Merge pull request #19057 from Microsoft/fix17564

Fix 'this' capturing for dynamic import

src/compiler/binder.ts

@@ -2699,6 +2699,12 @@ namespace ts {
 
         if (expression.kind === SyntaxKind.ImportKeyword) {
             transformFlags |= TransformFlags.ContainsDynamicImport;
+
+            // A dynamic 'import()' call that contains a lexical 'this' will
+            // require a captured 'this' when emitting down-level.
+            if (subtreeFlags & TransformFlags.ContainsLexicalThis) {
+                transformFlags |= TransformFlags.ContainsCapturedLexicalThis;
+            }
         }
 
         node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;

src/compiler/transformers/module/module.ts

@@ -561,46 +561,89 @@ namespace ts {
             // });
             const resolve = createUniqueName("resolve");
             const reject = createUniqueName("reject");
-            return createNew(
-                createIdentifier("Promise"),
-                /*typeArguments*/ undefined,
-                [createFunctionExpression(
+            const parameters = [
+                createParameter(/*decorator*/ undefined, /*modifiers*/ undefined, /*dotDotDotToken*/ undefined, /*name*/ resolve),
+                createParameter(/*decorator*/ undefined, /*modifiers*/ undefined, /*dotDotDotToken*/ undefined, /*name*/ reject)
+            ];
+            const body = createBlock([
+                createStatement(
+                    createCall(
+                        createIdentifier("require"),
+                        /*typeArguments*/ undefined,
+                        [createArrayLiteral([firstOrUndefined(node.arguments) || createOmittedExpression()]), resolve, reject]
+                    )
+                )
+            ]);
+
+            let func: FunctionExpression | ArrowFunction;
+            if (languageVersion >= ScriptTarget.ES2015) {
+                func = createArrowFunction(
+                    /*modifiers*/ undefined,
+                    /*typeParameters*/ undefined,
+                    parameters,
+                    /*type*/ undefined,
+                    /*equalsGreaterThanToken*/ undefined,
+                    body);
+            }
+            else {
+                func = createFunctionExpression(
                     /*modifiers*/ undefined,
                     /*asteriskToken*/ undefined,
                     /*name*/ undefined,
                     /*typeParameters*/ undefined,
-                    [createParameter(/*decorator*/ undefined, /*modifiers*/ undefined, /*dotDotDotToken*/ undefined, /*name*/ resolve),
-                     createParameter(/*decorator*/ undefined, /*modifiers*/ undefined, /*dotDotDotToken*/ undefined, /*name*/ reject)],
+                    parameters,
                     /*type*/ undefined,
-                    createBlock([createStatement(
-                        createCall(
-                            createIdentifier("require"),
-                            /*typeArguments*/ undefined,
-                            [createArrayLiteral([firstOrUndefined(node.arguments) || createOmittedExpression()]), resolve, reject]
-                        ))])
-            )]);
+                    body);
+
+                // if there is a lexical 'this' in the import call arguments, ensure we indicate
+                // that this new function expression indicates it captures 'this' so that the
+                // es2015 transformer will properly substitute 'this' with '_this'.
+                if (node.transformFlags & TransformFlags.ContainsLexicalThis) {
+                    setEmitFlags(func, EmitFlags.CapturesThis);
+                }
+            }
+
+            return createNew(createIdentifier("Promise"), /*typeArguments*/ undefined, [func]);
         }
 
-    function transformImportCallExpressionCommonJS(node: ImportCall): Expression {
+        function transformImportCallExpressionCommonJS(node: ImportCall): Expression {
             // import("./blah")
             // emit as
             // Promise.resolve().then(function () { return require(x); }) /*CommonJs Require*/
             // We have to wrap require in then callback so that require is done in asynchronously
             // if we simply do require in resolve callback in Promise constructor. We will execute the loading immediately
-            return createCall(
-                createPropertyAccess(
-                    createCall(createPropertyAccess(createIdentifier("Promise"), "resolve"), /*typeArguments*/ undefined, /*argumentsArray*/ []),
-                    "then"),
-                /*typeArguments*/ undefined,
-                [createFunctionExpression(
+            const promiseResolveCall = createCall(createPropertyAccess(createIdentifier("Promise"), "resolve"), /*typeArguments*/ undefined, /*argumentsArray*/ []);
+            const requireCall = createCall(createIdentifier("require"), /*typeArguments*/ undefined, node.arguments);
+
+            let func: FunctionExpression | ArrowFunction;
+            if (languageVersion >= ScriptTarget.ES2015) {
+                func = createArrowFunction(
+                    /*modifiers*/ undefined,
+                    /*typeParameters*/ undefined,
+                    /*parameters*/ [],
+                    /*type*/ undefined,
+                    /*equalsGreaterThanToken*/ undefined,
+                    requireCall);
+            }
+            else {
+                func = createFunctionExpression(
                     /*modifiers*/ undefined,
                     /*asteriskToken*/ undefined,
                     /*name*/ undefined,
                     /*typeParameters*/ undefined,
-                    /*parameters*/ undefined,
+                    /*parameters*/ [],
                     /*type*/ undefined,
-                    createBlock([createReturn(createCall(createIdentifier("require"), /*typeArguments*/ undefined, node.arguments))])
-                )]);
+                    createBlock([createReturn(requireCall)]));
+
+                // if there is a lexical 'this' in the import call arguments, ensure we indicate
+                // that this new function expression indicates it captures 'this' so that the
+                // es2015 transformer will properly substitute 'this' with '_this'.
+                if (node.transformFlags & TransformFlags.ContainsLexicalThis) {
+                    setEmitFlags(func, EmitFlags.CapturesThis);
+                }
+            }
+
+            return createCall(createPropertyAccess(promiseResolveCall, "then"), /*typeArguments*/ undefined, [func]);
         }
 
         /**

tests/baselines/reference/dynamicImportWithNestedThis_es2015.js

@@ -0,0 +1,37 @@
+//// [dynamicImportWithNestedThis_es2015.ts]
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+	private _path = './other';
+
+	dynamic() {
+		return import(this._path);
+	}
+}
+
+const c = new C();
+c.dynamic();
+
+//// [dynamicImportWithNestedThis_es2015.js]
+(function (factory) {
+    if (typeof module === "object" && typeof module.exports === "object") {
+        var v = factory(require, exports);
+        if (v !== undefined) module.exports = v;
+    }
+    else if (typeof define === "function" && define.amd) {
+        define(["require", "exports"], factory);
+    }
+})(function (require, exports) {
+    "use strict";
+    var __syncRequire = typeof module === "object" && typeof module.exports === "object";
+    // https://github.com/Microsoft/TypeScript/issues/17564
+    class C {
+        constructor() {
+            this._path = './other';
+        }
+        dynamic() {
+            return __syncRequire ? Promise.resolve().then(() => require(this._path)) : new Promise((resolve_1, reject_1) => { require([this._path], resolve_1, reject_1); });
+        }
+    }
+    const c = new C();
+    c.dynamic();
+});

tests/baselines/reference/dynamicImportWithNestedThis_es2015.symbols

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/dynamicImportWithNestedThis_es2015.ts ===
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+>C : Symbol(C, Decl(dynamicImportWithNestedThis_es2015.ts, 0, 0))
+
+	private _path = './other';
+>_path : Symbol(C._path, Decl(dynamicImportWithNestedThis_es2015.ts, 1, 9))
+
+	dynamic() {
+>dynamic : Symbol(C.dynamic, Decl(dynamicImportWithNestedThis_es2015.ts, 2, 27))
+
+		return import(this._path);
+>this._path : Symbol(C._path, Decl(dynamicImportWithNestedThis_es2015.ts, 1, 9))
+>this : Symbol(C, Decl(dynamicImportWithNestedThis_es2015.ts, 0, 0))
+>_path : Symbol(C._path, Decl(dynamicImportWithNestedThis_es2015.ts, 1, 9))
+	}
+}
+
+const c = new C();
+>c : Symbol(c, Decl(dynamicImportWithNestedThis_es2015.ts, 9, 5))
+>C : Symbol(C, Decl(dynamicImportWithNestedThis_es2015.ts, 0, 0))
+
+c.dynamic();
+>c.dynamic : Symbol(C.dynamic, Decl(dynamicImportWithNestedThis_es2015.ts, 2, 27))
+>c : Symbol(c, Decl(dynamicImportWithNestedThis_es2015.ts, 9, 5))
+>dynamic : Symbol(C.dynamic, Decl(dynamicImportWithNestedThis_es2015.ts, 2, 27))
+

tests/baselines/reference/dynamicImportWithNestedThis_es2015.types

@@ -0,0 +1,31 @@
+=== tests/cases/compiler/dynamicImportWithNestedThis_es2015.ts ===
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+>C : C
+
+	private _path = './other';
+>_path : string
+>'./other' : "./other"
+
+	dynamic() {
+>dynamic : () => Promise<any>
+
+		return import(this._path);
+>import(this._path) : Promise<any>
+>this._path : string
+>this : this
+>_path : string
+	}
+}
+
+const c = new C();
+>c : C
+>new C() : C
+>C : typeof C
+
+c.dynamic();
+>c.dynamic() : Promise<any>
+>c.dynamic : () => Promise<any>
+>c : C
+>dynamic : () => Promise<any>
+

tests/baselines/reference/dynamicImportWithNestedThis_es5.js

@@ -0,0 +1,39 @@
+//// [dynamicImportWithNestedThis_es5.ts]
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+	private _path = './other';
+
+	dynamic() {
+		return import(this._path);
+	}
+}
+
+const c = new C();
+c.dynamic();
+
+//// [dynamicImportWithNestedThis_es5.js]
+(function (factory) {
+    if (typeof module === "object" && typeof module.exports === "object") {
+        var v = factory(require, exports);
+        if (v !== undefined) module.exports = v;
+    }
+    else if (typeof define === "function" && define.amd) {
+        define(["require", "exports"], factory);
+    }
+})(function (require, exports) {
+    "use strict";
+    var __syncRequire = typeof module === "object" && typeof module.exports === "object";
+    // https://github.com/Microsoft/TypeScript/issues/17564
+    var C = /** @class */ (function () {
+        function C() {
+            this._path = './other';
+        }
+        C.prototype.dynamic = function () {
+            var _this = this;
+            return __syncRequire ? Promise.resolve().then(function () { return require(_this._path); }) : new Promise(function (resolve_1, reject_1) { require([_this._path], resolve_1, reject_1); });
+        };
+        return C;
+    }());
+    var c = new C();
+    c.dynamic();
+});

tests/baselines/reference/dynamicImportWithNestedThis_es5.symbols

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/dynamicImportWithNestedThis_es5.ts ===
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+>C : Symbol(C, Decl(dynamicImportWithNestedThis_es5.ts, 0, 0))
+
+	private _path = './other';
+>_path : Symbol(C._path, Decl(dynamicImportWithNestedThis_es5.ts, 1, 9))
+
+	dynamic() {
+>dynamic : Symbol(C.dynamic, Decl(dynamicImportWithNestedThis_es5.ts, 2, 27))
+
+		return import(this._path);
+>this._path : Symbol(C._path, Decl(dynamicImportWithNestedThis_es5.ts, 1, 9))
+>this : Symbol(C, Decl(dynamicImportWithNestedThis_es5.ts, 0, 0))
+>_path : Symbol(C._path, Decl(dynamicImportWithNestedThis_es5.ts, 1, 9))
+	}
+}
+
+const c = new C();
+>c : Symbol(c, Decl(dynamicImportWithNestedThis_es5.ts, 9, 5))
+>C : Symbol(C, Decl(dynamicImportWithNestedThis_es5.ts, 0, 0))
+
+c.dynamic();
+>c.dynamic : Symbol(C.dynamic, Decl(dynamicImportWithNestedThis_es5.ts, 2, 27))
+>c : Symbol(c, Decl(dynamicImportWithNestedThis_es5.ts, 9, 5))
+>dynamic : Symbol(C.dynamic, Decl(dynamicImportWithNestedThis_es5.ts, 2, 27))
+

tests/baselines/reference/dynamicImportWithNestedThis_es5.types

@@ -0,0 +1,31 @@
+=== tests/cases/compiler/dynamicImportWithNestedThis_es5.ts ===
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+>C : C
+
+	private _path = './other';
+>_path : string
+>'./other' : "./other"
+
+	dynamic() {
+>dynamic : () => Promise<any>
+
+		return import(this._path);
+>import(this._path) : Promise<any>
+>this._path : string
+>this : this
+>_path : string
+	}
+}
+
+const c = new C();
+>c : C
+>new C() : C
+>C : typeof C
+
+c.dynamic();
+>c.dynamic() : Promise<any>
+>c.dynamic : () => Promise<any>
+>c : C
+>dynamic : () => Promise<any>
+

tests/baselines/reference/importCallExpressionAsyncES6AMD.js

@@ -42,34 +42,34 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     function fn() {
         return __awaiter(this, void 0, void 0, function* () {
-            const req = yield new Promise(function (resolve_1, reject_1) { require(['./test'], resolve_1, reject_1); }); // ONE
+            const req = yield new Promise((resolve_1, reject_1) => { require(['./test'], resolve_1, reject_1); }); // ONE
         });
     }
     exports.fn = fn;
     class cl1 {
         m() {
             return __awaiter(this, void 0, void 0, function* () {
-                const req = yield new Promise(function (resolve_2, reject_2) { require(['./test'], resolve_2, reject_2); }); // TWO
+                const req = yield new Promise((resolve_2, reject_2) => { require(['./test'], resolve_2, reject_2); }); // TWO
             });
         }
     }
     exports.cl1 = cl1;
     exports.obj = {
         m: () => __awaiter(this, void 0, void 0, function* () {
-            const req = yield new Promise(function (resolve_3, reject_3) { require(['./test'], resolve_3, reject_3); }); // THREE
+            const req = yield new Promise((resolve_3, reject_3) => { require(['./test'], resolve_3, reject_3); }); // THREE
         })
     };
     class cl2 {
         constructor() {
             this.p = {
                 m: () => __awaiter(this, void 0, void 0, function* () {
-                    const req = yield new Promise(function (resolve_4, reject_4) { require(['./test'], resolve_4, reject_4); }); // FOUR
+                    const req = yield new Promise((resolve_4, reject_4) => { require(['./test'], resolve_4, reject_4); }); // FOUR
                 })
             };
         }
     }
     exports.cl2 = cl2;
     exports.l = () => __awaiter(this, void 0, void 0, function* () {
-        const req = yield new Promise(function (resolve_5, reject_5) { require(['./test'], resolve_5, reject_5); }); // FIVE
+        const req = yield new Promise((resolve_5, reject_5) => { require(['./test'], resolve_5, reject_5); }); // FIVE
     });
 });

tests/baselines/reference/importCallExpressionAsyncES6CJS.js

@@ -41,33 +41,33 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 Object.defineProperty(exports, "__esModule", { value: true });
 function fn() {
     return __awaiter(this, void 0, void 0, function* () {
-        const req = yield Promise.resolve().then(function () { return require('./test'); }); // ONE
+        const req = yield Promise.resolve().then(() => require('./test')); // ONE
     });
 }
 exports.fn = fn;
 class cl1 {
     m() {
         return __awaiter(this, void 0, void 0, function* () {
-            const req = yield Promise.resolve().then(function () { return require('./test'); }); // TWO
+            const req = yield Promise.resolve().then(() => require('./test')); // TWO
         });
     }
 }
 exports.cl1 = cl1;
 exports.obj = {
     m: () => __awaiter(this, void 0, void 0, function* () {
-        const req = yield Promise.resolve().then(function () { return require('./test'); }); // THREE
+        const req = yield Promise.resolve().then(() => require('./test')); // THREE
     })
 };
 class cl2 {
     constructor() {
         this.p = {
             m: () => __awaiter(this, void 0, void 0, function* () {
-                const req = yield Promise.resolve().then(function () { return require('./test'); }); // FOUR
+                const req = yield Promise.resolve().then(() => require('./test')); // FOUR
             })
         };
     }
 }
 exports.cl2 = cl2;
 exports.l = () => __awaiter(this, void 0, void 0, function* () {
-    const req = yield Promise.resolve().then(function () { return require('./test'); }); // FIVE
+    const req = yield Promise.resolve().then(() => require('./test')); // FIVE
 });

tests/baselines/reference/importCallExpressionAsyncES6UMD.js

@@ -51,34 +51,34 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
     Object.defineProperty(exports, "__esModule", { value: true });
     function fn() {
         return __awaiter(this, void 0, void 0, function* () {
-            const req = yield __syncRequire ? Promise.resolve().then(function () { return require('./test'); }) : new Promise(function (resolve_1, reject_1) { require(['./test'], resolve_1, reject_1); }); // ONE
+            const req = yield __syncRequire ? Promise.resolve().then(() => require('./test')) : new Promise((resolve_1, reject_1) => { require(['./test'], resolve_1, reject_1); }); // ONE
         });
     }
     exports.fn = fn;
     class cl1 {
         m() {
             return __awaiter(this, void 0, void 0, function* () {
-                const req = yield __syncRequire ? Promise.resolve().then(function () { return require('./test'); }) : new Promise(function (resolve_2, reject_2) { require(['./test'], resolve_2, reject_2); }); // TWO
+                const req = yield __syncRequire ? Promise.resolve().then(() => require('./test')) : new Promise((resolve_2, reject_2) => { require(['./test'], resolve_2, reject_2); }); // TWO
             });
         }
     }
     exports.cl1 = cl1;
     exports.obj = {
         m: () => __awaiter(this, void 0, void 0, function* () {
-            const req = yield __syncRequire ? Promise.resolve().then(function () { return require('./test'); }) : new Promise(function (resolve_3, reject_3) { require(['./test'], resolve_3, reject_3); }); // THREE
+            const req = yield __syncRequire ? Promise.resolve().then(() => require('./test')) : new Promise((resolve_3, reject_3) => { require(['./test'], resolve_3, reject_3); }); // THREE
         })
     };
     class cl2 {
         constructor() {
             this.p = {
                 m: () => __awaiter(this, void 0, void 0, function* () {
-                    const req = yield __syncRequire ? Promise.resolve().then(function () { return require('./test'); }) : new Promise(function (resolve_4, reject_4) { require(['./test'], resolve_4, reject_4); }); // FOUR
+                    const req = yield __syncRequire ? Promise.resolve().then(() => require('./test')) : new Promise((resolve_4, reject_4) => { require(['./test'], resolve_4, reject_4); }); // FOUR
                 })
             };
         }
     }
     exports.cl2 = cl2;
     exports.l = () => __awaiter(this, void 0, void 0, function* () {
-        const req = yield __syncRequire ? Promise.resolve().then(function () { return require('./test'); }) : new Promise(function (resolve_5, reject_5) { require(['./test'], resolve_5, reject_5); }); // FIVE
+        const req = yield __syncRequire ? Promise.resolve().then(() => require('./test')) : new Promise((resolve_5, reject_5) => { require(['./test'], resolve_5, reject_5); }); // FIVE
     });
 });

tests/baselines/reference/importCallExpressionCheckReturntype1.js

@@ -30,6 +30,6 @@ exports.C = C;
 //// [1.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-let p1 = Promise.resolve().then(function () { return require("./defaultPath"); });
-let p2 = Promise.resolve().then(function () { return require("./defaultPath"); });
-let p3 = Promise.resolve().then(function () { return require("./defaultPath"); });
+let p1 = Promise.resolve().then(() => require("./defaultPath"));
+let p2 = Promise.resolve().then(() => require("./defaultPath"));
+let p3 = Promise.resolve().then(() => require("./defaultPath"));

tests/baselines/reference/importCallExpressionDeclarationEmit1.js

@@ -15,12 +15,12 @@ function returnDynamicLoad(path: string) {
 }
 
 //// [importCallExpressionDeclarationEmit1.js]
-Promise.resolve().then(function () { return require(getSpecifier()); });
-var p0 = Promise.resolve().then(function () { return require(`${directory}\${moduleFile}`); });
-var p1 = Promise.resolve().then(function () { return require(getSpecifier()); });
-const p2 = Promise.resolve().then(function () { return require(whatToLoad ? getSpecifier() : "defaulPath"); });
+Promise.resolve().then(() => require(getSpecifier()));
+var p0 = Promise.resolve().then(() => require(`${directory}\${moduleFile}`));
+var p1 = Promise.resolve().then(() => require(getSpecifier()));
+const p2 = Promise.resolve().then(() => require(whatToLoad ? getSpecifier() : "defaulPath"));
 function returnDynamicLoad(path) {
-    return Promise.resolve().then(function () { return require(path); });
+    return Promise.resolve().then(() => require(path));
 }
 
 

tests/baselines/reference/importCallExpressionES6AMD.js

@@ -39,23 +39,23 @@ define(["require", "exports"], function (require, exports) {
 define(["require", "exports"], function (require, exports) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
-    new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); });
-    var p1 = new Promise(function (resolve_2, reject_2) { require(["./0"], resolve_2, reject_2); });
+    new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); });
+    var p1 = new Promise((resolve_2, reject_2) => { require(["./0"], resolve_2, reject_2); });
     p1.then(zero => {
         return zero.foo();
     });
-    exports.p2 = new Promise(function (resolve_3, reject_3) { require(["./0"], resolve_3, reject_3); });
+    exports.p2 = new Promise((resolve_3, reject_3) => { require(["./0"], resolve_3, reject_3); });
     function foo() {
-        const p2 = new Promise(function (resolve_4, reject_4) { require(["./0"], resolve_4, reject_4); });
+        const p2 = new Promise((resolve_4, reject_4) => { require(["./0"], resolve_4, reject_4); });
     }
     class C {
         method() {
-            const loadAsync = new Promise(function (resolve_5, reject_5) { require(["./0"], resolve_5, reject_5); });
+            const loadAsync = new Promise((resolve_5, reject_5) => { require(["./0"], resolve_5, reject_5); });
         }
     }
     class D {
         method() {
-            const loadAsync = new Promise(function (resolve_6, reject_6) { require(["./0"], resolve_6, reject_6); });
+            const loadAsync = new Promise((resolve_6, reject_6) => { require(["./0"], resolve_6, reject_6); });
         }
     }
     exports.D = D;

tests/baselines/reference/importCallExpressionES6CJS.js

@@ -36,23 +36,23 @@ exports.foo = foo;
 //// [1.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-Promise.resolve().then(function () { return require("./0"); });
-var p1 = Promise.resolve().then(function () { return require("./0"); });
+Promise.resolve().then(() => require("./0"));
+var p1 = Promise.resolve().then(() => require("./0"));
 p1.then(zero => {
     return zero.foo();
 });
-exports.p2 = Promise.resolve().then(function () { return require("./0"); });
+exports.p2 = Promise.resolve().then(() => require("./0"));
 function foo() {
-    const p2 = Promise.resolve().then(function () { return require("./0"); });
+    const p2 = Promise.resolve().then(() => require("./0"));
 }
 class C {
     method() {
-        const loadAsync = Promise.resolve().then(function () { return require("./0"); });
+        const loadAsync = Promise.resolve().then(() => require("./0"));
     }
 }
 class D {
     method() {
-        const loadAsync = Promise.resolve().then(function () { return require("./0"); });
+        const loadAsync = Promise.resolve().then(() => require("./0"));
     }
 }
 exports.D = D;

tests/baselines/reference/importCallExpressionES6UMD.js

@@ -56,23 +56,23 @@ export class D {
     "use strict";
     var __syncRequire = typeof module === "object" && typeof module.exports === "object";
     Object.defineProperty(exports, "__esModule", { value: true });
-    __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); });
-    var p1 = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_2, reject_2) { require(["./0"], resolve_2, reject_2); });
+    __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); });
+    var p1 = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_2, reject_2) => { require(["./0"], resolve_2, reject_2); });
     p1.then(zero => {
         return zero.foo();
     });
-    exports.p2 = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_3, reject_3) { require(["./0"], resolve_3, reject_3); });
+    exports.p2 = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_3, reject_3) => { require(["./0"], resolve_3, reject_3); });
     function foo() {
-        const p2 = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_4, reject_4) { require(["./0"], resolve_4, reject_4); });
+        const p2 = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_4, reject_4) => { require(["./0"], resolve_4, reject_4); });
     }
     class C {
         method() {
-            const loadAsync = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_5, reject_5) { require(["./0"], resolve_5, reject_5); });
+            const loadAsync = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_5, reject_5) => { require(["./0"], resolve_5, reject_5); });
         }
     }
     class D {
         method() {
-            const loadAsync = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_6, reject_6) { require(["./0"], resolve_6, reject_6); });
+            const loadAsync = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_6, reject_6) => { require(["./0"], resolve_6, reject_6); });
         }
     }
     exports.D = D;

tests/baselines/reference/importCallExpressionGrammarError.js

@@ -12,8 +12,8 @@ const p4 = import("pathToModule", "secondModule");
 
 //// [importCallExpressionGrammarError.js]
 var a = ["./0"];
-Promise.resolve().then(function () { return require(...["PathModule"]); });
-var p1 = Promise.resolve().then(function () { return require(...a); });
-const p2 = Promise.resolve().then(function () { return require(); });
-const p3 = Promise.resolve().then(function () { return require(); });
-const p4 = Promise.resolve().then(function () { return require("pathToModule", "secondModule"); });
+Promise.resolve().then(() => require(...["PathModule"]));
+var p1 = Promise.resolve().then(() => require(...a));
+const p2 = Promise.resolve().then(() => require());
+const p3 = Promise.resolve().then(() => require());
+const p4 = Promise.resolve().then(() => require("pathToModule", "secondModule"));

tests/baselines/reference/importCallExpressionInAMD1.js

@@ -27,13 +27,13 @@ define(["require", "exports"], function (require, exports) {
 define(["require", "exports"], function (require, exports) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
-    new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); });
-    var p1 = new Promise(function (resolve_2, reject_2) { require(["./0"], resolve_2, reject_2); });
+    new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); });
+    var p1 = new Promise((resolve_2, reject_2) => { require(["./0"], resolve_2, reject_2); });
     p1.then(zero => {
         return zero.foo();
     });
-    exports.p2 = new Promise(function (resolve_3, reject_3) { require(["./0"], resolve_3, reject_3); });
+    exports.p2 = new Promise((resolve_3, reject_3) => { require(["./0"], resolve_3, reject_3); });
     function foo() {
-        const p2 = new Promise(function (resolve_4, reject_4) { require(["./0"], resolve_4, reject_4); });
+        const p2 = new Promise((resolve_4, reject_4) => { require(["./0"], resolve_4, reject_4); });
     }
 });

tests/baselines/reference/importCallExpressionInAMD2.js

@@ -35,5 +35,5 @@ define(["require", "exports"], function (require, exports) {
             b.print();
         });
     }
-    foo(new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); }));
+    foo(new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); }));
 });

tests/baselines/reference/importCallExpressionInAMD3.js

@@ -26,7 +26,7 @@ define(["require", "exports"], function (require, exports) {
 define(["require", "exports"], function (require, exports) {
     "use strict";
     async function foo() {
-        class C extends (await new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); })).B {
+        class C extends (await new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); })).B {
         }
         var c = new C();
         c.print();

tests/baselines/reference/importCallExpressionInAMD4.js

@@ -64,30 +64,30 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     class C {
         constructor() {
-            this.myModule = new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); });
+            this.myModule = new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); });
         }
         method() {
-            const loadAsync = new Promise(function (resolve_2, reject_2) { require(["./0"], resolve_2, reject_2); });
+            const loadAsync = new Promise((resolve_2, reject_2) => { require(["./0"], resolve_2, reject_2); });
             this.myModule.then(Zero => {
                 console.log(Zero.foo());
             }, async (err) => {
                 console.log(err);
-                let one = await new Promise(function (resolve_3, reject_3) { require(["./1"], resolve_3, reject_3); });
+                let one = await new Promise((resolve_3, reject_3) => { require(["./1"], resolve_3, reject_3); });
                 console.log(one.backup());
             });
         }
     }
     class D {
         constructor() {
-            this.myModule = new Promise(function (resolve_4, reject_4) { require(["./0"], resolve_4, reject_4); });
+            this.myModule = new Promise((resolve_4, reject_4) => { require(["./0"], resolve_4, reject_4); });
         }
         method() {
-            const loadAsync = new Promise(function (resolve_5, reject_5) { require(["./0"], resolve_5, reject_5); });
+            const loadAsync = new Promise((resolve_5, reject_5) => { require(["./0"], resolve_5, reject_5); });
             this.myModule.then(Zero => {
                 console.log(Zero.foo());
             }, async (err) => {
                 console.log(err);
-                let one = await new Promise(function (resolve_6, reject_6) { require(["./1"], resolve_6, reject_6); });
+                let one = await new Promise((resolve_6, reject_6) => { require(["./1"], resolve_6, reject_6); });
                 console.log(one.backup());
             });
         }

tests/baselines/reference/importCallExpressionInCJS1.js

@@ -24,12 +24,12 @@ exports.foo = foo;
 //// [1.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-Promise.resolve().then(function () { return require("./0"); });
-var p1 = Promise.resolve().then(function () { return require("./0"); });
+Promise.resolve().then(() => require("./0"));
+var p1 = Promise.resolve().then(() => require("./0"));
 p1.then(zero => {
     return zero.foo();
 });
-exports.p2 = Promise.resolve().then(function () { return require("./0"); });
+exports.p2 = Promise.resolve().then(() => require("./0"));
 function foo() {
-    const p2 = Promise.resolve().then(function () { return require("./0"); });
+    const p2 = Promise.resolve().then(() => require("./0"));
 }

tests/baselines/reference/importCallExpressionInCJS2.js

@@ -32,9 +32,9 @@ exports.backup = backup;
 async function compute(promise) {
     let j = await promise;
     if (!j) {
-        j = await Promise.resolve().then(function () { return require("./1"); });
+        j = await Promise.resolve().then(() => require("./1"));
         return j.backup();
     }
     return j.foo();
 }
-compute(Promise.resolve().then(function () { return require("./0"); }));
+compute(Promise.resolve().then(() => require("./0")));

tests/baselines/reference/importCallExpressionInCJS3.js

@@ -31,4 +31,4 @@ function foo(x) {
         b.print();
     });
 }
-foo(Promise.resolve().then(function () { return require("./0"); }));
+foo(Promise.resolve().then(() => require("./0")));

tests/baselines/reference/importCallExpressionInCJS4.js

@@ -22,7 +22,7 @@ class B {
 exports.B = B;
 //// [2.js]
 async function foo() {
-    class C extends (await Promise.resolve().then(function () { return require("./0"); })).B {
+    class C extends (await Promise.resolve().then(() => require("./0"))).B {
     }
     var c = new C();
     c.print();

tests/baselines/reference/importCallExpressionInCJS5.js

@@ -59,30 +59,30 @@ exports.backup = backup;
 Object.defineProperty(exports, "__esModule", { value: true });
 class C {
     constructor() {
-        this.myModule = Promise.resolve().then(function () { return require("./0"); });
+        this.myModule = Promise.resolve().then(() => require("./0"));
     }
     method() {
-        const loadAsync = Promise.resolve().then(function () { return require("./0"); });
+        const loadAsync = Promise.resolve().then(() => require("./0"));
         this.myModule.then(Zero => {
             console.log(Zero.foo());
         }, async (err) => {
             console.log(err);
-            let one = await Promise.resolve().then(function () { return require("./1"); });
+            let one = await Promise.resolve().then(() => require("./1"));
             console.log(one.backup());
         });
     }
 }
 class D {
     constructor() {
-        this.myModule = Promise.resolve().then(function () { return require("./0"); });
+        this.myModule = Promise.resolve().then(() => require("./0"));
     }
     method() {
-        const loadAsync = Promise.resolve().then(function () { return require("./0"); });
+        const loadAsync = Promise.resolve().then(() => require("./0"));
         this.myModule.then(Zero => {
             console.log(Zero.foo());
         }, async (err) => {
             console.log(err);
-            let one = await Promise.resolve().then(function () { return require("./1"); });
+            let one = await Promise.resolve().then(() => require("./1"));
             console.log(one.backup());
         });
     }

tests/baselines/reference/importCallExpressionInExportEqualsAMD.js

@@ -17,6 +17,6 @@ define(["require", "exports"], function (require, exports) {
 define(["require", "exports"], function (require, exports) {
     "use strict";
     return async function () {
-        const something = await new Promise(function (resolve_1, reject_1) { require(["./something"], resolve_1, reject_1); });
+        const something = await new Promise((resolve_1, reject_1) => { require(["./something"], resolve_1, reject_1); });
     };
 });

tests/baselines/reference/importCallExpressionInExportEqualsCJS.js

@@ -14,5 +14,5 @@ module.exports = 42;
 //// [index.js]
 "use strict";
 module.exports = async function () {
-    const something = await Promise.resolve().then(function () { return require("./something"); });
+    const something = await Promise.resolve().then(() => require("./something"));
 };

tests/baselines/reference/importCallExpressionInExportEqualsUMD.js

@@ -34,6 +34,6 @@ export = async function() {
     "use strict";
     var __syncRequire = typeof module === "object" && typeof module.exports === "object";
     return async function () {
-        const something = await (__syncRequire ? Promise.resolve().then(function () { return require("./something"); }) : new Promise(function (resolve_1, reject_1) { require(["./something"], resolve_1, reject_1); }));
+        const something = await (__syncRequire ? Promise.resolve().then(() => require("./something")) : new Promise((resolve_1, reject_1) => { require(["./something"], resolve_1, reject_1); }));
     };
 });

tests/baselines/reference/importCallExpressionInScriptContext1.js

@@ -13,5 +13,5 @@ Object.defineProperty(exports, "__esModule", { value: true });
 function foo() { return "foo"; }
 exports.foo = foo;
 //// [1.js]
-var p1 = Promise.resolve().then(function () { return require("./0"); });
+var p1 = Promise.resolve().then(() => require("./0"));
 function arguments() { } // this is allow as the file doesn't have implicit "use strict"

tests/baselines/reference/importCallExpressionInScriptContext2.js

@@ -15,5 +15,5 @@ function foo() { return "foo"; }
 exports.foo = foo;
 //// [1.js]
 "use strict";
-var p1 = Promise.resolve().then(function () { return require("./0"); });
+var p1 = Promise.resolve().then(() => require("./0"));
 function arguments() { }

tests/baselines/reference/importCallExpressionInUMD1.js

@@ -44,13 +44,13 @@ function foo() {
     "use strict";
     var __syncRequire = typeof module === "object" && typeof module.exports === "object";
     Object.defineProperty(exports, "__esModule", { value: true });
-    __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); });
-    var p1 = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_2, reject_2) { require(["./0"], resolve_2, reject_2); });
+    __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); });
+    var p1 = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_2, reject_2) => { require(["./0"], resolve_2, reject_2); });
     p1.then(zero => {
         return zero.foo();
     });
-    exports.p2 = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_3, reject_3) { require(["./0"], resolve_3, reject_3); });
+    exports.p2 = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_3, reject_3) => { require(["./0"], resolve_3, reject_3); });
     function foo() {
-        const p2 = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_4, reject_4) { require(["./0"], resolve_4, reject_4); });
+        const p2 = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_4, reject_4) => { require(["./0"], resolve_4, reject_4); });
     }
 });

tests/baselines/reference/importCallExpressionInUMD2.js

@@ -52,5 +52,5 @@ foo(import("./0"));
             b.print();
         });
     }
-    foo(__syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); }));
+    foo(__syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); }));
 });

tests/baselines/reference/importCallExpressionInUMD3.js

@@ -43,7 +43,7 @@ foo();
     "use strict";
     var __syncRequire = typeof module === "object" && typeof module.exports === "object";
     async function foo() {
-        class C extends (await (__syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); }))).B {
+        class C extends (await (__syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); }))).B {
         }
         var c = new C();
         c.print();

tests/baselines/reference/importCallExpressionInUMD4.js

@@ -89,30 +89,30 @@ export class D {
     Object.defineProperty(exports, "__esModule", { value: true });
     class C {
         constructor() {
-            this.myModule = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_1, reject_1) { require(["./0"], resolve_1, reject_1); });
+            this.myModule = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_1, reject_1) => { require(["./0"], resolve_1, reject_1); });
         }
         method() {
-            const loadAsync = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_2, reject_2) { require(["./0"], resolve_2, reject_2); });
+            const loadAsync = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_2, reject_2) => { require(["./0"], resolve_2, reject_2); });
             this.myModule.then(Zero => {
                 console.log(Zero.foo());
             }, async (err) => {
                 console.log(err);
-                let one = await (__syncRequire ? Promise.resolve().then(function () { return require("./1"); }) : new Promise(function (resolve_3, reject_3) { require(["./1"], resolve_3, reject_3); }));
+                let one = await (__syncRequire ? Promise.resolve().then(() => require("./1")) : new Promise((resolve_3, reject_3) => { require(["./1"], resolve_3, reject_3); }));
                 console.log(one.backup());
             });
         }
     }
     class D {
         constructor() {
-            this.myModule = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_4, reject_4) { require(["./0"], resolve_4, reject_4); });
+            this.myModule = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_4, reject_4) => { require(["./0"], resolve_4, reject_4); });
         }
         method() {
-            const loadAsync = __syncRequire ? Promise.resolve().then(function () { return require("./0"); }) : new Promise(function (resolve_5, reject_5) { require(["./0"], resolve_5, reject_5); });
+            const loadAsync = __syncRequire ? Promise.resolve().then(() => require("./0")) : new Promise((resolve_5, reject_5) => { require(["./0"], resolve_5, reject_5); });
             this.myModule.then(Zero => {
                 console.log(Zero.foo());
             }, async (err) => {
                 console.log(err);
-                let one = await (__syncRequire ? Promise.resolve().then(function () { return require("./1"); }) : new Promise(function (resolve_6, reject_6) { require(["./1"], resolve_6, reject_6); }));
+                let one = await (__syncRequire ? Promise.resolve().then(() => require("./1")) : new Promise((resolve_6, reject_6) => { require(["./1"], resolve_6, reject_6); }));
                 console.log(one.backup());
             });
         }

tests/baselines/reference/importCallExpressionReturnPromiseOfAny.js

@@ -42,20 +42,20 @@ exports.C = C;
 //// [1.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-Promise.resolve().then(function () { return require(`${directory}\${moduleFile}`); });
-Promise.resolve().then(function () { return require(getSpecifier()); });
-var p1 = Promise.resolve().then(function () { return require(ValidSomeCondition() ? "./0" : "externalModule"); });
-var p1 = Promise.resolve().then(function () { return require(getSpecifier()); });
-var p11 = Promise.resolve().then(function () { return require(getSpecifier()); });
-const p2 = Promise.resolve().then(function () { return require(whatToLoad ? getSpecifier() : "defaulPath"); });
+Promise.resolve().then(() => require(`${directory}\${moduleFile}`));
+Promise.resolve().then(() => require(getSpecifier()));
+var p1 = Promise.resolve().then(() => require(ValidSomeCondition() ? "./0" : "externalModule"));
+var p1 = Promise.resolve().then(() => require(getSpecifier()));
+var p11 = Promise.resolve().then(() => require(getSpecifier()));
+const p2 = Promise.resolve().then(() => require(whatToLoad ? getSpecifier() : "defaulPath"));
 p1.then(zero => {
     return zero.foo(); // ok, zero is any
 });
 let j;
-var p3 = Promise.resolve().then(function () { return require(j = getSpecifier()); });
+var p3 = Promise.resolve().then(() => require(j = getSpecifier()));
 function* loadModule(directories) {
     for (const directory of directories) {
         const path = `${directory}\moduleFile`;
-        Promise.resolve().then(function () { return require(yield path); });
+        Promise.resolve().then(() => require(yield path));
     }
 }

tests/baselines/reference/importCallExpressionSpecifierNotStringTypeError.js

@@ -15,11 +15,11 @@ var p4 = import(()=>"PathToModule");
 
 //// [importCallExpressionSpecifierNotStringTypeError.js]
 // Error specifier is not assignable to string
-Promise.resolve().then(function () { return require(getSpecifier()); });
-var p1 = Promise.resolve().then(function () { return require(getSpecifier()); });
-const p2 = Promise.resolve().then(function () { return require(whatToLoad ? getSpecifier() : "defaulPath"); });
+Promise.resolve().then(() => require(getSpecifier()));
+var p1 = Promise.resolve().then(() => require(getSpecifier()));
+const p2 = Promise.resolve().then(() => require(whatToLoad ? getSpecifier() : "defaulPath"));
 p1.then(zero => {
     return zero.foo(); // ok, zero is any
 });
-var p3 = Promise.resolve().then(function () { return require(["path1", "path2"]); });
-var p4 = Promise.resolve().then(function () { return require(() => "PathToModule"); });
+var p3 = Promise.resolve().then(() => require(["path1", "path2"]));
+var p4 = Promise.resolve().then(() => require(() => "PathToModule"));

tests/baselines/reference/importCallExpressionWithTypeArgument.js

@@ -15,5 +15,5 @@ function foo() { return "foo"; }
 exports.foo = foo;
 //// [1.js]
 "use strict";
-var p1 = Promise.resolve().then(function () { return require("./0"); }); // error
-var p2 = Promise.resolve().then(function () { return require("./0"); }); // error
+var p1 = Promise.resolve().then(() => require("./0")); // error
+var p2 = Promise.resolve().then(() => require("./0")); // error

tests/cases/compiler/dynamicImportWithNestedThis_es2015.ts

@@ -0,0 +1,14 @@
+// @lib: es2015
+// @target: es2015
+// @module: umd
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+	private _path = './other';
+
+	dynamic() {
+		return import(this._path);
+	}
+}
+
+const c = new C();
+c.dynamic();

tests/cases/compiler/dynamicImportWithNestedThis_es5.ts

@@ -0,0 +1,14 @@
+// @lib: es2015
+// @target: es5
+// @module: umd
+// https://github.com/Microsoft/TypeScript/issues/17564
+class C {
+	private _path = './other';
+
+	dynamic() {
+		return import(this._path);
+	}
+}
+
+const c = new C();
+c.dynamic();