diff --git a/ThirdPartyNoticeText.txt b/ThirdPartyNoticeText.txt
index 6fbb7e4a0ce..a9ffbddbd89 100644
--- a/ThirdPartyNoticeText.txt
+++ b/ThirdPartyNoticeText.txt
@@ -21,7 +21,7 @@ Third Party Code Components
 --------------------------------------------
 
 ------------------- DefinitelyTyped --------------------
-This file is based on or incorporates material from the projects listed below (collectively ?Third Party Code?). Microsoft is not the original author of the Third Party Code. The original copyright notice and the license, under which Microsoft received such Third Party Code, are set forth below. Such licenses and notices are provided for informational purposes only. Microsoft, not the third party, licenses the Third Party Code to you under the terms set forth in the EULA for the Microsoft Product. Microsoft reserves all other rights not expressly granted under this agreement, whether by implication, estoppel or otherwise. 
+This file is based on or incorporates material from the projects listed below (collectively "Third Party Code"). Microsoft is not the original author of the Third Party Code. The original copyright notice and the license, under which Microsoft received such Third Party Code, are set forth below. Such licenses and notices are provided for informational purposes only. Microsoft, not the third party, licenses the Third Party Code to you under the terms set forth in the EULA for the Microsoft Product. Microsoft reserves all other rights not expressly granted under this agreement, whether by implication, estoppel or otherwise. 
 DefinitelyTyped
 This project is licensed under the MIT license.
 Copyrights are respective of each contributor listed at the beginning of each definition file.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 06591a7ab3d..0181c8c78f6 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -51,6 +51,7 @@ namespace ts {
         const compilerOptions = host.getCompilerOptions();
         const languageVersion = compilerOptions.target || ScriptTarget.ES3;
         const modulekind = getEmitModuleKind(compilerOptions);
+        const noUnusedIdentifiers = !!compilerOptions.noUnusedLocals || !!compilerOptions.noUnusedParameters;
         const allowSyntheticDefaultImports = typeof compilerOptions.allowSyntheticDefaultImports !== "undefined" ? compilerOptions.allowSyntheticDefaultImports : modulekind === ModuleKind.System;
         const strictNullChecks = compilerOptions.strictNullChecks;
 
@@ -187,6 +188,7 @@ namespace ts {
         let jsxElementClassType: Type;
 
         let deferredNodes: Node[];
+        let deferredUnusedIdentifierNodes: Node[];
 
         let flowLoopStart = 0;
         let flowLoopCount = 0;
@@ -394,7 +396,7 @@ namespace ts {
                 target.flags |= source.flags;
                 if (source.valueDeclaration &&
                     (!target.valueDeclaration ||
-                     (target.valueDeclaration.kind === SyntaxKind.ModuleDeclaration && source.valueDeclaration.kind !== SyntaxKind.ModuleDeclaration))) {
+                        (target.valueDeclaration.kind === SyntaxKind.ModuleDeclaration && source.valueDeclaration.kind !== SyntaxKind.ModuleDeclaration))) {
                     // other kinds of value declarations take precedence over modules
                     target.valueDeclaration = source.valueDeclaration;
                 }
@@ -664,8 +666,8 @@ namespace ts {
                                 useResult = result.flags & SymbolFlags.TypeParameter
                                     // type parameters are visible in parameter list, return type and type parameter list
                                     ? lastLocation === (<FunctionLikeDeclaration>location).type ||
-                                      lastLocation.kind === SyntaxKind.Parameter ||
-                                      lastLocation.kind === SyntaxKind.TypeParameter
+                                    lastLocation.kind === SyntaxKind.Parameter ||
+                                    lastLocation.kind === SyntaxKind.TypeParameter
                                     // local types not visible outside the function body
                                     : false;
                             }
@@ -847,6 +849,10 @@ namespace ts {
                 location = location.parent;
             }
 
+            if (result && nameNotFoundMessage && noUnusedIdentifiers) {
+                result.isReferenced = true;
+            }
+
             if (!result) {
                 result = getSymbol(globals, name, meaning);
             }
@@ -854,7 +860,7 @@ namespace ts {
             if (!result) {
                 if (nameNotFoundMessage) {
                     if (!checkAndReportErrorForMissingPrefix(errorLocation, name, nameArg) &&
-                       !checkAndReportErrorForExtendingInterface(errorLocation)) {
+                        !checkAndReportErrorForExtendingInterface(errorLocation)) {
                         error(errorLocation, nameNotFoundMessage, typeof nameArg === "string" ? nameArg : declarationNameToString(nameArg));
                     }
                 }
@@ -961,7 +967,7 @@ namespace ts {
                 return true;
             }
             return false;
-         }
+        }
 
         function checkResolvedBlockScopedVariable(result: Symbol, errorLocation: Node): void {
             Debug.assert((result.flags & SymbolFlags.BlockScopedVariable) !== 0);
@@ -1022,8 +1028,8 @@ namespace ts {
                 const exportDefaultSymbol = isShorthandAmbientModule(moduleSymbol.valueDeclaration) ?
                     moduleSymbol :
                     moduleSymbol.exports["export="] ?
-                    getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
-                    resolveSymbol(moduleSymbol.exports["default"]);
+                        getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
+                        resolveSymbol(moduleSymbol.exports["default"]);
 
                 if (!exportDefaultSymbol && !allowSyntheticDefaultImports) {
                     error(node.name, Diagnostics.Module_0_has_no_default_export, symbolToString(moduleSymbol));
@@ -4536,7 +4542,7 @@ namespace ts {
                     : undefined;
                 const typeParameters = classType ? classType.localTypeParameters :
                     declaration.typeParameters ? getTypeParametersFromDeclaration(declaration.typeParameters) :
-                    getTypeParametersFromJSDocTemplate(declaration);
+                        getTypeParametersFromJSDocTemplate(declaration);
                 const returnType = getSignatureReturnTypeFromDeclaration(declaration, minArgumentCount, isJSConstructSignature, classType);
                 const typePredicate = declaration.type && declaration.type.kind === SyntaxKind.TypePredicate ?
                     createTypePredicateFromTypePredicateNode(declaration.type as TypePredicateNode) :
@@ -5165,7 +5171,7 @@ namespace ts {
             if (typeSet.length === 0) {
                 return typeSet.containsNull ? typeSet.containsNonWideningType ? nullType : nullWideningType :
                     typeSet.containsUndefined ? typeSet.containsNonWideningType ? undefinedType : undefinedWideningType :
-                    neverType;
+                        neverType;
             }
             else if (typeSet.length === 1) {
                 return typeSet[0];
@@ -5401,8 +5407,8 @@ namespace ts {
             const count = sources.length;
             const mapper: TypeMapper =
                 count == 1 ? createUnaryTypeMapper(sources[0], targets ? targets[0] : anyType) :
-                count == 2 ? createBinaryTypeMapper(sources[0], targets ? targets[0] : anyType, sources[1], targets ? targets[1] : anyType) :
-                createArrayTypeMapper(sources, targets);
+                    count == 2 ? createBinaryTypeMapper(sources[0], targets ? targets[0] : anyType, sources[1], targets ? targets[1] : anyType) :
+                        createArrayTypeMapper(sources, targets);
             mapper.mappedTypes = sources;
             return mapper;
         }
@@ -5725,8 +5731,8 @@ namespace ts {
         }
 
         function isSignatureAssignableTo(source: Signature,
-                                         target: Signature,
-                                         ignoreReturnTypes: boolean): boolean {
+            target: Signature,
+            ignoreReturnTypes: boolean): boolean {
             return compareSignaturesRelated(source, target, ignoreReturnTypes, /*reportErrors*/ false, /*errorReporter*/ undefined, compareTypesAssignable) !== Ternary.False;
         }
 
@@ -5734,11 +5740,11 @@ namespace ts {
          * See signatureRelatedTo, compareSignaturesIdentical
          */
         function compareSignaturesRelated(source: Signature,
-                                          target: Signature,
-                                          ignoreReturnTypes: boolean,
-                                          reportErrors: boolean,
-                                          errorReporter: (d: DiagnosticMessage, arg0?: string, arg1?: string) => void,
-                                          compareTypes: (s: Type, t: Type, reportErrors?: boolean) => Ternary): Ternary {
+            target: Signature,
+            ignoreReturnTypes: boolean,
+            reportErrors: boolean,
+            errorReporter: (d: DiagnosticMessage, arg0?: string, arg1?: string) => void,
+            compareTypes: (s: Type, t: Type, reportErrors?: boolean) => Ternary): Ternary {
             // TODO (drosen): De-duplicate code between related functions.
             if (source === target) {
                 return Ternary.True;
@@ -5820,10 +5826,10 @@ namespace ts {
         }
 
         function compareTypePredicateRelatedTo(source: TypePredicate,
-                                               target: TypePredicate,
-                                               reportErrors: boolean,
-                                               errorReporter: (d: DiagnosticMessage, arg0?: string, arg1?: string) => void,
-                                               compareTypes: (s: Type, t: Type, reportErrors?: boolean) => Ternary): Ternary {
+            target: TypePredicate,
+            reportErrors: boolean,
+            errorReporter: (d: DiagnosticMessage, arg0?: string, arg1?: string) => void,
+            compareTypes: (s: Type, t: Type, reportErrors?: boolean) => Ternary): Ternary {
             if (source.kind !== target.kind) {
                 if (reportErrors) {
                     errorReporter(Diagnostics.A_this_based_type_guard_is_not_compatible_with_a_parameter_based_type_guard);
@@ -6904,7 +6910,7 @@ namespace ts {
         function isStringLiteralUnionType(type: Type): boolean {
             return type.flags & TypeFlags.StringLiteral ? true :
                 type.flags & TypeFlags.Union ? forEach((<UnionType>type).types, isStringLiteralUnionType) :
-                false;
+                    false;
         }
 
         /**
@@ -6986,11 +6992,11 @@ namespace ts {
             const resolved = <ResolvedType>type;
             const members = transformTypeOfMembers(type, getRegularTypeOfObjectLiteral);
             const regularNew = createAnonymousType(resolved.symbol,
-                                                   members,
-                                                   resolved.callSignatures,
-                                                   resolved.constructSignatures,
-                                                   resolved.stringIndexInfo,
-                                                   resolved.numberIndexInfo);
+                members,
+                resolved.callSignatures,
+                resolved.constructSignatures,
+                resolved.stringIndexInfo,
+                resolved.numberIndexInfo);
             regularNew.flags = resolved.flags & ~TypeFlags.FreshObjectLiteral;
             (<FreshObjectLiteralType>type).regularType = regularNew;
             return regularNew;
@@ -7818,7 +7824,7 @@ namespace ts {
                         // We cache results of flow type resolution for shared nodes that were previously visited in
                         // the same getFlowTypeOfReference invocation. A node is considered shared when it is the
                         // antecedent of more than one node.
-                        for (let i = visitedFlowStart; i < visitedFlowCount;  i++) {
+                        for (let i = visitedFlowStart; i < visitedFlowCount; i++) {
                             if (visitedFlowNodes[i] === flow) {
                                 return visitedFlowTypes[i];
                             }
@@ -8205,7 +8211,7 @@ namespace ts {
                 const targetType = type.flags & TypeFlags.TypeParameter ? getApparentType(type) : type;
                 return isTypeAssignableTo(candidate, targetType) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
-                    getIntersectionType([type, candidate]);
+                        getIntersectionType([type, candidate]);
             }
 
             function narrowTypeByTypePredicate(type: Type, callExpression: CallExpression, assumeTrue: boolean): Type {
@@ -8319,21 +8325,8 @@ namespace ts {
             return container === declarationContainer;
         }
 
-        function updateReferencesForInterfaceHeritiageClauseTargets(node: InterfaceDeclaration): void {
-            const extendedTypeNode = getClassExtendsHeritageClauseElement(node);
-            if (extendedTypeNode) {
-                const t = getTypeFromTypeNode(extendedTypeNode);
-                if (t !== unknownType && t.symbol && (compilerOptions.noUnusedLocals || compilerOptions.noUnusedParameters) && !isInAmbientContext(node)) {
-                    t.symbol.hasReference = true;
-                }
-            }
-        }
-
         function checkIdentifier(node: Identifier): Type {
             const symbol = getResolvedSymbol(node);
-            if (symbol && (compilerOptions.noUnusedLocals || compilerOptions.noUnusedParameters) && !isInAmbientContext(node)) {
-                symbol.hasReference = true;
-            }
 
             // As noted in ECMAScript 6 language spec, arrow functions never have an arguments objects.
             // Although in down-level emit of arrow function, we emit it using function expression which means that
@@ -8624,9 +8617,9 @@ namespace ts {
                     getSpecialPropertyAssignmentKind(container.parent) === SpecialPropertyAssignmentKind.PrototypeProperty) {
                     // Get the 'x' of 'x.prototype.y = f' (here, 'f' is 'container')
                     const className = (((container.parent as BinaryExpression)   // x.prototype.y = f
-                                        .left as PropertyAccessExpression)       // x.prototype.y
-                                        .expression as PropertyAccessExpression) // x.prototype
-                                        .expression;                             // x
+                        .left as PropertyAccessExpression)       // x.prototype.y
+                        .expression as PropertyAccessExpression) // x.prototype
+                        .expression;                             // x
                     const classSymbol = checkExpression(className).symbol;
                     if (classSymbol && classSymbol.members && (classSymbol.flags & SymbolFlags.Function)) {
                         return getInferredClassType(classSymbol);
@@ -9871,7 +9864,7 @@ namespace ts {
                 elemType = checkExpression(node.tagName);
             }
             if (elemType.flags & TypeFlags.Union) {
-                const types = (<UnionOrIntersectionType> elemType).types;
+                const types = (<UnionOrIntersectionType>elemType).types;
                 return getUnionType(types.map(type => {
                     return getResolvedJsxType(node, type, elemClassType);
                 }));
@@ -10248,8 +10241,16 @@ namespace ts {
                 return unknownType;
             }
 
-            if ((compilerOptions.noUnusedLocals || compilerOptions.noUnusedParameters) && !isInAmbientContext(node)) {
-                prop.hasReference = true;
+            if (noUnusedIdentifiers &&
+                (prop.flags & SymbolFlags.ClassMember) &&
+                prop.valueDeclaration && (prop.valueDeclaration.flags & NodeFlags.Private)) {
+                if (prop.flags & SymbolFlags.Instantiated) {
+                    getSymbolLinks(prop).target.isReferenced = true;
+
+                }
+                else {
+                    prop.isReferenced = true;
+                }
             }
 
             getNodeLinks(node).resolvedSymbol = prop;
@@ -11803,7 +11804,7 @@ namespace ts {
                 // if inference didn't come up with anything but {}, fall back to the binding pattern if present.
                 if (links.type === emptyObjectType &&
                     (parameter.valueDeclaration.name.kind === SyntaxKind.ObjectBindingPattern ||
-                     parameter.valueDeclaration.name.kind === SyntaxKind.ArrayBindingPattern)) {
+                        parameter.valueDeclaration.name.kind === SyntaxKind.ArrayBindingPattern)) {
                     links.type = getTypeFromBindingPattern(<BindingPattern>parameter.valueDeclaration.name);
                 }
                 assignBindingElementTypes(<ParameterDeclaration>parameter.valueDeclaration);
@@ -12194,8 +12195,7 @@ namespace ts {
                         }
                     }
                 }
-                checkUnusedIdentifiers(node);
-                checkUnusedTypeParameters(node);
+                registerForUnusedIdentifiersCheck(node);
             }
         }
 
@@ -12544,6 +12544,12 @@ namespace ts {
             if (exprOrAssignment.kind === SyntaxKind.ShorthandPropertyAssignment) {
                 const prop = <ShorthandPropertyAssignment>exprOrAssignment;
                 if (prop.objectAssignmentInitializer) {
+                    // In strict null checking mode, if a default value of a non-undefined type is specified, remove
+                    // undefined from the final type.
+                    if (strictNullChecks &&
+                        !(getCombinedTypeFlags(checkExpression(prop.objectAssignmentInitializer)) & TypeFlags.Undefined)) {
+                        sourceType = getTypeWithFacts(sourceType, TypeFacts.NEUndefined);
+                    }
                     checkBinaryLikeExpression(prop.name, prop.equalsToken, prop.objectAssignmentInitializer, contextualMapper);
                 }
                 target = (<ShorthandPropertyAssignment>exprOrAssignment).name;
@@ -13423,8 +13429,7 @@ namespace ts {
             checkGrammarConstructorTypeParameters(node) || checkGrammarConstructorTypeAnnotation(node);
 
             checkSourceElement(node.body);
-            checkUnusedIdentifiers(node);
-            checkUnusedTypeParameters(node);
+            registerForUnusedIdentifiersCheck(node);
 
             const symbol = getSymbolOfNode(node);
             const firstDeclaration = getDeclarationOfKind(symbol, node.kind);
@@ -13570,6 +13575,7 @@ namespace ts {
             }
             if (node.parent.kind !== SyntaxKind.ObjectLiteralExpression) {
                 checkSourceElement(node.body);
+                registerForUnusedIdentifiersCheck(node);
             }
             else {
                 checkNodeDeferred(node);
@@ -13586,6 +13592,7 @@ namespace ts {
 
         function checkAccessorDeferred(node: AccessorDeclaration) {
             checkSourceElement(node.body);
+            registerForUnusedIdentifiersCheck(node);
         }
 
         function checkMissingDeclaration(node: Node) {
@@ -13618,9 +13625,6 @@ namespace ts {
             checkGrammarTypeArguments(node, node.typeArguments);
             const type = getTypeFromTypeReference(node);
             if (type !== unknownType) {
-                if (type.symbol && (compilerOptions.noUnusedLocals || compilerOptions.noUnusedParameters) && !isInAmbientContext(node)) {
-                    type.symbol.hasReference = true;
-                }
                 if (node.typeArguments) {
                     // Do type argument local checks only if referenced type is successfully resolved
                     forEach(node.typeArguments, checkSourceElement);
@@ -14471,8 +14475,7 @@ namespace ts {
             }
 
             checkSourceElement(node.body);
-            checkUnusedIdentifiers(node);
-            checkUnusedTypeParameters(node);
+
             if (!node.asteriskToken) {
                 const returnOrPromisedType = node.type && (isAsync ? checkAsyncFunctionReturnType(node) : getTypeFromTypeNode(node.type));
                 checkAllCodePathsInNonVoidFunctionReturnOrThrow(node, returnOrPromisedType);
@@ -14492,40 +14495,96 @@ namespace ts {
                     getReturnTypeOfSignature(getSignatureFromDeclaration(node));
                 }
             }
+
+            registerForUnusedIdentifiersCheck(node);
         }
 
-        function checkUnusedIdentifiers(node: FunctionDeclaration | MethodDeclaration | ConstructorDeclaration | FunctionExpression | ArrowFunction | ForInStatement | Block | CatchClause): void {
-            if (node.parent.kind !== SyntaxKind.InterfaceDeclaration && (compilerOptions.noUnusedLocals || compilerOptions.noUnusedParameters) && !isInAmbientContext(node)) {
+        function registerForUnusedIdentifiersCheck(node: Node) {
+            if (deferredUnusedIdentifierNodes) {
+                deferredUnusedIdentifierNodes.push(node);
+            }
+        }
+
+        function checkUnusedIdentifiers() {
+            if (deferredUnusedIdentifierNodes) {
+                for (const node of deferredUnusedIdentifierNodes) {
+                    switch (node.kind) {
+                        case SyntaxKind.SourceFile:
+                        case SyntaxKind.ModuleDeclaration:
+                            checkUnusedModuleMembers(<ModuleDeclaration | SourceFile>node);
+                            break;
+                        case SyntaxKind.ClassDeclaration:
+                        case SyntaxKind.ClassExpression:
+                            checkUnusedClassMembers(<ClassDeclaration | ClassExpression>node);
+                            checkUnusedTypeParameters(<ClassDeclaration | ClassExpression>node);
+                            break;
+                        case SyntaxKind.InterfaceDeclaration:
+                            checkUnusedTypeParameters(<InterfaceDeclaration>node);
+                            break;
+                        case SyntaxKind.Block:
+                        case SyntaxKind.CaseBlock:
+                        case SyntaxKind.ForStatement:
+                        case SyntaxKind.ForInStatement:
+                        case SyntaxKind.ForOfStatement:
+                            checkUnusedLocalsAndParameters(node);
+                            break;
+                        case SyntaxKind.Constructor:
+                        case SyntaxKind.FunctionExpression:
+                        case SyntaxKind.FunctionDeclaration:
+                        case SyntaxKind.ArrowFunction:
+                        case SyntaxKind.MethodDeclaration:
+                        case SyntaxKind.GetAccessor:
+                        case SyntaxKind.SetAccessor:
+                            if ((<FunctionLikeDeclaration>node).body) {
+                                checkUnusedLocalsAndParameters(<FunctionLikeDeclaration>node);
+                            }
+                            checkUnusedTypeParameters(<FunctionLikeDeclaration>node);
+                            break;
+                        case SyntaxKind.MethodSignature:
+                        case SyntaxKind.CallSignature:
+                        case SyntaxKind.ConstructSignature:
+                        case SyntaxKind.IndexSignature:
+                        case SyntaxKind.FunctionType:
+                        case SyntaxKind.ConstructorType:
+                            checkUnusedTypeParameters(<FunctionLikeDeclaration>node);
+                            break;
+                    };
+                }
+            }
+        }
+
+        function checkUnusedLocalsAndParameters(node: Node): void {
+            if (node.parent.kind !== SyntaxKind.InterfaceDeclaration && noUnusedIdentifiers && !isInAmbientContext(node)) {
                 for (const key in node.locals) {
                     if (hasProperty(node.locals, key)) {
                         const local = node.locals[key];
-                        if (!local.hasReference && local.valueDeclaration) {
-                            if (local.valueDeclaration.kind !== SyntaxKind.Parameter && compilerOptions.noUnusedLocals) {
-                                error(local.valueDeclaration.name, Diagnostics._0_is_declared_but_never_used, local.name);
-                            }
-                            else if (local.valueDeclaration.kind === SyntaxKind.Parameter && compilerOptions.noUnusedParameters) {
-                                if (local.valueDeclaration.flags === 0) {
+                        if (!local.isReferenced) {
+                            if (local.valueDeclaration && local.valueDeclaration.kind === SyntaxKind.Parameter) {
+                                if (compilerOptions.noUnusedParameters && !isParameterPropertyDeclaration(<ParameterDeclaration>local.valueDeclaration)) {
                                     error(local.valueDeclaration.name, Diagnostics._0_is_declared_but_never_used, local.name);
                                 }
                             }
+                            else if (compilerOptions.noUnusedLocals) {
+                                forEach(local.declarations, d => error(d.name || d, Diagnostics._0_is_declared_but_never_used, local.name));
+                            }
                         }
                     }
                 }
             }
         }
 
-        function checkUnusedClassLocals(node: ClassDeclaration): void {
+        function checkUnusedClassMembers(node: ClassDeclaration | ClassExpression): void {
             if (compilerOptions.noUnusedLocals && !isInAmbientContext(node)) {
                 if (node.members) {
                     for (const member of node.members) {
                         if (member.kind === SyntaxKind.MethodDeclaration || member.kind === SyntaxKind.PropertyDeclaration) {
-                            if (isPrivateNode(member) && !member.symbol.hasReference) {
+                            if (!member.symbol.isReferenced && member.flags & NodeFlags.Private) {
                                 error(member.name, Diagnostics._0_is_declared_but_never_used, member.symbol.name);
                             }
                         }
                         else if (member.kind === SyntaxKind.Constructor) {
                             for (const parameter of (<ConstructorDeclaration>member).parameters) {
-                                if (isPrivateNode(parameter) && !parameter.symbol.hasReference) {
+                                if (!parameter.symbol.isReferenced && parameter.flags & NodeFlags.Private) {
                                     error(parameter.name, Diagnostics._0_is_declared_but_never_used, parameter.symbol.name);
                                 }
                             }
@@ -14535,11 +14594,11 @@ namespace ts {
             }
         }
 
-        function checkUnusedTypeParameters(node: ClassDeclaration | FunctionDeclaration | MethodDeclaration | FunctionExpression | ArrowFunction | ConstructorDeclaration | SignatureDeclaration | InterfaceDeclaration) {
+        function checkUnusedTypeParameters(node: ClassDeclaration | ClassExpression | FunctionDeclaration | MethodDeclaration | FunctionExpression | ArrowFunction | ConstructorDeclaration | SignatureDeclaration | InterfaceDeclaration) {
             if (compilerOptions.noUnusedLocals && !isInAmbientContext(node)) {
                 if (node.typeParameters) {
                     for (const typeParameter of node.typeParameters) {
-                        if (!typeParameter.symbol.hasReference) {
+                        if (!typeParameter.symbol.isReferenced) {
                             error(typeParameter.name, Diagnostics._0_is_declared_but_never_used, typeParameter.symbol.name);
                         }
                     }
@@ -14547,17 +14606,17 @@ namespace ts {
             }
         }
 
-        function isPrivateNode(node: Node): boolean {
-            return (node.flags & NodeFlags.Private) !== 0;
-        }
-
-        function checkUnusedModuleLocals(node: ModuleDeclaration | SourceFile): void {
+        function checkUnusedModuleMembers(node: ModuleDeclaration | SourceFile): void {
             if (compilerOptions.noUnusedLocals && !isInAmbientContext(node)) {
                 for (const key in node.locals) {
                     if (hasProperty(node.locals, key)) {
                         const local = node.locals[key];
-                        if (!local.hasReference && !local.exportSymbol) {
-                            forEach(local.declarations, d => error(d.name, Diagnostics._0_is_declared_but_never_used, local.name));
+                        if (!local.isReferenced && !local.exportSymbol) {
+                            for (const declaration of local.declarations) {
+                                if (!isAmbientModule(declaration)) {
+                                    error(declaration.name, Diagnostics._0_is_declared_but_never_used, local.name);
+                                }
+                            }
                         }
                     }
                 }
@@ -14570,7 +14629,9 @@ namespace ts {
                 checkGrammarStatementInAmbientContext(node);
             }
             forEach(node.statements, checkSourceElement);
-            checkUnusedIdentifiers(node);
+            if (node.locals) {
+                registerForUnusedIdentifiersCheck(node);
+            }
         }
 
         function checkCollisionWithArgumentsInGeneratedCode(node: SignatureDeclaration) {
@@ -15035,6 +15096,9 @@ namespace ts {
             if (node.condition) checkExpression(node.condition);
             if (node.incrementor) checkExpression(node.incrementor);
             checkSourceElement(node.statement);
+            if (node.locals) {
+                registerForUnusedIdentifiersCheck(node);
+            }
         }
 
         function checkForOfStatement(node: ForOfStatement): void {
@@ -15075,7 +15139,9 @@ namespace ts {
             }
 
             checkSourceElement(node.statement);
-            checkUnusedIdentifiers(node);
+            if (node.locals) {
+                registerForUnusedIdentifiersCheck(node);
+            }
         }
 
         function checkForInStatement(node: ForInStatement) {
@@ -15123,7 +15189,9 @@ namespace ts {
             }
 
             checkSourceElement(node.statement);
-            checkUnusedIdentifiers(node);
+            if (node.locals) {
+                registerForUnusedIdentifiersCheck(node);
+            }
         }
 
         function checkForInOrForOfVariableDeclaration(iterationStatement: ForInStatement | ForOfStatement): void {
@@ -15388,7 +15456,7 @@ namespace ts {
 
         function isUnwrappedReturnTypeVoidOrAny(func: FunctionLikeDeclaration, returnType: Type): boolean {
             const unwrappedReturnType = isAsyncFunctionLike(func) ? getPromisedType(returnType) : returnType;
-            return maybeTypeOfKind(unwrappedReturnType, TypeFlags.Void | TypeFlags.Any);
+            return unwrappedReturnType && maybeTypeOfKind(unwrappedReturnType, TypeFlags.Void | TypeFlags.Any);
         }
 
         function checkReturnStatement(node: ReturnStatement) {
@@ -15496,6 +15564,9 @@ namespace ts {
                 }
                 forEach(clause.statements, checkSourceElement);
             });
+            if (node.caseBlock.locals) {
+                registerForUnusedIdentifiersCheck(node.caseBlock);
+            }
         }
 
         function checkLabeledStatement(node: LabeledStatement) {
@@ -15563,7 +15634,6 @@ namespace ts {
                 }
 
                 checkBlock(catchClause.block);
-                checkUnusedIdentifiers(catchClause);
             }
 
             if (node.finallyBlock) {
@@ -15717,6 +15787,7 @@ namespace ts {
 
         function checkClassExpressionDeferred(node: ClassExpression) {
             forEach(node.members, checkSourceElement);
+            registerForUnusedIdentifiersCheck(node);
         }
 
         function checkClassDeclaration(node: ClassDeclaration) {
@@ -15725,8 +15796,8 @@ namespace ts {
             }
             checkClassLikeDeclaration(node);
             forEach(node.members, checkSourceElement);
-            checkUnusedClassLocals(node);
-            checkUnusedTypeParameters(node);
+
+            registerForUnusedIdentifiersCheck(node);
         }
 
         function checkClassLikeDeclaration(node: ClassLikeDeclaration) {
@@ -16036,7 +16107,6 @@ namespace ts {
 
             if (produceDiagnostics) {
                 checkTypeForDuplicateIndexSignatures(node);
-                updateReferencesForInterfaceHeritiageClauseTargets(node);
                 checkUnusedTypeParameters(node);
             }
         }
@@ -16434,7 +16504,9 @@ namespace ts {
 
             if (node.body) {
                 checkSourceElement(node.body);
-                checkUnusedModuleLocals(node);
+                if (!isGlobalScopeAugmentation(node)) {
+                    registerForUnusedIdentifiersCheck(node);
+                }
             }
         }
 
@@ -16615,9 +16687,6 @@ namespace ts {
                         if (target.flags & SymbolFlags.Type) {
                             checkTypeNameIsReserved(node.name, Diagnostics.Import_name_cannot_be_0);
                         }
-                        if ((compilerOptions.noUnusedLocals || compilerOptions.noUnusedParameters) && !isInAmbientContext(node)) {
-                            target.hasReference = true;
-                        }
                     }
                 }
                 else {
@@ -16959,12 +17028,22 @@ namespace ts {
                 potentialThisCollisions.length = 0;
 
                 deferredNodes = [];
+                deferredUnusedIdentifierNodes = produceDiagnostics && noUnusedIdentifiers ? [] : undefined;
+
                 forEach(node.statements, checkSourceElement);
-                if (isExternalModule(node)) {
-                    checkUnusedModuleLocals(node);
-                }
+
                 checkDeferredNodes();
+
+                if (isExternalModule(node)) {
+                    registerForUnusedIdentifiersCheck(node);
+                }
+
+                if (!node.isDeclarationFile) {
+                    checkUnusedIdentifiers();
+                }
+
                 deferredNodes = undefined;
+                deferredUnusedIdentifierNodes = undefined;
 
                 if (isExternalOrCommonJsModule(node)) {
                     checkExternalModuleExports(node);
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 149f11e155d..2c2aa711711 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -1156,12 +1156,12 @@ namespace ts {
             if (token === SyntaxKind.ExportKeyword) {
                 nextToken();
                 if (token === SyntaxKind.DefaultKeyword) {
-                    return lookAhead(nextTokenIsClassOrFunction);
+                    return lookAhead(nextTokenIsClassOrFunctionOrAsync);
                 }
                 return token !== SyntaxKind.AsteriskToken && token !== SyntaxKind.AsKeyword && token !== SyntaxKind.OpenBraceToken && canFollowModifier();
             }
             if (token === SyntaxKind.DefaultKeyword) {
-                return nextTokenIsClassOrFunction();
+                return nextTokenIsClassOrFunctionOrAsync();
             }
             if (token === SyntaxKind.StaticKeyword) {
                 nextToken();
@@ -1183,9 +1183,9 @@ namespace ts {
                 || isLiteralPropertyName();
         }
 
-        function nextTokenIsClassOrFunction(): boolean {
+        function nextTokenIsClassOrFunctionOrAsync(): boolean {
             nextToken();
-            return token === SyntaxKind.ClassKeyword || token === SyntaxKind.FunctionKeyword;
+            return token === SyntaxKind.ClassKeyword || token === SyntaxKind.FunctionKeyword || token === SyntaxKind.AsyncKeyword;
         }
 
         // True if positioned at the start of a list element
@@ -5071,7 +5071,7 @@ namespace ts {
          * In such situations, 'permitInvalidConstAsModifier' should be set to true.
          */
         function parseModifiers(permitInvalidConstAsModifier?: boolean): ModifiersArray {
-            let flags = 0;
+            let flags: NodeFlags = 0;
             let modifiers: ModifiersArray;
             while (true) {
                 const modifierStart = scanner.getStartPos();
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index befb206ef08..dca38d10ea2 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -779,13 +779,18 @@ namespace ts {
         while (true) {
             const baseName = getBaseFileName(directory);
             if (baseName !== "node_modules") {
-                const result =
-                    // first: try to load module as-is
-                    loadModuleFromNodeModulesFolder(moduleName, directory, failedLookupLocations, state) ||
-                    // second: try to load module from the scope '@types'
-                    loadModuleFromNodeModulesFolder(combinePaths("@types", moduleName), directory, failedLookupLocations, state);
-                if (result) {
-                    return result;
+                // Try to load source from the package
+                const packageResult = loadModuleFromNodeModulesFolder(moduleName, directory, failedLookupLocations, state);
+                if (packageResult && hasTypeScriptFileExtension(packageResult)) {
+                    // Always prefer a TypeScript (.ts, .tsx, .d.ts) file shipped with the package
+                    return packageResult;
+                }
+                else {
+                    // Else prefer a types package over non-TypeScript results (e.g. JavaScript files)
+                    const typesResult = loadModuleFromNodeModulesFolder(combinePaths("@types", moduleName), directory, failedLookupLocations, state);
+                    if (typesResult || packageResult) {
+                        return typesResult || packageResult;
+                    }
                 }
             }
 
@@ -1097,7 +1102,7 @@ namespace ts {
         const modulesWithElidedImports: Map<boolean> = {};
 
         // Track source files that are JavaScript files found by searching under node_modules, as these shouldn't be compiled.
-        const jsFilesFoundSearchingNodeModules: Map<boolean> = {};
+        const sourceFilesFoundSearchingNodeModules: Map<boolean> = {};
 
         const start = new Date().getTime();
 
@@ -1379,7 +1384,7 @@ namespace ts {
                 getSourceFile: program.getSourceFile,
                 getSourceFileByPath: program.getSourceFileByPath,
                 getSourceFiles: program.getSourceFiles,
-                getFilesFromNodeModules: () => jsFilesFoundSearchingNodeModules,
+                isSourceFileFromExternalLibrary: (file: SourceFile) => !!lookUp(sourceFilesFoundSearchingNodeModules, file.path),
                 writeFile: writeFileCallback || (
                     (fileName, data, writeByteOrderMark, onError, sourceFiles) => host.writeFile(fileName, data, writeByteOrderMark, onError, sourceFiles)),
                 isEmitBlocked,
@@ -2071,15 +2076,17 @@ namespace ts {
                     // - noResolve is falsy
                     // - module name comes from the list of imports
                     // - it's not a top level JavaScript module that exceeded the search max
-                    const isJsFileUnderNodeModules = resolution && resolution.isExternalLibraryImport &&
-                                                 hasJavaScriptFileExtension(resolution.resolvedFileName);
+                    const isFromNodeModulesSearch = resolution && resolution.isExternalLibraryImport;
+                    const isJsFileFromNodeModules = isFromNodeModulesSearch && hasJavaScriptFileExtension(resolution.resolvedFileName);
 
-                    if (isJsFileUnderNodeModules) {
-                        jsFilesFoundSearchingNodeModules[resolvedPath] = true;
+                    if (isFromNodeModulesSearch) {
+                        sourceFilesFoundSearchingNodeModules[resolvedPath] = true;
+                    }
+                    if (isJsFileFromNodeModules) {
                         currentNodeModulesJsDepth++;
                     }
 
-                    const elideImport = isJsFileUnderNodeModules && currentNodeModulesJsDepth > maxNodeModulesJsDepth;
+                    const elideImport = isJsFileFromNodeModules && currentNodeModulesJsDepth > maxNodeModulesJsDepth;
                     const shouldAddFile = resolution && !options.noResolve && i < file.imports.length && !elideImport;
 
                     if (elideImport) {
@@ -2094,7 +2101,7 @@ namespace ts {
                                 file.imports[i].end);
                     }
 
-                    if (isJsFileUnderNodeModules) {
+                    if (isJsFileFromNodeModules) {
                         currentNodeModulesJsDepth--;
                     }
                 }
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 7960a9b34c6..cd971c3b0f6 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -469,7 +469,7 @@ namespace ts {
     }
 
     export interface ModifiersArray extends NodeArray<Modifier> {
-        flags: number;
+        flags: NodeFlags;
     }
 
     // @kind(SyntaxKind.AbstractKeyword)
@@ -2108,6 +2108,8 @@ namespace ts {
         PropertyOrAccessor = Property | Accessor,
         Export = ExportNamespace | ExportType | ExportValue,
 
+        ClassMember = Method | Accessor | Property,
+
         /* @internal */
         // The set of things we consider semantically classifiable.  Used to speed up the LS during
         // classification.
@@ -2129,7 +2131,7 @@ namespace ts {
         /* @internal */ parent?: Symbol;        // Parent symbol
         /* @internal */ exportSymbol?: Symbol;  // Exported symbol associated with this symbol
         /* @internal */ constEnumOnlyModule?: boolean; // True if module contains only const enums or other modules with only const enums
-        /* @internal */ hasReference?: boolean; // True if the symbol is referenced elsewhere
+        /* @internal */ isReferenced?: boolean; // True if the symbol is referenced elsewhere
     }
 
     /* @internal */
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index e8f2832cd59..7892af6624f 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -36,7 +36,7 @@ namespace ts {
         getSourceFiles(): SourceFile[];
 
         /* @internal */
-        getFilesFromNodeModules(): Map<boolean>;
+        isSourceFileFromExternalLibrary(file: SourceFile): boolean;
 
         getCommonSourceDirectory(): string;
         getCanonicalFileName(fileName: string): string;
@@ -2277,10 +2277,9 @@ namespace ts {
         }
         else {
             const sourceFiles = targetSourceFile === undefined ? host.getSourceFiles() : [targetSourceFile];
-            const nodeModulesFiles = host.getFilesFromNodeModules();
             for (const sourceFile of sourceFiles) {
                 // Don't emit if source file is a declaration file, or was located under node_modules
-                if (!isDeclarationFile(sourceFile) && !lookUp(nodeModulesFiles, sourceFile.path)) {
+                if (!isDeclarationFile(sourceFile) && !host.isSourceFileFromExternalLibrary(sourceFile)) {
                     onSingleFileEmit(host, sourceFile);
                 }
             }
@@ -2314,10 +2313,9 @@ 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 nodeModulesFiles = host.getFilesFromNodeModules();
             const bundledSources = filter(host.getSourceFiles(),
                 sourceFile => !isDeclarationFile(sourceFile) &&
-                              !lookUp(nodeModulesFiles, sourceFile.path) &&
+                              !host.isSourceFileFromExternalLibrary(sourceFile) &&
                               (!isExternalModule(sourceFile) ||
                                !!getEmitModuleKind(options)));
             if (bundledSources.length) {
diff --git a/src/lib/scripthost.d.ts b/src/lib/scripthost.d.ts
index baf93f55d55..b163a7e5154 100644
--- a/src/lib/scripthost.d.ts
+++ b/src/lib/scripthost.d.ts
@@ -284,5 +284,8 @@ interface VarDate { }
 
 interface DateConstructor {
     new (vd: VarDate): Date;
+}
+
+interface Date {
     getVarDate: () => VarDate;
-}
\ No newline at end of file
+}
diff --git a/src/services/formatting/smartIndenter.ts b/src/services/formatting/smartIndenter.ts
index 9d5e5b34401..77d5300fa18 100644
--- a/src/services/formatting/smartIndenter.ts
+++ b/src/services/formatting/smartIndenter.ts
@@ -497,7 +497,7 @@ namespace ts.formatting {
                     return childKind !== SyntaxKind.NamedExports;
                 case SyntaxKind.ImportDeclaration:
                     return childKind !== SyntaxKind.ImportClause ||
-                        (<ImportClause>child).namedBindings.kind !== SyntaxKind.NamedImports;
+                        ((<ImportClause>child).namedBindings && (<ImportClause>child).namedBindings.kind !== SyntaxKind.NamedImports);
                 case SyntaxKind.JsxElement:
                     return childKind !== SyntaxKind.JsxClosingElement;
             }
diff --git a/src/services/navigationBar.ts b/src/services/navigationBar.ts
index bfbaf5a6287..022c538e762 100644
--- a/src/services/navigationBar.ts
+++ b/src/services/navigationBar.ts
@@ -412,8 +412,7 @@ namespace ts.NavigationBar {
             case SyntaxKind.JSDocTypedefTag:
                 return getJSDocTypedefTagName(<JSDocTypedefTag>node);
             default:
-                Debug.fail();
-                return "";
+                return "<unknown>";
         }
     }
 
diff --git a/tests/baselines/reference/asyncFunctionNoReturnType.errors.txt b/tests/baselines/reference/asyncFunctionNoReturnType.errors.txt
new file mode 100644
index 00000000000..a7dbb6ecb64
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionNoReturnType.errors.txt
@@ -0,0 +1,25 @@
+error TS2318: Cannot find global type 'Promise'.
+tests/cases/compiler/asyncFunctionNoReturnType.ts(1,1): error TS1311: Async functions are only available when targeting ECMAScript 2015 or higher.
+tests/cases/compiler/asyncFunctionNoReturnType.ts(1,1): error TS1057: An async function or method must have a valid awaitable return type.
+tests/cases/compiler/asyncFunctionNoReturnType.ts(1,1): error TS7030: Not all code paths return a value.
+tests/cases/compiler/asyncFunctionNoReturnType.ts(2,9): error TS2304: Cannot find name 'window'.
+tests/cases/compiler/asyncFunctionNoReturnType.ts(3,9): error TS7030: Not all code paths return a value.
+
+
+!!! error TS2318: Cannot find global type 'Promise'.
+==== tests/cases/compiler/asyncFunctionNoReturnType.ts (5 errors) ====
+    async () => {
+    ~~~~~
+!!! error TS1311: Async functions are only available when targeting ECMAScript 2015 or higher.
+    ~~~~~~~~~~~~~
+!!! error TS1057: An async function or method must have a valid awaitable return type.
+    ~~~~~~~~~~~~~
+!!! error TS7030: Not all code paths return a value.
+        if (window)
+            ~~~~~~
+!!! error TS2304: Cannot find name 'window'.
+            return;
+            ~~~~~~~
+!!! error TS7030: Not all code paths return a value.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionNoReturnType.js b/tests/baselines/reference/asyncFunctionNoReturnType.js
new file mode 100644
index 00000000000..dd84e17c88b
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionNoReturnType.js
@@ -0,0 +1,20 @@
+//// [asyncFunctionNoReturnType.ts]
+async () => {
+    if (window)
+        return;
+}
+
+
+//// [asyncFunctionNoReturnType.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator.throw(value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments)).next());
+    });
+};
+(function () __awaiter(this, void 0, void 0, function* () {
+    if (window)
+        return;
+}));
diff --git a/tests/baselines/reference/destructuringAssignmentWithDefault.js b/tests/baselines/reference/destructuringAssignmentWithDefault.js
new file mode 100644
index 00000000000..ce3837e1162
--- /dev/null
+++ b/tests/baselines/reference/destructuringAssignmentWithDefault.js
@@ -0,0 +1,11 @@
+//// [destructuringAssignmentWithDefault.ts]
+const a: { x?: number } = { };
+let x = 0;
+({x = 1} = a);
+
+
+//// [destructuringAssignmentWithDefault.js]
+var a = {};
+var x = 0;
+(_a = a.x, x = _a === void 0 ? 1 : _a, a);
+var _a;
diff --git a/tests/baselines/reference/destructuringAssignmentWithDefault.symbols b/tests/baselines/reference/destructuringAssignmentWithDefault.symbols
new file mode 100644
index 00000000000..b011834c4f0
--- /dev/null
+++ b/tests/baselines/reference/destructuringAssignmentWithDefault.symbols
@@ -0,0 +1,12 @@
+=== tests/cases/compiler/destructuringAssignmentWithDefault.ts ===
+const a: { x?: number } = { };
+>a : Symbol(a, Decl(destructuringAssignmentWithDefault.ts, 0, 5))
+>x : Symbol(x, Decl(destructuringAssignmentWithDefault.ts, 0, 10))
+
+let x = 0;
+>x : Symbol(x, Decl(destructuringAssignmentWithDefault.ts, 1, 3))
+
+({x = 1} = a);
+>x : Symbol(x, Decl(destructuringAssignmentWithDefault.ts, 2, 2))
+>a : Symbol(a, Decl(destructuringAssignmentWithDefault.ts, 0, 5))
+
diff --git a/tests/baselines/reference/destructuringAssignmentWithDefault.types b/tests/baselines/reference/destructuringAssignmentWithDefault.types
new file mode 100644
index 00000000000..1dc1fe23533
--- /dev/null
+++ b/tests/baselines/reference/destructuringAssignmentWithDefault.types
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/destructuringAssignmentWithDefault.ts ===
+const a: { x?: number } = { };
+>a : { x?: number | undefined; }
+>x : number | undefined
+>{ } : {}
+
+let x = 0;
+>x : number
+>0 : number
+
+({x = 1} = a);
+>({x = 1} = a) : { x?: number | undefined; }
+>{x = 1} = a : { x?: number | undefined; }
+>{x = 1} : { x?: number; }
+>x : number
+>a : { x?: number | undefined; }
+
diff --git a/tests/baselines/reference/exportDefaultAsyncFunction.js b/tests/baselines/reference/exportDefaultAsyncFunction.js
new file mode 100644
index 00000000000..a06b41b5e73
--- /dev/null
+++ b/tests/baselines/reference/exportDefaultAsyncFunction.js
@@ -0,0 +1,18 @@
+//// [exportDefaultAsyncFunction.ts]
+export default async function foo(): Promise<void> {}
+foo();
+
+
+//// [exportDefaultAsyncFunction.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator.throw(value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments)).next());
+    });
+};
+export default function foo() {
+    return __awaiter(this, void 0, void 0, function* () { });
+}
+foo();
diff --git a/tests/baselines/reference/exportDefaultAsyncFunction.symbols b/tests/baselines/reference/exportDefaultAsyncFunction.symbols
new file mode 100644
index 00000000000..47178519558
--- /dev/null
+++ b/tests/baselines/reference/exportDefaultAsyncFunction.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/exportDefaultAsyncFunction.ts ===
+export default async function foo(): Promise<void> {}
+>foo : Symbol(foo, Decl(exportDefaultAsyncFunction.ts, 0, 0))
+>Promise : Symbol(Promise, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --))
+
+foo();
+>foo : Symbol(foo, Decl(exportDefaultAsyncFunction.ts, 0, 0))
+
diff --git a/tests/baselines/reference/exportDefaultAsyncFunction.types b/tests/baselines/reference/exportDefaultAsyncFunction.types
new file mode 100644
index 00000000000..7258c6fcf0c
--- /dev/null
+++ b/tests/baselines/reference/exportDefaultAsyncFunction.types
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/exportDefaultAsyncFunction.ts ===
+export default async function foo(): Promise<void> {}
+>foo : () => Promise<void>
+>Promise : Promise<T>
+
+foo();
+>foo() : Promise<void>
+>foo : () => Promise<void>
+
diff --git a/tests/baselines/reference/moduleAugmentationInDependency2.js b/tests/baselines/reference/moduleAugmentationInDependency2.js
index 381f1e72d8f..0a5d83695a3 100644
--- a/tests/baselines/reference/moduleAugmentationInDependency2.js
+++ b/tests/baselines/reference/moduleAugmentationInDependency2.js
@@ -8,8 +8,6 @@ export {};
 //// [app.ts]
 import "A"
 
-//// [index.js]
-"use strict";
 //// [app.js]
 "use strict";
 require("A");
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.js b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.js
index 1958800f918..e4440299cc7 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.js
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.js
@@ -31,9 +31,6 @@ exports.x = 1;
 //// [file2.js]
 "use strict";
 exports.y = 1;
-//// [file4.js]
-"use strict";
-exports.z1 = 1;
 //// [file1.js]
 "use strict";
 var file1_1 = require("folder2/file1");
diff --git a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/maxDepthIncreased/root.js b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/maxDepthIncreased/root.js
index 77951a4889d..9ef3915c851 100644
--- a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/maxDepthIncreased/root.js
+++ b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/maxDepthIncreased/root.js
@@ -1,6 +1,7 @@
-define(["require", "exports", "m1"], function (require, exports, m1) {
+define(["require", "exports", "m1", "m4"], function (require, exports, m1, m4) {
     "use strict";
     m1.f1("test");
     m1.f2.a = 10;
-    m1.f2.person.age = "10"; // Error: Should be number
+    m1.f2.person.age = "10"; // Should error if loaded the .js files correctly
+    var r2 = 3 + m4.foo; // Should be OK if correctly using the @types .d.ts file
 });
diff --git a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.errors.txt b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.errors.txt
index f63c2a789e8..f511000d5ac 100644
--- a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.errors.txt
+++ b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.errors.txt
@@ -1,4 +1,4 @@
-maxDepthIncreased/root.ts(4,1): error TS2322: Type 'string' is not assignable to type 'number'.
+maxDepthIncreased/root.ts(7,1): error TS2322: Type 'string' is not assignable to type 'number'.
 
 
 ==== index.js (0 errors) ====
@@ -28,11 +28,19 @@ maxDepthIncreased/root.ts(4,1): error TS2322: Type 'string' is not assignable to
     
     exports.f2 = m2;
     
+==== entry.d.ts (0 errors) ====
+    export declare var foo: number;
+    
 ==== maxDepthIncreased/root.ts (1 errors) ====
     import * as m1 from "m1";
+    import * as m4 from "m4";
+    
     m1.f1("test");
     m1.f2.a = 10;
-    m1.f2.person.age = "10"; // Error: Should be number
+    
+    m1.f2.person.age = "10";    // Should error if loaded the .js files correctly
     ~~~~~~~~~~~~~~~~
 !!! error TS2322: Type 'string' is not assignable to type 'number'.
+    
+    let r2 = 3 + m4.foo; // Should be OK if correctly using the @types .d.ts file
     
\ No newline at end of file
diff --git a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.json b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.json
index 1350bf6441e..bb3234f1db2 100644
--- a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.json
+++ b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/amd/nodeModulesMaxDepthIncreased.json
@@ -10,6 +10,7 @@
         "maxDepthIncreased/node_modules/m2/node_modules/m3/index.js",
         "maxDepthIncreased/node_modules/m2/entry.js",
         "maxDepthIncreased/node_modules/m1/index.js",
+        "maxDepthIncreased/node_modules/@types/m4/entry.d.ts",
         "maxDepthIncreased/root.ts"
     ],
     "emittedFiles": [
diff --git a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/maxDepthIncreased/root.js b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/maxDepthIncreased/root.js
index 3a0a96991b0..f6783cda79b 100644
--- a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/maxDepthIncreased/root.js
+++ b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/maxDepthIncreased/root.js
@@ -1,5 +1,7 @@
 "use strict";
 var m1 = require("m1");
+var m4 = require("m4");
 m1.f1("test");
 m1.f2.a = 10;
-m1.f2.person.age = "10"; // Error: Should be number
+m1.f2.person.age = "10"; // Should error if loaded the .js files correctly
+var r2 = 3 + m4.foo; // Should be OK if correctly using the @types .d.ts file
diff --git a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.errors.txt b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.errors.txt
index f63c2a789e8..f511000d5ac 100644
--- a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.errors.txt
+++ b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.errors.txt
@@ -1,4 +1,4 @@
-maxDepthIncreased/root.ts(4,1): error TS2322: Type 'string' is not assignable to type 'number'.
+maxDepthIncreased/root.ts(7,1): error TS2322: Type 'string' is not assignable to type 'number'.
 
 
 ==== index.js (0 errors) ====
@@ -28,11 +28,19 @@ maxDepthIncreased/root.ts(4,1): error TS2322: Type 'string' is not assignable to
     
     exports.f2 = m2;
     
+==== entry.d.ts (0 errors) ====
+    export declare var foo: number;
+    
 ==== maxDepthIncreased/root.ts (1 errors) ====
     import * as m1 from "m1";
+    import * as m4 from "m4";
+    
     m1.f1("test");
     m1.f2.a = 10;
-    m1.f2.person.age = "10"; // Error: Should be number
+    
+    m1.f2.person.age = "10";    // Should error if loaded the .js files correctly
     ~~~~~~~~~~~~~~~~
 !!! error TS2322: Type 'string' is not assignable to type 'number'.
+    
+    let r2 = 3 + m4.foo; // Should be OK if correctly using the @types .d.ts file
     
\ No newline at end of file
diff --git a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.json b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.json
index 1350bf6441e..bb3234f1db2 100644
--- a/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.json
+++ b/tests/baselines/reference/project/nodeModulesMaxDepthIncreased/node/nodeModulesMaxDepthIncreased.json
@@ -10,6 +10,7 @@
         "maxDepthIncreased/node_modules/m2/node_modules/m3/index.js",
         "maxDepthIncreased/node_modules/m2/entry.js",
         "maxDepthIncreased/node_modules/m1/index.js",
+        "maxDepthIncreased/node_modules/@types/m4/entry.d.ts",
         "maxDepthIncreased/root.ts"
     ],
     "emittedFiles": [
diff --git a/tests/baselines/reference/unusedImports11.js b/tests/baselines/reference/unusedImports11.js
new file mode 100644
index 00000000000..86561e1021e
--- /dev/null
+++ b/tests/baselines/reference/unusedImports11.js
@@ -0,0 +1,41 @@
+//// [tests/cases/compiler/unusedImports11.ts] ////
+
+//// [b.ts]
+
+export class Member {}
+export default Member;
+
+
+//// [a.ts]
+import { Member } from './b';
+import d, { Member as M } from './b';
+import * as ns from './b';
+import r = require("./b");
+
+new Member();
+new d();
+new M();
+new ns.Member();
+new r.Member();
+
+//// [b.js]
+"use strict";
+var Member = (function () {
+    function Member() {
+    }
+    return Member;
+}());
+exports.Member = Member;
+exports.__esModule = true;
+exports["default"] = Member;
+//// [a.js]
+"use strict";
+var b_1 = require('./b');
+var b_2 = require('./b');
+var ns = require('./b');
+var r = require("./b");
+new b_1.Member();
+new b_2["default"]();
+new b_2.Member();
+new ns.Member();
+new r.Member();
diff --git a/tests/baselines/reference/unusedImports11.symbols b/tests/baselines/reference/unusedImports11.symbols
new file mode 100644
index 00000000000..995b4a40c2a
--- /dev/null
+++ b/tests/baselines/reference/unusedImports11.symbols
@@ -0,0 +1,43 @@
+=== tests/cases/compiler/a.ts ===
+import { Member } from './b';
+>Member : Symbol(Member, Decl(a.ts, 0, 8))
+
+import d, { Member as M } from './b';
+>d : Symbol(d, Decl(a.ts, 1, 6))
+>Member : Symbol(M, Decl(a.ts, 1, 11))
+>M : Symbol(M, Decl(a.ts, 1, 11))
+
+import * as ns from './b';
+>ns : Symbol(ns, Decl(a.ts, 2, 6))
+
+import r = require("./b");
+>r : Symbol(r, Decl(a.ts, 2, 26))
+
+new Member();
+>Member : Symbol(Member, Decl(a.ts, 0, 8))
+
+new d();
+>d : Symbol(d, Decl(a.ts, 1, 6))
+
+new M();
+>M : Symbol(M, Decl(a.ts, 1, 11))
+
+new ns.Member();
+>ns.Member : Symbol(Member, Decl(b.ts, 0, 0))
+>ns : Symbol(ns, Decl(a.ts, 2, 6))
+>Member : Symbol(Member, Decl(b.ts, 0, 0))
+
+new r.Member();
+>r.Member : Symbol(Member, Decl(b.ts, 0, 0))
+>r : Symbol(r, Decl(a.ts, 2, 26))
+>Member : Symbol(Member, Decl(b.ts, 0, 0))
+
+=== tests/cases/compiler/b.ts ===
+
+export class Member {}
+>Member : Symbol(Member, Decl(b.ts, 0, 0))
+
+export default Member;
+>Member : Symbol(Member, Decl(b.ts, 0, 0))
+
+
diff --git a/tests/baselines/reference/unusedImports11.types b/tests/baselines/reference/unusedImports11.types
new file mode 100644
index 00000000000..1d71a0226b6
--- /dev/null
+++ b/tests/baselines/reference/unusedImports11.types
@@ -0,0 +1,48 @@
+=== tests/cases/compiler/a.ts ===
+import { Member } from './b';
+>Member : typeof Member
+
+import d, { Member as M } from './b';
+>d : typeof Member
+>Member : typeof Member
+>M : typeof Member
+
+import * as ns from './b';
+>ns : typeof ns
+
+import r = require("./b");
+>r : typeof ns
+
+new Member();
+>new Member() : Member
+>Member : typeof Member
+
+new d();
+>new d() : Member
+>d : typeof Member
+
+new M();
+>new M() : Member
+>M : typeof Member
+
+new ns.Member();
+>new ns.Member() : Member
+>ns.Member : typeof Member
+>ns : typeof ns
+>Member : typeof Member
+
+new r.Member();
+>new r.Member() : Member
+>r.Member : typeof Member
+>r : typeof ns
+>Member : typeof Member
+
+=== tests/cases/compiler/b.ts ===
+
+export class Member {}
+>Member : Member
+
+export default Member;
+>Member : Member
+
+
diff --git a/tests/baselines/reference/unusedImports12.errors.txt b/tests/baselines/reference/unusedImports12.errors.txt
new file mode 100644
index 00000000000..89b0687317b
--- /dev/null
+++ b/tests/baselines/reference/unusedImports12.errors.txt
@@ -0,0 +1,29 @@
+tests/cases/compiler/a.ts(1,10): error TS6133: 'Member' is declared but never used.
+tests/cases/compiler/a.ts(2,8): error TS6133: 'd' is declared but never used.
+tests/cases/compiler/a.ts(2,23): error TS6133: 'M' is declared but never used.
+tests/cases/compiler/a.ts(3,13): error TS6133: 'ns' is declared but never used.
+tests/cases/compiler/a.ts(4,8): error TS6133: 'r' is declared but never used.
+
+
+==== tests/cases/compiler/a.ts (5 errors) ====
+    import { Member } from './b';
+             ~~~~~~
+!!! error TS6133: 'Member' is declared but never used.
+    import d, { Member as M } from './b';
+           ~
+!!! error TS6133: 'd' is declared but never used.
+                          ~
+!!! error TS6133: 'M' is declared but never used.
+    import * as ns from './b';
+                ~~
+!!! error TS6133: 'ns' is declared but never used.
+    import r = require("./b");
+           ~
+!!! error TS6133: 'r' is declared but never used.
+    
+==== tests/cases/compiler/b.ts (0 errors) ====
+    
+    export class Member {}
+    export default Member;
+    
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedImports12.js b/tests/baselines/reference/unusedImports12.js
new file mode 100644
index 00000000000..ece9b105bc9
--- /dev/null
+++ b/tests/baselines/reference/unusedImports12.js
@@ -0,0 +1,27 @@
+//// [tests/cases/compiler/unusedImports12.ts] ////
+
+//// [b.ts]
+
+export class Member {}
+export default Member;
+
+
+//// [a.ts]
+import { Member } from './b';
+import d, { Member as M } from './b';
+import * as ns from './b';
+import r = require("./b");
+
+
+//// [b.js]
+"use strict";
+var Member = (function () {
+    function Member() {
+    }
+    return Member;
+}());
+exports.Member = Member;
+exports.__esModule = true;
+exports["default"] = Member;
+//// [a.js]
+"use strict";
diff --git a/tests/baselines/reference/unusedLocalsAndParameters.errors.txt b/tests/baselines/reference/unusedLocalsAndParameters.errors.txt
new file mode 100644
index 00000000000..a7b1d1b37f4
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParameters.errors.txt
@@ -0,0 +1,159 @@
+tests/cases/compiler/unusedLocalsAndParameters.ts(5,12): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(10,22): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(16,5): error TS6133: 'farrow' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(16,15): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(19,7): error TS6133: 'C' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(21,12): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(24,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+tests/cases/compiler/unusedLocalsAndParameters.ts(24,11): error TS6133: 'v' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(28,5): error TS6133: 'E' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(30,12): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(33,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+tests/cases/compiler/unusedLocalsAndParameters.ts(33,11): error TS6133: 'v' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(39,12): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(42,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+tests/cases/compiler/unusedLocalsAndParameters.ts(42,11): error TS6133: 'v' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(49,10): error TS6133: 'i' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(53,10): error TS6133: 'i' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(57,17): error TS6133: 'n' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(64,11): error TS6133: 'c' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(69,11): error TS6133: 'a' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(72,11): error TS6133: 'c' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(75,11): error TS6133: 'c' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(80,11): error TS6133: 'N' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParameters.ts(81,9): error TS6133: 'x' is declared but never used.
+
+
+==== tests/cases/compiler/unusedLocalsAndParameters.ts (24 errors) ====
+    
+    export { };
+    
+    // function declaration paramter
+    function f(a) {
+               ~
+!!! error TS6133: 'a' is declared but never used.
+    }
+    f(0);
+    
+    // function expression paramter
+    var fexp = function (a) {
+                         ~
+!!! error TS6133: 'a' is declared but never used.
+    };
+    
+    fexp(0);
+    
+    // arrow function paramter
+    var farrow = (a) => {
+        ~~~~~~
+!!! error TS6133: 'farrow' is declared but never used.
+                  ~
+!!! error TS6133: 'a' is declared but never used.
+    };
+    
+    class C {
+          ~
+!!! error TS6133: 'C' is declared but never used.
+        // Method declaration paramter
+        method(a) {
+               ~
+!!! error TS6133: 'a' is declared but never used.
+        }
+        // Accessor declaration paramter
+        set x(v: number) {
+            ~
+!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+              ~
+!!! error TS6133: 'v' is declared but never used.
+        }
+    }
+    
+    var E = class {
+        ~
+!!! error TS6133: 'E' is declared but never used.
+        // Method declaration paramter
+        method(a) {
+               ~
+!!! error TS6133: 'a' is declared but never used.
+        }
+        // Accessor declaration paramter
+        set x(v: number) {
+            ~
+!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+              ~
+!!! error TS6133: 'v' is declared but never used.
+        }
+    }
+    
+    var o = {
+        // Object literal method declaration paramter
+        method(a) {
+               ~
+!!! error TS6133: 'a' is declared but never used.
+        },
+        // Accessor declaration paramter
+        set x(v: number) {
+            ~
+!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+              ~
+!!! error TS6133: 'v' is declared but never used.
+        }
+    };
+    
+    o;
+    
+    // in a for..in statment
+    for (let i in o) {
+             ~
+!!! error TS6133: 'i' is declared but never used.
+    }
+    
+    // in a for..of statment
+    for (let i of [1, 2, 3]) {
+             ~
+!!! error TS6133: 'i' is declared but never used.
+    }
+    
+    // in a for. statment
+    for (let i = 0, n; i < 10; i++) {
+                    ~
+!!! error TS6133: 'n' is declared but never used.
+    }
+    
+    // in a block
+    
+    const condition = false;
+    if (condition) {
+        const c = 0;
+              ~
+!!! error TS6133: 'c' is declared but never used.
+    }
+    
+    // in try/catch/finally
+    try {
+        const a = 0;
+              ~
+!!! error TS6133: 'a' is declared but never used.
+    }
+    catch (e) {
+        const c = 1;
+              ~
+!!! error TS6133: 'c' is declared but never used.
+    }
+    finally {
+        const c = 0;
+              ~
+!!! error TS6133: 'c' is declared but never used.
+    }
+    
+    
+    // in a namespace
+    namespace N {
+              ~
+!!! error TS6133: 'N' is declared but never used.
+        var x;
+            ~
+!!! error TS6133: 'x' is declared but never used.
+    }
+    
+        
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedLocalsAndParameters.js b/tests/baselines/reference/unusedLocalsAndParameters.js
new file mode 100644
index 00000000000..64ff373db4a
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParameters.js
@@ -0,0 +1,168 @@
+//// [unusedLocalsAndParameters.ts]
+
+export { };
+
+// function declaration paramter
+function f(a) {
+}
+f(0);
+
+// function expression paramter
+var fexp = function (a) {
+};
+
+fexp(0);
+
+// arrow function paramter
+var farrow = (a) => {
+};
+
+class C {
+    // Method declaration paramter
+    method(a) {
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+    }
+}
+
+var E = class {
+    // Method declaration paramter
+    method(a) {
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+    }
+}
+
+var o = {
+    // Object literal method declaration paramter
+    method(a) {
+    },
+    // Accessor declaration paramter
+    set x(v: number) {
+    }
+};
+
+o;
+
+// in a for..in statment
+for (let i in o) {
+}
+
+// in a for..of statment
+for (let i of [1, 2, 3]) {
+}
+
+// in a for. statment
+for (let i = 0, n; i < 10; i++) {
+}
+
+// in a block
+
+const condition = false;
+if (condition) {
+    const c = 0;
+}
+
+// in try/catch/finally
+try {
+    const a = 0;
+}
+catch (e) {
+    const c = 1;
+}
+finally {
+    const c = 0;
+}
+
+
+// in a namespace
+namespace N {
+    var x;
+}
+
+    
+
+//// [unusedLocalsAndParameters.js]
+"use strict";
+// function declaration paramter
+function f(a) {
+}
+f(0);
+// function expression paramter
+var fexp = function (a) {
+};
+fexp(0);
+// arrow function paramter
+var farrow = function (a) {
+};
+var C = (function () {
+    function C() {
+    }
+    // Method declaration paramter
+    C.prototype.method = function (a) {
+    };
+    Object.defineProperty(C.prototype, "x", {
+        // Accessor declaration paramter
+        set: function (v) {
+        },
+        enumerable: true,
+        configurable: true
+    });
+    return C;
+}());
+var E = (function () {
+    function class_1() {
+    }
+    // Method declaration paramter
+    class_1.prototype.method = function (a) {
+    };
+    Object.defineProperty(class_1.prototype, "x", {
+        // Accessor declaration paramter
+        set: function (v) {
+        },
+        enumerable: true,
+        configurable: true
+    });
+    return class_1;
+}());
+var o = {
+    // Object literal method declaration paramter
+    method: function (a) {
+    },
+    // Accessor declaration paramter
+    set x(v) {
+    }
+};
+o;
+// in a for..in statment
+for (var i in o) {
+}
+// in a for..of statment
+for (var _i = 0, _a = [1, 2, 3]; _i < _a.length; _i++) {
+    var i = _a[_i];
+}
+// in a for. statment
+for (var i = 0, n = void 0; i < 10; i++) {
+}
+// in a block
+var condition = false;
+if (condition) {
+    var c = 0;
+}
+// in try/catch/finally
+try {
+    var a = 0;
+}
+catch (e) {
+    var c = 1;
+}
+finally {
+    var c = 0;
+}
+// in a namespace
+var N;
+(function (N) {
+    var x;
+})(N || (N = {}));
diff --git a/tests/baselines/reference/unusedLocalsAndParametersDeferred.errors.txt b/tests/baselines/reference/unusedLocalsAndParametersDeferred.errors.txt
new file mode 100644
index 00000000000..63afd213f1c
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersDeferred.errors.txt
@@ -0,0 +1,172 @@
+tests/cases/compiler/unusedLocalsAndParametersDeferred.ts(42,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+tests/cases/compiler/unusedLocalsAndParametersDeferred.ts(65,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+tests/cases/compiler/unusedLocalsAndParametersDeferred.ts(87,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+
+
+==== tests/cases/compiler/unusedLocalsAndParametersDeferred.ts (3 errors) ====
+    
+    export { };
+    
+    function defered<T>(a: () => T): T {
+        return a();
+    }
+    
+    // function declaration paramter
+    function f(a) {
+        defered(() => {
+            a;
+        });
+    }
+    f(0);
+    
+    // function expression paramter
+    var fexp = function (a) {
+        defered(() => {
+            a;
+        });
+    };
+    fexp(1);
+    
+    // arrow function paramter
+    var farrow = (a) => {
+        defered(() => {
+            a;
+        });
+    };
+    farrow(2);
+    
+    let prop1;
+    
+    class C {
+        // Method declaration paramter
+        method(a) {
+            defered(() => {
+                a;
+            });
+        }
+        // Accessor declaration paramter
+        set x(v: number) {
+            ~
+!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+            defered(() => {
+                v;
+            });
+        }
+        // in a property initalizer
+        p = defered(() => {
+            prop1;
+        });
+    }
+    
+    new C();
+    
+    let prop2;
+    
+    var E = class {
+        // Method declaration paramter
+        method(a) {
+            defered(() => {
+                a;
+            });
+        }
+        // Accessor declaration paramter
+        set x(v: number) {
+            ~
+!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+            defered(() => {
+                v;
+            });
+        }
+        // in a property initalizer
+        p = defered(() => {
+            prop2;
+        });
+    }
+    
+    new E();
+    
+    
+    var o = {
+        // Object literal method declaration paramter
+        method(a) {
+            defered(() => {
+                a;
+            });
+        },
+        // Accessor declaration paramter
+        set x(v: number) {
+            ~
+!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
+            defered(() => {
+                v;
+            });
+        },
+        // in a property initalizer
+        p: defered(() => {
+            prop1;
+        })
+    };
+    
+    o;
+    
+    // in a for..in statment
+    for (let i in o) {
+        defered(() => {
+            i;
+        });
+    }
+    
+    // in a for..of statment
+    for (let i of [1,2,3]) {
+        defered(() => {
+            i;
+        });
+    }
+    
+    // in a for. statment
+    for (let i = 0; i < 10; i++) {
+        defered(() => {
+            i;
+        });
+    }
+    
+    // in a block
+    
+    const condition = false;
+    if (condition) {
+        const c = 0;
+        defered(() => {
+            c;
+        });
+    }
+    
+    // in try/catch/finally
+    try {
+        const a = 0;
+        defered(() => {
+            a;
+        });
+    }
+    catch (e) {
+        const c = 1;
+        defered(() => {
+            c;
+        });
+    }
+    finally {
+        const c = 0;
+        defered(() => {
+            c;
+        });
+    }
+    
+    
+    // in a namespace
+    namespace N {
+        var x;
+        defered(() => {
+            x;
+        });
+    }
+    N;
+        
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedLocalsAndParametersDeferred.js b/tests/baselines/reference/unusedLocalsAndParametersDeferred.js
new file mode 100644
index 00000000000..7fbfd15c526
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersDeferred.js
@@ -0,0 +1,325 @@
+//// [unusedLocalsAndParametersDeferred.ts]
+
+export { };
+
+function defered<T>(a: () => T): T {
+    return a();
+}
+
+// function declaration paramter
+function f(a) {
+    defered(() => {
+        a;
+    });
+}
+f(0);
+
+// function expression paramter
+var fexp = function (a) {
+    defered(() => {
+        a;
+    });
+};
+fexp(1);
+
+// arrow function paramter
+var farrow = (a) => {
+    defered(() => {
+        a;
+    });
+};
+farrow(2);
+
+let prop1;
+
+class C {
+    // Method declaration paramter
+    method(a) {
+        defered(() => {
+            a;
+        });
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+        defered(() => {
+            v;
+        });
+    }
+    // in a property initalizer
+    p = defered(() => {
+        prop1;
+    });
+}
+
+new C();
+
+let prop2;
+
+var E = class {
+    // Method declaration paramter
+    method(a) {
+        defered(() => {
+            a;
+        });
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+        defered(() => {
+            v;
+        });
+    }
+    // in a property initalizer
+    p = defered(() => {
+        prop2;
+    });
+}
+
+new E();
+
+
+var o = {
+    // Object literal method declaration paramter
+    method(a) {
+        defered(() => {
+            a;
+        });
+    },
+    // Accessor declaration paramter
+    set x(v: number) {
+        defered(() => {
+            v;
+        });
+    },
+    // in a property initalizer
+    p: defered(() => {
+        prop1;
+    })
+};
+
+o;
+
+// in a for..in statment
+for (let i in o) {
+    defered(() => {
+        i;
+    });
+}
+
+// in a for..of statment
+for (let i of [1,2,3]) {
+    defered(() => {
+        i;
+    });
+}
+
+// in a for. statment
+for (let i = 0; i < 10; i++) {
+    defered(() => {
+        i;
+    });
+}
+
+// in a block
+
+const condition = false;
+if (condition) {
+    const c = 0;
+    defered(() => {
+        c;
+    });
+}
+
+// in try/catch/finally
+try {
+    const a = 0;
+    defered(() => {
+        a;
+    });
+}
+catch (e) {
+    const c = 1;
+    defered(() => {
+        c;
+    });
+}
+finally {
+    const c = 0;
+    defered(() => {
+        c;
+    });
+}
+
+
+// in a namespace
+namespace N {
+    var x;
+    defered(() => {
+        x;
+    });
+}
+N;
+    
+
+//// [unusedLocalsAndParametersDeferred.js]
+"use strict";
+function defered(a) {
+    return a();
+}
+// function declaration paramter
+function f(a) {
+    defered(function () {
+        a;
+    });
+}
+f(0);
+// function expression paramter
+var fexp = function (a) {
+    defered(function () {
+        a;
+    });
+};
+fexp(1);
+// arrow function paramter
+var farrow = function (a) {
+    defered(function () {
+        a;
+    });
+};
+farrow(2);
+var prop1;
+var C = (function () {
+    function C() {
+        // in a property initalizer
+        this.p = defered(function () {
+            prop1;
+        });
+    }
+    // Method declaration paramter
+    C.prototype.method = function (a) {
+        defered(function () {
+            a;
+        });
+    };
+    Object.defineProperty(C.prototype, "x", {
+        // Accessor declaration paramter
+        set: function (v) {
+            defered(function () {
+                v;
+            });
+        },
+        enumerable: true,
+        configurable: true
+    });
+    return C;
+}());
+new C();
+var prop2;
+var E = (function () {
+    function class_1() {
+        // in a property initalizer
+        this.p = defered(function () {
+            prop2;
+        });
+    }
+    // Method declaration paramter
+    class_1.prototype.method = function (a) {
+        defered(function () {
+            a;
+        });
+    };
+    Object.defineProperty(class_1.prototype, "x", {
+        // Accessor declaration paramter
+        set: function (v) {
+            defered(function () {
+                v;
+            });
+        },
+        enumerable: true,
+        configurable: true
+    });
+    return class_1;
+}());
+new E();
+var o = {
+    // Object literal method declaration paramter
+    method: function (a) {
+        defered(function () {
+            a;
+        });
+    },
+    // Accessor declaration paramter
+    set x(v) {
+        defered(function () {
+            v;
+        });
+    },
+    // in a property initalizer
+    p: defered(function () {
+        prop1;
+    })
+};
+o;
+// in a for..in statment
+var _loop_1 = function(i) {
+    defered(function () {
+        i;
+    });
+};
+for (var i in o) {
+    _loop_1(i);
+}
+// in a for..of statment
+var _loop_2 = function(i) {
+    defered(function () {
+        i;
+    });
+};
+for (var _i = 0, _a = [1, 2, 3]; _i < _a.length; _i++) {
+    var i = _a[_i];
+    _loop_2(i);
+}
+// in a for. statment
+var _loop_3 = function(i) {
+    defered(function () {
+        i;
+    });
+};
+for (var i = 0; i < 10; i++) {
+    _loop_3(i);
+}
+// in a block
+var condition = false;
+if (condition) {
+    var c_1 = 0;
+    defered(function () {
+        c_1;
+    });
+}
+// in try/catch/finally
+try {
+    var a_1 = 0;
+    defered(function () {
+        a_1;
+    });
+}
+catch (e) {
+    var c_2 = 1;
+    defered(function () {
+        c_2;
+    });
+}
+finally {
+    var c_3 = 0;
+    defered(function () {
+        c_3;
+    });
+}
+// in a namespace
+var N;
+(function (N) {
+    var x;
+    defered(function () {
+        x;
+    });
+})(N || (N = {}));
+N;
diff --git a/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.js b/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.js
new file mode 100644
index 00000000000..221d49a0fdf
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.js
@@ -0,0 +1,45 @@
+//// [unusedLocalsAndParametersOverloadSignatures.ts]
+
+export function func(details: number, message: string, ...args: any[]): void;
+export function func(details: number, message: string): any {
+    return details + message;
+}
+
+export class C {
+    constructor(details: number, message: string, ...args: any[]);
+    constructor(details: number, message: string) {
+        details + message;
+    }
+
+    method(details: number, message: string, ...args: any[]): void;
+    method(details: number, message: string): any {
+        return details + message;
+    }
+}
+
+
+export function genericFunc<T>(details: number, message: T, ...args: any[]): void;
+export function genericFunc(details: number, message: any): any {
+    return details + message;
+}
+
+//// [unusedLocalsAndParametersOverloadSignatures.js]
+"use strict";
+function func(details, message) {
+    return details + message;
+}
+exports.func = func;
+var C = (function () {
+    function C(details, message) {
+        details + message;
+    }
+    C.prototype.method = function (details, message) {
+        return details + message;
+    };
+    return C;
+}());
+exports.C = C;
+function genericFunc(details, message) {
+    return details + message;
+}
+exports.genericFunc = genericFunc;
diff --git a/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.symbols b/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.symbols
new file mode 100644
index 00000000000..da3c47f2e42
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.symbols
@@ -0,0 +1,70 @@
+=== tests/cases/compiler/unusedLocalsAndParametersOverloadSignatures.ts ===
+
+export function func(details: number, message: string, ...args: any[]): void;
+>func : Symbol(func, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 0, 0), Decl(unusedLocalsAndParametersOverloadSignatures.ts, 1, 77))
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 1, 21))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 1, 37))
+>args : Symbol(args, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 1, 54))
+
+export function func(details: number, message: string): any {
+>func : Symbol(func, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 0, 0), Decl(unusedLocalsAndParametersOverloadSignatures.ts, 1, 77))
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 2, 21))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 2, 37))
+
+    return details + message;
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 2, 21))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 2, 37))
+}
+
+export class C {
+>C : Symbol(C, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 4, 1))
+
+    constructor(details: number, message: string, ...args: any[]);
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 7, 16))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 7, 32))
+>args : Symbol(args, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 7, 49))
+
+    constructor(details: number, message: string) {
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 8, 16))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 8, 32))
+
+        details + message;
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 8, 16))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 8, 32))
+    }
+
+    method(details: number, message: string, ...args: any[]): void;
+>method : Symbol(C.method, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 10, 5), Decl(unusedLocalsAndParametersOverloadSignatures.ts, 12, 67))
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 12, 11))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 12, 27))
+>args : Symbol(args, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 12, 44))
+
+    method(details: number, message: string): any {
+>method : Symbol(C.method, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 10, 5), Decl(unusedLocalsAndParametersOverloadSignatures.ts, 12, 67))
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 13, 11))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 13, 27))
+
+        return details + message;
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 13, 11))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 13, 27))
+    }
+}
+
+
+export function genericFunc<T>(details: number, message: T, ...args: any[]): void;
+>genericFunc : Symbol(genericFunc, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 16, 1), Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 82))
+>T : Symbol(T, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 28))
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 31))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 47))
+>T : Symbol(T, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 28))
+>args : Symbol(args, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 59))
+
+export function genericFunc(details: number, message: any): any {
+>genericFunc : Symbol(genericFunc, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 16, 1), Decl(unusedLocalsAndParametersOverloadSignatures.ts, 19, 82))
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 20, 28))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 20, 44))
+
+    return details + message;
+>details : Symbol(details, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 20, 28))
+>message : Symbol(message, Decl(unusedLocalsAndParametersOverloadSignatures.ts, 20, 44))
+}
diff --git a/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.types b/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.types
new file mode 100644
index 00000000000..2a216c8acd2
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersOverloadSignatures.types
@@ -0,0 +1,74 @@
+=== tests/cases/compiler/unusedLocalsAndParametersOverloadSignatures.ts ===
+
+export function func(details: number, message: string, ...args: any[]): void;
+>func : (details: number, message: string, ...args: any[]) => void
+>details : number
+>message : string
+>args : any[]
+
+export function func(details: number, message: string): any {
+>func : (details: number, message: string, ...args: any[]) => void
+>details : number
+>message : string
+
+    return details + message;
+>details + message : string
+>details : number
+>message : string
+}
+
+export class C {
+>C : C
+
+    constructor(details: number, message: string, ...args: any[]);
+>details : number
+>message : string
+>args : any[]
+
+    constructor(details: number, message: string) {
+>details : number
+>message : string
+
+        details + message;
+>details + message : string
+>details : number
+>message : string
+    }
+
+    method(details: number, message: string, ...args: any[]): void;
+>method : (details: number, message: string, ...args: any[]) => void
+>details : number
+>message : string
+>args : any[]
+
+    method(details: number, message: string): any {
+>method : (details: number, message: string, ...args: any[]) => void
+>details : number
+>message : string
+
+        return details + message;
+>details + message : string
+>details : number
+>message : string
+    }
+}
+
+
+export function genericFunc<T>(details: number, message: T, ...args: any[]): void;
+>genericFunc : <T>(details: number, message: T, ...args: any[]) => void
+>T : T
+>details : number
+>message : T
+>T : T
+>args : any[]
+
+export function genericFunc(details: number, message: any): any {
+>genericFunc : <T>(details: number, message: T, ...args: any[]) => void
+>details : number
+>message : any
+
+    return details + message;
+>details + message : any
+>details : number
+>message : any
+}
diff --git a/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.js b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.js
new file mode 100644
index 00000000000..b854278a3e3
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.js
@@ -0,0 +1,35 @@
+//// [unusedLocalsAndParametersTypeAliases.ts]
+
+// used in a declaration
+type handler1 = () => void;
+export interface I1 {
+    getHandler: handler1;
+}
+
+// exported
+export type handler2 = () => void;
+
+// used in extends clause
+type handler3 = () => void;
+export interface I3<T extends handler3> {
+    getHandler: T;
+}
+
+// used in another type alias declaration
+type handler4 = () => void;
+type handler5 = handler4 | (()=>number);
+var x: handler5;
+x();
+
+// used as type argument
+type handler6 = () => void;
+var y: Array<handler6>;
+y[0]();
+    
+
+//// [unusedLocalsAndParametersTypeAliases.js]
+"use strict";
+var x;
+x();
+var y;
+y[0]();
diff --git a/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.symbols b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.symbols
new file mode 100644
index 00000000000..9f9004d7a28
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.symbols
@@ -0,0 +1,59 @@
+=== tests/cases/compiler/unusedLocalsAndParametersTypeAliases.ts ===
+
+// used in a declaration
+type handler1 = () => void;
+>handler1 : Symbol(handler1, Decl(unusedLocalsAndParametersTypeAliases.ts, 0, 0))
+
+export interface I1 {
+>I1 : Symbol(I1, Decl(unusedLocalsAndParametersTypeAliases.ts, 2, 27))
+
+    getHandler: handler1;
+>getHandler : Symbol(I1.getHandler, Decl(unusedLocalsAndParametersTypeAliases.ts, 3, 21))
+>handler1 : Symbol(handler1, Decl(unusedLocalsAndParametersTypeAliases.ts, 0, 0))
+}
+
+// exported
+export type handler2 = () => void;
+>handler2 : Symbol(handler2, Decl(unusedLocalsAndParametersTypeAliases.ts, 5, 1))
+
+// used in extends clause
+type handler3 = () => void;
+>handler3 : Symbol(handler3, Decl(unusedLocalsAndParametersTypeAliases.ts, 8, 34))
+
+export interface I3<T extends handler3> {
+>I3 : Symbol(I3, Decl(unusedLocalsAndParametersTypeAliases.ts, 11, 27))
+>T : Symbol(T, Decl(unusedLocalsAndParametersTypeAliases.ts, 12, 20))
+>handler3 : Symbol(handler3, Decl(unusedLocalsAndParametersTypeAliases.ts, 8, 34))
+
+    getHandler: T;
+>getHandler : Symbol(I3.getHandler, Decl(unusedLocalsAndParametersTypeAliases.ts, 12, 41))
+>T : Symbol(T, Decl(unusedLocalsAndParametersTypeAliases.ts, 12, 20))
+}
+
+// used in another type alias declaration
+type handler4 = () => void;
+>handler4 : Symbol(handler4, Decl(unusedLocalsAndParametersTypeAliases.ts, 14, 1))
+
+type handler5 = handler4 | (()=>number);
+>handler5 : Symbol(handler5, Decl(unusedLocalsAndParametersTypeAliases.ts, 17, 27))
+>handler4 : Symbol(handler4, Decl(unusedLocalsAndParametersTypeAliases.ts, 14, 1))
+
+var x: handler5;
+>x : Symbol(x, Decl(unusedLocalsAndParametersTypeAliases.ts, 19, 3))
+>handler5 : Symbol(handler5, Decl(unusedLocalsAndParametersTypeAliases.ts, 17, 27))
+
+x();
+>x : Symbol(x, Decl(unusedLocalsAndParametersTypeAliases.ts, 19, 3))
+
+// used as type argument
+type handler6 = () => void;
+>handler6 : Symbol(handler6, Decl(unusedLocalsAndParametersTypeAliases.ts, 20, 4))
+
+var y: Array<handler6>;
+>y : Symbol(y, Decl(unusedLocalsAndParametersTypeAliases.ts, 24, 3))
+>Array : Symbol(Array, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>handler6 : Symbol(handler6, Decl(unusedLocalsAndParametersTypeAliases.ts, 20, 4))
+
+y[0]();
+>y : Symbol(y, Decl(unusedLocalsAndParametersTypeAliases.ts, 24, 3))
+    
diff --git a/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.types b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.types
new file mode 100644
index 00000000000..82c87deb7d0
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases.types
@@ -0,0 +1,63 @@
+=== tests/cases/compiler/unusedLocalsAndParametersTypeAliases.ts ===
+
+// used in a declaration
+type handler1 = () => void;
+>handler1 : () => void
+
+export interface I1 {
+>I1 : I1
+
+    getHandler: handler1;
+>getHandler : () => void
+>handler1 : () => void
+}
+
+// exported
+export type handler2 = () => void;
+>handler2 : () => void
+
+// used in extends clause
+type handler3 = () => void;
+>handler3 : () => void
+
+export interface I3<T extends handler3> {
+>I3 : I3<T>
+>T : T
+>handler3 : () => void
+
+    getHandler: T;
+>getHandler : T
+>T : T
+}
+
+// used in another type alias declaration
+type handler4 = () => void;
+>handler4 : () => void
+
+type handler5 = handler4 | (()=>number);
+>handler5 : (() => void) | (() => number)
+>handler4 : () => void
+
+var x: handler5;
+>x : (() => void) | (() => number)
+>handler5 : (() => void) | (() => number)
+
+x();
+>x() : void | number
+>x : (() => void) | (() => number)
+
+// used as type argument
+type handler6 = () => void;
+>handler6 : () => void
+
+var y: Array<handler6>;
+>y : (() => void)[]
+>Array : T[]
+>handler6 : () => void
+
+y[0]();
+>y[0]() : void
+>y[0] : () => void
+>y : (() => void)[]
+>0 : number
+    
diff --git a/tests/baselines/reference/unusedLocalsAndParametersTypeAliases2.errors.txt b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases2.errors.txt
new file mode 100644
index 00000000000..d6abf6f2f3f
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases2.errors.txt
@@ -0,0 +1,20 @@
+tests/cases/compiler/unusedLocalsAndParametersTypeAliases2.ts(3,6): error TS6133: 'handler1' is declared but never used.
+tests/cases/compiler/unusedLocalsAndParametersTypeAliases2.ts(7,10): error TS6133: 'handler2' is declared but never used.
+
+
+==== tests/cases/compiler/unusedLocalsAndParametersTypeAliases2.ts (2 errors) ====
+    
+    // unused
+    type handler1 = () => void;
+         ~~~~~~~~
+!!! error TS6133: 'handler1' is declared but never used.
+    
+    
+    function foo() {
+        type handler2 = () => void;
+             ~~~~~~~~
+!!! error TS6133: 'handler2' is declared but never used.
+        foo();
+    }
+    
+    export {}
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedLocalsAndParametersTypeAliases2.js b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases2.js
new file mode 100644
index 00000000000..7da916370ca
--- /dev/null
+++ b/tests/baselines/reference/unusedLocalsAndParametersTypeAliases2.js
@@ -0,0 +1,18 @@
+//// [unusedLocalsAndParametersTypeAliases2.ts]
+
+// unused
+type handler1 = () => void;
+
+
+function foo() {
+    type handler2 = () => void;
+    foo();
+}
+
+export {}
+
+//// [unusedLocalsAndParametersTypeAliases2.js]
+"use strict";
+function foo() {
+    foo();
+}
diff --git a/tests/baselines/reference/unusedParameterInCatchClause.errors.txt b/tests/baselines/reference/unusedParameterInCatchClause.errors.txt
deleted file mode 100644
index e996763e2c6..00000000000
--- a/tests/baselines/reference/unusedParameterInCatchClause.errors.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-tests/cases/compiler/unusedParameterInCatchClause.ts(3,18): error TS6133: 'ex' is declared but never used.
-
-
-==== tests/cases/compiler/unusedParameterInCatchClause.ts (1 errors) ====
-    
-    function f1() {
-        try {} catch(ex){}
-                     ~~
-!!! error TS6133: 'ex' is declared but never used.
-    }
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedParameterInCatchClause.symbols b/tests/baselines/reference/unusedParameterInCatchClause.symbols
new file mode 100644
index 00000000000..9406d3ea53e
--- /dev/null
+++ b/tests/baselines/reference/unusedParameterInCatchClause.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/unusedParameterInCatchClause.ts ===
+
+function f1() {
+>f1 : Symbol(f1, Decl(unusedParameterInCatchClause.ts, 0, 0))
+
+    try {} catch(ex){}
+>ex : Symbol(ex, Decl(unusedParameterInCatchClause.ts, 2, 17))
+}
diff --git a/tests/baselines/reference/unusedParameterInCatchClause.types b/tests/baselines/reference/unusedParameterInCatchClause.types
new file mode 100644
index 00000000000..ad23b5d753b
--- /dev/null
+++ b/tests/baselines/reference/unusedParameterInCatchClause.types
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/unusedParameterInCatchClause.ts ===
+
+function f1() {
+>f1 : () => void
+
+    try {} catch(ex){}
+>ex : any
+}
diff --git a/tests/baselines/reference/unusedPrivateMembers.js b/tests/baselines/reference/unusedPrivateMembers.js
new file mode 100644
index 00000000000..cdb540349c3
--- /dev/null
+++ b/tests/baselines/reference/unusedPrivateMembers.js
@@ -0,0 +1,114 @@
+//// [unusedPrivateMembers.ts]
+
+class Test1 {
+    private initializeInternal() {
+    }
+
+    public test() {
+        var x = new Test1();
+        x.initializeInternal();
+    }
+}
+
+class Test2 {
+    private p = 0;
+    public test() {
+        var x = new Test2();
+        x.p;
+    }
+}
+
+class Test3 {
+    private get x () {
+        return 0;
+    }
+
+    public test() {
+        var x = new Test3();
+        x.x;
+    }
+}
+
+class Test4 {
+    private set x(v) {
+        v;
+    }
+
+    public test() {
+        var x = new Test4();
+        x.x;
+    }
+}
+
+class Test5<T> {
+    private p: T;
+    public test() {
+        var x = new Test5<number>();
+        x.p;
+    }
+}
+
+
+//// [unusedPrivateMembers.js]
+var Test1 = (function () {
+    function Test1() {
+    }
+    Test1.prototype.initializeInternal = function () {
+    };
+    Test1.prototype.test = function () {
+        var x = new Test1();
+        x.initializeInternal();
+    };
+    return Test1;
+}());
+var Test2 = (function () {
+    function Test2() {
+        this.p = 0;
+    }
+    Test2.prototype.test = function () {
+        var x = new Test2();
+        x.p;
+    };
+    return Test2;
+}());
+var Test3 = (function () {
+    function Test3() {
+    }
+    Object.defineProperty(Test3.prototype, "x", {
+        get: function () {
+            return 0;
+        },
+        enumerable: true,
+        configurable: true
+    });
+    Test3.prototype.test = function () {
+        var x = new Test3();
+        x.x;
+    };
+    return Test3;
+}());
+var Test4 = (function () {
+    function Test4() {
+    }
+    Object.defineProperty(Test4.prototype, "x", {
+        set: function (v) {
+            v;
+        },
+        enumerable: true,
+        configurable: true
+    });
+    Test4.prototype.test = function () {
+        var x = new Test4();
+        x.x;
+    };
+    return Test4;
+}());
+var Test5 = (function () {
+    function Test5() {
+    }
+    Test5.prototype.test = function () {
+        var x = new Test5();
+        x.p;
+    };
+    return Test5;
+}());
diff --git a/tests/baselines/reference/unusedPrivateMembers.symbols b/tests/baselines/reference/unusedPrivateMembers.symbols
new file mode 100644
index 00000000000..0d4426a594a
--- /dev/null
+++ b/tests/baselines/reference/unusedPrivateMembers.symbols
@@ -0,0 +1,113 @@
+=== tests/cases/compiler/unusedPrivateMembers.ts ===
+
+class Test1 {
+>Test1 : Symbol(Test1, Decl(unusedPrivateMembers.ts, 0, 0))
+
+    private initializeInternal() {
+>initializeInternal : Symbol(Test1.initializeInternal, Decl(unusedPrivateMembers.ts, 1, 13))
+    }
+
+    public test() {
+>test : Symbol(Test1.test, Decl(unusedPrivateMembers.ts, 3, 5))
+
+        var x = new Test1();
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 6, 11))
+>Test1 : Symbol(Test1, Decl(unusedPrivateMembers.ts, 0, 0))
+
+        x.initializeInternal();
+>x.initializeInternal : Symbol(Test1.initializeInternal, Decl(unusedPrivateMembers.ts, 1, 13))
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 6, 11))
+>initializeInternal : Symbol(Test1.initializeInternal, Decl(unusedPrivateMembers.ts, 1, 13))
+    }
+}
+
+class Test2 {
+>Test2 : Symbol(Test2, Decl(unusedPrivateMembers.ts, 9, 1))
+
+    private p = 0;
+>p : Symbol(Test2.p, Decl(unusedPrivateMembers.ts, 11, 13))
+
+    public test() {
+>test : Symbol(Test2.test, Decl(unusedPrivateMembers.ts, 12, 18))
+
+        var x = new Test2();
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 14, 11))
+>Test2 : Symbol(Test2, Decl(unusedPrivateMembers.ts, 9, 1))
+
+        x.p;
+>x.p : Symbol(Test2.p, Decl(unusedPrivateMembers.ts, 11, 13))
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 14, 11))
+>p : Symbol(Test2.p, Decl(unusedPrivateMembers.ts, 11, 13))
+    }
+}
+
+class Test3 {
+>Test3 : Symbol(Test3, Decl(unusedPrivateMembers.ts, 17, 1))
+
+    private get x () {
+>x : Symbol(Test3.x, Decl(unusedPrivateMembers.ts, 19, 13))
+
+        return 0;
+    }
+
+    public test() {
+>test : Symbol(Test3.test, Decl(unusedPrivateMembers.ts, 22, 5))
+
+        var x = new Test3();
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 25, 11))
+>Test3 : Symbol(Test3, Decl(unusedPrivateMembers.ts, 17, 1))
+
+        x.x;
+>x.x : Symbol(Test3.x, Decl(unusedPrivateMembers.ts, 19, 13))
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 25, 11))
+>x : Symbol(Test3.x, Decl(unusedPrivateMembers.ts, 19, 13))
+    }
+}
+
+class Test4 {
+>Test4 : Symbol(Test4, Decl(unusedPrivateMembers.ts, 28, 1))
+
+    private set x(v) {
+>x : Symbol(Test4.x, Decl(unusedPrivateMembers.ts, 30, 13))
+>v : Symbol(v, Decl(unusedPrivateMembers.ts, 31, 18))
+
+        v;
+>v : Symbol(v, Decl(unusedPrivateMembers.ts, 31, 18))
+    }
+
+    public test() {
+>test : Symbol(Test4.test, Decl(unusedPrivateMembers.ts, 33, 5))
+
+        var x = new Test4();
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 36, 11))
+>Test4 : Symbol(Test4, Decl(unusedPrivateMembers.ts, 28, 1))
+
+        x.x;
+>x.x : Symbol(Test4.x, Decl(unusedPrivateMembers.ts, 30, 13))
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 36, 11))
+>x : Symbol(Test4.x, Decl(unusedPrivateMembers.ts, 30, 13))
+    }
+}
+
+class Test5<T> {
+>Test5 : Symbol(Test5, Decl(unusedPrivateMembers.ts, 39, 1))
+>T : Symbol(T, Decl(unusedPrivateMembers.ts, 41, 12))
+
+    private p: T;
+>p : Symbol(Test5.p, Decl(unusedPrivateMembers.ts, 41, 16))
+>T : Symbol(T, Decl(unusedPrivateMembers.ts, 41, 12))
+
+    public test() {
+>test : Symbol(Test5.test, Decl(unusedPrivateMembers.ts, 42, 17))
+
+        var x = new Test5<number>();
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 44, 11))
+>Test5 : Symbol(Test5, Decl(unusedPrivateMembers.ts, 39, 1))
+
+        x.p;
+>x.p : Symbol(Test5.p, Decl(unusedPrivateMembers.ts, 41, 16))
+>x : Symbol(x, Decl(unusedPrivateMembers.ts, 44, 11))
+>p : Symbol(Test5.p, Decl(unusedPrivateMembers.ts, 41, 16))
+    }
+}
+
diff --git a/tests/baselines/reference/unusedPrivateMembers.types b/tests/baselines/reference/unusedPrivateMembers.types
new file mode 100644
index 00000000000..1d303068f24
--- /dev/null
+++ b/tests/baselines/reference/unusedPrivateMembers.types
@@ -0,0 +1,121 @@
+=== tests/cases/compiler/unusedPrivateMembers.ts ===
+
+class Test1 {
+>Test1 : Test1
+
+    private initializeInternal() {
+>initializeInternal : () => void
+    }
+
+    public test() {
+>test : () => void
+
+        var x = new Test1();
+>x : Test1
+>new Test1() : Test1
+>Test1 : typeof Test1
+
+        x.initializeInternal();
+>x.initializeInternal() : void
+>x.initializeInternal : () => void
+>x : Test1
+>initializeInternal : () => void
+    }
+}
+
+class Test2 {
+>Test2 : Test2
+
+    private p = 0;
+>p : number
+>0 : number
+
+    public test() {
+>test : () => void
+
+        var x = new Test2();
+>x : Test2
+>new Test2() : Test2
+>Test2 : typeof Test2
+
+        x.p;
+>x.p : number
+>x : Test2
+>p : number
+    }
+}
+
+class Test3 {
+>Test3 : Test3
+
+    private get x () {
+>x : number
+
+        return 0;
+>0 : number
+    }
+
+    public test() {
+>test : () => void
+
+        var x = new Test3();
+>x : Test3
+>new Test3() : Test3
+>Test3 : typeof Test3
+
+        x.x;
+>x.x : number
+>x : Test3
+>x : number
+    }
+}
+
+class Test4 {
+>Test4 : Test4
+
+    private set x(v) {
+>x : any
+>v : any
+
+        v;
+>v : any
+    }
+
+    public test() {
+>test : () => void
+
+        var x = new Test4();
+>x : Test4
+>new Test4() : Test4
+>Test4 : typeof Test4
+
+        x.x;
+>x.x : any
+>x : Test4
+>x : any
+    }
+}
+
+class Test5<T> {
+>Test5 : Test5<T>
+>T : T
+
+    private p: T;
+>p : T
+>T : T
+
+    public test() {
+>test : () => void
+
+        var x = new Test5<number>();
+>x : Test5<number>
+>new Test5<number>() : Test5<number>
+>Test5 : typeof Test5
+
+        x.p;
+>x.p : number
+>x : Test5<number>
+>p : number
+    }
+}
+
diff --git a/tests/baselines/reference/unusedSwitchStatment.errors.txt b/tests/baselines/reference/unusedSwitchStatment.errors.txt
new file mode 100644
index 00000000000..58359eed90d
--- /dev/null
+++ b/tests/baselines/reference/unusedSwitchStatment.errors.txt
@@ -0,0 +1,31 @@
+tests/cases/compiler/unusedSwitchStatment.ts(4,13): error TS6133: 'x' is declared but never used.
+tests/cases/compiler/unusedSwitchStatment.ts(7,15): error TS6133: 'c' is declared but never used.
+tests/cases/compiler/unusedSwitchStatment.ts(10,13): error TS6133: 'z' is declared but never used.
+
+
+==== tests/cases/compiler/unusedSwitchStatment.ts (3 errors) ====
+    
+    switch (1) {
+        case 0:
+            let x;
+                ~
+!!! error TS6133: 'x' is declared but never used.
+            break;
+        case 1:
+            const c = 1;
+                  ~
+!!! error TS6133: 'c' is declared but never used.
+            break;
+        default:
+            let z = 2;
+                ~
+!!! error TS6133: 'z' is declared but never used.
+    }
+    
+    
+    switch (2) {
+        case 0:
+            let x;
+        case 1:
+            x++;
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedSwitchStatment.js b/tests/baselines/reference/unusedSwitchStatment.js
new file mode 100644
index 00000000000..2fd0d1fc49e
--- /dev/null
+++ b/tests/baselines/reference/unusedSwitchStatment.js
@@ -0,0 +1,38 @@
+//// [unusedSwitchStatment.ts]
+
+switch (1) {
+    case 0:
+        let x;
+        break;
+    case 1:
+        const c = 1;
+        break;
+    default:
+        let z = 2;
+}
+
+
+switch (2) {
+    case 0:
+        let x;
+    case 1:
+        x++;
+}
+
+//// [unusedSwitchStatment.js]
+switch (1) {
+    case 0:
+        var x = void 0;
+        break;
+    case 1:
+        var c = 1;
+        break;
+    default:
+        var z = 2;
+}
+switch (2) {
+    case 0:
+        var x = void 0;
+    case 1:
+        x++;
+}
diff --git a/tests/cases/compiler/asyncFunctionNoReturnType.ts b/tests/cases/compiler/asyncFunctionNoReturnType.ts
new file mode 100644
index 00000000000..4a4b5316d72
--- /dev/null
+++ b/tests/cases/compiler/asyncFunctionNoReturnType.ts
@@ -0,0 +1,5 @@
+// @noImplicitReturns: true
+async () => {
+    if (window)
+        return;
+}
diff --git a/tests/cases/compiler/destructuringAssignmentWithDefault.ts b/tests/cases/compiler/destructuringAssignmentWithDefault.ts
new file mode 100644
index 00000000000..45ade402eb8
--- /dev/null
+++ b/tests/cases/compiler/destructuringAssignmentWithDefault.ts
@@ -0,0 +1,4 @@
+// @strictNullChecks: true
+const a: { x?: number } = { };
+let x = 0;
+({x = 1} = a);
diff --git a/tests/cases/compiler/exportDefaultAsyncFunction.ts b/tests/cases/compiler/exportDefaultAsyncFunction.ts
new file mode 100644
index 00000000000..c05296711ec
--- /dev/null
+++ b/tests/cases/compiler/exportDefaultAsyncFunction.ts
@@ -0,0 +1,3 @@
+// @target: es6
+export default async function foo(): Promise<void> {}
+foo();
diff --git a/tests/cases/compiler/unusedImports11.ts b/tests/cases/compiler/unusedImports11.ts
new file mode 100644
index 00000000000..4f2fed649d1
--- /dev/null
+++ b/tests/cases/compiler/unusedImports11.ts
@@ -0,0 +1,19 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+// @filename: b.ts
+export class Member {}
+export default Member;
+
+
+// @filename: a.ts
+import { Member } from './b';
+import d, { Member as M } from './b';
+import * as ns from './b';
+import r = require("./b");
+
+new Member();
+new d();
+new M();
+new ns.Member();
+new r.Member();
\ No newline at end of file
diff --git a/tests/cases/compiler/unusedImports12.ts b/tests/cases/compiler/unusedImports12.ts
new file mode 100644
index 00000000000..14206284b64
--- /dev/null
+++ b/tests/cases/compiler/unusedImports12.ts
@@ -0,0 +1,13 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+// @filename: b.ts
+export class Member {}
+export default Member;
+
+
+// @filename: a.ts
+import { Member } from './b';
+import d, { Member as M } from './b';
+import * as ns from './b';
+import r = require("./b");
diff --git a/tests/cases/compiler/unusedLocalsAndParameters.ts b/tests/cases/compiler/unusedLocalsAndParameters.ts
new file mode 100644
index 00000000000..1f4fc944ff4
--- /dev/null
+++ b/tests/cases/compiler/unusedLocalsAndParameters.ts
@@ -0,0 +1,86 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+export { };
+
+// function declaration paramter
+function f(a) {
+}
+f(0);
+
+// function expression paramter
+var fexp = function (a) {
+};
+
+fexp(0);
+
+// arrow function paramter
+var farrow = (a) => {
+};
+
+class C {
+    // Method declaration paramter
+    method(a) {
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+    }
+}
+
+var E = class {
+    // Method declaration paramter
+    method(a) {
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+    }
+}
+
+var o = {
+    // Object literal method declaration paramter
+    method(a) {
+    },
+    // Accessor declaration paramter
+    set x(v: number) {
+    }
+};
+
+o;
+
+// in a for..in statment
+for (let i in o) {
+}
+
+// in a for..of statment
+for (let i of [1, 2, 3]) {
+}
+
+// in a for. statment
+for (let i = 0, n; i < 10; i++) {
+}
+
+// in a block
+
+const condition = false;
+if (condition) {
+    const c = 0;
+}
+
+// in try/catch/finally
+try {
+    const a = 0;
+}
+catch (e) {
+    const c = 1;
+}
+finally {
+    const c = 0;
+}
+
+
+// in a namespace
+namespace N {
+    var x;
+}
+
+    
\ No newline at end of file
diff --git a/tests/cases/compiler/unusedLocalsAndParametersDeferred.ts b/tests/cases/compiler/unusedLocalsAndParametersDeferred.ts
new file mode 100644
index 00000000000..75b98308199
--- /dev/null
+++ b/tests/cases/compiler/unusedLocalsAndParametersDeferred.ts
@@ -0,0 +1,162 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+export { };
+
+function defered<T>(a: () => T): T {
+    return a();
+}
+
+// function declaration paramter
+function f(a) {
+    defered(() => {
+        a;
+    });
+}
+f(0);
+
+// function expression paramter
+var fexp = function (a) {
+    defered(() => {
+        a;
+    });
+};
+fexp(1);
+
+// arrow function paramter
+var farrow = (a) => {
+    defered(() => {
+        a;
+    });
+};
+farrow(2);
+
+let prop1;
+
+class C {
+    // Method declaration paramter
+    method(a) {
+        defered(() => {
+            a;
+        });
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+        defered(() => {
+            v;
+        });
+    }
+    // in a property initalizer
+    p = defered(() => {
+        prop1;
+    });
+}
+
+new C();
+
+let prop2;
+
+var E = class {
+    // Method declaration paramter
+    method(a) {
+        defered(() => {
+            a;
+        });
+    }
+    // Accessor declaration paramter
+    set x(v: number) {
+        defered(() => {
+            v;
+        });
+    }
+    // in a property initalizer
+    p = defered(() => {
+        prop2;
+    });
+}
+
+new E();
+
+
+var o = {
+    // Object literal method declaration paramter
+    method(a) {
+        defered(() => {
+            a;
+        });
+    },
+    // Accessor declaration paramter
+    set x(v: number) {
+        defered(() => {
+            v;
+        });
+    },
+    // in a property initalizer
+    p: defered(() => {
+        prop1;
+    })
+};
+
+o;
+
+// in a for..in statment
+for (let i in o) {
+    defered(() => {
+        i;
+    });
+}
+
+// in a for..of statment
+for (let i of [1,2,3]) {
+    defered(() => {
+        i;
+    });
+}
+
+// in a for. statment
+for (let i = 0; i < 10; i++) {
+    defered(() => {
+        i;
+    });
+}
+
+// in a block
+
+const condition = false;
+if (condition) {
+    const c = 0;
+    defered(() => {
+        c;
+    });
+}
+
+// in try/catch/finally
+try {
+    const a = 0;
+    defered(() => {
+        a;
+    });
+}
+catch (e) {
+    const c = 1;
+    defered(() => {
+        c;
+    });
+}
+finally {
+    const c = 0;
+    defered(() => {
+        c;
+    });
+}
+
+
+// in a namespace
+namespace N {
+    var x;
+    defered(() => {
+        x;
+    });
+}
+N;
+    
\ No newline at end of file
diff --git a/tests/cases/compiler/unusedLocalsAndParametersOverloadSignatures.ts b/tests/cases/compiler/unusedLocalsAndParametersOverloadSignatures.ts
new file mode 100644
index 00000000000..32affb28be3
--- /dev/null
+++ b/tests/cases/compiler/unusedLocalsAndParametersOverloadSignatures.ts
@@ -0,0 +1,25 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+export function func(details: number, message: string, ...args: any[]): void;
+export function func(details: number, message: string): any {
+    return details + message;
+}
+
+export class C {
+    constructor(details: number, message: string, ...args: any[]);
+    constructor(details: number, message: string) {
+        details + message;
+    }
+
+    method(details: number, message: string, ...args: any[]): void;
+    method(details: number, message: string): any {
+        return details + message;
+    }
+}
+
+
+export function genericFunc<T>(details: number, message: T, ...args: any[]): void;
+export function genericFunc(details: number, message: any): any {
+    return details + message;
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/unusedLocalsAndParametersTypeAliases.ts b/tests/cases/compiler/unusedLocalsAndParametersTypeAliases.ts
new file mode 100644
index 00000000000..b94f88845bc
--- /dev/null
+++ b/tests/cases/compiler/unusedLocalsAndParametersTypeAliases.ts
@@ -0,0 +1,29 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+// used in a declaration
+type handler1 = () => void;
+export interface I1 {
+    getHandler: handler1;
+}
+
+// exported
+export type handler2 = () => void;
+
+// used in extends clause
+type handler3 = () => void;
+export interface I3<T extends handler3> {
+    getHandler: T;
+}
+
+// used in another type alias declaration
+type handler4 = () => void;
+type handler5 = handler4 | (()=>number);
+var x: handler5;
+x();
+
+// used as type argument
+type handler6 = () => void;
+var y: Array<handler6>;
+y[0]();
+    
\ No newline at end of file
diff --git a/tests/cases/compiler/unusedLocalsAndParametersTypeAliases2.ts b/tests/cases/compiler/unusedLocalsAndParametersTypeAliases2.ts
new file mode 100644
index 00000000000..23d23a5bc18
--- /dev/null
+++ b/tests/cases/compiler/unusedLocalsAndParametersTypeAliases2.ts
@@ -0,0 +1,13 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+// unused
+type handler1 = () => void;
+
+
+function foo() {
+    type handler2 = () => void;
+    foo();
+}
+
+export {}
\ No newline at end of file
diff --git a/tests/cases/compiler/unusedPrivateMembers.ts b/tests/cases/compiler/unusedPrivateMembers.ts
new file mode 100644
index 00000000000..ab4e5ba9bca
--- /dev/null
+++ b/tests/cases/compiler/unusedPrivateMembers.ts
@@ -0,0 +1,51 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+//@target:ES5
+
+class Test1 {
+    private initializeInternal() {
+    }
+
+    public test() {
+        var x = new Test1();
+        x.initializeInternal();
+    }
+}
+
+class Test2 {
+    private p = 0;
+    public test() {
+        var x = new Test2();
+        x.p;
+    }
+}
+
+class Test3 {
+    private get x () {
+        return 0;
+    }
+
+    public test() {
+        var x = new Test3();
+        x.x;
+    }
+}
+
+class Test4 {
+    private set x(v) {
+        v;
+    }
+
+    public test() {
+        var x = new Test4();
+        x.x;
+    }
+}
+
+class Test5<T> {
+    private p: T;
+    public test() {
+        var x = new Test5<number>();
+        x.p;
+    }
+}
diff --git a/tests/cases/compiler/unusedSwitchStatment.ts b/tests/cases/compiler/unusedSwitchStatment.ts
new file mode 100644
index 00000000000..53f93b913aa
--- /dev/null
+++ b/tests/cases/compiler/unusedSwitchStatment.ts
@@ -0,0 +1,21 @@
+//@noUnusedLocals:true
+//@noUnusedParameters:true
+
+switch (1) {
+    case 0:
+        let x;
+        break;
+    case 1:
+        const c = 1;
+        break;
+    default:
+        let z = 2;
+}
+
+
+switch (2) {
+    case 0:
+        let x;
+    case 1:
+        x++;
+}
\ No newline at end of file
diff --git a/tests/cases/fourslash/formattingIllegalImportClause.ts b/tests/cases/fourslash/formattingIllegalImportClause.ts
new file mode 100644
index 00000000000..9e97087c000
--- /dev/null
+++ b/tests/cases/fourslash/formattingIllegalImportClause.ts
@@ -0,0 +1,26 @@
+/// <reference path='fourslash.ts' />
+
+//// var expect = require('expect.js');
+//// import React   from 'react'/*1*/;
+//// import { mount } from 'enzyme';
+//// require('../setup');
+//// var Amount = require('../../src/js/components/amount');
+
+//// describe('<Failed />', () => {
+////   var history
+////   beforeEach(() => {
+////     history = createMemoryHistory();
+////     sinon.spy(history, 'pushState');
+////   });
+
+////   afterEach(() => {
+////   })
+
+////   it('redirects to order summary', () => {
+
+////   });
+//// });
+
+format.document();
+goTo.marker("1");
+verify.currentLineContentIs("import React from 'react';")
\ No newline at end of file
diff --git a/tests/cases/fourslash/navigationBarNamespaceImportWithNoName.ts b/tests/cases/fourslash/navigationBarNamespaceImportWithNoName.ts
new file mode 100644
index 00000000000..732e2deb1dd
--- /dev/null
+++ b/tests/cases/fourslash/navigationBarNamespaceImportWithNoName.ts
@@ -0,0 +1,13 @@
+////import *{} from 'foo';
+verify.navigationBar([
+    {
+        "text": "\"navigationBarNamespaceImportWithNoName\"",
+        "kind": "module",
+        "childItems": [
+            {
+                "text": "<unknown>",
+                "kind": "alias"
+            }
+        ]
+    }
+]);
diff --git a/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/@types/m4/entry.d.ts b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/@types/m4/entry.d.ts
new file mode 100644
index 00000000000..f0fc245910a
--- /dev/null
+++ b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/@types/m4/entry.d.ts
@@ -0,0 +1 @@
+export declare var foo: number;
diff --git a/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/@types/m4/package.json b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/@types/m4/package.json
new file mode 100644
index 00000000000..53ac1558a23
--- /dev/null
+++ b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/@types/m4/package.json
@@ -0,0 +1,5 @@
+{
+  "types": "entry.d.ts",
+  "name": "m4",
+  "version": "1.0.0"
+}
\ No newline at end of file
diff --git a/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/m4/entry.js b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/m4/entry.js
new file mode 100644
index 00000000000..a1cb557b18d
--- /dev/null
+++ b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/m4/entry.js
@@ -0,0 +1 @@
+exports.test = "hello, world";
diff --git a/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/m4/package.json b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/m4/package.json
new file mode 100644
index 00000000000..4ae99f312fc
--- /dev/null
+++ b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/node_modules/m4/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "m4",
+  "version": "1.0.0",
+  "main": "entry.js"
+}
\ No newline at end of file
diff --git a/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/root.ts b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/root.ts
index 9ed943bebba..2b80564ae26 100644
--- a/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/root.ts
+++ b/tests/cases/projects/NodeModulesSearch/maxDepthIncreased/root.ts
@@ -1,4 +1,9 @@
 import * as m1 from "m1";
+import * as m4 from "m4";
+
 m1.f1("test");
 m1.f2.a = 10;
-m1.f2.person.age = "10"; // Error: Should be number
+
+m1.f2.person.age = "10";    // Should error if loaded the .js files correctly
+
+let r2 = 3 + m4.foo; // Should be OK if correctly using the @types .d.ts file