fix: treat module as normal variable in ESM

Author: fi3ework

packages/core/src/config.ts

@@ -602,7 +602,7 @@ const composeFormatConfig = ({
   bundle?: boolean;
   umdName?: Rspack.LibraryName;
 }): EnvironmentConfig => {
-  const jsParserOptions = {
+  const jsParserOptions: Record<string, Rspack.JavascriptParserOptions> = {
     cjs: {
       requireResolve: false,
       requireDynamic: false,
@@ -611,11 +611,14 @@ const composeFormatConfig = ({
     esm: {
       importMeta: false,
       importDynamic: false,
+      commonjs: {
+        exports: 'skipInEsm',
+      },
     },
     others: {
       worker: false,
     },
-  } as const;
+  };
 
   // The built-in Rslib plugin will apply to all formats except the `mf` format.
   // The `mf` format functions more like an application than a library and requires additional webpack runtime.

packages/core/tests/__snapshots__/config.test.ts.snap

@@ -461,6 +461,9 @@ exports[`Should compose create Rsbuild config correctly > Merge Rsbuild config i
         typeReexportsPresence: 'tolerant',
         importMeta: false,
         importDynamic: false,
+        commonjs: {
+          exports: 'skipInEsm'
+        },
         requireResolve: false,
         requireDynamic: false,
         requireAsExpression: false,
@@ -1158,6 +1161,9 @@ exports[`Should compose create Rsbuild config correctly > Merge Rsbuild config i
         typeReexportsPresence: 'tolerant',
         importMeta: false,
         importDynamic: false,
+        commonjs: {
+          exports: 'skipInEsm'
+        },
         requireResolve: false,
         requireDynamic: false,
         requireAsExpression: false,
@@ -3658,6 +3664,9 @@ exports[`Should compose create Rsbuild config correctly > Merge Rsbuild config i
             "module": {
               "parser": {
                 "javascript": {
+                  "commonjs": {
+                    "exports": "skipInEsm",
+                  },
                   "importDynamic": false,
                   "importMeta": false,
                   "requireAsExpression": false,
@@ -3944,6 +3953,9 @@ exports[`Should compose create Rsbuild config correctly > Merge Rsbuild config i
             "module": {
               "parser": {
                 "javascript": {
+                  "commonjs": {
+                    "exports": "skipInEsm",
+                  },
                   "importDynamic": false,
                   "importMeta": false,
                   "requireAsExpression": false,

pnpm-lock.yaml

@@ -114,32 +114,18 @@ test('throw error when using mf with `bundle: false`', async () => {
   );
 });
 
-test("API plugin's api should be skipped in parser", async () => {
-  const fixturePath = path.resolve(__dirname, 'api-plugin');
-  const { entries } = await buildAndGetResults({
+test('ESM interop should be correct', async () => {
+  const fixturePath = path.resolve(__dirname, 'esm-interop');
+  const { entryFiles } = await buildAndGetResults({
     fixturePath,
   });
 
-  expect(entries.esm).toMatchInlineSnapshot(`
-		"const a = require.cache;
-		const b = require.extensions;
-		const c = require.config;
-		const d = require.version;
-		const e = require.include;
-		const f = require.onError;
-		export { a, b, c, d, e, f };
-		"
-	`);
-
-  expect(entries.cjs).toContain('const a = require.cache;');
-  expect(entries.cjs).toContain('const b = require.extensions;');
-  expect(entries.cjs).toContain('const c = require.config;');
-  expect(entries.cjs).toContain('const d = require.version;');
-  expect(entries.cjs).toContain('const e = require.include;');
-  expect(entries.cjs).toContain('const f = require.onError;');
+  const cjsOutput = await import(entryFiles.cjs);
+  expect(typeof cjsOutput.default.path1.basename).toBe('function');
+  expect(cjsOutput.default.path1).toBe(cjsOutput.default.path2);
 });
 
-test('ESM interop should be correct', async () => {
+test('`module` should be correctly handled by `parserOptions.commonjs.exports = "skipInEsm"`', async () => {
   const fixturePath = path.resolve(__dirname, 'esm-interop');
   const { entryFiles } = await buildAndGetResults({
     fixturePath,

tests/integration/format/index.test.ts

@@ -0,0 +1,28 @@
+import path from 'node:path';
+import { expect, test } from '@rstest/core';
+import { buildAndGetResults } from 'test-helper';
+
+test("API plugin's api should be skipped in parser", async () => {
+  const fixturePath = path.resolve(__dirname);
+  const { entries } = await buildAndGetResults({
+    fixturePath,
+  });
+
+  expect(entries.esm).toMatchInlineSnapshot(`
+		"const a = require.cache;
+		const b = require.extensions;
+		const c = require.config;
+		const d = require.version;
+		const e = require.include;
+		const f = require.onError;
+		export { a, b, c, d, e, f };
+		"
+	`);
+
+  expect(entries.cjs).toContain('const a = require.cache;');
+  expect(entries.cjs).toContain('const b = require.extensions;');
+  expect(entries.cjs).toContain('const c = require.config;');
+  expect(entries.cjs).toContain('const d = require.version;');
+  expect(entries.cjs).toContain('const e = require.include;');
+  expect(entries.cjs).toContain('const f = require.onError;');
+});

tests/integration/parser-javascript/api-plugin/index.test.ts

@@ -1,5 +1,5 @@
 {
-  "name": "api-plugin-test",
+  "name": "parser-javascript-api-plugin-test",
   "version": "1.0.0",
   "private": true,
   "type": "module"

tests/integration/format/api-plugin/package.json renamed to tests/integration/parser-javascript/api-plugin/package.json

@@ -0,0 +1,7 @@
+const value = () => 42;
+
+// Make the export immutable
+Object.defineProperty(module, 'exports', {
+  enumerable: true,
+  get: value,
+});

tests/integration/format/api-plugin/rslib.config.ts renamed to tests/integration/parser-javascript/api-plugin/rslib.config.ts

@@ -0,0 +1,57 @@
+import path from 'node:path';
+import { expect, test } from '@rstest/core';
+import { buildAndGetResults, queryContent } from 'test-helper';
+
+test('`module` variable should be preserved as-is by `javascript.commonjs.exports = "false"`', async () => {
+  const fixturePath = path.resolve(__dirname);
+  const { contents } = await buildAndGetResults({
+    fixturePath,
+  });
+
+  const esm1 = queryContent(contents.esm, 'm1.mjs', { basename: true });
+  const esm2 = queryContent(contents.esm, 'm2.mjs', { basename: true });
+  const cjs1 = queryContent(contents.cjs, 'm1.js', { basename: true });
+  const cjs2 = queryContent(contents.cjs, 'm2.js', { basename: true });
+
+  expect(
+    (
+      await Promise.all([
+        import(esm1.path),
+        import(esm2.path),
+        import(cjs1.path),
+        import(cjs2.path),
+      ])
+    ).map((m) => m.value),
+  ).toEqual([42, 42, 42, 42]);
+
+  const checksM1 = [
+    'if (module.children) module.children = module.children.filter((item)=>item.filename !== path);',
+    'module.exports = original',
+    'if (module.exports && module.exports.test) return module.exports.test()',
+  ];
+
+  const checksEsm2 = [
+    'if (node_module.children) node_module.children = node_module.children.filter((item)=>item.filename !== path);',
+    'node_module.exports = original',
+    'if (node_module.exports && node_module.exports.test) return node_module.exports.test()',
+  ];
+
+  const checksCjs2 = [
+    'if (external_node_module_default().children) external_node_module_default().children = external_node_module_default().children.filter((item)=>item.filename !== path);',
+    'external_node_module_default().exports = original',
+    'if (external_node_module_default().exports && external_node_module_default().exports.test) return external_node_module_default().exports.test()',
+  ];
+
+  for (const check of checksM1) {
+    expect(esm1.content).toContain(check);
+    expect(cjs1.content).toContain(check);
+  }
+
+  for (const check of checksEsm2) {
+    expect(esm2.content).toContain(check);
+  }
+
+  for (const check of checksCjs2) {
+    expect(cjs2.content).toContain(check);
+  }
+});