#8708 Implement globalSetupPerWorker

Author: eyalroth

packages/jest-runner/src/__tests__/testRunner.test.ts

@@ -20,6 +20,7 @@ jest.mock('jest-worker', () => ({
         end: jest.fn().mockResolvedValue({forceExited: false}),
         getStderr: jest.fn(),
         getStdout: jest.fn(),
+        runInAllWorkers: jest.fn(),
         worker: jest.fn((data, callback) => require(worker)(data, callback)),
       }),
   ),

packages/jest-runner/src/index.ts

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {performance} from 'perf_hooks';
 import chalk from 'chalk';
 import Emittery from 'emittery';
 import pLimit from 'p-limit';
@@ -171,6 +172,16 @@ export default class TestRunner extends EmittingTestRunner {
       });
     });
 
+    if (tests.length > 0) {
+      performance.mark('jest/globalSetupPerWorker:start');
+      await worker.runInAllWorkers('runGlobal', {
+        allTests: tests,
+        globalConfig: this._globalConfig,
+        moduleName: 'globalSetupPerWorker',
+      });
+      performance.mark('jest/globalSetupPerWorker:end');
+    }
+
     const runAllTests = Promise.all(
       tests.map(test =>
         runTestInWorker(test).then(

packages/jest-runner/src/runGlobalHook.ts

@@ -18,7 +18,11 @@ export default async function runGlobalHook({
 }: {
   allTests: Array<Test>;
   globalConfig: Config.GlobalConfig;
-  moduleName: 'globalSetup' | 'globalTeardown';
+  moduleName:
+    | 'globalSetup'
+    | 'globalSetupPerWorker'
+    | 'globalTeardown'
+    | 'globalTeardownPerWorker';
 }): Promise<void> {
   const globalModulePaths = new Set(
     allTests.map(test => test.context.config[moduleName]),

packages/jest-runner/src/testWorker.ts

@@ -9,6 +9,7 @@
 import exit from 'exit-x';
 import type {
   SerializableError,
+  Test,
   TestFileEvent,
   TestResult,
 } from '@jest/test-result';
@@ -18,6 +19,7 @@ import {separateMessageFromStack} from 'jest-message-util';
 import type Resolver from 'jest-resolve';
 import Runtime from 'jest-runtime';
 import {messageParent} from 'jest-worker';
+import runGlobalHook from './runGlobalHook';
 import runTest from './runTest';
 import type {ErrorWithCode, TestRunnerSerializedContext} from './types';
 
@@ -114,3 +116,11 @@ export async function worker({
     throw formatError(error);
   }
 }
+
+export async function runGlobal(args: {
+  allTests: Array<Test>;
+  globalConfig: Config.GlobalConfig;
+  moduleName: 'globalSetupPerWorker' | 'globalTeardownPerWorker';
+}): Promise<void> {
+  return await runGlobalHook(args);
+}

packages/jest-worker/src/index.ts

@@ -10,12 +10,15 @@ import {isAbsolute} from 'path';
 import {fileURLToPath} from 'url';
 import Farm from './Farm';
 import WorkerPool from './WorkerPool';
-import type {
-  PoolExitResult,
-  WorkerFarmOptions,
-  WorkerModule,
-  WorkerPoolInterface,
-  WorkerPoolOptions,
+import {
+  CHILD_MESSAGE_CALL,
+  type ChildMessageCall,
+  type OnEnd,
+  type PoolExitResult,
+  type WorkerFarmOptions,
+  type WorkerModule,
+  type WorkerPoolInterface,
+  type WorkerPoolOptions,
 } from './types';
 
 export {default as PriorityQueue} from './PriorityQueue';
@@ -171,6 +174,39 @@ export class Worker {
     return this._workerPool.getStdout();
   }
 
+  async runInAllWorkers(
+    method: string,
+    ...args: Array<unknown>
+  ): Promise<Array<unknown>> {
+    const promises = this._workerPool.getWorkers().map(
+      worker =>
+        new Promise((resolve, reject) => {
+          const request: ChildMessageCall = [
+            CHILD_MESSAGE_CALL,
+            false,
+            method,
+            args,
+          ];
+
+          const onStart = noop;
+
+          const onEnd: OnEnd = (error: Error | null, result: unknown) => {
+            if (error) {
+              reject(error);
+            } else {
+              resolve(result);
+            }
+          };
+
+          const onCustomMessage = noop;
+
+          worker.send(request, onStart, onEnd, onCustomMessage);
+        }),
+    );
+
+    return await Promise.all(promises);
+  }
+
   async start(): Promise<void> {
     await this._workerPool.start();
   }
@@ -184,3 +220,7 @@ export class Worker {
     return this._workerPool.end();
   }
 }
+
+function noop(): void {
+  // noop
+}