Hoist initial assignment to exported names in cjs to they are not blocked by bindings made by __exportStar (#37093)

* Hoist initial assignment to exported names in cjs to they are not blocked by bindings made by __exportStar

* Copy hoisted identifiers so they do not create sourcemaps

* Accept updated baselines

Author: weswigham

src/compiler/transformers/module/module.ts

@@ -96,6 +96,9 @@ namespace ts {
             if (shouldEmitUnderscoreUnderscoreESModule()) {
                 append(statements, createUnderscoreUnderscoreESModule());
             }
+            if (length(currentModuleInfo.exportedNames)) {
+                append(statements, createExpressionStatement(reduceLeft(currentModuleInfo.exportedNames, (prev, nextId) => createAssignment(createPropertyAccess(createIdentifier("exports"), createIdentifier(idText(nextId))), prev), createVoidZero() as Expression)));
+            }
 
             append(statements, visitNode(currentModuleInfo.externalHelpersImportDeclaration, sourceElementVisitor, isStatement));
             addRange(statements, visitNodes(node.statements, sourceElementVisitor, isStatement, statementOffset));
@@ -414,6 +417,9 @@ namespace ts {
             if (shouldEmitUnderscoreUnderscoreESModule()) {
                 append(statements, createUnderscoreUnderscoreESModule());
             }
+            if (length(currentModuleInfo.exportedNames)) {
+                append(statements, createExpressionStatement(reduceLeft(currentModuleInfo.exportedNames, (prev, nextId) => createAssignment(createPropertyAccess(createIdentifier("exports"), createIdentifier(idText(nextId))), prev), createVoidZero() as Expression)));
+            }
 
             // Visit each statement of the module body.
             append(statements, visitNode(currentModuleInfo.externalHelpersImportDeclaration, sourceElementVisitor, isStatement));
@@ -1188,7 +1194,7 @@ namespace ts {
 
                         variables = append(variables, variable);
                     }
-                    else {
+                    else if (variable.initializer) {
                         expressions = append(expressions, transformInitializedVariable(variable));
                     }
                 }

src/testRunner/unittests/tsserver/compileOnSave.ts

@@ -714,7 +714,7 @@ namespace ts.projectSystem {
 
             const expectedEmittedFileName = "/a/b/f1.js";
             assert.isTrue(host.fileExists(expectedEmittedFileName));
-            assert.equal(host.readFile(expectedEmittedFileName), `"use strict";\r\nexports.__esModule = true;\r\nfunction Foo() { return 10; }\r\nexports.Foo = Foo;\r\n`);
+            assert.equal(host.readFile(expectedEmittedFileName), `"use strict";\r\nexports.__esModule = true;\r\nexports.Foo = void 0;\r\nfunction Foo() { return 10; }\r\nexports.Foo = Foo;\r\n`);
         });
 
         it("shoud not emit js files in external projects", () => {