Consider the commonjs module indicator as a module indicator (microsoft#18490)

weswigham · web-flow · commit 16efae24338f · 2017-11-09T16:49:04.000-08:00
* Consider the commonjs module indicator as an indicator that something is effectively an external module

* Only use commonjs module indicator when targeting commonjs
diff --git a/src/compiler/transformers/module/module.ts b/src/compiler/transformers/module/module.ts
@@ -57,7 +57,7 @@ namespace ts {
          * @param node The SourceFile node.
          */
         function transformSourceFile(node: SourceFile) {
-            if (node.isDeclarationFile || !(isExternalModule(node) || compilerOptions.isolatedModules || node.transformFlags & TransformFlags.ContainsDynamicImport)) {
+            if (node.isDeclarationFile || !(isEffectiveExternalModule(node, compilerOptions) || node.transformFlags & TransformFlags.ContainsDynamicImport)) {
                 return node;
             }
 
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
@@ -461,7 +461,7 @@ namespace ts {
     }
 
     export function isEffectiveExternalModule(node: SourceFile, compilerOptions: CompilerOptions) {
-        return isExternalModule(node) || compilerOptions.isolatedModules;
+        return isExternalModule(node) || compilerOptions.isolatedModules || ((getEmitModuleKind(compilerOptions) === ModuleKind.CommonJS) && !!node.commonJsModuleIndicator);
     }
 
     /* @internal */
diff --git a/tests/baselines/reference/javascriptCommonjsModule.js b/tests/baselines/reference/javascriptCommonjsModule.js
@@ -0,0 +1,23 @@
+//// [index.js]
+class Foo {}
+
+class Bar extends Foo {}
+
+module.exports = Bar;
+
+
+//// [index.js]
+var tslib_1 = require("tslib");
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+var Bar = /** @class */ (function (_super) {
+    tslib_1.__extends(Bar, _super);
+    function Bar() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return Bar;
+}(Foo));
+module.exports = Bar;
diff --git a/tests/baselines/reference/javascriptCommonjsModule.symbols b/tests/baselines/reference/javascriptCommonjsModule.symbols
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/index.js ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+class Bar extends Foo {}
+>Bar : Symbol(Bar, Decl(index.js, 0, 12))
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+module.exports = Bar;
+>module : Symbol(export=, Decl(index.js, 2, 24))
+>exports : Symbol(export=, Decl(index.js, 2, 24))
+>Bar : Symbol(Bar, Decl(index.js, 0, 12))
+
diff --git a/tests/baselines/reference/javascriptCommonjsModule.types b/tests/baselines/reference/javascriptCommonjsModule.types
@@ -0,0 +1,15 @@
+=== tests/cases/compiler/index.js ===
+class Foo {}
+>Foo : Foo
+
+class Bar extends Foo {}
+>Bar : Bar
+>Foo : Foo
+
+module.exports = Bar;
+>module.exports = Bar : typeof Bar
+>module.exports : any
+>module : any
+>exports : any
+>Bar : typeof Bar
+
diff --git a/tests/cases/compiler/javascriptCommonjsModule.ts b/tests/cases/compiler/javascriptCommonjsModule.ts
@@ -0,0 +1,11 @@
+// @allowJS: true
+// @outDir: ./out
+// @module: commonjs
+// @noEmitHelpers: true
+// @importHelpers: true
+// @filename: index.js
+class Foo {}
+
+class Bar extends Foo {}
+
+module.exports = Bar;

Original file line number	Diff line number	Diff line change
`@@ -57,7 +57,7 @@ namespace ts {`
`57`	`57`	`* @param node The SourceFile node.`
`58`	`58`	`*/`
`59`	`59`	`function transformSourceFile(node: SourceFile) {`
`60`		`- if (node.isDeclarationFile \|\| !(isExternalModule(node) \|\| compilerOptions.isolatedModules \|\| node.transformFlags & TransformFlags.ContainsDynamicImport)) {`
	`60`	`+ if (node.isDeclarationFile \|\| !(isEffectiveExternalModule(node, compilerOptions) \|\| node.transformFlags & TransformFlags.ContainsDynamicImport)) {`
`61`	`61`	`return node;`
`62`	`62`	`}`
`63`	`63`
Original file line number	Diff line number	Diff line change
`@@ -461,7 +461,7 @@ namespace ts {`
`461`	`461`	`}`
`462`	`462`
`463`	`463`	`export function isEffectiveExternalModule(node: SourceFile, compilerOptions: CompilerOptions) {`
`464`		`- return isExternalModule(node) \|\| compilerOptions.isolatedModules;`
	`464`	`+ return isExternalModule(node) \|\| compilerOptions.isolatedModules \|\| ((getEmitModuleKind(compilerOptions) === ModuleKind.CommonJS) && !!node.commonJsModuleIndicator);`
`465`	`465`	`}`
`466`	`466`
`467`	`467`	`/* @internal */`