feat(worker): add worker count env variable to processes (#3821)

Add the `STRYKER_MUTATOR_WORKER` environment variable to each worker process. This can be used to prevent use of shared recourses, like a database or files system in your tests.

packages/core/src/checker/checker-child-process-proxy.ts

@@ -6,6 +6,7 @@ import { Disposable } from 'typed-inject';
 import { ChildProcessProxy } from '../child-proxy/child-process-proxy.js';
 import { LoggingClientContext } from '../logging/index.js';
 import { Resource } from '../concurrent/pool.js';
+import { IdGenerator } from '../child-proxy/id-generator.js';
 
 import { CheckerWorker } from './checker-worker.js';
 import { CheckerResource } from './checker-resource.js';
@@ -17,7 +18,8 @@ export class CheckerChildProcessProxy implements CheckerResource, Disposable, Re
     options: StrykerOptions,
     fileDescriptions: FileDescriptions,
     pluginModulePaths: readonly string[],
-    loggingContext: LoggingClientContext
+    loggingContext: LoggingClientContext,
+    idGenerator: IdGenerator
   ) {
     this.childProcess = ChildProcessProxy.create(
       new URL('./checker-worker.js', import.meta.url).toString(),
@@ -27,7 +29,8 @@ export class CheckerChildProcessProxy implements CheckerResource, Disposable, Re
       pluginModulePaths,
       process.cwd(),
       CheckerWorker,
-      options.checkerNodeArgs
+      options.checkerNodeArgs,
+      idGenerator
     );
   }
 

packages/core/src/checker/checker-factory.ts

@@ -2,6 +2,8 @@ import { FileDescriptions, StrykerOptions } from '@stryker-mutator/api/core';
 import { LoggerFactoryMethod } from '@stryker-mutator/api/logging';
 import { commonTokens, tokens } from '@stryker-mutator/api/plugin';
 
+import { IdGenerator } from '../child-proxy/id-generator.js';
+
 import { coreTokens } from '../di/index.js';
 import { LoggingClientContext } from '../logging/logging-client-context.js';
 
@@ -14,20 +16,22 @@ createCheckerFactory.inject = tokens(
   commonTokens.fileDescriptions,
   coreTokens.loggingContext,
   coreTokens.pluginModulePaths,
-  commonTokens.getLogger
+  commonTokens.getLogger,
+  coreTokens.workerIdGenerator
 );
 export function createCheckerFactory(
   options: StrykerOptions,
   fileDescriptions: FileDescriptions,
   loggingContext: LoggingClientContext,
   pluginModulePaths: readonly string[],
-  getLogger: LoggerFactoryMethod
+  getLogger: LoggerFactoryMethod,
+  idGenerator: IdGenerator
 ): () => CheckerFacade {
   return () =>
     new CheckerFacade(
       () =>
         new CheckerRetryDecorator(
-          () => new CheckerChildProcessProxy(options, fileDescriptions, pluginModulePaths, loggingContext),
+          () => new CheckerChildProcessProxy(options, fileDescriptions, pluginModulePaths, loggingContext, idGenerator),
           getLogger(CheckerRetryDecorator.name)
         )
     );

packages/core/src/child-proxy/child-process-proxy.ts

@@ -16,6 +16,7 @@ import { ChildProcessCrashedError } from './child-process-crashed-error.js';
 import { InitMessage, ParentMessage, ParentMessageKind, WorkerMessage, WorkerMessageKind } from './message-protocol.js';
 import { OutOfMemoryError } from './out-of-memory-error.js';
 import { ChildProcessContext } from './child-process-proxy-worker.js';
+import { IdGenerator } from './id-generator.js';
 
 type Func<TS extends any[], R> = (...args: TS) => R;
 
@@ -51,11 +52,23 @@ export class ChildProcessProxy<T> implements Disposable {
     fileDescriptions: FileDescriptions,
     pluginModulePaths: readonly string[],
     workingDirectory: string,
-    execArgv: string[]
+    execArgv: string[],
+    idGenerator: IdGenerator
   ) {
-    this.worker = childProcess.fork(fileURLToPath(new URL('./child-process-proxy-worker.js', import.meta.url)), { silent: true, execArgv });
+    const workerId = idGenerator.next().toString();
+    this.worker = childProcess.fork(fileURLToPath(new URL('./child-process-proxy-worker.js', import.meta.url)), {
+      silent: true,
+      execArgv,
+      env: { STRYKER_MUTATOR_WORKER: workerId, ...process.env },
+    });
     this.initTask = new Task();
-    this.log.debug('Started %s in child process %s%s', namedExport, this.worker.pid, execArgv.length ? ` (using args ${execArgv.join(' ')})` : '');
+    this.log.debug(
+      'Started %s in worker process %s with pid %s %s',
+      namedExport,
+      workerId,
+      this.worker.pid,
+      execArgv.length ? ` (using args ${execArgv.join(' ')})` : ''
+    );
     // Listen to `close`, not `exit`, see https://github.com/stryker-mutator/stryker-js/issues/1634
     this.worker.on('close', this.handleUnexpectedExit);
     this.worker.on('error', this.handleError);
@@ -87,7 +100,8 @@ export class ChildProcessProxy<T> implements Disposable {
     pluginModulePaths: readonly string[],
     workingDirectory: string,
     injectableClass: InjectableClass<ChildProcessContext, R, Tokens>,
-    execArgv: string[]
+    execArgv: string[],
+    idGenerator: IdGenerator
   ): ChildProcessProxy<R> {
     return new ChildProcessProxy(
       modulePath,
@@ -97,7 +111,8 @@ export class ChildProcessProxy<T> implements Disposable {
       fileDescriptions,
       pluginModulePaths,
       workingDirectory,
-      execArgv
+      execArgv,
+      idGenerator
     );
   }
 

packages/core/src/child-proxy/id-generator.ts

@@ -0,0 +1,6 @@
+export class IdGenerator {
+  private id = 0;
+  public next(): number {
+    return this.id++;
+  }
+}

packages/core/src/di/core-tokens.ts

@@ -29,3 +29,4 @@ export const fs = 'fs';
 export const testCoverage = 'testCoverage';
 export const incrementalDiffer = 'incrementalDiffer';
 export const project = 'project';
+export const workerIdGenerator = 'worker-id-generator';

packages/core/src/process/2-mutant-instrumenter-executor.ts

@@ -16,6 +16,8 @@ import { TemporaryDirectory } from '../utils/temporary-directory.js';
 import { UnexpectedExitHandler } from '../unexpected-exit-handler.js';
 import { FileSystem, Project } from '../fs/index.js';
 
+import { IdGenerator } from '../child-proxy/id-generator.js';
+
 import { DryRunContext } from './3-dry-run-executor.js';
 
 export interface MutantInstrumenterContext extends PluginContext {
@@ -58,6 +60,7 @@ export class MutantInstrumenterExecutor {
 
     const checkerPoolProvider = concurrencyTokenProviderProvider
       .provideValue(coreTokens.checkerConcurrencyTokens, concurrencyTokenProvider.checkerToken$)
+      .provideClass(coreTokens.workerIdGenerator, IdGenerator)
       .provideFactory(coreTokens.checkerFactory, createCheckerFactory)
       .provideFactory(coreTokens.checkerPool, createCheckerPool);
     const checkerPool = checkerPoolProvider.resolve(coreTokens.checkerPool);

packages/core/src/process/3-dry-run-executor.ts

@@ -30,6 +30,8 @@ import { CheckerFacade } from '../checker/index.js';
 import { StrictReporter } from '../reporters/index.js';
 import { objectUtils } from '../utils/object-utils.js';
 
+import { IdGenerator } from '../child-proxy/id-generator.js';
+
 import { MutationTestContext } from './4-mutation-test-executor.js';
 import { MutantInstrumenterContext } from './2-mutant-instrumenter-executor.js';
 
@@ -69,8 +71,9 @@ export class DryRunExecutor {
 
   public async execute(): Promise<Injector<MutationTestContext>> {
     const testRunnerInjector = this.injector
-      .provideValue(coreTokens.testRunnerConcurrencyTokens, this.concurrencyTokenProvider.testRunnerToken$)
+      .provideClass(coreTokens.workerIdGenerator, IdGenerator)
       .provideFactory(coreTokens.testRunnerFactory, createTestRunnerFactory)
+      .provideValue(coreTokens.testRunnerConcurrencyTokens, this.concurrencyTokenProvider.testRunnerToken$)
       .provideFactory(coreTokens.testRunnerPool, createTestRunnerPool);
     const testRunnerPool = testRunnerInjector.resolve(coreTokens.testRunnerPool);
     const { result, timing } = await lastValueFrom(testRunnerPool.schedule(of(0), (testRunner) => this.executeDryRun(testRunner)));
@@ -87,7 +90,8 @@ export class DryRunExecutor {
       .provideFactory(coreTokens.testCoverage, TestCoverage.from)
       .provideClass(coreTokens.incrementalDiffer, IncrementalDiffer)
       .provideClass(coreTokens.mutantTestPlanner, MutantTestPlanner)
-      .provideClass(coreTokens.mutationTestReportHelper, MutationTestReportHelper);
+      .provideClass(coreTokens.mutationTestReportHelper, MutationTestReportHelper)
+      .provideClass(coreTokens.workerIdGenerator, IdGenerator);
   }
 
   private validateResultCompleted(runResult: DryRunResult): asserts runResult is CompleteDryRunResult {

packages/core/src/test-runner/child-process-test-runner-proxy.ts

@@ -9,6 +9,8 @@ import { ChildProcessCrashedError } from '../child-proxy/child-process-crashed-e
 import { ChildProcessProxy } from '../child-proxy/child-process-proxy.js';
 import { LoggingClientContext } from '../logging/index.js';
 
+import { IdGenerator } from '../child-proxy/id-generator.js';
+
 import { ChildProcessTestRunnerWorker } from './child-process-test-runner-worker.js';
 
 const MAX_WAIT_FOR_DISPOSE = 2000;
@@ -25,7 +27,8 @@ export class ChildProcessTestRunnerProxy implements TestRunner {
     sandboxWorkingDirectory: string,
     loggingContext: LoggingClientContext,
     pluginModulePaths: readonly string[],
-    private readonly log: Logger
+    private readonly log: Logger,
+    idGenerator: IdGenerator
   ) {
     this.worker = ChildProcessProxy.create(
       new URL('./child-process-test-runner-worker.js', import.meta.url).toString(),
@@ -35,7 +38,8 @@ export class ChildProcessTestRunnerProxy implements TestRunner {
       pluginModulePaths,
       sandboxWorkingDirectory,
       ChildProcessTestRunnerWorker,
-      options.testRunnerNodeArgs
+      options.testRunnerNodeArgs,
+      idGenerator
     );
   }
 

packages/core/src/test-runner/index.ts

@@ -7,6 +7,8 @@ import { LoggingClientContext } from '../logging/index.js';
 import { coreTokens } from '../di/index.js';
 import { Sandbox } from '../sandbox/sandbox.js';
 
+import { IdGenerator } from '../child-proxy/id-generator.js';
+
 import { RetryRejectedDecorator } from './retry-rejected-decorator.js';
 import { TimeoutDecorator } from './timeout-decorator.js';
 import { ChildProcessTestRunnerProxy } from './child-process-test-runner-proxy.js';
@@ -20,15 +22,17 @@ createTestRunnerFactory.inject = tokens(
   coreTokens.sandbox,
   coreTokens.loggingContext,
   commonTokens.getLogger,
-  coreTokens.pluginModulePaths
+  coreTokens.pluginModulePaths,
+  coreTokens.workerIdGenerator
 );
 export function createTestRunnerFactory(
   options: StrykerOptions,
   fileDescriptions: FileDescriptions,
   sandbox: Pick<Sandbox, 'workingDirectory'>,
   loggingContext: LoggingClientContext,
   getLogger: LoggerFactoryMethod,
-  pluginModulePaths: readonly string[]
+  pluginModulePaths: readonly string[],
+  idGenerator: IdGenerator
 ): () => TestRunner {
   if (CommandTestRunner.is(options.testRunner)) {
     return () => new RetryRejectedDecorator(() => new TimeoutDecorator(() => new CommandTestRunner(sandbox.workingDirectory, options)));
@@ -48,7 +52,8 @@ export function createTestRunnerFactory(
                         sandbox.workingDirectory,
                         loggingContext,
                         pluginModulePaths,
-                        getLogger(ChildProcessTestRunnerProxy.name)
+                        getLogger(ChildProcessTestRunnerProxy.name),
+                        idGenerator
                       )
                   ),
                 options

packages/core/test/integration/checker/create-checker-factory.it.spec.ts

@@ -10,6 +10,8 @@ import { CheckerFacade, createCheckerFactory } from '../../../src/checker/index.
 import { coreTokens } from '../../../src/di/index.js';
 import { LoggingClientContext } from '../../../src/logging/index.js';
 
+import { IdGenerator } from '../../../src/child-proxy/id-generator.js';
+
 import { TwoTimesTheCharm } from './additional-checkers.js';
 
 describe(`${createCheckerFactory.name} integration`, () => {
@@ -34,6 +36,7 @@ describe(`${createCheckerFactory.name} integration`, () => {
     createSut = testInjector.injector
       .provideValue(coreTokens.loggingContext, loggingContext)
       .provideValue(coreTokens.pluginModulePaths, pluginModulePaths)
+      .provideClass(coreTokens.workerIdGenerator, IdGenerator)
       .injectFunction(createCheckerFactory);
   });
 

packages/core/test/integration/child-proxy/child-process-proxy.it.spec.ts

@@ -16,6 +16,8 @@ import { currentLogMock } from '../../helpers/log-mock.js';
 import { Mock } from '../../helpers/producers.js';
 import { sleep } from '../../helpers/test-utils.js';
 
+import { IdGenerator } from '../../../src/child-proxy/id-generator.js';
+
 import { Echo } from './echo.js';
 
 describe(ChildProcessProxy.name, () => {
@@ -25,6 +27,7 @@ describe(ChildProcessProxy.name, () => {
   let fileDescriptions: FileDescriptions;
   const testRunnerName = 'echoRunner';
   const workingDir = '..';
+  const idGenerator: IdGenerator = new IdGenerator();
 
   beforeEach(async () => {
     fileDescriptions = {
@@ -35,6 +38,7 @@ describe(ChildProcessProxy.name, () => {
     const port = await loggingServer.listen();
     testInjector.options.testRunner = testRunnerName;
     log = currentLogMock();
+    idGenerator.next();
     sut = ChildProcessProxy.create(
       new URL('./echo.js', import.meta.url).toString(),
       { port, level: LogLevel.Debug },
@@ -46,7 +50,8 @@ describe(ChildProcessProxy.name, () => {
       [
         '--no-warnings', // test if node args are forwarded with this setting, see https://nodejs.org/api/cli.html#cli_no_warnings
         '--max-old-space-size=32', // reduce the amount of time we have to wait on the OOM test
-      ]
+      ],
+      idGenerator
     );
   });
 

packages/core/test/integration/test-runner/create-test-runner-factory.it.spec.ts

@@ -15,6 +15,8 @@ import { sleep } from '../../helpers/test-utils.js';
 import { coreTokens } from '../../../src/di/index.js';
 import { TestRunnerResource } from '../../../src/concurrent/index.js';
 
+import { IdGenerator } from '../../../src/child-proxy/id-generator.js';
+
 import { additionalTestRunnersFileUrl, CounterTestRunner } from './additional-test-runners.js';
 
 describe(`${createTestRunnerFactory.name} integration`, () => {
@@ -45,6 +47,7 @@ describe(`${createTestRunnerFactory.name} integration`, () => {
       .provideValue(coreTokens.sandbox, { workingDirectory: path.dirname(fileURLToPath(import.meta.url)) })
       .provideValue(coreTokens.loggingContext, loggingContext)
       .provideValue(coreTokens.pluginModulePaths, pluginModulePaths)
+      .provideClass(coreTokens.workerIdGenerator, IdGenerator)
       .injectFunction(createTestRunnerFactory);
 
     rmSync(CounterTestRunner.COUNTER_FILE);

packages/core/test/unit/checker/checker-child-process-proxy.spec.ts

@@ -8,20 +8,23 @@ import { CheckerChildProcessProxy } from '../../../src/checker/checker-child-pro
 import { CheckerWorker } from '../../../src/checker/checker-worker.js';
 import { ChildProcessProxy } from '../../../src/child-proxy/child-process-proxy.js';
 import { LoggingClientContext } from '../../../src/logging/index.js';
+import { IdGenerator } from '../../../src/child-proxy/id-generator.js';
 
 describe(CheckerChildProcessProxy.name, () => {
   let childProcessProxyCreateStub: sinon.SinonStubbedMember<typeof ChildProcessProxy.create>;
   let loggingContext: LoggingClientContext;
   let fileDescriptions: FileDescriptions;
+  let idGeneratorStub: sinon.SinonStubbedInstance<IdGenerator>;
 
   beforeEach(() => {
     childProcessProxyCreateStub = sinon.stub(ChildProcessProxy, 'create');
     loggingContext = { port: 4200, level: LogLevel.Fatal };
     fileDescriptions = { 'foo.js': { mutate: true } };
+    idGeneratorStub = sinon.createStubInstance(IdGenerator);
   });
 
   function createSut(): CheckerChildProcessProxy {
-    return new CheckerChildProcessProxy(testInjector.options, fileDescriptions, ['plugin', 'paths'], loggingContext);
+    return new CheckerChildProcessProxy(testInjector.options, fileDescriptions, ['plugin', 'paths'], loggingContext, idGeneratorStub);
   }
 
   describe('constructor', () => {
@@ -36,7 +39,8 @@ describe(CheckerChildProcessProxy.name, () => {
         ['plugin', 'paths'],
         process.cwd(),
         CheckerWorker,
-        []
+        [],
+        idGeneratorStub
       );
     });
     it('should provide arguments', () => {
@@ -51,7 +55,8 @@ describe(CheckerChildProcessProxy.name, () => {
         sinon.match.any,
         sinon.match.any,
         sinon.match.any,
-        ['foo', 'bar']
+        ['foo', 'bar'],
+        idGeneratorStub
       );
     });
   });