From 5999a521f6e852de92681acf8c91c01f102edab6 Mon Sep 17 00:00:00 2001
From: Ron Buckton <rbuckton@microsoft.com>
Date: Sat, 31 Dec 2016 19:12:57 -0800
Subject: [PATCH] Support for an external exportStar helper

---
 src/compiler/checker.ts                       |  8 ++-
 src/compiler/factory.ts                       | 52 ++++++++++++-------
 src/compiler/transformers/module/module.ts    | 24 ++++-----
 src/compiler/types.ts                         |  3 +-
 tests/baselines/reference/importHelpersAmd.js |  8 ++-
 .../reference/importHelpersAmd.symbols        | 19 ++++++-
 .../reference/importHelpersAmd.types          | 17 ++++++
 .../importHelpersInAmbientContext.js          |  4 +-
 .../importHelpersInAmbientContext.symbols     | 16 ++++++
 .../importHelpersInAmbientContext.types       | 16 ++++++
 .../importHelpersNoHelpers.errors.txt         | 21 +++++---
 .../reference/importHelpersNoHelpers.js       |  8 +++
 .../reference/importHelpersSystem.js          | 12 +++++
 .../reference/importHelpersSystem.symbols     |  3 +-
 .../reference/importHelpersSystem.types       |  1 +
 tests/cases/compiler/importHelpersAmd.ts      |  4 ++
 .../compiler/importHelpersInAmbientContext.ts |  3 ++
 .../cases/compiler/importHelpersNoHelpers.ts  |  4 ++
 tests/cases/compiler/importHelpersSystem.ts   |  1 +
 19 files changed, 178 insertions(+), 46 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 33b3505661..2900932bc0 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -19160,6 +19160,10 @@ namespace ts {
                     if (moduleSymbol && hasExportAssignmentSymbol(moduleSymbol)) {
                         error(node.moduleSpecifier, Diagnostics.Module_0_uses_export_and_cannot_be_used_with_export_Asterisk, symbolToString(moduleSymbol));
                     }
+
+                    if (modulekind !== ModuleKind.System && modulekind !== ModuleKind.ES2015) {
+                        checkExternalEmitHelpers(node, ExternalEmitHelpers.ExportStar);
+                    }
                 }
             }
         }
@@ -20788,7 +20792,7 @@ namespace ts {
         function checkExternalEmitHelpers(location: Node, helpers: ExternalEmitHelpers) {
             if ((requestedExternalEmitHelpers & helpers) !== helpers && compilerOptions.importHelpers) {
                 const sourceFile = getSourceFileOfNode(location);
-                if (isEffectiveExternalModule(sourceFile, compilerOptions)) {
+                if (!isDeclarationFile(sourceFile) && isEffectiveExternalModule(sourceFile, compilerOptions)) {
                     const helpersModule = resolveHelpersModule(sourceFile, location);
                     if (helpersModule !== unknownSymbol) {
                         const uncheckedHelpers = helpers & ~requestedExternalEmitHelpers;
@@ -20817,6 +20821,8 @@ namespace ts {
                 case ExternalEmitHelpers.Param: return "__param";
                 case ExternalEmitHelpers.Awaiter: return "__awaiter";
                 case ExternalEmitHelpers.Generator: return "__generator";
+                case ExternalEmitHelpers.ExportStar: return "__exportStar";
+                default: Debug.fail("Unrecognized helper");
             }
         }
 
diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index ac1f52a991..033d694ade 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -2808,25 +2808,37 @@ namespace ts {
         return emitNode && emitNode.externalHelpersModuleName;
     }
 
-    export function getOrCreateExternalHelpersModuleNameIfNeeded(node: SourceFile, compilerOptions: CompilerOptions) {
-        if (compilerOptions.importHelpers && (isExternalModule(node) || compilerOptions.isolatedModules)) {
+    export function getOrCreateExternalHelpersModuleNameIfNeeded(node: SourceFile, compilerOptions: CompilerOptions, hasExportStarsToExportValues?: boolean) {
+        if (compilerOptions.importHelpers && isEffectiveExternalModule(node, compilerOptions)) {
             const externalHelpersModuleName = getExternalHelpersModuleName(node);
             if (externalHelpersModuleName) {
                 return externalHelpersModuleName;
             }
 
-            const helpers = getEmitHelpers(node);
-            if (helpers) {
-                for (const helper of helpers) {
-                    if (!helper.scoped) {
-                        const parseNode = getOriginalNode(node, isSourceFile);
-                        const emitNode = getOrCreateEmitNode(parseNode);
-                        return emitNode.externalHelpersModuleName || (emitNode.externalHelpersModuleName = createUniqueName(externalHelpersModuleNameText));
+            const moduleKind = getEmitModuleKind(compilerOptions);
+            let create = hasExportStarsToExportValues
+                && moduleKind !== ModuleKind.System
+                && moduleKind !== ModuleKind.ES2015;
+            if (!create) {
+                const helpers = getEmitHelpers(node);
+                if (helpers) {
+                    for (const helper of helpers) {
+                        if (!helper.scoped) {
+                            create = true;
+                            break;
+                        }
                     }
                 }
             }
+
+            if (create) {
+                const parseNode = getOriginalNode(node, isSourceFile);
+                const emitNode = getOrCreateEmitNode(parseNode);
+                return emitNode.externalHelpersModuleName || (emitNode.externalHelpersModuleName = createUniqueName(externalHelpersModuleNameText));
+            }
         }
     }
+
     /**
      * Adds an EmitHelper to a node.
      */
@@ -3293,17 +3305,6 @@ namespace ts {
         let exportEquals: ExportAssignment = undefined;
         let hasExportStarsToExportValues = false;
 
-        const externalHelpersModuleName = getOrCreateExternalHelpersModuleNameIfNeeded(sourceFile, compilerOptions);
-        const externalHelpersImportDeclaration = externalHelpersModuleName && createImportDeclaration(
-            /*decorators*/ undefined,
-            /*modifiers*/ undefined,
-            createImportClause(/*name*/ undefined, createNamespaceImport(externalHelpersModuleName)),
-            createLiteral(externalHelpersModuleNameText));
-
-        if (externalHelpersImportDeclaration) {
-            externalImports.push(externalHelpersImportDeclaration);
-        }
-
         for (const node of sourceFile.statements) {
             switch (node.kind) {
                 case SyntaxKind.ImportDeclaration:
@@ -3414,6 +3415,17 @@ namespace ts {
             }
         }
 
+        const externalHelpersModuleName = getOrCreateExternalHelpersModuleNameIfNeeded(sourceFile, compilerOptions, hasExportStarsToExportValues);
+        const externalHelpersImportDeclaration = externalHelpersModuleName && createImportDeclaration(
+            /*decorators*/ undefined,
+            /*modifiers*/ undefined,
+            createImportClause(/*name*/ undefined, createNamespaceImport(externalHelpersModuleName)),
+            createLiteral(externalHelpersModuleNameText));
+
+        if (externalHelpersImportDeclaration) {
+            externalImports.unshift(externalHelpersImportDeclaration);
+        }
+
         return { externalImports, exportSpecifiers, exportEquals, hasExportStarsToExportValues, exportedBindings, exportedNames, externalHelpersImportDeclaration };
     }
 
diff --git a/src/compiler/transformers/module/module.ts b/src/compiler/transformers/module/module.ts
index 170af0778c..da8a55ed3b 100644
--- a/src/compiler/transformers/module/module.ts
+++ b/src/compiler/transformers/module/module.ts
@@ -87,7 +87,7 @@ namespace ts {
             addExportEqualsIfNeeded(statements, /*emitAsReturn*/ false);
 
             const updated = updateSourceFileNode(node, createNodeArray(statements, node.statements));
-            if (currentModuleInfo.hasExportStarsToExportValues) {
+            if (currentModuleInfo.hasExportStarsToExportValues && !compilerOptions.importHelpers) {
                 addEmitHelper(updated, exportStarHelper);
             }
 
@@ -377,7 +377,7 @@ namespace ts {
             addExportEqualsIfNeeded(statements, /*emitAsReturn*/ true);
 
             const body = createBlock(statements, /*location*/ undefined, /*multiLine*/ true);
-            if (currentModuleInfo.hasExportStarsToExportValues) {
+            if (currentModuleInfo.hasExportStarsToExportValues && !compilerOptions.importHelpers) {
                 // If we have any `export * from ...` declarations
                 // we need to inform the emitter to add the __export helper.
                 addEmitHelper(body, exportStarHelper);
@@ -691,15 +691,7 @@ namespace ts {
             else {
                 // export * from "mod";
                 return createStatement(
-                    createCall(
-                        createIdentifier("__export"),
-                        /*typeArguments*/ undefined,
-                        [
-                            moduleKind !== ModuleKind.AMD
-                                ? createRequireCall(node)
-                                : generatedName
-                        ]
-                    ),
+                    createExportStarHelper(context, moduleKind !== ModuleKind.AMD ? createRequireCall(node) : generatedName),
                     /*location*/ node
                 );
             }
@@ -1441,6 +1433,14 @@ namespace ts {
         text: `
             function __export(m) {
                 for (var p in m) if (!exports.hasOwnProperty(p)) exports[p] = m[p];
-            }`
+            }
+        `
     };
+
+    function createExportStarHelper(context: TransformationContext, module: Expression) {
+        const compilerOptions = context.getCompilerOptions();
+        return compilerOptions.importHelpers
+            ? createCall(getHelperName("__exportStar"), /*typeArguments*/ undefined, [module, createIdentifier("exports")])
+            : createCall(createIdentifier("__export"), /*typeArguments*/ undefined, [module]);
+    }
 }
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 6eebb0b99d..26045ba168 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3733,9 +3733,10 @@ namespace ts {
         Param = 1 << 5,             // __param (used by TypeScript decorators transformation)
         Awaiter = 1 << 6,           // __awaiter (used by ES2017 async functions transformation)
         Generator = 1 << 7,         // __generator (used by ES2015 generator transformation)
+        ExportStar = 1 << 8,        // __exportStar (used by CommonJS/AMD/UMD module transformation)
 
         FirstEmitHelper = Extends,
-        LastEmitHelper = Generator
+        LastEmitHelper = ExportStar
     }
 
     /* @internal */
diff --git a/tests/baselines/reference/importHelpersAmd.js b/tests/baselines/reference/importHelpersAmd.js
index fea93840fa..96d398e05e 100644
--- a/tests/baselines/reference/importHelpersAmd.js
+++ b/tests/baselines/reference/importHelpersAmd.js
@@ -5,16 +5,19 @@ export class A { }
 
 //// [b.ts]
 import { A } from "./a";
+export * from "./a";
 export class B extends A { }
 
 //// [tslib.d.ts]
 export declare function __extends(d: Function, b: Function): void;
 export declare function __assign(t: any, ...sources: any[]): any;
+export declare function __rest(t: any, propertyNames: string[]): any;
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 export declare function __param(paramIndex: number, decorator: Function): Function;
 export declare function __metadata(metadataKey: any, metadataValue: any): Function;
 export declare function __awaiter(thisArg: any, _arguments: any, P: Function, generator: Function): any;
-
+export declare function __generator(thisArg: any, body: Function): any;
+export declare function __exportStar(m: any, exports: any): void;
 
 //// [a.js]
 define(["require", "exports"], function (require, exports) {
@@ -27,8 +30,9 @@ define(["require", "exports"], function (require, exports) {
     exports.A = A;
 });
 //// [b.js]
-define(["require", "exports", "tslib", "./a"], function (require, exports, tslib_1, a_1) {
+define(["require", "exports", "tslib", "./a", "./a"], function (require, exports, tslib_1, a_1, a_2) {
     "use strict";
+    tslib_1.__exportStar(a_2, exports);
     var B = (function (_super) {
         tslib_1.__extends(B, _super);
         function B() {
diff --git a/tests/baselines/reference/importHelpersAmd.symbols b/tests/baselines/reference/importHelpersAmd.symbols
index 47528a8bba..68506b4c35 100644
--- a/tests/baselines/reference/importHelpersAmd.symbols
+++ b/tests/baselines/reference/importHelpersAmd.symbols
@@ -6,8 +6,9 @@ export class A { }
 import { A } from "./a";
 >A : Symbol(A, Decl(b.ts, 0, 8))
 
+export * from "./a";
 export class B extends A { }
->B : Symbol(B, Decl(b.ts, 0, 24))
+>B : Symbol(B, Decl(b.ts, 1, 20))
 >A : Symbol(A, Decl(b.ts, 0, 8))
 
 === tests/cases/compiler/tslib.d.ts ===
@@ -23,6 +24,11 @@ export declare function __assign(t: any, ...sources: any[]): any;
 >t : Symbol(t, Decl(tslib.d.ts, --, --))
 >sources : Symbol(sources, Decl(tslib.d.ts, --, --))
 
+export declare function __rest(t: any, propertyNames: string[]): any;
+>__rest : Symbol(__rest, Decl(tslib.d.ts, --, --))
+>t : Symbol(t, Decl(tslib.d.ts, --, --))
+>propertyNames : Symbol(propertyNames, Decl(tslib.d.ts, --, --))
+
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 >__decorate : Symbol(__decorate, Decl(tslib.d.ts, --, --))
 >decorators : Symbol(decorators, Decl(tslib.d.ts, --, --))
@@ -53,3 +59,14 @@ export declare function __awaiter(thisArg: any, _arguments: any, P: Function, ge
 >generator : Symbol(generator, Decl(tslib.d.ts, --, --))
 >Function : Symbol(Function, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
 
+export declare function __generator(thisArg: any, body: Function): any;
+>__generator : Symbol(__generator, Decl(tslib.d.ts, --, --))
+>thisArg : Symbol(thisArg, Decl(tslib.d.ts, --, --))
+>body : Symbol(body, Decl(tslib.d.ts, --, --))
+>Function : Symbol(Function, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+export declare function __exportStar(m: any, exports: any): void;
+>__exportStar : Symbol(__exportStar, Decl(tslib.d.ts, --, --))
+>m : Symbol(m, Decl(tslib.d.ts, --, --))
+>exports : Symbol(exports, Decl(tslib.d.ts, --, --))
+
diff --git a/tests/baselines/reference/importHelpersAmd.types b/tests/baselines/reference/importHelpersAmd.types
index 9ff756ffaa..23456ae233 100644
--- a/tests/baselines/reference/importHelpersAmd.types
+++ b/tests/baselines/reference/importHelpersAmd.types
@@ -6,6 +6,7 @@ export class A { }
 import { A } from "./a";
 >A : typeof A
 
+export * from "./a";
 export class B extends A { }
 >B : B
 >A : A
@@ -23,6 +24,11 @@ export declare function __assign(t: any, ...sources: any[]): any;
 >t : any
 >sources : any[]
 
+export declare function __rest(t: any, propertyNames: string[]): any;
+>__rest : (t: any, propertyNames: string[]) => any
+>t : any
+>propertyNames : string[]
+
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 >__decorate : (decorators: Function[], target: any, key?: string | symbol, desc?: any) => any
 >decorators : Function[]
@@ -53,3 +59,14 @@ export declare function __awaiter(thisArg: any, _arguments: any, P: Function, ge
 >generator : Function
 >Function : Function
 
+export declare function __generator(thisArg: any, body: Function): any;
+>__generator : (thisArg: any, body: Function) => any
+>thisArg : any
+>body : Function
+>Function : Function
+
+export declare function __exportStar(m: any, exports: any): void;
+>__exportStar : (m: any, exports: any) => void
+>m : any
+>exports : any
+
diff --git a/tests/baselines/reference/importHelpersInAmbientContext.js b/tests/baselines/reference/importHelpersInAmbientContext.js
index b9db8c4751..9433b41d11 100644
--- a/tests/baselines/reference/importHelpersInAmbientContext.js
+++ b/tests/baselines/reference/importHelpersInAmbientContext.js
@@ -49,11 +49,13 @@ declare namespace N {
 //// [tslib.d.ts]
 export declare function __extends(d: Function, b: Function): void;
 export declare function __assign(t: any, ...sources: any[]): any;
+export declare function __rest(t: any, propertyNames: string[]): any;
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 export declare function __param(paramIndex: number, decorator: Function): Function;
 export declare function __metadata(metadataKey: any, metadataValue: any): Function;
 export declare function __awaiter(thisArg: any, _arguments: any, P: Function, generator: Function): any;
-
+export declare function __generator(thisArg: any, body: Function): any;
+export declare function __exportStar(m: any, exports: any): void;
 
 //// [b.js]
 "use strict";
diff --git a/tests/baselines/reference/importHelpersInAmbientContext.symbols b/tests/baselines/reference/importHelpersInAmbientContext.symbols
index 7da1ea9504..5b9b7e61e7 100644
--- a/tests/baselines/reference/importHelpersInAmbientContext.symbols
+++ b/tests/baselines/reference/importHelpersInAmbientContext.symbols
@@ -99,6 +99,11 @@ export declare function __assign(t: any, ...sources: any[]): any;
 >t : Symbol(t, Decl(tslib.d.ts, --, --))
 >sources : Symbol(sources, Decl(tslib.d.ts, --, --))
 
+export declare function __rest(t: any, propertyNames: string[]): any;
+>__rest : Symbol(__rest, Decl(tslib.d.ts, --, --))
+>t : Symbol(t, Decl(tslib.d.ts, --, --))
+>propertyNames : Symbol(propertyNames, Decl(tslib.d.ts, --, --))
+
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 >__decorate : Symbol(__decorate, Decl(tslib.d.ts, --, --))
 >decorators : Symbol(decorators, Decl(tslib.d.ts, --, --))
@@ -129,3 +134,14 @@ export declare function __awaiter(thisArg: any, _arguments: any, P: Function, ge
 >generator : Symbol(generator, Decl(tslib.d.ts, --, --))
 >Function : Symbol(Function, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
 
+export declare function __generator(thisArg: any, body: Function): any;
+>__generator : Symbol(__generator, Decl(tslib.d.ts, --, --))
+>thisArg : Symbol(thisArg, Decl(tslib.d.ts, --, --))
+>body : Symbol(body, Decl(tslib.d.ts, --, --))
+>Function : Symbol(Function, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+export declare function __exportStar(m: any, exports: any): void;
+>__exportStar : Symbol(__exportStar, Decl(tslib.d.ts, --, --))
+>m : Symbol(m, Decl(tslib.d.ts, --, --))
+>exports : Symbol(exports, Decl(tslib.d.ts, --, --))
+
diff --git a/tests/baselines/reference/importHelpersInAmbientContext.types b/tests/baselines/reference/importHelpersInAmbientContext.types
index 5f3102b68f..ac0803e6bd 100644
--- a/tests/baselines/reference/importHelpersInAmbientContext.types
+++ b/tests/baselines/reference/importHelpersInAmbientContext.types
@@ -99,6 +99,11 @@ export declare function __assign(t: any, ...sources: any[]): any;
 >t : any
 >sources : any[]
 
+export declare function __rest(t: any, propertyNames: string[]): any;
+>__rest : (t: any, propertyNames: string[]) => any
+>t : any
+>propertyNames : string[]
+
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 >__decorate : (decorators: Function[], target: any, key?: string | symbol, desc?: any) => any
 >decorators : Function[]
@@ -129,3 +134,14 @@ export declare function __awaiter(thisArg: any, _arguments: any, P: Function, ge
 >generator : Function
 >Function : Function
 
+export declare function __generator(thisArg: any, body: Function): any;
+>__generator : (thisArg: any, body: Function) => any
+>thisArg : any
+>body : Function
+>Function : Function
+
+export declare function __exportStar(m: any, exports: any): void;
+>__exportStar : (m: any, exports: any) => void
+>m : any
+>exports : any
+
diff --git a/tests/baselines/reference/importHelpersNoHelpers.errors.txt b/tests/baselines/reference/importHelpersNoHelpers.errors.txt
index a0c089a9dd..4034fbc649 100644
--- a/tests/baselines/reference/importHelpersNoHelpers.errors.txt
+++ b/tests/baselines/reference/importHelpersNoHelpers.errors.txt
@@ -1,12 +1,16 @@
-tests/cases/compiler/external.ts(2,16): error TS2343: This syntax requires an imported helper named '__extends', but module 'tslib' has no exported member '__extends'.
-tests/cases/compiler/external.ts(6,1): error TS2343: This syntax requires an imported helper named '__decorate', but module 'tslib' has no exported member '__decorate'.
-tests/cases/compiler/external.ts(6,1): error TS2343: This syntax requires an imported helper named '__metadata', but module 'tslib' has no exported member '__metadata'.
-tests/cases/compiler/external.ts(8,12): error TS2343: This syntax requires an imported helper named '__param', but module 'tslib' has no exported member '__param'.
-tests/cases/compiler/external.ts(13,13): error TS2343: This syntax requires an imported helper named '__assign', but module 'tslib' has no exported member '__assign'.
-tests/cases/compiler/external.ts(14,12): error TS2343: This syntax requires an imported helper named '__rest', but module 'tslib' has no exported member '__rest'.
+tests/cases/compiler/external.ts(1,1): error TS2343: This syntax requires an imported helper named '__exportStar', but module 'tslib' has no exported member '__exportStar'.
+tests/cases/compiler/external.ts(3,16): error TS2343: This syntax requires an imported helper named '__extends', but module 'tslib' has no exported member '__extends'.
+tests/cases/compiler/external.ts(7,1): error TS2343: This syntax requires an imported helper named '__decorate', but module 'tslib' has no exported member '__decorate'.
+tests/cases/compiler/external.ts(7,1): error TS2343: This syntax requires an imported helper named '__metadata', but module 'tslib' has no exported member '__metadata'.
+tests/cases/compiler/external.ts(9,12): error TS2343: This syntax requires an imported helper named '__param', but module 'tslib' has no exported member '__param'.
+tests/cases/compiler/external.ts(14,13): error TS2343: This syntax requires an imported helper named '__assign', but module 'tslib' has no exported member '__assign'.
+tests/cases/compiler/external.ts(15,12): error TS2343: This syntax requires an imported helper named '__rest', but module 'tslib' has no exported member '__rest'.
 
 
-==== tests/cases/compiler/external.ts (6 errors) ====
+==== tests/cases/compiler/external.ts (7 errors) ====
+    export * from "./other";
+    ~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2343: This syntax requires an imported helper named '__exportStar', but module 'tslib' has no exported member '__exportStar'.
     export class A { }
     export class B extends A { }
                    ~~~~~~~~~
@@ -34,6 +38,9 @@ tests/cases/compiler/external.ts(14,12): error TS2343: This syntax requires an i
                ~
 !!! error TS2343: This syntax requires an imported helper named '__rest', but module 'tslib' has no exported member '__rest'.
     
+==== tests/cases/compiler/other.ts (0 errors) ====
+    export const x = 1;
+    
 ==== tests/cases/compiler/script.ts (0 errors) ====
     class A { }
     class B extends A { }
diff --git a/tests/baselines/reference/importHelpersNoHelpers.js b/tests/baselines/reference/importHelpersNoHelpers.js
index 560e16d1cc..ae709c086b 100644
--- a/tests/baselines/reference/importHelpersNoHelpers.js
+++ b/tests/baselines/reference/importHelpersNoHelpers.js
@@ -1,6 +1,7 @@
 //// [tests/cases/compiler/importHelpersNoHelpers.ts] ////
 
 //// [external.ts]
+export * from "./other";
 export class A { }
 export class B extends A { }
 
@@ -16,6 +17,9 @@ const o = { a: 1 };
 const y = { ...o };
 const { ...x } = y;
 
+//// [other.ts]
+export const x = 1;
+
 //// [script.ts]
 class A { }
 class B extends A { }
@@ -32,9 +36,13 @@ class C {
 export {}
 
 
+//// [other.js]
+"use strict";
+exports.x = 1;
 //// [external.js]
 "use strict";
 var tslib_1 = require("tslib");
+tslib_1.__exportStar(require("./other"), exports);
 var A = (function () {
     function A() {
     }
diff --git a/tests/baselines/reference/importHelpersSystem.js b/tests/baselines/reference/importHelpersSystem.js
index 20f2d299c5..43556ae6b7 100644
--- a/tests/baselines/reference/importHelpersSystem.js
+++ b/tests/baselines/reference/importHelpersSystem.js
@@ -5,6 +5,7 @@ export class A { }
 
 //// [b.ts]
 import { A } from "./a";
+export * from "./a";
 export class B extends A { }
 
 //// [tslib.d.ts]
@@ -38,6 +39,16 @@ System.register(["tslib", "./a"], function (exports_1, context_1) {
     "use strict";
     var __moduleName = context_1 && context_1.id;
     var tslib_1, a_1, B;
+    var exportedNames_1 = {
+        "B": true
+    };
+    function exportStar_1(m) {
+        var exports = {};
+        for (var n in m) {
+            if (n !== "default" && !exportedNames_1.hasOwnProperty(n)) exports[n] = m[n];
+        }
+        exports_1(exports);
+    }
     return {
         setters: [
             function (tslib_1_1) {
@@ -45,6 +56,7 @@ System.register(["tslib", "./a"], function (exports_1, context_1) {
             },
             function (a_1_1) {
                 a_1 = a_1_1;
+                exportStar_1(a_1_1);
             }
         ],
         execute: function () {
diff --git a/tests/baselines/reference/importHelpersSystem.symbols b/tests/baselines/reference/importHelpersSystem.symbols
index 47528a8bba..d7d588a67e 100644
--- a/tests/baselines/reference/importHelpersSystem.symbols
+++ b/tests/baselines/reference/importHelpersSystem.symbols
@@ -6,8 +6,9 @@ export class A { }
 import { A } from "./a";
 >A : Symbol(A, Decl(b.ts, 0, 8))
 
+export * from "./a";
 export class B extends A { }
->B : Symbol(B, Decl(b.ts, 0, 24))
+>B : Symbol(B, Decl(b.ts, 1, 20))
 >A : Symbol(A, Decl(b.ts, 0, 8))
 
 === tests/cases/compiler/tslib.d.ts ===
diff --git a/tests/baselines/reference/importHelpersSystem.types b/tests/baselines/reference/importHelpersSystem.types
index 9ff756ffaa..de9ef3e944 100644
--- a/tests/baselines/reference/importHelpersSystem.types
+++ b/tests/baselines/reference/importHelpersSystem.types
@@ -6,6 +6,7 @@ export class A { }
 import { A } from "./a";
 >A : typeof A
 
+export * from "./a";
 export class B extends A { }
 >B : B
 >A : A
diff --git a/tests/cases/compiler/importHelpersAmd.ts b/tests/cases/compiler/importHelpersAmd.ts
index bef63328d5..38b02424b9 100644
--- a/tests/cases/compiler/importHelpersAmd.ts
+++ b/tests/cases/compiler/importHelpersAmd.ts
@@ -6,12 +6,16 @@ export class A { }
 
 // @filename: b.ts
 import { A } from "./a";
+export * from "./a";
 export class B extends A { }
 
 // @filename: tslib.d.ts
 export declare function __extends(d: Function, b: Function): void;
 export declare function __assign(t: any, ...sources: any[]): any;
+export declare function __rest(t: any, propertyNames: string[]): any;
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 export declare function __param(paramIndex: number, decorator: Function): Function;
 export declare function __metadata(metadataKey: any, metadataValue: any): Function;
 export declare function __awaiter(thisArg: any, _arguments: any, P: Function, generator: Function): any;
+export declare function __generator(thisArg: any, body: Function): any;
+export declare function __exportStar(m: any, exports: any): void;
\ No newline at end of file
diff --git a/tests/cases/compiler/importHelpersInAmbientContext.ts b/tests/cases/compiler/importHelpersInAmbientContext.ts
index 8bfa5b2540..340961802a 100644
--- a/tests/cases/compiler/importHelpersInAmbientContext.ts
+++ b/tests/cases/compiler/importHelpersInAmbientContext.ts
@@ -49,7 +49,10 @@ declare namespace N {
 // @filename: tslib.d.ts
 export declare function __extends(d: Function, b: Function): void;
 export declare function __assign(t: any, ...sources: any[]): any;
+export declare function __rest(t: any, propertyNames: string[]): any;
 export declare function __decorate(decorators: Function[], target: any, key?: string | symbol, desc?: any): any;
 export declare function __param(paramIndex: number, decorator: Function): Function;
 export declare function __metadata(metadataKey: any, metadataValue: any): Function;
 export declare function __awaiter(thisArg: any, _arguments: any, P: Function, generator: Function): any;
+export declare function __generator(thisArg: any, body: Function): any;
+export declare function __exportStar(m: any, exports: any): void;
\ No newline at end of file
diff --git a/tests/cases/compiler/importHelpersNoHelpers.ts b/tests/cases/compiler/importHelpersNoHelpers.ts
index 4ab48aba7d..787058890a 100644
--- a/tests/cases/compiler/importHelpersNoHelpers.ts
+++ b/tests/cases/compiler/importHelpersNoHelpers.ts
@@ -5,6 +5,7 @@
 // @experimentalDecorators: true
 // @emitDecoratorMetadata: true
 // @filename: external.ts
+export * from "./other";
 export class A { }
 export class B extends A { }
 
@@ -20,6 +21,9 @@ const o = { a: 1 };
 const y = { ...o };
 const { ...x } = y;
 
+// @filename: other.ts
+export const x = 1;
+
 // @filename: script.ts
 class A { }
 class B extends A { }
diff --git a/tests/cases/compiler/importHelpersSystem.ts b/tests/cases/compiler/importHelpersSystem.ts
index 5b6081f17f..87e6278570 100644
--- a/tests/cases/compiler/importHelpersSystem.ts
+++ b/tests/cases/compiler/importHelpersSystem.ts
@@ -6,6 +6,7 @@ export class A { }
 
 // @filename: b.ts
 import { A } from "./a";
+export * from "./a";
 export class B extends A { }
 
 // @filename: tslib.d.ts