feat(workspace-plugin): recognize .cjs configs + add optional attw target

monosize.config.mjs

@@ -20,6 +20,12 @@ const config = {
       'react-dom': 'ReactDOM',
       'react/compiler-runtime': 'ReactCompilerRuntime',
     };
+    // ESM-first packages emit bare subpath imports (e.g. `use-sync-external-store/shim`) that lack
+    // a file extension. Once measured packages are `type: module`, webpack treats their `lib/` as
+    // ESM and enforces fully-specified imports; disable that so legacy CJS deps still resolve.
+    config.module = config.module ?? {};
+    config.module.rules = config.module.rules ?? [];
+    config.module.rules.push({ test: /\.[cm]?js$/, resolve: { fullySpecified: false } });
     return config;
   }),
   reportResolvers: {

package.json

@@ -32,6 +32,7 @@
   "devDependencies": {
     "@actions/core": "1.9.1",
     "@actions/github": "5.0.3",
+    "@arethetypeswrong/cli": "0.18.3",
     "@babel/core": "7.29.0",
     "@babel/generator": "7.29.1",
     "@babel/parser": "7.29.3",

scripts/monorepo/src/getDependencies.spec.js

@@ -10,62 +10,66 @@ describe(`#getDependencies`, () => {
   it(`should return package/s dependency tree array for all,devDeps and production dependencies`, async () => {
     const deps = await getDependencies(packageName);
 
-    expect(deps.dependencies).toMatchInlineSnapshot(`
+    // graph traversal order is not deterministic across machines; sort by name for a stable snapshot
+    /** @type {(a: { name: string }, b: { name: string }) => number} */
+    const byName = (a, b) => a.name.localeCompare(b.name);
+
+    expect([...deps.dependencies].sort(byName)).toMatchInlineSnapshot(`
       Array [
         Object {
           "dependencyType": "dependencies",
-          "isTopLevel": true,
-          "name": "react-shared-contexts",
+          "isTopLevel": false,
+          "name": "keyboard-keys",
         },
         Object {
           "dependencyType": "dependencies",
           "isTopLevel": true,
-          "name": "react-theme",
+          "name": "react-jsx-runtime",
         },
         Object {
           "dependencyType": "dependencies",
           "isTopLevel": true,
-          "name": "react-utilities",
+          "name": "react-shared-contexts",
         },
         Object {
           "dependencyType": "dependencies",
           "isTopLevel": true,
-          "name": "react-jsx-runtime",
+          "name": "react-theme",
         },
         Object {
           "dependencyType": "dependencies",
-          "isTopLevel": false,
-          "name": "tokens",
+          "isTopLevel": true,
+          "name": "react-utilities",
         },
         Object {
           "dependencyType": "dependencies",
           "isTopLevel": false,
-          "name": "keyboard-keys",
+          "name": "tokens",
         },
       ]
     `);
 
-    expect(deps.devDependencies).toMatchInlineSnapshot(`
+    expect([...deps.devDependencies].sort(byName)).toMatchInlineSnapshot(`
       Array [
         Object {
           "dependencyType": "devDependencies",
-          "isTopLevel": true,
-          "name": "react-conformance",
+          "isTopLevel": false,
+          "name": "eslint-plugin",
         },
         Object {
           "dependencyType": "devDependencies",
-          "isTopLevel": true,
-          "name": "react-conformance-griffel",
+          "isTopLevel": false,
+          "name": "eslint-plugin-react-components",
         },
         Object {
           "dependencyType": "devDependencies",
-          "isTopLevel": false,
-          "name": "eslint-plugin",
+          "isTopLevel": true,
+          "name": "react-conformance",
         },
         Object {
           "dependencyType": "devDependencies",
-          "isTopLevel": false,
-          "name": "eslint-plugin-react-components",
+          "isTopLevel": true,
+          "name": "react-conformance-griffel",
         },
         Object {
           "dependencyType": "devDependencies",
@@ -82,7 +86,7 @@ describe(`#getDependencies`, () => {
 
     expect(packageInfo.absoluteRootPath).toEqual(expect.stringContaining('packages/react-components/react-text'));
     expect(packageInfo?.dependencies).toEqual(expect.any(Object));
-    expect(packageInfo?.main).toEqual('lib-commonjs/index.js');
+    expect(packageInfo?.main).toEqual('lib-commonjs/index.cjs');
     expect(packageInfo?.module).toEqual('lib/index.js');
 
     const depResultWithoutProjectScope = await getDependencies('react-text');

tools/workspace-plugin/src/plugins/workspace-plugin.spec.ts

@@ -49,6 +49,37 @@ describe(`workspace-plugin`, () => {
     expect(getTargetsNames(results)).toEqual(['clean', 'format', 'type-check']);
   });
 
+  it('should add the test target when a jest.config.cjs (type:module) exists', async () => {
+    await tempFs.createFiles({
+      'proj/project.json': serializeJson({}),
+      'proj/package.json': serializeJson({ type: 'module' }),
+      'proj/jest.config.cjs': 'module.exports = {}',
+    });
+    const results = await createNodesFunction(['proj/project.json'], options, context);
+
+    expect(getTargetsNames(results)).toContain('test');
+  });
+
+  it('should add an optional attw target only when package.json declares exports', async () => {
+    await tempFs.createFiles({
+      'with-exports/project.json': serializeJson({ projectType: 'library', tags: ['vNext'] }),
+      'with-exports/package.json': serializeJson({ exports: { '.': './lib/index.js' } }),
+      'no-exports/project.json': serializeJson({ projectType: 'library', tags: ['vNext'] }),
+      'no-exports/package.json': serializeJson({}),
+    });
+
+    const withExports = await createNodesFunction(['with-exports/project.json'], options, context);
+    const noExports = await createNodesFunction(['no-exports/project.json'], options, context);
+
+    expect(getTargetsNames(withExports, 'with-exports')).toContain('attw');
+    expect(getTargets(withExports, 'with-exports')?.attw).toMatchObject({
+      executor: 'nx:run-commands',
+      dependsOn: ['build'],
+      options: { cwd: 'with-exports', command: expect.stringContaining('attw --pack --profile node16') },
+    });
+    expect(getTargetsNames(noExports, 'no-exports')).not.toContain('attw');
+  });
+
   it('should add lint,test task only if configuration exists', async () => {
     await tempFs.createFiles({
       'proj/project.json': serializeJson({}),

tools/workspace-plugin/src/plugins/workspace-plugin.ts

@@ -276,6 +276,11 @@ function buildWorkspaceProjectConfiguration(
       targets[options.verifyPackaging.targetName] = verifyPackagingTarget;
     }
 
+    const attwTarget = buildAttwTarget(projectRoot, config);
+    if (attwTarget) {
+      targets.attw = attwTarget;
+    }
+
     let metadata: WorkspaceTargets['metadata'];
 
     if (isReactProject) {
@@ -405,7 +410,11 @@ function buildTestTarget(
   context: CreateNodesContextV2,
   config: TaskBuilderConfig,
 ): TargetConfiguration<JestConfig.InitialOptions & Pick<RunCommandsOptions, 'cwd'>> | null {
-  if (!existsSync(join(projectRoot, 'jest.config.js')) && !existsSync(join(projectRoot, 'jest.config.ts'))) {
+  if (
+    !existsSync(join(projectRoot, 'jest.config.js')) &&
+    !existsSync(join(projectRoot, 'jest.config.cjs')) &&
+    !existsSync(join(projectRoot, 'jest.config.ts'))
+  ) {
     return null;
   }
 
@@ -430,6 +439,28 @@ function buildTestTarget(
   };
 }
 
+function buildAttwTarget(projectRoot: string, config: TaskBuilderConfig): TargetConfiguration | null {
+  // optional, published-library-only types/exports validation. Not part of `build` or CI gates.
+  if (!config.packageJSON.exports) {
+    return null;
+  }
+
+  return {
+    executor: 'nx:run-commands',
+    cache: true,
+    dependsOn: ['build'],
+    options: {
+      cwd: projectRoot,
+      command: `${config.pmc.exec} attw --pack --profile node16`,
+    },
+    inputs: ['default', { externalDependencies: ['@arethetypeswrong/cli'] }],
+    metadata: {
+      description: 'Validate package types & export map with @arethetypeswrong/cli (optional)',
+      technologies: ['typescript'],
+    },
+  };
+}
+
 function buildLintTarget(
   projectRoot: string,
   options: Required<WorkspacePluginOptions>,
@@ -864,16 +895,22 @@ function buildReactIntegrationTesterProjectConfiguration(
       hasTypeCheck: storybookAdjacent || libraryWithStoriesAdj,
       hasE2E: existsSync(join(projectRootPath, 'cypress.config.ts')) && !storybookAdjacent,
       hasTest:
-        (existsSync(join(projectRootPath, 'jest.config.js')) || existsSync(join(projectRootPath, 'jest.config.ts'))) &&
+        (existsSync(join(projectRootPath, 'jest.config.js')) ||
+          existsSync(join(projectRootPath, 'jest.config.cjs')) ||
+          existsSync(join(projectRootPath, 'jest.config.ts'))) &&
         !storybookAdjacent,
     };
 
-    const ritConfigPathLocal = join(projectRootPath, 'rit.config.js');
+    // web packages ship as `type: module`, so their CommonJS rit config uses `.cjs`; fall back to `.js`
+    const ritConfigPathLocal = [
+      resolve(projectRootPath, 'rit.config.cjs'),
+      resolve(projectRootPath, 'rit.config.js'),
+    ].find(candidate => existsSync(candidate));
 
-    if (existsSync(ritConfigPathLocal)) {
+    if (ritConfigPathLocal) {
       try {
         type RITConfig = { react: Record<string, { runConfig?: Record<string, { configPath: string }> }> };
-        const loaded = require(resolve(projectRootPath, 'rit.config.js'));
+        const loaded = require(ritConfigPathLocal);
         const rit: RITConfig = loaded?.default ?? loaded;
 
         if (rit && typeof rit === 'object' && rit.react && rit.react[reactVersion]) {