fix(core): FileLoader support .mjs as first-class

packages/core/src/loader/file_loader.ts

@@ -64,7 +64,7 @@ export interface FileLoaderParseItem {
 type NormalizedFileLoaderOptions = FileLoaderOptions & Required<Pick<FileLoaderOptions, 'caseStyle' | 'loaderFS'>>;
 
 function getDefaultFileLoaderMatch(): string[] {
-  return isSupportTypeScript() ? ['**/*.(js|ts)', '!**/*.d.ts'] : ['**/*.js'];
+  return isSupportTypeScript() ? ['**/*.(js|ts|mjs|cjs)', '!**/*.d.ts'] : ['**/*.{js,mjs,cjs}'];
 }
 
 /**
@@ -220,8 +220,12 @@ export class FileLoader {
       for (const filepath of filepaths) {
         const fullpath = path.join(directory, filepath);
         if (!this.options.loaderFS.stat(fullpath).isFile()) continue;
-        if (filepath.endsWith('.js')) {
-          const filepathTs = filepath.replace(/\.js$/, '.ts');
+        // A compiled `.js` / `.mjs` / `.cjs` sitting next to its `.ts` source (e.g. `tsc`
+        // or `tsdown` output kept in the same directory during development) must not be
+        // loaded on top of the source file — otherwise both are attached to the same
+        // property and `can't overwrite property` is thrown. The `.ts` source always wins.
+        if (filepath.endsWith('.js') || filepath.endsWith('.mjs') || filepath.endsWith('.cjs')) {
+          const filepathTs = filepath.replace(/\.(?:js|mjs|cjs)$/, '.ts');
           if (filepaths.includes(filepathTs)) {
             debug('[parse] ignore %s, because %s exists', fullpath, filepathTs);
             continue;

packages/core/test/egg-ts.test.ts

@@ -127,6 +127,28 @@ describe('test/egg-ts.test.ts', () => {
     assert(app.serviceClasses.test);
   });
 
+  it('should load mjs/cjs and prefer the ts source over its compiled mjs/cjs', async () => {
+    mm(process.env, 'EGG_TYPESCRIPT', 'true');
+    app = createApp('egg-ts-js');
+
+    // loadService must not throw "can't overwrite property" even though
+    // `dual.ts`+`dual.mjs` and `dualc.ts`+`dualc.cjs` coexist in the directory.
+    await app.loader.loadService();
+
+    // standalone `.mjs` / `.cjs` are scanned and loaded as first-class files
+    assert(app.serviceClasses.pureMjs);
+    assert.equal(app.serviceClasses.pureMjs.loadedFrom, 'mjs');
+    assert(app.serviceClasses.pureCjs);
+    assert.equal(app.serviceClasses.pureCjs.loadedFrom, 'cjs');
+
+    // priority: when a `.ts` source and its compiled `.mjs`/`.cjs` coexist,
+    // the `.ts` source wins and the compiled sibling is ignored.
+    assert(app.serviceClasses.dual);
+    assert.equal(app.serviceClasses.dual.loadedFrom, 'ts');
+    assert(app.serviceClasses.dualc);
+    assert.equal(app.serviceClasses.dualc.loadedFrom, 'ts');
+  });
+
   it('should auto require tsconfig-paths', async () => {
     mm(process.env, 'EGG_TYPESCRIPT', 'true');
     app = createApp('egg-ts-js-tsconfig-paths');

packages/core/test/fixtures/egg-ts-js/app/service/dual.mjs

@@ -0,0 +1,7 @@
+// Compiled output of `dual.ts`. Must be ignored while `dual.ts` exists.
+export default class DualServiceMjs {
+  static loadedFrom = 'mjs';
+  which() {
+    return 'mjs';
+  }
+}

packages/core/test/fixtures/egg-ts-js/app/service/dual.ts

@@ -0,0 +1,8 @@
+// `dual.ts` + `dual.mjs` coexist (compiled output kept beside the source).
+// The `.ts` source must win; `dual.mjs` must be ignored.
+module.exports = class DualService {
+  static loadedFrom = 'ts';
+  which() {
+    return 'ts';
+  }
+};

packages/core/test/fixtures/egg-ts-js/app/service/dualc.cjs

@@ -0,0 +1,7 @@
+// Compiled output of `dualc.ts`. Must be ignored while `dualc.ts` exists.
+module.exports = class DualcServiceCjs {
+  static loadedFrom = 'cjs';
+  which() {
+    return 'cjs';
+  }
+};

packages/core/test/fixtures/egg-ts-js/app/service/dualc.ts

@@ -0,0 +1,7 @@
+// `dualc.ts` + `dualc.cjs` coexist. The `.ts` source must win; `dualc.cjs` ignored.
+module.exports = class DualcService {
+  static loadedFrom = 'ts';
+  which() {
+    return 'ts';
+  }
+};

packages/core/test/fixtures/egg-ts-js/app/service/pureCjs.cjs

@@ -0,0 +1,6 @@
+module.exports = class PureCjsService {
+  static loadedFrom = 'cjs';
+  cjs() {
+    return 'from cjs service';
+  }
+};

packages/core/test/fixtures/egg-ts-js/app/service/pureMjs.mjs

@@ -0,0 +1,6 @@
+export default class PureMjsService {
+  static loadedFrom = 'mjs';
+  mjs() {
+    return 'from mjs service';
+  }
+}