fix(yarn): only pass -W to yarn classic

src/packageManager.ts

@@ -50,9 +50,12 @@ class Yarn implements PackageManager {
   name = 'Yarn'
   cli = 'yarn'
   private workspace: boolean
+  private classic = false;
 
-  constructor(rootDir: string) {
+  constructor(rootDir: string, version?: string) {
     this.workspace = this.isWorkspace(rootDir);
+    if (version)
+      this.classic = version.startsWith('0') || version.startsWith('1');
   }
 
   private isWorkspace(rootDir: string) {
@@ -81,7 +84,7 @@ class Yarn implements PackageManager {
   }
 
   installDevDependency(name: string): string {
-    return `yarn add --dev ${this.workspace ? '-W ' : ''}${name}`
+    return `yarn add --dev ${(this.workspace && this.classic) ? '-W ' : ''}${name}`
   }
 
   runPlaywrightTest(args: string): string {
@@ -132,10 +135,13 @@ class PNPM implements PackageManager {
 }
 
 export function determinePackageManager(rootDir: string): PackageManager {
-  if (process.env.npm_config_user_agent) {
-    if (process.env.npm_config_user_agent.includes('yarn'))
-      return new Yarn(rootDir);
-    if (process.env.npm_config_user_agent.includes('pnpm'))
+  const userAgent = process.env.npm_config_user_agent;
+  if (userAgent) {
+    if (userAgent.includes('yarn')) {
+      const yarnVersion = userAgent.match(/yarn\/(\d+\.\d+\.\d+)/)?.[1];
+      return new Yarn(rootDir, yarnVersion);
+    }
+    if (userAgent.includes('pnpm'))
       return new PNPM(rootDir);
   }
   return new NPM();

tests/baseFixtures.ts

@@ -22,6 +22,13 @@ import type { PromptOptions } from '../src/generator';
 
 export type PackageManager = 'npm' | 'pnpm' | 'yarn-classic' | 'yarn-berry';
 
+const userAgents: Record<PackageManager, string | undefined> = {
+  'yarn-classic': 'yarn/1.22.10',
+  'yarn-berry': 'yarn/4.0.0',
+  pnpm: 'pnpm/0.0.0',
+  npm: undefined,
+};
+
 export type TestFixtures = {
   packageManager: PackageManager;
   dir: string;
@@ -82,7 +89,7 @@ export const test = base.extend<TestFixtures>({
         cwd: dir,
         env: {
           ...process.env,
-          'npm_config_user_agent': packageManager.startsWith('yarn') ? 'yarn' : packageManager === 'pnpm' ? 'pnpm/0.0.0' : undefined,
+          npm_config_user_agent: userAgents[packageManager],
           'TEST_OPTIONS': JSON.stringify(options),
         },
       });

tests/integration.spec.ts

@@ -115,7 +115,7 @@ test('should generate in the root of pnpm workspace', async ({ run, packageManag
 });
 
 test('should generate in the root of yarn workspaces', async ({ run, packageManager }) => {
-  test.skip(packageManager !== 'yarn-classic');
+  test.skip(packageManager !== 'yarn-berry' && packageManager !== 'yarn-classic');
 
   const dir = test.info().outputDir;
   fs.mkdirSync(dir, { recursive: true });
@@ -130,12 +130,13 @@ test('should generate in the root of yarn workspaces', async ({ run, packageMana
     fs.mkdirSync(packageDir, { recursive: true });
     childProcess.execSync(`yarn init -y`, { cwd: packageDir });
   }
-  childProcess.execSync(`yarn install`, { cwd: dir });
+  childProcess.execSync(`yarn install`, { cwd: dir, stdio: 'inherit', env: { ...process.env, YARN_ENABLE_IMMUTABLE_INSTALLS: 'false', YARN_ENABLE_HARDENED_MODE: '0' } });
 
   await run([], { installGitHubActions: false, testDir: 'tests', language: 'TypeScript', installPlaywrightDependencies: false, installPlaywrightBrowsers: false });
   assertLockFilesExist(dir, packageManager);
   expect(fs.existsSync(path.join(dir, 'tests/example.spec.ts'))).toBeTruthy();
-  expect(fs.existsSync(path.join(dir, 'node_modules/playwright'))).toBeTruthy();
+  const writesNodeModules = packageManager === 'yarn-classic';
+  expect(fs.existsSync(path.join(dir, 'node_modules/playwright'))).toBe(writesNodeModules);
   expect(fs.existsSync(path.join(dir, 'playwright.config.ts'))).toBeTruthy();
 });