Emit an export assignment even when the initializer is elided

Author: weswigham

src/compiler/transformers/module/module.ts

@@ -1180,7 +1180,6 @@ namespace ts {
                 let modifiers: NodeArray<Modifier> | undefined;
 
                 // If we're exporting these variables, then these just become assignments to 'exports.x'.
-                // We only want to emit assignments for variables with initializers.
                 for (const variable of node.declarationList.declarations) {
                     if (isIdentifier(variable.name) && isLocalName(variable.name)) {
                         if (!modifiers) {
@@ -1189,9 +1188,7 @@ namespace ts {
 
                         variables = append(variables, variable);
                     }
-                    else if (variable.initializer) {
-                        expressions = append(expressions, transformInitializedVariable(variable));
-                    }
+                    expressions = append(expressions, transformInitializedVariable(variable));
                 }
 
                 if (variables) {
@@ -1259,7 +1256,7 @@ namespace ts {
                         ),
                         /*location*/ node.name
                     ),
-                    visitNode(node.initializer, moduleExpressionElementVisitor)
+                    node.initializer ? visitNode(node.initializer, moduleExpressionElementVisitor) : createIdentifier("undefined")
                 );
             }
         }

tests/baselines/reference/TwoInternalModulesThatMergeEachWithExportedLocalVarsOfTheSameName.js

@@ -33,6 +33,7 @@ export module A {
 "use strict";
 exports.__esModule = true;
 var A;
+exports.A = undefined;
 (function (A) {
     var Utils;
     (function (Utils) {
@@ -47,6 +48,7 @@ var A;
 "use strict";
 exports.__esModule = true;
 var A;
+exports.A = undefined;
 (function (A) {
     // collision with 'Origin' var in other part of merged module
     A.Origin = { x: 0, y: 0 };

tests/baselines/reference/aliasUsedAsNameValue.js

@@ -21,6 +21,7 @@ export var a = function () {
 //// [aliasUsedAsNameValue_0.js]
 "use strict";
 exports.__esModule = true;
+exports.id = undefined;
 //// [aliasUsedAsNameValue_1.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/amdImportAsPrimaryExpression.js

@@ -17,6 +17,7 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
     var E1;
+    exports.E1 = undefined;
     (function (E1) {
         E1[E1["A"] = 0] = "A";
         E1[E1["B"] = 1] = "B";

tests/baselines/reference/amdImportNotAsPrimaryExpression.js

@@ -44,6 +44,7 @@ define(["require", "exports"], function (require, exports) {
     }());
     exports.C1 = C1;
     var E1;
+    exports.E1 = undefined;
     (function (E1) {
         E1[E1["A"] = 0] = "A";
         E1[E1["B"] = 1] = "B";

tests/baselines/reference/amdModuleConstEnumUsage.js

@@ -19,6 +19,7 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
     var CharCode;
+    exports.CharCode = undefined;
     (function (CharCode) {
         CharCode[CharCode["A"] = 0] = "A";
         CharCode[CharCode["B"] = 1] = "B";

tests/baselines/reference/chainedImportAlias.js

@@ -15,6 +15,7 @@ y.m.foo();
 "use strict";
 exports.__esModule = true;
 var m;
+exports.m = undefined;
 (function (m) {
     function foo() { }
     m.foo = foo;

tests/baselines/reference/circularReference.js

@@ -38,6 +38,7 @@ export module M1 {
 exports.__esModule = true;
 var foo2 = require("./foo2");
 var M1;
+exports.M1 = undefined;
 (function (M1) {
     var C1 = /** @class */ (function () {
         function C1() {
@@ -54,6 +55,7 @@ var M1;
 exports.__esModule = true;
 var foo1 = require("./foo1");
 var M1;
+exports.M1 = undefined;
 (function (M1) {
     var C1 = /** @class */ (function () {
         function C1() {

tests/baselines/reference/classMemberInitializerWithLamdaScoping4.js

@@ -18,6 +18,7 @@ export class Test1 {
 //// [classMemberInitializerWithLamdaScoping3_0.js]
 "use strict";
 exports.__esModule = true;
+exports.field1 = undefined;
 //// [classMemberInitializerWithLamdaScoping3_1.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/collisionExportsRequireAndEnum.js

@@ -65,11 +65,13 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
     var require;
+    exports.require = undefined;
     (function (require) {
         require[require["_thisVal1"] = 0] = "_thisVal1";
         require[require["_thisVal2"] = 1] = "_thisVal2";
     })(require = exports.require || (exports.require = {}));
     var exports;
+    exports.exports = undefined;
     (function (exports) {
         exports[exports["_thisVal1"] = 0] = "_thisVal1";
         exports[exports["_thisVal2"] = 1] = "_thisVal2";

tests/baselines/reference/collisionExportsRequireAndInternalModuleAlias.js

@@ -27,6 +27,7 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
     var m;
+    exports.m = undefined;
     (function (m) {
         var c = /** @class */ (function () {
             function c() {

tests/baselines/reference/collisionExportsRequireAndModule.js

@@ -96,6 +96,7 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
     var require;
+    exports.require = undefined;
     (function (require) {
         var C = /** @class */ (function () {
             function C() {
@@ -109,6 +110,7 @@ define(["require", "exports"], function (require, exports) {
     }
     exports.foo = foo;
     var exports;
+    exports.exports = undefined;
     (function (exports) {
         var C = /** @class */ (function () {
             function C() {

tests/baselines/reference/commentOnExportEnumDeclaration.js

@@ -13,6 +13,10 @@ exports.__esModule = true;
  * comment
  */
 var Color;
+/**
+ * comment
+ */
+exports.Color = undefined;
 (function (Color) {
     Color[Color["r"] = 0] = "r";
     Color[Color["g"] = 1] = "g";

tests/baselines/reference/commentsBeforeVariableStatement1.js

@@ -7,4 +7,6 @@ export var b: number;
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    /** b's comment*/
+    exports.b = undefined;
 });

tests/baselines/reference/commentsDottedModuleName.js

@@ -12,6 +12,8 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     /** this is multi declare module*/
     var outerModule;
+    /** this is multi declare module*/
+    exports.outerModule = undefined;
     (function (outerModule) {
         var InnerModule;
         (function (InnerModule) {

tests/baselines/reference/commentsExternalModules.js

@@ -66,6 +66,8 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     /** Module comment*/
     var m1;
+    /** Module comment*/
+    exports.m1 = undefined;
     (function (m1) {
         /** foo's comment*/
         function foo() {
@@ -95,6 +97,8 @@ define(["require", "exports"], function (require, exports) {
     var myvar = new m1.m2.c();
     /** Module comment */
     var m4;
+    /** Module comment */
+    exports.m4 = undefined;
     (function (m4) {
         /** foo's comment
         */

tests/baselines/reference/commentsExternalModules2.js

@@ -66,6 +66,8 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     /** Module comment*/
     var m1;
+    /** Module comment*/
+    exports.m1 = undefined;
     (function (m1) {
         /** foo's comment*/
         function foo() {
@@ -95,6 +97,8 @@ define(["require", "exports"], function (require, exports) {
     var myvar = new m1.m2.c();
     /** Module comment */
     var m4;
+    /** Module comment */
+    exports.m4 = undefined;
     (function (m4) {
         /** foo's comment
         */

tests/baselines/reference/commentsExternalModules3.js

@@ -65,6 +65,8 @@ export var newVar2 = new extMod.m4.m2.c();
 Object.defineProperty(exports, "__esModule", { value: true });
 /** Module comment*/
 var m1;
+/** Module comment*/
+exports.m1 = undefined;
 (function (m1) {
     /** foo's comment*/
     function foo() {
@@ -94,6 +96,8 @@ m1.fooExport();
 var myvar = new m1.m2.c();
 /** Module comment */
 var m4;
+/** Module comment */
+exports.m4 = undefined;
 (function (m4) {
     /** foo's comment
     */

tests/baselines/reference/commentsMultiModuleMultiFile.js

@@ -41,6 +41,8 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     /** this is multi declare module*/
     var multiM;
+    /** this is multi declare module*/
+    exports.multiM = undefined;
     (function (multiM) {
         /// class b comment
         var b = /** @class */ (function () {
@@ -76,6 +78,8 @@ define(["require", "exports"], function (require, exports) {
     Object.defineProperty(exports, "__esModule", { value: true });
     /** this is multi module 3 comment*/
     var multiM;
+    /** this is multi module 3 comment*/
+    exports.multiM = undefined;
     (function (multiM) {
         /** class d comment*/
         var d = /** @class */ (function () {

tests/baselines/reference/commonJSImportNotAsPrimaryExpression.js

@@ -43,6 +43,7 @@ var C1 = /** @class */ (function () {
 }());
 exports.C1 = C1;
 var E1;
+exports.E1 = undefined;
 (function (E1) {
     E1[E1["A"] = 0] = "A";
     E1[E1["B"] = 1] = "B";

tests/baselines/reference/constEnumPreserveEmitReexport.js

@@ -15,6 +15,7 @@ export { MyConstEnum as default } from './ConstEnum';
 "use strict";
 exports.__esModule = true;
 var MyConstEnum;
+exports.MyConstEnum = undefined;
 (function (MyConstEnum) {
     MyConstEnum[MyConstEnum["Foo"] = 0] = "Foo";
     MyConstEnum[MyConstEnum["Bar"] = 1] = "Bar";

tests/baselines/reference/controlFlowManyConsecutiveConditionsNoTimeout.js

@@ -136,6 +136,7 @@ while (true) {
 "use strict";
 exports.__esModule = true;
 var Choice;
+exports.Choice = undefined;
 (function (Choice) {
     Choice[Choice["One"] = 0] = "One";
     Choice[Choice["Two"] = 1] = "Two";

tests/baselines/reference/declFileAmbientExternalModuleWithSingleExportedModule.js

@@ -21,6 +21,7 @@ export var x: SubModule.m.m3.c;
 //// [declFileAmbientExternalModuleWithSingleExportedModule_1.js]
 "use strict";
 exports.__esModule = true;
+exports.x = undefined;
 
 
 //// [declFileAmbientExternalModuleWithSingleExportedModule_0.d.ts]

tests/baselines/reference/declFileExportAssignmentOfGenericInterface.js

@@ -20,6 +20,7 @@ define(["require", "exports"], function (require, exports) {
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = undefined;
     exports.x.a;
 });
 

tests/baselines/reference/declFileExportImportChain.js

@@ -61,6 +61,7 @@ define(["require", "exports", "declFileExportImportChain_b1"], function (require
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = undefined;
 });
 
 

tests/baselines/reference/declFileExportImportChain2.js

@@ -52,6 +52,7 @@ define(["require", "exports", "declFileExportImportChain2_b"], function (require
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = undefined;
 });
 
 

tests/baselines/reference/declFileForExportedImport.js

@@ -14,6 +14,7 @@ var z = b.x;
 //// [declFileForExportedImport_0.js]
 "use strict";
 exports.__esModule = true;
+exports.x = undefined;
 //// [declFileForExportedImport_1.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/declFileGenericType.js

@@ -56,6 +56,7 @@ var __extends = (this && this.__extends) || (function () {
 })();
 exports.__esModule = true;
 var C;
+exports.C = undefined;
 (function (C) {
     var A = /** @class */ (function () {
         function A() {
@@ -89,6 +90,7 @@ var C;
     }());
     C.D = D;
 })(C = exports.C || (exports.C = {}));
+exports.a = undefined;
 exports.b = C.F;
 exports.c = C.F2;
 exports.d = C.F3;

tests/baselines/reference/declarationEmitNameConflicts.js

@@ -66,6 +66,7 @@ module.exports = f;
 exports.__esModule = true;
 var im = require("./declarationEmit_nameConflicts_1");
 var M;
+exports.M = undefined;
 (function (M) {
     function f() { }
     M.f = f;

tests/baselines/reference/declarationEmitNameConflictsWithAlias.js

@@ -10,6 +10,7 @@ export module M {
 "use strict";
 exports.__esModule = true;
 var M;
+exports.M = undefined;
 (function (M) {
 })(M = exports.M || (exports.M = {}));
 

tests/baselines/reference/declarationEmitNoNonRequiredParens.js

@@ -11,6 +11,7 @@ export const bar = (null as TestType[Extract<keyof TestType, string>][]);
 "use strict";
 exports.__esModule = true;
 var Test;
+exports.Test = undefined;
 (function (Test) {
     Test[Test["A"] = 0] = "A";
     Test[Test["B"] = 1] = "B";

tests/baselines/reference/decoratorOnImportEquals2.js

@@ -12,6 +12,7 @@ declare function dec<T>(target: T): T;
 //// [decoratorOnImportEquals2_0.js]
 "use strict";
 exports.__esModule = true;
+exports.X = undefined;
 //// [decoratorOnImportEquals2_1.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/defaultDeclarationEmitShadowedNamedCorrectly.js

@@ -34,6 +34,7 @@ var MyComponent = /** @class */ (function () {
 }());
 exports["default"] = MyComponent;
 var Something;
+exports.Something = undefined;
 (function (Something) {
     var MyComponent = 2; // Shadow declaration, so symbol is only usable via the self-import
     Something.create = make(me["default"]);

tests/baselines/reference/destructuringAssignmentWithExportedName.js

@@ -29,6 +29,7 @@ export { exportedFoo as foo, nonexportedFoo as nfoo };
 "use strict";
 var _a, _b, _c, _d, _e;
 Object.defineProperty(exports, "__esModule", { value: true });
+exports.exportedFoo = undefined;
 exports.foo = exports.exportedFoo;
 let nonexportedFoo;
 exports.nonexportedFoo = nonexportedFoo;

tests/baselines/reference/downlevelLetConst13.js

@@ -29,6 +29,7 @@ exports.bar2 = [2][0];
 exports.bar3 = { a: 1 }.a;
 exports.bar4 = { a: 1 }.a;
 var M;
+exports.M = undefined;
 (function (M) {
     M.baz = 100;
     M.baz2 = true;

tests/baselines/reference/enumDeclarationEmitInitializerHasImport.js

@@ -14,6 +14,7 @@ export const value = provider.Enum.Value1;
 "use strict";
 exports.__esModule = true;
 var Enum;
+exports.Enum = undefined;
 (function (Enum) {
     Enum[Enum["Value1"] = 0] = "Value1";
     Enum[Enum["Value2"] = 1] = "Value2";

tests/baselines/reference/enumFromExternalModule.js

@@ -14,6 +14,7 @@ var x = f.Mode.Open;
 "use strict";
 exports.__esModule = true;
 var Mode;
+exports.Mode = undefined;
 (function (Mode) {
     Mode[Mode["Open"] = 0] = "Open";
 })(Mode = exports.Mode || (exports.Mode = {}));