feat(egg-bin): support vitest threads pool mode

Add --pool flag to egg-bin test command (default: threads) and propagate
via EGG_VITEST_POOL env var so @eggjs/mock can auto-switch cluster-client
to worker_threads IPC when running in threads pool.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: killagu

plugins/mock/src/lib/format_options.ts

@@ -88,6 +88,12 @@ export function formatOptions(initOptions?: MockOptions): MockApplicationOptions
     options.cache = false;
   }
 
+  // when running under vitest threads pool, use worker_threads start mode
+  // so egg cluster-client uses thread-based IPC instead of process-based
+  if (!options.startMode && process.env.EGG_VITEST_POOL === 'threads') {
+    options.startMode = 'worker_threads';
+  }
+
   debug('[formatOptions] options: %j', options);
   return options;
 }

plugins/mock/src/lib/types.ts

@@ -52,6 +52,11 @@ export interface MockOptions {
   mockCtxStorage?: boolean;
 
   beforeInit?: (app: any) => Promise<void>;
+
+  /**
+   * Start mode for egg cluster-client
+   */
+  startMode?: 'process' | 'worker_threads';
 }
 
 export interface MockClusterOptions extends MockOptions {

pnpm-lock.yaml

@@ -85,6 +85,7 @@
     "npminstall": "catalog:",
     "rimraf": "catalog:",
     "runscript": "catalog:",
+    "sdk-base": "catalog:",
     "typescript": "catalog:"
   },
   "peerDependencies": {

tools/egg-bin/package.json

@@ -59,6 +59,11 @@ export default class Test<T extends typeof Test> extends BaseCommand<T> {
       default: false,
       char: 'w',
     }),
+    pool: Flags.string({
+      description: 'vitest worker pool type',
+      options: ['forks', 'threads'],
+      default: process.env.EGG_VITEST_POOL ?? 'threads',
+    }),
   };
 
   public async run(): Promise<void> {
@@ -141,6 +146,9 @@ export default class Test<T extends typeof Test> extends BaseCommand<T> {
     // expose timeout to test fixtures (e.g. for testing timeout behavior)
     process.env.EGG_BIN_TIMEOUT = String(flags.timeout);
 
+    // propagate pool mode so downstream code (e.g. @eggjs/mock) can detect it
+    process.env.EGG_VITEST_POOL = flags.pool;
+
     debug('run test with vitest, files: %o, flags: %o', files, flags);
     const config = await this.buildVitestConfig(files);
 
@@ -245,7 +253,7 @@ export default class Test<T extends typeof Test> extends BaseCommand<T> {
       setupFiles,
       runner,
       reporters: [process.env.TEST_REPORTER ?? 'default'],
-      pool: 'forks',
+      pool: flags.pool as 'forks' | 'threads',
       fileParallelism: process.env.EGG_FILE_PARALLELISM !== 'false',
       // vitest 4 moved poolOptions to top-level
       execArgv: [...this.globalExecArgv],

tools/egg-bin/src/commands/test.ts

@@ -117,6 +117,17 @@ describe('test/commands/test.test.ts', () => {
         .end();
     });
 
+    it('should success on ts with --pool threads and cluster-client', async () => {
+      const cwd = getFixtures('example-ts-cluster-client');
+      await coffee
+        .fork(eggBin, ['test', '--pool', 'threads'], { cwd })
+        .debug()
+        .expect('stdout', /index\.test\.ts/)
+        .expect('stdout', /Tests.*passed/)
+        .expect('code', 0)
+        .end();
+    });
+
     it('should success with --bail', async () => {
       await coffee
         .fork(eggBin, ['test', '--bail'], { cwd })