fix: resolve named CommonJS imports in dev-server bundling

src/tools/esbuild/node-modules-bundler.spec.ts

@@ -1,4 +1,12 @@
-import { requiresLinking } from './node-modules-bundler.js';
+import {
+  buildSyntheticCjsEntry,
+  canSkipTransform,
+  isCommonjsCandidate,
+  isEsmInteropError,
+  isIdentifierName,
+  planCjsWrap,
+  requiresLinking,
+} from './node-modules-bundler.js';
 
 describe('requiresLinking', () => {
   it('returns true for partially-compiled sources containing a declaration prefix', () => {
@@ -32,3 +40,166 @@ describe('requiresLinking', () => {
     expect(requiresLinking('/node_modules/@angular/common/fesm2022/common.mjs', source)).toBe(true);
   });
 });
+
+describe('canSkipTransform', () => {
+  it('skips .mjs files in dev that do not need linking', () => {
+    expect(canSkipTransform('/node_modules/some-lib/index.mjs', false, false)).toBe(true);
+  });
+
+  it('does not skip .js files in dev (may be CommonJS/UMD)', () => {
+    expect(canSkipTransform('/node_modules/dayjs/dayjs.min.js', false, false)).toBe(false);
+  });
+
+  it('does not skip when advancedOptimizations is enabled', () => {
+    expect(canSkipTransform('/node_modules/some-lib/index.mjs', false, true)).toBe(false);
+  });
+
+  it('does not skip when linking is required', () => {
+    expect(canSkipTransform('/node_modules/my-design-system/fesm2022/lib.mjs', true, false)).toBe(
+      false
+    );
+  });
+});
+
+describe('isIdentifierName', () => {
+  it('accepts valid identifiers', () => {
+    expect(isIdentifierName('isDayjs')).toBe(true);
+    expect(isIdentifierName('_private')).toBe(true);
+    expect(isIdentifierName('$dollar')).toBe(true);
+    expect(isIdentifierName('en')).toBe(true);
+  });
+
+  it('accepts reserved words (valid after `as` in an export clause)', () => {
+    expect(isIdentifierName('default')).toBe(true);
+    expect(isIdentifierName('class')).toBe(true);
+    expect(isIdentifierName('import')).toBe(true);
+  });
+
+  it('rejects non-identifier keys', () => {
+    expect(isIdentifierName('foo-bar')).toBe(false);
+    expect(isIdentifierName('1abc')).toBe(false);
+    expect(isIdentifierName('with space')).toBe(false);
+    expect(isIdentifierName('')).toBe(false);
+  });
+});
+
+describe('planCjsWrap', () => {
+  it('wraps a UMD function whose named exports hang off it (dayjs shape)', () => {
+    const dayjs = (() => undefined) as (() => void) & Record<string, unknown>;
+    dayjs.extend = () => undefined;
+    dayjs.isDayjs = () => undefined;
+    dayjs.locale = () => undefined;
+
+    const plan = planCjsWrap(dayjs);
+    expect(plan.wrap).toBe(true);
+    expect(plan.keys).toEqual(['extend', 'isDayjs', 'locale']);
+  });
+
+  it('wraps a plain CommonJS exports object', () => {
+    expect(planCjsWrap({ Op: 1, AttributeMap: 2 })).toEqual({
+      wrap: true,
+      keys: ['Op', 'AttributeMap'],
+    });
+  });
+
+  it('does not wrap an ES module namespace', () => {
+    const ns = { foo: 1, default: 2, [Symbol.toStringTag]: 'Module' };
+    expect(planCjsWrap(ns)).toEqual({ wrap: false, keys: [] });
+  });
+
+  it('does not wrap a transpiled __esModule interop object', () => {
+    expect(planCjsWrap({ __esModule: true, foo: 1 })).toEqual({ wrap: false, keys: [] });
+  });
+
+  it('does not wrap when there are no re-exportable named keys', () => {
+    expect(planCjsWrap({ default: 1 })).toEqual({ wrap: false, keys: [] });
+    const fn = () => undefined;
+    expect(planCjsWrap(fn)).toEqual({ wrap: false, keys: [] });
+  });
+
+  it('excludes default, __esModule and invalid identifiers but keeps reserved words', () => {
+    const plan = planCjsWrap({ good: 1, class: 2, default: 3, __esModule: false, 'bad-key': 4 });
+    expect(plan.keys).toEqual(['good', 'class']);
+  });
+
+  it('does not wrap primitives or null', () => {
+    expect(planCjsWrap(null)).toEqual({ wrap: false, keys: [] });
+    expect(planCjsWrap(42)).toEqual({ wrap: false, keys: [] });
+    expect(planCjsWrap('str')).toEqual({ wrap: false, keys: [] });
+  });
+});
+
+describe('buildSyntheticCjsEntry', () => {
+  it('re-exports default plus each named binding via an alias export clause', () => {
+    const out = buildSyntheticCjsEntry('/abs/dayjs.min.js', ['isDayjs', 'extend']);
+    expect(out).toBe(
+      [
+        'import _nfDefault from "/abs/dayjs.min.js";',
+        'export default _nfDefault;',
+        'const _nf0 = _nfDefault["isDayjs"];',
+        'const _nf1 = _nfDefault["extend"];',
+        'export { _nf0 as isDayjs, _nf1 as extend };',
+        '',
+      ].join('\n')
+    );
+  });
+
+  it('re-exports a reserved-word key without escaping (valid after `as`)', () => {
+    const out = buildSyntheticCjsEntry('/abs/x.js', ['class']);
+    expect(out).toContain('const _nf0 = _nfDefault["class"];');
+    expect(out).toContain('export { _nf0 as class };');
+  });
+
+  it('emits only the default re-export when there are no named keys', () => {
+    const out = buildSyntheticCjsEntry('/abs/x.js', []);
+    expect(out).toBe('import _nfDefault from "/abs/x.js";\nexport default _nfDefault;\n');
+  });
+
+  it('escapes the import path (Windows backslashes)', () => {
+    const out = buildSyntheticCjsEntry('C:\\pkg\\index.js', []);
+    expect(out).toContain('import _nfDefault from "C:\\\\pkg\\\\index.js";');
+  });
+});
+
+describe('isCommonjsCandidate', () => {
+  it('treats .cjs as CommonJS regardless of package type', () => {
+    expect(isCommonjsCandidate('/pkg/index.cjs', undefined)).toBe(true);
+    expect(isCommonjsCandidate('/pkg/index.cjs', 'module')).toBe(true);
+  });
+
+  it('treats .mjs as ESM regardless of package type', () => {
+    expect(isCommonjsCandidate('/pkg/core.mjs', undefined)).toBe(false);
+    expect(isCommonjsCandidate('/pkg/core.mjs', 'commonjs')).toBe(false);
+  });
+
+  it('treats .js as CommonJS unless the nearest package.json is type: module', () => {
+    expect(isCommonjsCandidate('/pkg/dayjs.min.js', undefined)).toBe(true);
+    expect(isCommonjsCandidate('/pkg/index.js', 'commonjs')).toBe(true);
+    expect(isCommonjsCandidate('/pkg/index.js', 'module')).toBe(false);
+  });
+
+  it('does not treat other extensions as CommonJS candidates', () => {
+    expect(isCommonjsCandidate('/pkg/data.json', undefined)).toBe(false);
+    expect(isCommonjsCandidate('/pkg/index.wasm', 'commonjs')).toBe(false);
+  });
+});
+
+describe('isEsmInteropError', () => {
+  it('recognizes require()-of-ESM error codes as benign', () => {
+    expect(isEsmInteropError({ code: 'ERR_REQUIRE_ESM' })).toBe(true);
+    expect(isEsmInteropError({ code: 'ERR_REQUIRE_ASYNC_MODULE' })).toBe(true);
+  });
+
+  it('recognizes ESM-syntax parse failures as benign', () => {
+    expect(isEsmInteropError(new SyntaxError("Unexpected token 'export'"))).toBe(true);
+    expect(isEsmInteropError(new SyntaxError('Cannot use import statement outside a module'))).toBe(
+      true
+    );
+  });
+
+  it('does not mask genuine runtime failures', () => {
+    expect(isEsmInteropError(new ReferenceError('window is not defined'))).toBe(false);
+    expect(isEsmInteropError(new TypeError('Cannot read properties of undefined'))).toBe(false);
+    expect(isEsmInteropError(undefined)).toBe(false);
+  });
+});