+
+    let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
+}
diff --git a/tests/cases/fourslash/completionListForObjectSpread.ts b/tests/cases/fourslash/completionListForObjectSpread.ts
new file mode 100644
index 00000000000..ca96797195c
--- /dev/null
+++ b/tests/cases/fourslash/completionListForObjectSpread.ts
@@ -0,0 +1,35 @@
+/// <reference path='fourslash.ts'/>
+////let o = { a: 1, b: 'no' }
+////let o2 = { b: 'yes', c: true }
+////let swap = { a: 'yes', b: -1 };
+////let addAfter: { a: number, b: string, c: boolean } =
+////    { ...o, c: false }
+////let addBefore: { a: number, b: string, c: boolean } =
+////    { c: false, ...o }
+////let ignore: { a: number, b: string } =
+////    { b: 'ignored', ...o }
+////ignore./*1*/a;
+////let combinedNestedChangeType: { a: number, b: boolean, c: number } =
+////    { ...{ a: 1, ...{ b: false, c: 'overriden' } }, c: -1 }
+////combinedNestedChangeType./*2*/a;
+////let spreadNull: { a: number } =
+////    { a: 7, ...null }
+////let spreadUndefined: { a: number } =
+////    { a: 7, ...undefined }
+////spreadNull./*3*/a;
+////spreadUndefined./*4*/a;
+goTo.marker('1');
+verify.memberListContains('a', '(property) a: number');
+verify.memberListContains('b', '(property) b: string');
+verify.memberListCount(2);
+goTo.marker('2');
+verify.memberListContains('a', '(property) a: number');
+verify.memberListContains('b', '(property) b: boolean');
+verify.memberListContains('c', '(property) c: number');
+verify.memberListCount(3);
+goTo.marker('3');
+verify.memberListContains('a', '(property) a: number');
+verify.memberListCount(1);
+goTo.marker('4');
+verify.memberListContains('a', '(property) a: number');
+verify.memberListCount(1);
diff --git a/tests/cases/fourslash/completionListForRest.ts b/tests/cases/fourslash/completionListForRest.ts
new file mode 100644
index 00000000000..b880a90b3df
--- /dev/null
+++ b/tests/cases/fourslash/completionListForRest.ts
@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts'/>
+////interface Gen {
+////    x: number;
+////    parent: Gen;
+////    millenial: string;
+////}
+////let t: Gen;
+////var { x, ...rest } = t;
+////rest./*1*/x;
+goTo.marker('1');
+verify.memberListContains('parent', '(property) Gen.parent: Gen');
+verify.memberListContains('millenial', '(property) Gen.millenial: string');
+verify.memberListCount(2);
diff --git a/tests/cases/fourslash/findAllRefsForObjectSpread.ts b/tests/cases/fourslash/findAllRefsForObjectSpread.ts
new file mode 100644
index 00000000000..05c83491f66
--- /dev/null
+++ b/tests/cases/fourslash/findAllRefsForObjectSpread.ts
@@ -0,0 +1,14 @@
+/// <reference path='fourslash.ts'/>
+
+////interface A1 { [|a|]: string };
+////interface A2 { [|a|]?: number };
+////let a1: A1;
+////let a2: A2;
+////let a12 = { ...a1, ...a2 };
+////a12.[|a|];
+const ranges = test.ranges();
+// members of spread types only refer to themselves and the resulting property
+verify.referencesOf(ranges[0], [ranges[0], ranges[2]]);
+verify.referencesOf(ranges[1], [ranges[1], ranges[2]]);
+// but the resulting property refers to everything
+verify.referencesOf(ranges[2], ranges);
diff --git a/tests/cases/fourslash/findAllRefsForRest.ts b/tests/cases/fourslash/findAllRefsForRest.ts
new file mode 100644
index 00000000000..c3a970e9e73
--- /dev/null
+++ b/tests/cases/fourslash/findAllRefsForRest.ts
@@ -0,0 +1,12 @@
+/// <reference path='fourslash.ts'/>
+////interface Gen {
+////    x: number
+////    [|parent|]: Gen;
+////    millenial: string;
+////}
+////let t: Gen;
+////var { x, ...rest } = t;
+////rest.[|parent|];
+const ranges = test.ranges();
+verify.referencesOf(ranges[0], ranges);
+verify.referencesOf(ranges[1], ranges);
diff --git a/tests/cases/fourslash/fourslash.ts b/tests/cases/fourslash/fourslash.ts
index 0a72d295295..295b8e422b9 100644
--- a/tests/cases/fourslash/fourslash.ts
+++ b/tests/cases/fourslash/fourslash.ts
@@ -194,6 +194,7 @@ declare namespace FourSlashInterface {
         currentSignatureHelpDocCommentIs(docComment: string): void;
         signatureHelpCountIs(expected: number): void;
         signatureHelpArgumentCountIs(expected: number): void;
+        signatureHelpCurrentArgumentListIsVariadic(expected: boolean);
         currentSignatureParameterCountIs(expected: number): void;
         currentSignatureTypeParameterCountIs(expected: number): void;
         currentSignatureHelpIs(expected: string): void;
diff --git a/tests/cases/fourslash/goToDefinitionObjectSpread.ts b/tests/cases/fourslash/goToDefinitionObjectSpread.ts
new file mode 100644
index 00000000000..b23d0a80448
--- /dev/null
+++ b/tests/cases/fourslash/goToDefinitionObjectSpread.ts
@@ -0,0 +1,9 @@
+/// <reference path='fourslash.ts'/>
+
+////interface A1 { /*1*/a: number };
+////interface A2 { /*2*/a?: number };
+////let a1: A1;
+////let a2: A2;
+////let a12 = { ...a1, ...a2 };
+////a12.a/*3*/;
+verify.goToDefinition('3', [ '1', '2' ]);
diff --git a/tests/cases/fourslash/goToDefinitionRest.ts b/tests/cases/fourslash/goToDefinitionRest.ts
new file mode 100644
index 00000000000..1459b9ffa88
--- /dev/null
+++ b/tests/cases/fourslash/goToDefinitionRest.ts
@@ -0,0 +1,12 @@
+
+/// <reference path='fourslash.ts'/>
+////interface Gen {
+////    x: number;
+////    /*1*/parent: Gen;
+////    millenial: string;
+////}
+////let t: Gen;
+////var { x, ...rest } = t;
+////rest./*2*/parent;
+const ranges = test.ranges();
+verify.goToDefinition('2', [ '1' ]);
diff --git a/tests/cases/fourslash/renameObjectSpread.ts b/tests/cases/fourslash/renameObjectSpread.ts
new file mode 100644
index 00000000000..eba148c0e39
--- /dev/null
+++ b/tests/cases/fourslash/renameObjectSpread.ts
@@ -0,0 +1,20 @@
+/// <reference path='fourslash.ts'/>
+
+////interface A1 { [|a|]: number };
+////interface A2 { [|a|]?: number };
+////let a1: A1;
+////let a2: A2;
+////let a12 = { ...a1, ...a2 };
+////a12.[|a|];
+const ranges = test.ranges();
+verify.assertHasRanges(ranges);
+
+// A1 unions with A2, so rename A1.a and a12.a
+goTo.position(ranges[0].start);
+verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false, [ranges[0], ranges[2]]);
+// A1 unions with A2, so rename A2.a and a12.a
+goTo.position(ranges[1].start);
+verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false, [ranges[1], ranges[2]]);
+// a12.a unions A1.a and A2.a, so rename A1.a, A2.a and a12.a
+goTo.position(ranges[2].start);
+verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false, [ranges[0], ranges[1], ranges[2]]);
diff --git a/tests/cases/fourslash/renameRest.ts b/tests/cases/fourslash/renameRest.ts
new file mode 100644
index 00000000000..a5cc2c38683
--- /dev/null
+++ b/tests/cases/fourslash/renameRest.ts
@@ -0,0 +1,15 @@
+/// <reference path='fourslash.ts'/>
+////interface Gen {
+////    x: number;
+////    [|parent|]: Gen;
+////    millenial: string;
+////}
+////let t: Gen;
+////var { x, ...rest } = t;
+////rest.[|parent|];
+const ranges = test.ranges();
+verify.assertHasRanges(ranges);
+goTo.position(ranges[0].start);
+verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false, ranges);
+goTo.position(ranges[1].start);
+verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false, ranges);
diff --git a/tests/cases/fourslash/server/getJavaScriptSyntacticDiagnostics02.ts b/tests/cases/fourslash/server/getJavaScriptSyntacticDiagnostics02.ts
index dd9becad10b..a19d170217c 100644
--- a/tests/cases/fourslash/server/getJavaScriptSyntacticDiagnostics02.ts
+++ b/tests/cases/fourslash/server/getJavaScriptSyntacticDiagnostics02.ts
@@ -15,6 +15,13 @@ verify.getSyntacticDiagnostics(`[
     "category": "error",
     "code": 8010
   },
+  {
+    "message": "\'types\' can only be used in a .ts file.",
+    "start": 52,
+    "length": 6,
+    "category": "error",
+    "code": 8010
+  },
   {
     "message": "Variable declaration expected.",
     "start": 67,
diff --git a/tests/cases/fourslash/signatureHelpTypeParametersNotVariadic.ts b/tests/cases/fourslash/signatureHelpTypeParametersNotVariadic.ts
new file mode 100644
index 00000000000..30b0bac7e71
--- /dev/null
+++ b/tests/cases/fourslash/signatureHelpTypeParametersNotVariadic.ts
@@ -0,0 +1,8 @@
+/// <reference path="fourslash.ts" />
+
+//// declare function f(a: any, ...b: any[]): any;
+//// f</*1*/>(1, 2);
+
+goTo.marker("1");
+verify.signatureHelpArgumentCountIs(0);
+verify.signatureHelpCurrentArgumentListIsVariadic(false);
\ No newline at end of file