diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 3fdc3630b4d..d38ce359e8b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -1023,8 +1023,8 @@ namespace ts {
             }
         }
 
-        function getDeclarationOfAliasSymbol(symbol: Symbol): Declaration {
-            return findMap(symbol.declarations, d => isAliasSymbolDeclaration(d) ? d : undefined);
+        function getDeclarationOfAliasSymbol(symbol: Symbol): Declaration | undefined {
+            return forEach(symbol.declarations, d => isAliasSymbolDeclaration(d) ? d : undefined);
         }
 
         function getTargetOfImportEqualsDeclaration(node: ImportEqualsDeclaration): Symbol {
@@ -1191,6 +1191,7 @@ namespace ts {
             if (!links.target) {
                 links.target = resolvingSymbol;
                 const node = getDeclarationOfAliasSymbol(symbol);
+                Debug.assert(!!node);
                 const target = getTargetOfAliasDeclaration(node);
                 if (links.target === resolvingSymbol) {
                     links.target = target || unknownSymbol;
@@ -1226,6 +1227,7 @@ namespace ts {
             if (!links.referenced) {
                 links.referenced = true;
                 const node = getDeclarationOfAliasSymbol(symbol);
+                Debug.assert(!!node);
                 if (node.kind === SyntaxKind.ExportAssignment) {
                     // export default <symbol>
                     checkExpressionCached((<ExportAssignment>node).expression);
@@ -6301,6 +6303,18 @@ namespace ts {
                 reportError(message, sourceType, targetType);
             }
 
+            function tryElaborateErrorsForPrimitivesAndObjects(source: Type, target: Type) {
+                const sourceType = typeToString(source);
+                const targetType = typeToString(target);
+
+                if ((globalStringType === source && stringType === target) ||
+                    (globalNumberType === source && numberType === target) ||
+                    (globalBooleanType === source && booleanType === target) ||
+                    (getGlobalESSymbolType() === source && esSymbolType === target)) {
+                        reportError(Diagnostics._0_is_a_primitive_but_1_is_a_wrapper_object_Prefer_using_0_when_possible, targetType, sourceType);
+                }
+            }
+
             // Compare two types and return
             // Ternary.True if they are related with no assumptions,
             // Ternary.Maybe if they are related with assumptions of other relationships, or
@@ -6424,6 +6438,9 @@ namespace ts {
                 }
 
                 if (reportErrors) {
+                    if (source.flags & TypeFlags.ObjectType && target.flags & TypeFlags.Primitive) {
+                        tryElaborateErrorsForPrimitivesAndObjects(source, target);
+                    }
                     reportRelationError(headMessage, source, target);
                 }
                 return Ternary.False;
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 6406455d713..e1175c42438 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -885,7 +885,7 @@ namespace ts {
     function convertCompilerOptionsFromJsonWorker(jsonOptions: any,
         basePath: string, errors: Diagnostic[], configFileName?: string): CompilerOptions {
 
-        const options: CompilerOptions = getBaseFileName(configFileName) === "jsconfig.json" ? { allowJs: true } : {};
+        const options: CompilerOptions = getBaseFileName(configFileName) === "jsconfig.json" ? { allowJs: true, maxNodeModuleJsDepth: 2 } : {};
         convertOptionsFromJson(optionDeclarations, jsonOptions, basePath, options, Diagnostics.Unknown_compiler_option_0, errors);
         return options;
     }
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 6210a20afa6..b8978b32571 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1955,6 +1955,10 @@
         "category": "Error",
         "code": 2691
     },
+    "'{0}' is a primitive, but '{1}' is a wrapper object. Prefer using '{0}' when possible.": {
+        "category": "Error",
+        "code": 2692
+    },
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
         "code": 4000
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 64ef04cd67d..dac3374ab15 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1103,7 +1103,7 @@ namespace ts {
         // - This calls resolveModuleNames, and then calls findSourceFile for each resolved module.
         // As all these operations happen - and are nested - within the createProgram call, they close over the below variables.
         // The current resolution depth is tracked by incrementing/decrementing as the depth first search progresses.
-        const maxNodeModulesJsDepth = typeof options.maxNodeModuleJsDepth === "number" ? options.maxNodeModuleJsDepth : 2;
+        const maxNodeModulesJsDepth = typeof options.maxNodeModuleJsDepth === "number" ? options.maxNodeModuleJsDepth : 0;
         let currentNodeModulesDepth = 0;
 
         // If a module has some of its imports skipped due to being at the depth limit under node_modules, then track
diff --git a/src/harness/unittests/convertCompilerOptionsFromJson.ts b/src/harness/unittests/convertCompilerOptionsFromJson.ts
index d308bb2a6e6..9de18850477 100644
--- a/src/harness/unittests/convertCompilerOptionsFromJson.ts
+++ b/src/harness/unittests/convertCompilerOptionsFromJson.ts
@@ -403,6 +403,7 @@ namespace ts {
                 {
                     compilerOptions: <CompilerOptions>{
                         allowJs: true,
+                        maxNodeModuleJsDepth: 2,
                         module: ModuleKind.CommonJS,
                         target: ScriptTarget.ES5,
                         noImplicitAny: false,
@@ -429,6 +430,7 @@ namespace ts {
                 {
                     compilerOptions: <CompilerOptions>{
                         allowJs: false,
+                        maxNodeModuleJsDepth: 2,
                         module: ModuleKind.CommonJS,
                         target: ScriptTarget.ES5,
                         noImplicitAny: false,
@@ -450,7 +452,8 @@ namespace ts {
                 {
                     compilerOptions:
                     {
-                        allowJs: true
+                        allowJs: true,
+                        maxNodeModuleJsDepth: 2
                     },
                     errors: [{
                         file: undefined,
@@ -469,7 +472,8 @@ namespace ts {
                 {
                     compilerOptions:
                     {
-                        allowJs: true
+                        allowJs: true,
+                        maxNodeModuleJsDepth: 2
                     },
                     errors: <Diagnostic[]>[]
                 }
diff --git a/src/services/services.ts b/src/services/services.ts
index babb5cf4574..a55f2cf61b0 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -280,11 +280,14 @@ namespace ts {
                 let pos = this.pos;
                 const useJSDocScanner = this.kind >= SyntaxKind.FirstJSDocTagNode && this.kind <= SyntaxKind.LastJSDocTagNode;
                 const processNode = (node: Node) => {
-                    if (pos < node.pos) {
+                    const isJSDocTagNode = isJSDocTag(node);
+                    if (!isJSDocTagNode && pos < node.pos) {
                         pos = this.addSyntheticNodes(children, pos, node.pos, useJSDocScanner);
                     }
                     children.push(node);
-                    pos = node.end;
+                    if (!isJSDocTagNode) {
+                        pos = node.end;
+                    }
                 };
                 const processNodes = (nodes: NodeArray<Node>) => {
                     if (pos < nodes.pos) {
@@ -299,10 +302,6 @@ namespace ts {
                         processNode(jsDocComment);
                     }
                 }
-                // For syntactic classifications, all trivia are classcified together, including jsdoc comments.
-                // For that to work, the jsdoc comments should still be the leading trivia of the first child. 
-                // Restoring the scanner position ensures that. 
-                pos = this.pos;
                 forEachChild(this, processNode, processNodes);
                 if (pos < this.end) {
                     this.addSyntheticNodes(children, pos, this.end);
diff --git a/tests/baselines/reference/apparentTypeSubtyping.errors.txt b/tests/baselines/reference/apparentTypeSubtyping.errors.txt
index e1a53ef6a73..01fffeb3824 100644
--- a/tests/baselines/reference/apparentTypeSubtyping.errors.txt
+++ b/tests/baselines/reference/apparentTypeSubtyping.errors.txt
@@ -1,6 +1,7 @@
 tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSubtyping.ts(9,7): error TS2415: Class 'Derived<U>' incorrectly extends base class 'Base<string>'.
   Types of property 'x' are incompatible.
     Type 'String' is not assignable to type 'string'.
+      'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
 
 
 ==== tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSubtyping.ts (1 errors) ====
@@ -17,6 +18,7 @@ tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSubtypi
 !!! error TS2415: Class 'Derived<U>' incorrectly extends base class 'Base<string>'.
 !!! error TS2415:   Types of property 'x' are incompatible.
 !!! error TS2415:     Type 'String' is not assignable to type 'string'.
+!!! error TS2415:       'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
         x: String;
     }
     
diff --git a/tests/baselines/reference/apparentTypeSupertype.errors.txt b/tests/baselines/reference/apparentTypeSupertype.errors.txt
index 5fe5c92a5b3..c7610a80f2f 100644
--- a/tests/baselines/reference/apparentTypeSupertype.errors.txt
+++ b/tests/baselines/reference/apparentTypeSupertype.errors.txt
@@ -2,6 +2,7 @@ tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSuperty
   Types of property 'x' are incompatible.
     Type 'U' is not assignable to type 'string'.
       Type 'String' is not assignable to type 'string'.
+        'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
 
 
 ==== tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSupertype.ts (1 errors) ====
@@ -19,5 +20,6 @@ tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSuperty
 !!! error TS2415:   Types of property 'x' are incompatible.
 !!! error TS2415:     Type 'U' is not assignable to type 'string'.
 !!! error TS2415:       Type 'String' is not assignable to type 'string'.
+!!! error TS2415:         'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
         x: U;
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/arrayLiterals3.errors.txt b/tests/baselines/reference/arrayLiterals3.errors.txt
index f221fd96fab..1f0dd30c09c 100644
--- a/tests/baselines/reference/arrayLiterals3.errors.txt
+++ b/tests/baselines/reference/arrayLiterals3.errors.txt
@@ -17,6 +17,7 @@ tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(34,5): error
       Types of parameters 'items' and 'items' are incompatible.
         Type 'Number' is not assignable to type 'string | number'.
           Type 'Number' is not assignable to type 'number'.
+            'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
 
 
 ==== tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts (6 errors) ====
@@ -79,4 +80,5 @@ tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(34,5): error
 !!! error TS2322:       Types of parameters 'items' and 'items' are incompatible.
 !!! error TS2322:         Type 'Number' is not assignable to type 'string | number'.
 !!! error TS2322:           Type 'Number' is not assignable to type 'number'.
+!!! error TS2322:             'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
     
\ No newline at end of file
diff --git a/tests/baselines/reference/assignFromBooleanInterface.errors.txt b/tests/baselines/reference/assignFromBooleanInterface.errors.txt
index 4b06603a9bf..555b645cd7d 100644
--- a/tests/baselines/reference/assignFromBooleanInterface.errors.txt
+++ b/tests/baselines/reference/assignFromBooleanInterface.errors.txt
@@ -1,4 +1,5 @@
 tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface.ts(3,1): error TS2322: Type 'Boolean' is not assignable to type 'boolean'.
+  'boolean' is a primitive, but 'Boolean' is a wrapper object. Prefer using 'boolean' when possible.
 
 
 ==== tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface.ts (1 errors) ====
@@ -7,4 +8,5 @@ tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface.ts(3
     x = a;
     ~
 !!! error TS2322: Type 'Boolean' is not assignable to type 'boolean'.
+!!! error TS2322:   'boolean' is a primitive, but 'Boolean' is a wrapper object. Prefer using 'boolean' when possible.
     a = x;
\ No newline at end of file
diff --git a/tests/baselines/reference/assignFromBooleanInterface2.errors.txt b/tests/baselines/reference/assignFromBooleanInterface2.errors.txt
index c03eab60c74..6c7ebbe5ee8 100644
--- a/tests/baselines/reference/assignFromBooleanInterface2.errors.txt
+++ b/tests/baselines/reference/assignFromBooleanInterface2.errors.txt
@@ -3,6 +3,7 @@ tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface2.ts(
     Type '() => Object' is not assignable to type '() => boolean'.
       Type 'Object' is not assignable to type 'boolean'.
 tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface2.ts(19,1): error TS2322: Type 'Boolean' is not assignable to type 'boolean'.
+  'boolean' is a primitive, but 'Boolean' is a wrapper object. Prefer using 'boolean' when possible.
 tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface2.ts(20,1): error TS2322: Type 'NotBoolean' is not assignable to type 'boolean'.
 
 
@@ -33,6 +34,7 @@ tests/cases/conformance/types/primitives/boolean/assignFromBooleanInterface2.ts(
     x = a; // expected error
     ~
 !!! error TS2322: Type 'Boolean' is not assignable to type 'boolean'.
+!!! error TS2322:   'boolean' is a primitive, but 'Boolean' is a wrapper object. Prefer using 'boolean' when possible.
     x = b; // expected error
     ~
 !!! error TS2322: Type 'NotBoolean' is not assignable to type 'boolean'.
diff --git a/tests/baselines/reference/assignFromNumberInterface.errors.txt b/tests/baselines/reference/assignFromNumberInterface.errors.txt
index 0c8c4a5f5ac..1a70ef342d2 100644
--- a/tests/baselines/reference/assignFromNumberInterface.errors.txt
+++ b/tests/baselines/reference/assignFromNumberInterface.errors.txt
@@ -1,4 +1,5 @@
 tests/cases/conformance/types/primitives/number/assignFromNumberInterface.ts(3,1): error TS2322: Type 'Number' is not assignable to type 'number'.
+  'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
 
 
 ==== tests/cases/conformance/types/primitives/number/assignFromNumberInterface.ts (1 errors) ====
@@ -7,4 +8,5 @@ tests/cases/conformance/types/primitives/number/assignFromNumberInterface.ts(3,1
     x = a;
     ~
 !!! error TS2322: Type 'Number' is not assignable to type 'number'.
+!!! error TS2322:   'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
     a = x;
\ No newline at end of file
diff --git a/tests/baselines/reference/assignFromNumberInterface2.errors.txt b/tests/baselines/reference/assignFromNumberInterface2.errors.txt
index 85639cdeeaf..3297501d612 100644
--- a/tests/baselines/reference/assignFromNumberInterface2.errors.txt
+++ b/tests/baselines/reference/assignFromNumberInterface2.errors.txt
@@ -1,4 +1,5 @@
 tests/cases/conformance/types/primitives/number/assignFromNumberInterface2.ts(24,1): error TS2322: Type 'Number' is not assignable to type 'number'.
+  'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
 tests/cases/conformance/types/primitives/number/assignFromNumberInterface2.ts(25,1): error TS2322: Type 'NotNumber' is not assignable to type 'number'.
 
 
@@ -29,6 +30,7 @@ tests/cases/conformance/types/primitives/number/assignFromNumberInterface2.ts(25
     x = a; // expected error
     ~
 !!! error TS2322: Type 'Number' is not assignable to type 'number'.
+!!! error TS2322:   'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
     x = b; // expected error
     ~
 !!! error TS2322: Type 'NotNumber' is not assignable to type 'number'.
diff --git a/tests/baselines/reference/assignFromStringInterface.errors.txt b/tests/baselines/reference/assignFromStringInterface.errors.txt
index 6ec8afad120..7e7af4d1b9d 100644
--- a/tests/baselines/reference/assignFromStringInterface.errors.txt
+++ b/tests/baselines/reference/assignFromStringInterface.errors.txt
@@ -1,4 +1,5 @@
 tests/cases/conformance/types/primitives/string/assignFromStringInterface.ts(3,1): error TS2322: Type 'String' is not assignable to type 'string'.
+  'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
 
 
 ==== tests/cases/conformance/types/primitives/string/assignFromStringInterface.ts (1 errors) ====
@@ -7,4 +8,5 @@ tests/cases/conformance/types/primitives/string/assignFromStringInterface.ts(3,1
     x = a;
     ~
 !!! error TS2322: Type 'String' is not assignable to type 'string'.
+!!! error TS2322:   'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
     a = x;
\ No newline at end of file
diff --git a/tests/baselines/reference/assignFromStringInterface2.errors.txt b/tests/baselines/reference/assignFromStringInterface2.errors.txt
index 4e09eb6eacb..0fc3284bf00 100644
--- a/tests/baselines/reference/assignFromStringInterface2.errors.txt
+++ b/tests/baselines/reference/assignFromStringInterface2.errors.txt
@@ -1,4 +1,5 @@
 tests/cases/conformance/types/primitives/string/assignFromStringInterface2.ts(47,1): error TS2322: Type 'String' is not assignable to type 'string'.
+  'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
 tests/cases/conformance/types/primitives/string/assignFromStringInterface2.ts(48,1): error TS2322: Type 'NotString' is not assignable to type 'string'.
 
 
@@ -52,6 +53,7 @@ tests/cases/conformance/types/primitives/string/assignFromStringInterface2.ts(48
     x = a; // expected error
     ~
 !!! error TS2322: Type 'String' is not assignable to type 'string'.
+!!! error TS2322:   'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
     x = b; // expected error
     ~
 !!! error TS2322: Type 'NotString' is not assignable to type 'string'.
diff --git a/tests/baselines/reference/errorForConflictingExportEqualsValue.errors.txt b/tests/baselines/reference/errorForConflictingExportEqualsValue.errors.txt
new file mode 100644
index 00000000000..9a5858f46ab
--- /dev/null
+++ b/tests/baselines/reference/errorForConflictingExportEqualsValue.errors.txt
@@ -0,0 +1,9 @@
+tests/cases/compiler/errorForConflictingExportEqualsValue.ts(2,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
+
+
+==== tests/cases/compiler/errorForConflictingExportEqualsValue.ts (1 errors) ====
+    export var x;
+    export = {};
+    ~~~~~~~~~~~~
+!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/errorForConflictingExportEqualsValue.js b/tests/baselines/reference/errorForConflictingExportEqualsValue.js
new file mode 100644
index 00000000000..88762e7e846
--- /dev/null
+++ b/tests/baselines/reference/errorForConflictingExportEqualsValue.js
@@ -0,0 +1,8 @@
+//// [errorForConflictingExportEqualsValue.ts]
+export var x;
+export = {};
+
+
+//// [errorForConflictingExportEqualsValue.js]
+"use strict";
+module.exports = {};
diff --git a/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.errors.txt b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.errors.txt
new file mode 100644
index 00000000000..2218e7910ae
--- /dev/null
+++ b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.errors.txt
@@ -0,0 +1,26 @@
+/index.ts(4,5): error TS2339: Property 'y' does not exist on type 'typeof "shortid"'.
+
+
+==== /index.ts (1 errors) ====
+    /// <reference path="/typings/index.d.ts" />
+    import * as foo from "shortid";
+    foo.x // found in index.d.ts
+    foo.y // ignored from shortid/index.js
+        ~
+!!! error TS2339: Property 'y' does not exist on type 'typeof "shortid"'.
+    
+    
+==== /node_modules/shortid/node_modules/z/index.js (0 errors) ====
+    // z will not be found because maxNodeModulesJsDepth: 0
+    module.exports = { z: 'no' };
+    
+==== /node_modules/shortid/index.js (0 errors) ====
+    var z = require('z');
+    var y = { y: 'foo' };
+    module.exports = y;
+    
+==== /typings/index.d.ts (0 errors) ====
+    declare module "shortid" {
+        export var x: number;
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
new file mode 100644
index 00000000000..e53b2a0934f
--- /dev/null
+++ b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
@@ -0,0 +1,28 @@
+[
+    "======== Resolving module 'shortid' from '/index.ts'. ========",
+    "Explicitly specified module resolution kind: 'NodeJs'.",
+    "Loading module 'shortid' from 'node_modules' folder.",
+    "File '/node_modules/shortid.ts' does not exist.",
+    "File '/node_modules/shortid.tsx' does not exist.",
+    "File '/node_modules/shortid.d.ts' does not exist.",
+    "File '/node_modules/shortid.js' does not exist.",
+    "File '/node_modules/shortid.jsx' does not exist.",
+    "File '/node_modules/shortid/package.json' does not exist.",
+    "File '/node_modules/shortid/index.ts' does not exist.",
+    "File '/node_modules/shortid/index.tsx' does not exist.",
+    "File '/node_modules/shortid/index.d.ts' does not exist.",
+    "File '/node_modules/shortid/index.js' exist - use it as a name resolution result.",
+    "File '/node_modules/@types/shortid.ts' does not exist.",
+    "File '/node_modules/@types/shortid.tsx' does not exist.",
+    "File '/node_modules/@types/shortid.d.ts' does not exist.",
+    "File '/node_modules/@types/shortid.js' does not exist.",
+    "File '/node_modules/@types/shortid.jsx' does not exist.",
+    "File '/node_modules/@types/shortid/package.json' does not exist.",
+    "File '/node_modules/@types/shortid/index.ts' does not exist.",
+    "File '/node_modules/@types/shortid/index.tsx' does not exist.",
+    "File '/node_modules/@types/shortid/index.d.ts' does not exist.",
+    "File '/node_modules/@types/shortid/index.js' does not exist.",
+    "File '/node_modules/@types/shortid/index.jsx' does not exist.",
+    "Resolving real path for '/node_modules/shortid/index.js', result '/node_modules/shortid/index.js'",
+    "======== Module name 'shortid' was successfully resolved to '/node_modules/shortid/index.js'. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/nativeToBoxedTypes.errors.txt b/tests/baselines/reference/nativeToBoxedTypes.errors.txt
new file mode 100644
index 00000000000..03186a6d7e3
--- /dev/null
+++ b/tests/baselines/reference/nativeToBoxedTypes.errors.txt
@@ -0,0 +1,36 @@
+tests/cases/compiler/nativeToBoxedTypes.ts(3,1): error TS2322: Type 'Number' is not assignable to type 'number'.
+  'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
+tests/cases/compiler/nativeToBoxedTypes.ts(7,1): error TS2322: Type 'String' is not assignable to type 'string'.
+  'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
+tests/cases/compiler/nativeToBoxedTypes.ts(11,1): error TS2322: Type 'Boolean' is not assignable to type 'boolean'.
+  'boolean' is a primitive, but 'Boolean' is a wrapper object. Prefer using 'boolean' when possible.
+tests/cases/compiler/nativeToBoxedTypes.ts(14,10): error TS2304: Cannot find name 'Symbol'.
+
+
+==== tests/cases/compiler/nativeToBoxedTypes.ts (4 errors) ====
+    var N = new Number();
+    var n = 100;
+    n = N;
+    ~
+!!! error TS2322: Type 'Number' is not assignable to type 'number'.
+!!! error TS2322:   'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
+    
+    var S = new String();
+    var s = "foge";
+    s = S;
+    ~
+!!! error TS2322: Type 'String' is not assignable to type 'string'.
+!!! error TS2322:   'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.
+    
+    var B = new Boolean();
+    var b = true;
+    b = B;
+    ~
+!!! error TS2322: Type 'Boolean' is not assignable to type 'boolean'.
+!!! error TS2322:   'boolean' is a primitive, but 'Boolean' is a wrapper object. Prefer using 'boolean' when possible.
+    
+    var sym: symbol; 
+    var Sym: Symbol;
+             ~~~~~~
+!!! error TS2304: Cannot find name 'Symbol'.
+    sym = Sym;
\ No newline at end of file
diff --git a/tests/baselines/reference/nativeToBoxedTypes.js b/tests/baselines/reference/nativeToBoxedTypes.js
new file mode 100644
index 00000000000..db47c72fa10
--- /dev/null
+++ b/tests/baselines/reference/nativeToBoxedTypes.js
@@ -0,0 +1,30 @@
+//// [nativeToBoxedTypes.ts]
+var N = new Number();
+var n = 100;
+n = N;
+
+var S = new String();
+var s = "foge";
+s = S;
+
+var B = new Boolean();
+var b = true;
+b = B;
+
+var sym: symbol; 
+var Sym: Symbol;
+sym = Sym;
+
+//// [nativeToBoxedTypes.js]
+var N = new Number();
+var n = 100;
+n = N;
+var S = new String();
+var s = "foge";
+s = S;
+var B = new Boolean();
+var b = true;
+b = B;
+var sym;
+var Sym;
+sym = Sym;
diff --git a/tests/baselines/reference/primitiveMembers.errors.txt b/tests/baselines/reference/primitiveMembers.errors.txt
index da8b75f9bc5..49ef8c4e3cf 100644
--- a/tests/baselines/reference/primitiveMembers.errors.txt
+++ b/tests/baselines/reference/primitiveMembers.errors.txt
@@ -1,5 +1,6 @@
 tests/cases/compiler/primitiveMembers.ts(5,3): error TS2339: Property 'toBAZ' does not exist on type 'number'.
 tests/cases/compiler/primitiveMembers.ts(11,1): error TS2322: Type 'Number' is not assignable to type 'number'.
+  'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
 
 
 ==== tests/cases/compiler/primitiveMembers.ts (2 errors) ====
@@ -18,6 +19,7 @@ tests/cases/compiler/primitiveMembers.ts(11,1): error TS2322: Type 'Number' is n
     n = N;  // should not work, as 'number' has a different brand
     ~
 !!! error TS2322: Type 'Number' is not assignable to type 'number'.
+!!! error TS2322:   'number' is a primitive, but 'Number' is a wrapper object. Prefer using 'number' when possible.
     N = n; // should work
     
     var o: Object = {}
diff --git a/tests/baselines/reference/symbolType15.errors.txt b/tests/baselines/reference/symbolType15.errors.txt
index eb63e5798d5..205a2a999d0 100644
--- a/tests/baselines/reference/symbolType15.errors.txt
+++ b/tests/baselines/reference/symbolType15.errors.txt
@@ -1,4 +1,5 @@
 tests/cases/conformance/es6/Symbols/symbolType15.ts(5,1): error TS2322: Type 'Symbol' is not assignable to type 'symbol'.
+  'symbol' is a primitive, but 'Symbol' is a wrapper object. Prefer using 'symbol' when possible.
 
 
 ==== tests/cases/conformance/es6/Symbols/symbolType15.ts (1 errors) ====
@@ -8,4 +9,5 @@ tests/cases/conformance/es6/Symbols/symbolType15.ts(5,1): error TS2322: Type 'Sy
     symObj = sym;
     sym = symObj;
     ~~~
-!!! error TS2322: Type 'Symbol' is not assignable to type 'symbol'.
\ No newline at end of file
+!!! error TS2322: Type 'Symbol' is not assignable to type 'symbol'.
+!!! error TS2322:   'symbol' is a primitive, but 'Symbol' is a wrapper object. Prefer using 'symbol' when possible.
\ No newline at end of file
diff --git a/tests/cases/compiler/errorForConflictingExportEqualsValue.ts b/tests/cases/compiler/errorForConflictingExportEqualsValue.ts
new file mode 100644
index 00000000000..59af1f46690
--- /dev/null
+++ b/tests/cases/compiler/errorForConflictingExportEqualsValue.ts
@@ -0,0 +1,2 @@
+export var x;
+export = {};
diff --git a/tests/cases/compiler/maxNodeModuleJsDepthDefaultsToZero.ts b/tests/cases/compiler/maxNodeModuleJsDepthDefaultsToZero.ts
new file mode 100644
index 00000000000..9d154ec1e59
--- /dev/null
+++ b/tests/cases/compiler/maxNodeModuleJsDepthDefaultsToZero.ts
@@ -0,0 +1,36 @@
+// @module: commonjs
+// @moduleResolution: node
+// @allowJs: true
+// @traceResolution: true
+// @noEmit: true
+
+// @filename: /tsconfig.json
+{
+    "compileOnSave": true,
+    "compilerOptions": {
+        "module": "commonjs",
+        "moduleResolution": "node",
+        "outDir": "bin"
+    },
+    "exclude": [ "node_modules" ]
+}
+// @filename: /node_modules/shortid/node_modules/z/index.js
+// z will not be found because maxNodeModulesJsDepth: 0
+module.exports = { z: 'no' };
+
+// @filename: /node_modules/shortid/index.js
+var z = require('z');
+var y = { y: 'foo' };
+module.exports = y;
+
+// @filename: /typings/index.d.ts
+declare module "shortid" {
+    export var x: number;
+}
+
+// @filename: /index.ts
+/// <reference path="/typings/index.d.ts" />
+import * as foo from "shortid";
+foo.x // found in index.d.ts
+foo.y // ignored from shortid/index.js
+
diff --git a/tests/cases/compiler/nativeToBoxedTypes.ts b/tests/cases/compiler/nativeToBoxedTypes.ts
new file mode 100644
index 00000000000..a34dd5cdd3b
--- /dev/null
+++ b/tests/cases/compiler/nativeToBoxedTypes.ts
@@ -0,0 +1,15 @@
+var N = new Number();
+var n = 100;
+n = N;
+
+var S = new String();
+var s = "foge";
+s = S;
+
+var B = new Boolean();
+var b = true;
+b = B;
+
+var sym: symbol; 
+var Sym: Symbol;
+sym = Sym;
\ No newline at end of file
diff --git a/tests/cases/projects/NodeModulesSearch/importHigher/tsconfig.json b/tests/cases/projects/NodeModulesSearch/importHigher/tsconfig.json
index c7b95984b42..301db9c870a 100644
--- a/tests/cases/projects/NodeModulesSearch/importHigher/tsconfig.json
+++ b/tests/cases/projects/NodeModulesSearch/importHigher/tsconfig.json
@@ -2,6 +2,7 @@
   "compilerOptions": { 
     "allowJs": true,
     "declaration": false,
-    "moduleResolution": "node"
+    "moduleResolution": "node",
+    "maxNodeModuleJsDepth": 2
   }
 }