fix(@angular/cli): copy packageManager field and yarn config for temp installs

packages/angular/cli/src/package-managers/package-manager-descriptor.ts

@@ -208,6 +208,7 @@ export const SUPPORTED_PACKAGE_MANAGERS = {
     noLockfileFlag: '',
     ignoreScriptsFlag: '--mode=skip-build',
     configFiles: ['.yarnrc.yml', '.yarnrc.yaml'],
+    copyConfigFromProject: true,
     getRegistryOptions: (registry: string) => ({ env: { YARN_NPM_REGISTRY_SERVER: registry } }),
     versionCommand: ['--version'],
     listDependenciesCommand: ['info', '--name-only', '--json'],

packages/angular/cli/src/package-managers/package-manager.ts

@@ -689,8 +689,21 @@ export class PackageManager {
 
     // Some package managers, like yarn classic, do not write a package.json when adding a package.
     // This can cause issues with subsequent `require.resolve` calls.
-    // Writing an empty package.json file beforehand prevents this.
-    await this.host.writeFile(join(workingDirectory, 'package.json'), '{}');
+    // Writing a package.json file beforehand prevents this. To ensure corepack
+    // resolves the correct package manager version, copy the project's packageManager field.
+    let packageManagerVersion: string | undefined;
+    try {
+      packageManagerVersion = await this.getVersion();
+    } catch {
+      // Ignore version lookup errors.
+    }
+    const tempPackageJson = packageManagerVersion
+      ? { packageManager: `${this.name}@${packageManagerVersion}` }
+      : {};
+    await this.host.writeFile(
+      join(workingDirectory, 'package.json'),
+      JSON.stringify(tempPackageJson, null, 2),
+    );
 
     // To prevent pnpm from traversing up the directory tree and modifying the project's workspace lockfile,
     // copy the project's `pnpm-workspace.yaml` (excluding monorepo local overrides/packages)
@@ -711,12 +724,16 @@ export class PackageManager {
       }
     }
 
-    // Copy configuration files if the package manager requires it (e.g., bun).
+    // Copy configuration files if the package manager requires it (e.g., bun, yarn).
     if (this.descriptor.copyConfigFromProject) {
       for (const configFile of this.descriptor.configFiles) {
         try {
           const configPath = join(this.cwd, configFile);
-          await this.host.copyFile(configPath, join(workingDirectory, configFile));
+          let content = await this.host.readFile(configPath);
+          if (this.name === 'yarn') {
+            content = sanitizeYarnRc(content);
+          }
+          await this.host.writeFile(join(workingDirectory, configFile), content);
         } catch {
           // Ignore missing config files.
         }
@@ -829,3 +846,50 @@ function sanitizePnpmWorkspace(content: string): string {
 
   return result.join('\n');
 }
+
+/**
+ * Sanitizes the contents of `.yarnrc.yml` or `.yarnrc.yaml` for temporary package installation.
+ * It removes `yarnPath`, `plugins`, and `nodeLinker` fields, and appends `nodeLinker: node-modules`.
+ * @param content The original Yarn configuration content.
+ * @returns The sanitized Yarn configuration content.
+ */
+function sanitizeYarnRc(content: string): string {
+  const lines = content.split(/\r?\n/);
+  const result: string[] = [];
+  let inBlockToRemove = false;
+  let blockIndent = 0;
+
+  for (const line of lines) {
+    const trimmed = line.trim();
+    if (!trimmed) {
+      result.push(line);
+      continue;
+    }
+
+    const indent = line.length - line.trimStart().length;
+
+    if (inBlockToRemove) {
+      if (indent > blockIndent) {
+        continue;
+      }
+      inBlockToRemove = false;
+    }
+
+    if (
+      indent === 0 &&
+      (trimmed.startsWith('yarnPath:') ||
+        trimmed.startsWith('nodeLinker:') ||
+        trimmed.startsWith('plugins:'))
+    ) {
+      inBlockToRemove = true;
+      blockIndent = indent;
+      continue;
+    }
+
+    result.push(line);
+  }
+
+  result.push('nodeLinker: node-modules');
+
+  return result.join('\n');
+}

packages/angular/cli/src/package-managers/package-manager_spec.ts

@@ -193,6 +193,106 @@ describe('PackageManager', () => {
         '',
       );
     });
+
+    it('should copy and sanitize .yarnrc.yml when package manager is yarn and it exists', async () => {
+      const yarnDescriptor = SUPPORTED_PACKAGE_MANAGERS['yarn'];
+      const testHost = new MockHost({
+        '/tmp/project/node_modules': true,
+        '/tmp/project/.yarnrc.yml': [],
+      });
+      const pm = new PackageManager(testHost, '/tmp/project', yarnDescriptor);
+
+      const createTempDirectorySpy = spyOn(testHost, 'createTempDirectory').and.resolveTo(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc',
+      );
+      const writeFileSpy = spyOn(testHost, 'writeFile').and.resolveTo();
+      const mockYarnRcContent = [
+        'yarnPath: .yarn/releases/yarn-4.4.1.cjs',
+        'nodeLinker: pnp',
+        'customOption:',
+        '  nodeLinker: pnp-nested',
+        '  plugins:',
+        '    - nested-plugin',
+        'plugins:',
+        '  - path: .yarn/plugins/@yarnpkg/plugin-typescript.cjs',
+        '    spec: "@yarnpkg/plugin-typescript"',
+        'npmRegistryServer: "https://registry.npmjs.org"',
+      ].join('\n');
+
+      spyOn(testHost, 'readFile').and.callFake(async (filePath) => {
+        if (filePath.replace(/\\/g, '/').endsWith('.yarnrc.yml')) {
+          return mockYarnRcContent;
+        }
+        if (filePath.replace(/\\/g, '/').endsWith('package.json')) {
+          return JSON.stringify({ packageManager: 'yarn@4.4.1' });
+        }
+        throw new Error(`Unexpected readFile call for ${filePath}`);
+      });
+      spyOn(testHost, 'runCommand').and.resolveTo({ stdout: '4.4.1', stderr: '' });
+
+      const { workingDirectory } = await pm.acquireTempPackage('foo@1.0.0');
+
+      expect(workingDirectory).toBe('/tmp/project/node_modules/angular-cli-tmp-packages-abc');
+      expect(createTempDirectorySpy).toHaveBeenCalledWith('/tmp/project/node_modules');
+
+      const expectedYarnRcContent = [
+        'customOption:',
+        '  nodeLinker: pnp-nested',
+        '  plugins:',
+        '    - nested-plugin',
+        'npmRegistryServer: "https://registry.npmjs.org"',
+        'nodeLinker: node-modules',
+      ].join('\n');
+
+      expect(writeFileSpy).toHaveBeenCalledWith(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc/.yarnrc.yml',
+        expectedYarnRcContent,
+      );
+      expect(writeFileSpy).toHaveBeenCalledWith(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc/package.json',
+        JSON.stringify({ packageManager: 'yarn@4.4.1' }, null, 2),
+      );
+    });
+
+    it('should copy packageManager field to temp package.json if version is resolved', async () => {
+      const npmDescriptor = SUPPORTED_PACKAGE_MANAGERS['npm'];
+      const testHost = new MockHost({
+        '/tmp/project/node_modules': true,
+      });
+      const pm = new PackageManager(testHost, '/tmp/project', npmDescriptor);
+
+      spyOn(testHost, 'createTempDirectory').and.resolveTo(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc',
+      );
+      const writeFileSpy = spyOn(testHost, 'writeFile').and.resolveTo();
+      spyOn(testHost, 'runCommand').and.resolveTo({ stdout: '10.32.1', stderr: '' });
+
+      await pm.acquireTempPackage('foo@1.0.0');
+
+      expect(writeFileSpy).toHaveBeenCalledWith(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc/package.json',
+        JSON.stringify({ packageManager: 'npm@10.32.1' }, null, 2),
+      );
+    });
+
+    it('should write empty package.json if package manager version cannot be resolved', async () => {
+      const npmDescriptor = SUPPORTED_PACKAGE_MANAGERS['npm'];
+      const testHost = new MockHost({ '/tmp/project/node_modules': true });
+      const pm = new PackageManager(testHost, '/tmp/project', npmDescriptor);
+
+      spyOn(testHost, 'createTempDirectory').and.resolveTo(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc',
+      );
+      const writeFileSpy = spyOn(testHost, 'writeFile').and.resolveTo();
+      spyOn(testHost, 'runCommand').and.resolveTo({ stdout: '', stderr: '' });
+
+      await pm.acquireTempPackage('foo@1.0.0');
+
+      expect(writeFileSpy).toHaveBeenCalledWith(
+        '/tmp/project/node_modules/angular-cli-tmp-packages-abc/package.json',
+        '{}',
+      );
+    });
   });
 
   describe('getRegistryMetadata', () => {