Retain undefined initializations (#36806)

* Emit an export assignment even when the initializer is elided

* User a void 0; and elide assignments for enum/namespace-sourced exported variables

* HAHA, SIMPLIFY GREATLY

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) {
@@ -1189,7 +1188,7 @@ namespace ts {
 
                         variables = append(variables, variable);
                     }
-                    else if (variable.initializer) {
+                    else {
                         expressions = append(expressions, transformInitializedVariable(variable));
                     }
                 }
@@ -1259,7 +1258,7 @@ namespace ts {
                         ),
                         /*location*/ node.name
                     ),
-                    visitNode(node.initializer, moduleExpressionElementVisitor)
+                    node.initializer ? visitNode(node.initializer, moduleExpressionElementVisitor) : createVoidZero()
                 );
             }
         }

tests/baselines/reference/aliasUsedAsNameValue.js

@@ -21,6 +21,7 @@ export var a = function () {
 //// [aliasUsedAsNameValue_0.js]
 "use strict";
 exports.__esModule = true;
+exports.id = void 0;
 //// [aliasUsedAsNameValue_1.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/classMemberInitializerWithLamdaScoping4.js

@@ -18,6 +18,7 @@ export class Test1 {
 //// [classMemberInitializerWithLamdaScoping3_0.js]
 "use strict";
 exports.__esModule = true;
+exports.field1 = void 0;
 //// [classMemberInitializerWithLamdaScoping3_1.js]
 "use strict";
 exports.__esModule = true;

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 = void 0;
 });

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 = void 0;
 
 
 //// [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 = void 0;
     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 = void 0;
 });
 
 

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 = void 0;
 });
 
 

tests/baselines/reference/declFileForExportedImport.js

@@ -14,6 +14,7 @@ var z = b.x;
 //// [declFileForExportedImport_0.js]
 "use strict";
 exports.__esModule = true;
+exports.x = void 0;
 //// [declFileForExportedImport_1.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/declFileGenericType.js

@@ -89,6 +89,7 @@ var C;
     }());
     C.D = D;
 })(C = exports.C || (exports.C = {}));
+exports.a = void 0;
 exports.b = C.F;
 exports.c = C.F2;
 exports.d = C.F3;

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 = void 0;
 //// [decoratorOnImportEquals2_1.js]
 "use strict";
 exports.__esModule = true;

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 = void 0;
 exports.foo = exports.exportedFoo;
 let nonexportedFoo;
 exports.nonexportedFoo = nonexportedFoo;

tests/baselines/reference/errorForConflictingExportEqualsValue.js

@@ -6,5 +6,6 @@ import("./a");
 
 //// [a.js]
 "use strict";
+exports.x = void 0;
 Promise.resolve().then(function () { return require("./a"); });
 module.exports = exports.x;

tests/baselines/reference/excessPropertyChecksWithNestedIntersections.js

@@ -81,6 +81,7 @@ var c = { a: { x: 'hello', y: 2 } }; // error - y does not exist in type A
 var d = { a: { x: 'hello' }, c: 5 }; // ok
 var e = { a: { x: 2 }, c: 5 }; // error - types of property x are incompatible
 var f = { a: { x: 'hello', y: 2 }, c: 5 }; // error - y does not exist in type A
+exports.obj = void 0;
 exports.photo = {
     id: 1,
     url: '',

tests/baselines/reference/exportNonInitializedVariablesAMD.js

@@ -40,11 +40,17 @@ define(["require", "exports"], function (require, exports) {
     var ;
     let;
     var ;
+    exports.a = void 0;
+    exports.b = void 0;
+    exports.c = void 0;
+    exports.d = void 0;
     var A = /** @class */ (function () {
         function A() {
         }
         return A;
     }());
+    exports.e = void 0;
+    exports.f = void 0;
     var B;
     (function (B) {
         B.a = 1, B.c = 2;

tests/baselines/reference/exportNonInitializedVariablesCommonJS.js

@@ -39,11 +39,17 @@ exports.__esModule = true;
 var ;
 let;
 var ;
+exports.a = void 0;
+exports.b = void 0;
+exports.c = void 0;
+exports.d = void 0;
 var A = /** @class */ (function () {
     function A() {
     }
     return A;
 }());
+exports.e = void 0;
+exports.f = void 0;
 var B;
 (function (B) {
     B.a = 1, B.c = 2;

tests/baselines/reference/exportNonInitializedVariablesUMD.js

@@ -48,11 +48,17 @@ export let h1: D = new D;
     var ;
     let;
     var ;
+    exports.a = void 0;
+    exports.b = void 0;
+    exports.c = void 0;
+    exports.d = void 0;
     var A = /** @class */ (function () {
         function A() {
         }
         return A;
     }());
+    exports.e = void 0;
+    exports.f = void 0;
     var B;
     (function (B) {
         B.a = 1, B.c = 2;

tests/baselines/reference/exportStarForValues5.js

@@ -16,4 +16,5 @@ define(["require", "exports"], function (require, exports) {
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = void 0;
 });

tests/baselines/reference/giant.js

@@ -901,6 +901,7 @@ define(["require", "exports"], function (require, exports) {
         })(eM = M_1.eM || (M_1.eM = {}));
         ;
     })(M || (M = {}));
+    exports.eV = void 0;
     function eF() { }
     exports.eF = eF;
     ;

tests/baselines/reference/importDecl.js

@@ -90,6 +90,7 @@ var d = /** @class */ (function () {
     return d;
 }());
 exports.d = d;
+exports.x = void 0;
 function foo() { return null; }
 exports.foo = foo;
 //// [importDecl_require1.js]
@@ -113,6 +114,7 @@ var d = /** @class */ (function () {
     return d;
 }());
 exports.d = d;
+exports.x = void 0;
 function foo() { return null; }
 exports.foo = foo;
 //// [importDecl_require3.js]
@@ -124,6 +126,7 @@ var d = /** @class */ (function () {
     return d;
 }());
 exports.d = d;
+exports.x = void 0;
 function foo() { return null; }
 exports.foo = foo;
 //// [importDecl_require4.js]

tests/baselines/reference/importDeclarationUsedAsTypeQuery.js

@@ -23,6 +23,7 @@ exports.B = B;
 //// [importDeclarationUsedAsTypeQuery_1.js]
 "use strict";
 exports.__esModule = true;
+exports.x = void 0;
 
 
 //// [importDeclarationUsedAsTypeQuery_require.d.ts]

tests/baselines/reference/internalAliasInterfaceInsideTopLevelModuleWithExport.js

@@ -11,6 +11,7 @@ export var x: b;
 //// [internalAliasInterfaceInsideTopLevelModuleWithExport.js]
 "use strict";
 exports.__esModule = true;
+exports.x = void 0;
 
 
 //// [internalAliasInterfaceInsideTopLevelModuleWithExport.d.ts]

tests/baselines/reference/internalAliasInterfaceInsideTopLevelModuleWithoutExport.js

@@ -12,6 +12,7 @@ export var x: b;
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = void 0;
 });
 
 

tests/baselines/reference/internalAliasUninitializedModuleInsideLocalModuleWithoutExportAccessError.js

@@ -24,4 +24,5 @@ define(["require", "exports"], function (require, exports) {
     (function (c) {
         c.x.foo();
     })(c = exports.c || (exports.c = {}));
+    exports.z = void 0;
 });

tests/baselines/reference/internalAliasUninitializedModuleInsideTopLevelModuleWithExport.js

@@ -16,6 +16,7 @@ x.foo();
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = void 0;
     exports.x.foo();
 });
 

tests/baselines/reference/internalAliasUninitializedModuleInsideTopLevelModuleWithoutExport.js

@@ -15,6 +15,7 @@ x.foo();
 //// [internalAliasUninitializedModuleInsideTopLevelModuleWithoutExport.js]
 "use strict";
 exports.__esModule = true;
+exports.x = void 0;
 exports.x.foo();
 
 

tests/baselines/reference/isolatedModulesSpecifiedModule.js

@@ -4,3 +4,4 @@ export var x;
 //// [file1.js]
 "use strict";
 exports.__esModule = true;
+exports.x = void 0;

tests/baselines/reference/isolatedModulesUnspecifiedModule.js

@@ -4,3 +4,4 @@ export var x;
 //// [file1.js]
 "use strict";
 exports.__esModule = true;
+exports.x = void 0;

tests/baselines/reference/moduleAliasAsFunctionArgument.js

@@ -18,6 +18,7 @@ fn(a); // Error: property 'x' is missing from 'a'
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.x = void 0;
 });
 //// [moduleAliasAsFunctionArgument_1.js]
 define(["require", "exports", "moduleAliasAsFunctionArgument_0"], function (require, exports, a) {

tests/baselines/reference/nodeResolution4.js

@@ -15,6 +15,8 @@ var x = 1;
 //// [a.js]
 "use strict";
 exports.__esModule = true;
+/// <reference path="ref.ts"/>
+exports.y = void 0;
 //// [b.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/pathMappingBasedModuleResolution7_classic.js

@@ -32,6 +32,7 @@ export let y: number;
 define(["require", "exports"], function (require, exports) {
     "use strict";
     exports.__esModule = true;
+    exports.b = void 0;
 });
 //// [file2.js]
 define(["require", "exports", "module1", "templates/module2", "../file3"], function (require, exports, module1_1, module2_1, file3_1) {

tests/baselines/reference/pathMappingBasedModuleResolution7_node.js

@@ -31,6 +31,7 @@ export let y: number;
 //// [module2.js]
 "use strict";
 exports.__esModule = true;
+exports.b = void 0;
 //// [file2.js]
 "use strict";
 exports.__esModule = true;

tests/baselines/reference/privacyCheckTypeOfFunction.js

@@ -10,6 +10,7 @@ export var b = foo;
 exports.__esModule = true;
 function foo() {
 }
+exports.x = void 0;
 exports.b = foo;
 
 

tests/baselines/reference/privacyTopLevelInternalReferenceImportWithExport.js

@@ -177,9 +177,11 @@ define(["require", "exports"], function (require, exports) {
     var privateUse_im_public_v_private = exports.im_public_v_private;
     exports.publicUse_im_public_v_private = exports.im_public_v_private;
     var privateUse_im_public_i_private;
+    exports.publicUse_im_public_i_private = void 0;
     var privateUse_im_public_mi_private = new exports.im_public_mi_private.c();
     exports.publicUse_im_public_mi_private = new exports.im_public_mi_private.c();
     var privateUse_im_public_mu_private;
+    exports.publicUse_im_public_mu_private = void 0;
     // No Privacy errors - importing public elements
     exports.im_public_c_public = m_public.c_public;
     exports.im_public_e_public = m_public.e_public;
@@ -196,9 +198,11 @@ define(["require", "exports"], function (require, exports) {
     var privateUse_im_public_v_public = exports.im_public_v_public;
     exports.publicUse_im_public_v_public = exports.im_public_v_public;
     var privateUse_im_public_i_public;
+    exports.publicUse_im_public_i_public = void 0;
     var privateUse_im_public_mi_public = new exports.im_public_mi_public.c();
     exports.publicUse_im_public_mi_public = new exports.im_public_mi_public.c();
     var privateUse_im_public_mu_public;
+    exports.publicUse_im_public_mu_public = void 0;
 });
 
 

tests/baselines/reference/privacyTopLevelInternalReferenceImportWithoutExport.js

@@ -177,9 +177,11 @@ define(["require", "exports"], function (require, exports) {
     var privateUse_im_private_v_private = im_private_v_private;
     exports.publicUse_im_private_v_private = im_private_v_private;
     var privateUse_im_private_i_private;
+    exports.publicUse_im_private_i_private = void 0;
     var privateUse_im_private_mi_private = new im_private_mi_private.c();
     exports.publicUse_im_private_mi_private = new im_private_mi_private.c();
     var privateUse_im_private_mu_private;
+    exports.publicUse_im_private_mu_private = void 0;
     // No Privacy errors - importing public elements
     var im_private_c_public = m_public.c_public;
     var im_private_e_public = m_public.e_public;
@@ -196,9 +198,11 @@ define(["require", "exports"], function (require, exports) {
     var privateUse_im_private_v_public = im_private_v_public;
     exports.publicUse_im_private_v_public = im_private_v_public;
     var privateUse_im_private_i_public;
+    exports.publicUse_im_private_i_public = void 0;
     var privateUse_im_private_mi_public = new im_private_mi_public.c();
     exports.publicUse_im_private_mi_public = new im_private_mi_public.c();
     var privateUse_im_private_mu_public;
+    exports.publicUse_im_private_mu_public = void 0;
 });
 
 

tests/baselines/reference/privacyVar.js

@@ -324,7 +324,9 @@ var glo_C4_public = /** @class */ (function () {
     return glo_C4_public;
 }());
 var glo_v1_private;
+exports.glo_v2_public = void 0;
 var glo_v3_private;
+exports.glo_v4_public = void 0; // error
 var glo_v11_private = new glo_C1_public();
 exports.glo_v12_public = new glo_C1_public();
 var glo_v13_private = new glo_C2_private();

tests/baselines/reference/privacyVarDeclFile.js

@@ -460,6 +460,8 @@ var privateClassWithWithPublicPropertyTypes = /** @class */ (function () {
     }
     return privateClassWithWithPublicPropertyTypes;
 }());
+exports.publicVarWithPrivatePropertyTypes = void 0; // Error
+exports.publicVarWithPublicPropertyTypes = void 0;
 var privateVarWithPrivatePropertyTypes;
 var privateVarWithPublicPropertyTypes;
 var publicClassWithPrivateModulePropertyTypes = /** @class */ (function () {
@@ -468,6 +470,7 @@ var publicClassWithPrivateModulePropertyTypes = /** @class */ (function () {
     return publicClassWithPrivateModulePropertyTypes;
 }());
 exports.publicClassWithPrivateModulePropertyTypes = publicClassWithPrivateModulePropertyTypes;
+exports.publicVarWithPrivateModulePropertyTypes = void 0; // Error
 var privateClassWithPrivateModulePropertyTypes = /** @class */ (function () {
     function privateClassWithPrivateModulePropertyTypes() {
     }

tests/baselines/reference/project/declarationsCascadingImports/amd/m4.js

@@ -8,6 +8,7 @@ define(["require", "exports"], function (require, exports) {
     }());
     exports.d = d;
     ;
+    exports.x = void 0;
     function foo() {
         return new d();
     }