[Experiment]

Author: Josh-Cena

src/compiler/transformers/module/module.ts

@@ -755,7 +755,7 @@ namespace ts {
                 return factory.createComma(factory.createAssignment(temp, arg), factory.createConditionalExpression(
                     /*condition*/ factory.createIdentifier("__syncRequire"),
                     /*questionToken*/ undefined,
-                    /*whenTrue*/ createImportCallExpressionCommonJS(temp),
+                    /*whenTrue*/ createImportCallExpressionCommonJS(temp, /* isInlineable */ true),
                     /*colonToken*/ undefined,
                     /*whenFalse*/ createImportCallExpressionAMD(temp, containsLexicalThis)
                 ));
@@ -820,15 +820,15 @@ namespace ts {
             return promise;
         }
 
-        function createImportCallExpressionCommonJS(arg: Expression | undefined): Expression {
+        function createImportCallExpressionCommonJS(arg: Expression | undefined, isInlineable?: boolean): Expression {
             // import(x)
             // emit as
             // var _a;
             // (_a = x, Promise.resolve().then(() => require(_a)) /*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
             // If the arg is not inlineable, we have to evaluate it in the current scope with a temp var
-            const temp = arg && !isSimpleInlineableExpression(arg) ? factory.createTempVariable(hoistVariableDeclaration) : undefined;
+            const temp = arg && !isSimpleInlineableExpression(arg) && !isInlineable ? factory.createTempVariable(hoistVariableDeclaration) : undefined;
             const promiseResolveCall = factory.createCallExpression(
                 factory.createPropertyAccessExpression(factory.createIdentifier("Promise"), "resolve"),
                 /*typeArguments*/ undefined,

tests/baselines/reference/dynamicImportWithNestedThis_es2015.js

@@ -29,8 +29,8 @@ c.dynamic();
             this._path = './other';
         }
         dynamic() {
-            var _a, _b;
-            return _a = this._path, __syncRequire ? (_b = _a, Promise.resolve().then(() => require(_b))) : new Promise((resolve_1, reject_1) => { require([_a], resolve_1, reject_1); });
+            var _a;
+            return _a = this._path, __syncRequire ? Promise.resolve().then(() => require(_a)) : new Promise((resolve_1, reject_1) => { require([_a], resolve_1, reject_1); });
         }
     }
     const c = new C();

tests/baselines/reference/dynamicImportWithNestedThis_es5.js

@@ -29,8 +29,8 @@ c.dynamic();
             this._path = './other';
         }
         C.prototype.dynamic = function () {
-            var _a, _b;
-            return _a = this._path, __syncRequire ? (_b = _a, Promise.resolve().then(function () { return require(_b); })) : new Promise(function (resolve_1, reject_1) { require([_a], resolve_1, reject_1); });
+            var _a;
+            return _a = this._path, __syncRequire ? Promise.resolve().then(function () { return require(_a); }) : new Promise(function (resolve_1, reject_1) { require([_a], resolve_1, reject_1); });
         };
         return C;
     }());

tests/baselines/reference/importCallExpressionInUMD5.js

@@ -51,9 +51,9 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
     // https://github.com/microsoft/TypeScript/issues/36780
     function func() {
         return __awaiter(this, void 0, void 0, function* () {
-            var _a, _b;
+            var _a;
             const packageName = '.';
-            const packageJson = yield (_a = packageName + '/package.json', __syncRequire ? (_b = _a, Promise.resolve().then(() => require(_b))) : new Promise((resolve_1, reject_1) => { require([_a], resolve_1, reject_1); }));
+            const packageJson = yield (_a = packageName + '/package.json', __syncRequire ? Promise.resolve().then(() => require(_a)) : new Promise((resolve_1, reject_1) => { require([_a], resolve_1, reject_1); }));
         });
     }
 });

tests/baselines/reference/importCallExpressionNestedUMD.js

@@ -45,8 +45,8 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
     var __syncRequire = typeof module === "object" && typeof module.exports === "object";
     function foo() {
         return __awaiter(this, void 0, void 0, function* () {
-            var _a, _b;
-            return yield (_a = (yield __syncRequire ? Promise.resolve().then(() => require("./foo")) : new Promise((resolve_1, reject_1) => { require(["./foo"], resolve_1, reject_1); })).default, __syncRequire ? (_b = _a, Promise.resolve().then(() => require(_b))) : new Promise((resolve_2, reject_2) => { require([_a], resolve_2, reject_2); }));
+            var _a;
+            return yield (_a = (yield __syncRequire ? Promise.resolve().then(() => require("./foo")) : new Promise((resolve_1, reject_1) => { require(["./foo"], resolve_1, reject_1); })).default, __syncRequire ? Promise.resolve().then(() => require(_a)) : new Promise((resolve_2, reject_2) => { require([_a], resolve_2, reject_2); }));
         });
     }
 });

tests/baselines/reference/importCallExpressionNestedUMD2.js

@@ -73,10 +73,10 @@ var __generator = (this && this.__generator) || function (thisArg, body) {
     function foo() {
         return __awaiter(this, void 0, void 0, function () {
             return __generator(this, function (_a) {
-                var _b, _c;
+                var _b;
                 switch (_a.label) {
                     case 0: return [4 /*yield*/, __syncRequire ? Promise.resolve().then(function () { return require("./foo"); }) : new Promise(function (resolve_1, reject_1) { require(["./foo"], resolve_1, reject_1); })];
-                    case 1: return [4 /*yield*/, (_b = (_a.sent()).default, __syncRequire ? (_c = _b, Promise.resolve().then(function () { return require(_c); })) : new Promise(function (resolve_2, reject_2) { require([_b], resolve_2, reject_2); }))];
+                    case 1: return [4 /*yield*/, (_b = (_a.sent()).default, __syncRequire ? Promise.resolve().then(function () { return require(_b); }) : new Promise(function (resolve_2, reject_2) { require([_b], resolve_2, reject_2); }))];
                     case 2: return [2 /*return*/, _a.sent()];
                 }
             });