NathanWalker · Oct 21, 2026 · Oct 15, 2026 · Oct 15, 2026 · Oct 15, 2026 · Oct 21, 2026
diff --git a/packages/vite/hmr/server/deps-bundle.spec.ts b/packages/vite/hmr/server/deps-bundle.spec.ts
@@ -199,6 +199,13 @@ describe('collectDepsModuleExportInfo', () => {
 		expect(info.hasDefault).toBe(false);
 	});
 
+	it('reads a minified one-line .mjs as ESM (clsx shape)', () => {
+		const abs = write('min/clsx.mjs', `function r(e){return e}export function clsx(){return r(arguments[0])}export default clsx;`);
+		const info = collectDepsModuleExportInfo(abs, 'ios');
+		expect(info.names).toEqual(['clsx']);
+		expect(info.hasDefault).toBe(true);
+	});
+
 	it('flags UMD factories with no static export names as opaque CJS', () => {
 		const abs = write('umd.js', `!function(e,t){"object"==typeof exports?module.exports=t():e.lib=t()}(this,function(){return {}});\n`);
 		const info = collectDepsModuleExportInfo(abs, 'ios');
@@ -235,11 +242,12 @@ describe('buildDepsShimCode', () => {
 	});
 
 	it('filters reserved words and non-identifier names but keeps Unicode identifiers', () => {
-		const code = buildDepsShimCode('node_modules/pkg-a/index.js', ['ok', 'default', 'class', 'not-an-ident', '\u0275\u0275defineInjectable'], false);
+		const code = buildDepsShimCode('node_modules/pkg-a/index.js', ['ok', 'default', 'class', 'package', 'not-an-ident', '\u0275\u0275defineInjectable'], false);
 		expect(code).toContain('export const ok = ');
 		expect(code).toContain('export const \u0275\u0275defineInjectable = ');
 		expect(code).not.toContain('export const default');
 		expect(code).not.toContain('export const class');
+		expect(code).not.toContain('export const package');
 		expect(code).not.toContain('not-an-ident');
 	});
 });
@@ -595,18 +603,58 @@ describe('createDepsBundleService', () => {
 		expect(cjsShim).toContain('export const eTwo = ');
 	});
 
-	it('serves a default-only shim for bundled opaque CJS (no static export names)', async () => {
-		// pkg-b is `module.exports = { b: 1 }` — statically opaque. Its bundled
-		// namespace is `{ default: { b: 1 } }`, so the shim re-exports exactly
-		// that. Falling through to the per-module transform here would evaluate
-		// the package a SECOND time (the moment-timezone realm split from the
-		// §4.4 flag-on qualification).
+	it('serves a shim for bundled opaque CJS (no static export names), with the names it has when loaded', async () => {
+		// pkg-b is `module.exports = { b: 1 }` — statically opaque. Falling
+		// through to the per-module transform here would evaluate the package a
+		// SECOND time (the moment-timezone realm split from the §4.4 flag-on
+		// qualification).
 		const service = makeService();
 		await service.ensureBuilt();
 		const shim = service.getShimForSpec('/node_modules/pkg-b/index.js');
 		expect(shim).toContain(`import "${DEPS_BUNDLE_PATH}";`);
 		expect(shim).toContain('export default __ns_dep_ns__.default;');
-		expect(shim).not.toContain('export const ');
+		expect(shim).toContain('export const b = __ns_dep_ns__.b;');
+	});
+
+	it('exports the names of CJS and minified ESM entries a line scan cannot see (react, clsx), without loading files that never reference exports (zone.js)', async () => {
+		const root = mkdtempSync(path.join(realpathSync(tmpdir()), 'ns-deps-named-'));
+		try {
+			const write = (rel: string, contents: string) => {
+				mkdirSync(path.dirname(path.join(root, rel)), { recursive: true });
+				writeFileSync(path.join(root, rel), contents);
+			};
+			write('package.json', JSON.stringify({ name: 'fixture-app', version: '1.0.0' }));
+			write('node_modules/react-like/package.json', JSON.stringify({ name: 'react-like', version: '1.0.0', main: 'index.js' }));
+			write('node_modules/react-like/index.js', `if (process.env.NODE_ENV === 'production') {\n  module.exports = require('./cjs/react.production.js');\n} else {\n  module.exports = require('./cjs/react.development.js');\n}\n`);
+			write('node_modules/react-like/cjs/react.production.js', `exports.Fragment = Symbol.for('react.fragment');\nexports.createElement = () => null;\n`);
+			write('node_modules/react-like/cjs/react.development.js', `exports.Fragment = Symbol.for('react.fragment');\nexports.createElement = () => null;\n`);
+			write('node_modules/clsx-like/package.json', JSON.stringify({ name: 'clsx-like', version: '1.0.0', exports: { '.': { import: './dist/clsx.mjs', default: './dist/clsx.js' } } }));
+			write('node_modules/clsx-like/dist/clsx.mjs', `function r(e){return e}export function clsx(){return r(arguments[0])}export default clsx;`);
+			write('node_modules/clsx-like/dist/clsx.js', `function clsx(){}module.exports = clsx;module.exports.clsx = clsx;`);
+			write('node_modules/zone-like/package.json', JSON.stringify({ name: 'zone-like', version: '1.0.0', main: 'zone.js' }));
+			write('node_modules/zone-like/zone.js', `globalThis.__nsZoneLikeLoaded = true;\n`);
+			const service = createDepsBundleService({
+				projectRoot: root,
+				platform: 'ios',
+				mode: 'development',
+				flavor: 'typescript',
+				getRecordedPaths: () => ['/ns/m/node_modules/react-like/index.js', '/ns/m/node_modules/clsx-like/dist/clsx.mjs', '/ns/m/node_modules/zone-like/zone.js'],
+			});
+			await service.ensureBuilt();
+			const reactShim = service.getShimForSpec('/node_modules/react-like/index.js');
+			expect(reactShim).toContain('export const Fragment = __ns_dep_ns__.Fragment;');
+			expect(reactShim).toContain('export const createElement = __ns_dep_ns__.createElement;');
+			expect(reactShim).toContain('export default __ns_dep_ns__.default;');
+			const clsxShim = service.getShimForSpec('/node_modules/clsx-like/dist/clsx.mjs');
+			expect(clsxShim).toContain('export const clsx = __ns_dep_ns__.clsx;');
+			expect(clsxShim).toContain('export default __ns_dep_ns__.default;');
+			const zoneShim = service.getShimForSpec('/node_modules/zone-like/zone.js');
+			expect(zoneShim).toContain('export default __ns_dep_ns__.default;');
+			expect(zoneShim).not.toContain('export const ');
+			expect((globalThis as any).__nsZoneLikeLoaded).toBeUndefined();
+		} finally {
+			rmSync(root, { recursive: true, force: true });
+		}
 	});
 
 	it('falls through to per-module serving for unbundled and non-node_modules specs', async () => {

diff --git a/packages/vite/hmr/server/deps-bundle.ts b/packages/vite/hmr/server/deps-bundle.ts
@@ -73,6 +73,7 @@ import { getAngularLinkerFactory, runAngularLinker } from '../frameworks/angular
 import { getBlockedDeviceNodeModulesReason, isFlavorClientPackageSpecifier, resolveCandidateFilePath } from './websocket-module-specifiers.js';
 import { extractDirectExportedNames, JS_IDENTIFIER_RE, parseExportSpecList } from './websocket-core-bridge.js';
 import { hasExistingDefaultExport } from './ns-core-cjs-shape.js';
+import { getCjsNamedExports } from '../helpers/cjs-named-exports.js';
 import { loadPersistedBootRecording } from './boot-recording.js';
 import { setDeviceModuleHeaders } from './route-helpers.js';
 
@@ -842,14 +843,9 @@ export interface DepsModuleExportInfo {
 	/**
 	 * True for CJS files with `names: null` — UMD factories and
 	 * `module.exports = require('./x')` re-export chains (moment-timezone's
-	 * index.js). esbuild's CJS→ESM interop gives their bundled namespace
-	 * exactly ONE property, `default`, so a default-only shim IS the complete
-	 * export surface — and serving it preserves single-evaluation identity,
-	 * which is load-bearing for patch-style packages that mutate another
-	 * package at evaluation time (`moment.tz.load(...)`). ESM files with
-	 * `names: null` (bare `export * from 'pkg'`) must NOT get this flag:
-	 * their bundled namespace has real named exports the server cannot
-	 * enumerate, so they keep per-module serving.
+	 * index.js). ESM files with `names: null` (bare `export * from 'pkg'`)
+	 * must NOT get this flag: their bundled namespace has real named exports
+	 * the server cannot enumerate, so they keep per-module serving.
 	 */
 	opaqueCjs?: boolean;
 }
@@ -888,8 +884,7 @@ function resolveBareReExportTarget(spec: string, importerPath: string, platform:
 // `Object.defineProperty(exports, "NAME", ...)` assignments (transpiled-to-CJS
 // packages like downsample). UMD factories (`module.exports = fn()`) expose no
 // static names — those are flagged `opaqueCjs` so the shim path can still
-// serve their (default-only) namespace instead of re-evaluating them
-// per-module.
+// serve them from the bundle instead of re-evaluating them per-module.
 const CJS_EXPORT_ASSIGN_RE = /\bexports\.([$_\p{ID_Start}][$\p{ID_Continue}]*)\s*=/gu;
 const CJS_DEFINE_PROPERTY_RE = /\bObject\.defineProperty\(\s*exports\s*,\s*["']([$_\p{ID_Start}][$\p{ID_Continue}]*)["']/gu;
 
@@ -904,6 +899,17 @@ function collectCjsExportInfo(code: string): DepsModuleExportInfo {
 	return { names: Array.from(names).sort(), hasDefault };
 }
 
+// A file that never references `exports` has no CommonJS export surface, and
+// loading it only runs its side effects in the dev server process (zone.js
+// replaces the server's global Promise and timers).
+function loadedCjsExportNames(absPath: string): string[] {
+	try {
+		return /\bexports\b/.test(readFileSync(absPath, 'utf8')) ? getCjsNamedExports(absPath) : [];
+	} catch {
+		return [];
+	}
+}
+
 /**
  * Static export-name discovery for a node_modules file. ESM: direct exports
  * plus recursion through `export * from` chains — relative targets (the
@@ -913,8 +919,8 @@ function collectCjsExportInfo(code: string): DepsModuleExportInfo {
  * interop exposes those names on the bundled namespace at runtime). Returns
  * `names: null` for files whose export surface is not statically enumerable —
  * with two DIFFERENT consequences downstream: CJS/UMD files additionally carry
- * `opaqueCjs: true` and still get a default-only shim (their bundled
- * namespace has nothing but `default`); ESM files with an `export *` target
+ * `opaqueCjs: true` and still get a shim, with names enumerated by loading
+ * the file on the dev server; ESM files with an `export *` target
  * that resolves nowhere on disk keep per-module serving, where the transform
  * pipeline resolves the star through the import map. A BUNDLED file served
  * per-module evaluates a second time, so any resolvable star must be followed.
@@ -928,7 +934,7 @@ export function collectDepsModuleExportInfo(absPath: string, platform: string, s
 	} catch {
 		return { names: null, hasDefault: false };
 	}
-	if (!ESM_SYNTAX_RE.test(code)) return collectCjsExportInfo(code);
+	if (!/\.mjs$/i.test(absPath) && !ESM_SYNTAX_RE.test(code)) return collectCjsExportInfo(code);
 	const names = new Set<string>(extractDirectExportedNames(code));
 	let match: RegExpExecArray | null;
 	const starAsRe = /\bexport\s+\*\s+as\s+([$_\p{ID_Start}][$\p{ID_Continue}]*)\s+from\s+["'][^"']+["']/gu;
@@ -954,7 +960,7 @@ export function collectDepsModuleExportInfo(absPath: string, platform: string, s
 	return { names: Array.from(names).sort(), hasDefault: hasExistingDefaultExport(code) };
 }
 
-const RESERVED_EXPORT_NAMES = new Set(['default', 'break', 'case', 'catch', 'class', 'const', 'continue', 'debugger', 'delete', 'do', 'else', 'enum', 'export', 'extends', 'false', 'finally', 'for', 'function', 'if', 'import', 'in', 'instanceof', 'new', 'null', 'return', 'super', 'switch', 'this', 'throw', 'true', 'try', 'typeof', 'var', 'void', 'while', 'with', 'let', 'static', 'yield', 'await', 'eval', 'arguments', '__ns_dep_ns__']);
+const RESERVED_EXPORT_NAMES = new Set(['default', 'break', 'case', 'catch', 'class', 'const', 'continue', 'debugger', 'delete', 'do', 'else', 'enum', 'export', 'extends', 'false', 'finally', 'for', 'function', 'if', 'import', 'in', 'instanceof', 'new', 'null', 'return', 'super', 'switch', 'this', 'throw', 'true', 'try', 'typeof', 'var', 'void', 'while', 'with', 'let', 'static', 'yield', 'await', 'eval', 'arguments', 'implements', 'interface', 'package', 'private', 'protected', 'public', '__ns_dep_ns__']);
 
 /**
  * Shim served at `/ns/m/node_modules/...` for a bundled module. The static
@@ -1107,14 +1113,11 @@ export function createDepsBundleService(options: CreateDepsBundleServiceOptions)
 				const info: DepsModuleExportInfo = file ? collectDepsModuleExportInfo(file, String(options.platform)) : { names: null, hasDefault: false };
 				if (info.names !== null) {
 					shim = buildDepsShimCode(key, info.names, info.hasDefault);
-				} else if (info.opaqueCjs) {
-					// Statically opaque CJS/UMD (e.g. moment-timezone): the bundled
-					// namespace is `{ default: module.exports }` and nothing else, so
-					// a default-only shim is the COMPLETE surface. Serving the shim
-					// (not the per-module transform) keeps the single bundle
-					// evaluation — patch-style packages that mutate another package
-					// at eval time break if evaluated a second time.
-					shim = buildDepsShimCode(key, [], true);
+				} else if (info.opaqueCjs && file) {
+					// Serving the shim (not the per-module transform) keeps the single
+					// bundle evaluation — patch-style packages that mutate another
+					// package at eval time break if evaluated a second time.
+					shim = buildDepsShimCode(key, loadedCjsExportNames(file), true);
 				}
 			}
 			shimCache.set(spec, shim);