feat: support reporters written in ESM

CHANGELOG.md

@@ -2,7 +2,6 @@
 
 ### Features
 
-- `[jest-config, jest-haste-map, jest-resolve, jest-runner, jest-runtime, jest-test-sequencer, jest-transform, jest-types]` [**BREAKING**] Add custom HasteMap class implementation config option ([#11107](https://github.com/facebook/jest/pull/11107))
 - `[babel-jest]` Add async transformation ([#11192](https://github.com/facebook/jest/pull/11192))
 - `[jest-changed-files]` Use '--' to separate paths from revisions ([#11160](https://github.com/facebook/jest/pull/11160))
 - `[jest-circus]` [**BREAKING**] Fail tests when multiple `done()` calls are made ([#10624](https://github.com/facebook/jest/pull/10624))
@@ -13,13 +12,15 @@
 - `[jest-config, jest-runtime]` Support ESM for files other than `.js` and `.mjs` ([#10823](https://github.com/facebook/jest/pull/10823))
 - `[jest-config, jest-runtime]` [**BREAKING**] Use "modern" implementation as default for fake timers ([#10874](https://github.com/facebook/jest/pull/10874) & [#11197](https://github.com/facebook/jest/pull/11197))
 - `[jest-config` Allow passing `forceNodeFilesystemAPI` through to `jest-haste-map` ([#11264](https://github.com/facebook/jest/pull/11264))
+- `[jest-config, jest-haste-map, jest-resolve, jest-runner, jest-runtime, jest-test-sequencer, jest-transform, jest-types]` [**BREAKING**] Add custom HasteMap class implementation config option ([#11107](https://github.com/facebook/jest/pull/11107))
 - `[jest-core]` make `TestWatcher` extend `emittery` ([#10324](https://github.com/facebook/jest/pull/10324))
 - `[jest-core]` Run failed tests interactively the same way we do with snapshots ([#10858](https://github.com/facebook/jest/pull/10858))
 - `[jest-core]` more `TestSequencer` methods can be async ([#10980](https://github.com/facebook/jest/pull/10980))
 - `[jest-core]` Add support for `testSequencer` written in ESM ([#11207](https://github.com/facebook/jest/pull/11207))
 - `[jest-core]` Add support for `globalSetup` and `globalTeardown` written in ESM ([#11267](https://github.com/facebook/jest/pull/11267))
 - `[jest-core]` Add support for `watchPlugins` written in ESM ([#11315](https://github.com/facebook/jest/pull/11315))
 - `[jest-core]` Add support for `runner` written in ESM ([#11232](https://github.com/facebook/jest/pull/11232))
+- `[jest-core]` Add support for `reporters` written in ESM ([#11427](https://github.com/facebook/jest/pull/11427))
 - `[jest-each]` Add support for interpolation with object properties ([#11388](https://github.com/facebook/jest/pull/11388))
 - `[jest-environment-node]` Add AbortController to globals ([#11182](https://github.com/facebook/jest/pull/11182))
 - `[@jest/fake-timers]` Update to `@sinonjs/fake-timers` to v7 ([#11198](https://github.com/facebook/jest/pull/11198))
@@ -116,6 +117,7 @@
 - `[babel-jest]` [**BREAKING**] Migrate to ESM ([#11193](https://github.com/facebook/jest/pull/11193))
 - `[docs]` Correct example using `browser-resolve` ([#11140](https://github.com/facebook/jest/pull/11140))
 - `[docs]` Clarify `timers` configuration property ([#11376](https://github.com/facebook/jest/pull/11376))
+- `[jest, jest-core]` [**BREAKING**] Replace `TestScheduler` export with `createTestScheduler` ([#11427](https://github.com/facebook/jest/pull/11427))
 - `[jest-config]` [**BREAKING**] Remove `enabledTestsMap` config, use `filter` instead ([#10787](https://github.com/facebook/jest/pull/10787))
 - `[jest-console]` [**BREAKING**] Move `root` into `config` and take `GlobalConfig` as mandatory parameter for `getConsoleOutput` ([#10126](https://github.com/facebook/jest/pull/10126))
 - `[jest-console]` Export LogEntry ([#11017](https://github.com/facebook/jest/pull/11017))

e2e/__tests__/customReporters.test.ts

@@ -8,6 +8,7 @@
 import {tmpdir} from 'os';
 import * as path from 'path';
 import {wrap} from 'jest-snapshot-serializer-raw';
+import {onNodeVersions} from '@jest/test-utils';
 import {cleanup, extractSummary, writeFiles} from '../Utils';
 import runJest from '../runJest';
 
@@ -159,4 +160,29 @@ describe('Custom Reporters Integration', () => {
     expect(stderr).toMatch(/ON_RUN_START_ERROR/);
     expect(exitCode).toBe(1);
   });
+
+  onNodeVersions('^12.17.0 || >=13.2.0', () => {
+    test('supports reporter written in ESM', () => {
+      writeFiles(DIR, {
+        '__tests__/test.test.js': `test('test', () => {});`,
+        'package.json': JSON.stringify({
+          jest: {
+            reporters: ['default', '<rootDir>/reporter.mjs'],
+            testEnvironment: 'node',
+          },
+        }),
+        'reporter.mjs': `
+        export default class Reporter {
+          onRunStart() {
+            throw new Error('ON_RUN_START_ERROR');
+          }
+        };
+      `,
+      });
+
+      const {stderr, exitCode} = runJest(DIR);
+      expect(stderr).toMatch(/ON_RUN_START_ERROR/);
+      expect(exitCode).toBe(1);
+    });
+  });
 });

packages/jest-core/src/TestScheduler.ts

@@ -31,7 +31,7 @@ import {formatExecError} from 'jest-message-util';
 import TestRunner, {Test} from 'jest-runner';
 import type {Context} from 'jest-runtime';
 import snapshot = require('jest-snapshot');
-import {interopRequireDefault} from 'jest-util';
+import {requireOrImportModule} from 'jest-util';
 import ReporterDispatcher from './ReporterDispatcher';
 import type TestWatcher from './TestWatcher';
 import {shouldRunInBand} from './testSchedulerHelper';
@@ -49,7 +49,20 @@ export type TestSchedulerContext = {
   changedFiles?: Set<Config.Path>;
   sourcesRelatedToTestsInChangedFiles?: Set<Config.Path>;
 };
-export default class TestScheduler {
+
+export async function createTestScheduler(
+  globalConfig: Config.GlobalConfig,
+  options: TestSchedulerOptions,
+  context: TestSchedulerContext,
+): Promise<TestScheduler> {
+  const scheduler = new TestScheduler(globalConfig, options, context);
+
+  await scheduler._setupReporters();
+
+  return scheduler;
+}
+
+class TestScheduler {
   private readonly _dispatcher: ReporterDispatcher;
   private readonly _globalConfig: Config.GlobalConfig;
   private readonly _options: TestSchedulerOptions;
@@ -64,7 +77,6 @@ export default class TestScheduler {
     this._globalConfig = globalConfig;
     this._options = options;
     this._context = context;
-    this._setupReporters();
   }
 
   addReporter(reporter: Reporter): void {
@@ -337,7 +349,7 @@ export default class TestScheduler {
     );
   }
 
-  private _setupReporters() {
+  async _setupReporters() {
     const {collectCoverage, notify, reporters} = this._globalConfig;
     const isDefault = this._shouldAddDefaultReporters(reporters);
 
@@ -366,7 +378,7 @@ export default class TestScheduler {
     }
 
     if (reporters && Array.isArray(reporters)) {
-      this._addCustomReporters(reporters);
+      await this._addCustomReporters(reporters);
     }
   }
 
@@ -390,17 +402,16 @@ export default class TestScheduler {
     this.addReporter(new SummaryReporter(this._globalConfig));
   }
 
-  private _addCustomReporters(
+  private async _addCustomReporters(
     reporters: Array<string | Config.ReporterConfig>,
   ) {
-    reporters.forEach(reporter => {
+    for (const reporter of reporters) {
       const {options, path} = this._getReporterProps(reporter);
 
-      if (path === 'default') return;
+      if (path === 'default') continue;
 
       try {
-        // TODO: Use `requireAndTranspileModule` for Jest 26
-        const Reporter = interopRequireDefault(require(path)).default;
+        const Reporter = await requireOrImportModule<any>(path, true);
         this.addReporter(new Reporter(this._globalConfig, options));
       } catch (error) {
         error.message =
@@ -410,7 +421,7 @@ export default class TestScheduler {
           error.message;
         throw error;
       }
-    });
+    }
   }
 
   /**

packages/jest-core/src/__tests__/TestScheduler.test.js

@@ -8,7 +8,7 @@
 
 import {SummaryReporter} from '@jest/reporters';
 import {makeProjectConfig} from '@jest/test-utils';
-import TestScheduler from '../TestScheduler';
+import {createTestScheduler} from '../TestScheduler';
 import * as testSchedulerHelper from '../testSchedulerHelper';
 
 jest.mock('@jest/reporters');
@@ -35,8 +35,8 @@ beforeEach(() => {
   spyShouldRunInBand.mockClear();
 });
 
-test('config for reporters supports `default`', () => {
-  const undefinedReportersScheduler = new TestScheduler(
+test('config for reporters supports `default`', async () => {
+  const undefinedReportersScheduler = await createTestScheduler(
     {
       reporters: undefined,
     },
@@ -45,7 +45,7 @@ test('config for reporters supports `default`', () => {
   const numberOfReporters =
     undefinedReportersScheduler._dispatcher._reporters.length;
 
-  const stringDefaultReportersScheduler = new TestScheduler(
+  const stringDefaultReportersScheduler = await createTestScheduler(
     {
       reporters: ['default'],
     },
@@ -55,7 +55,7 @@ test('config for reporters supports `default`', () => {
     numberOfReporters,
   );
 
-  const defaultReportersScheduler = new TestScheduler(
+  const defaultReportersScheduler = await createTestScheduler(
     {
       reporters: [['default', {}]],
     },
@@ -65,7 +65,7 @@ test('config for reporters supports `default`', () => {
     numberOfReporters,
   );
 
-  const emptyReportersScheduler = new TestScheduler(
+  const emptyReportersScheduler = await createTestScheduler(
     {
       reporters: [],
     },
@@ -74,8 +74,8 @@ test('config for reporters supports `default`', () => {
   expect(emptyReportersScheduler._dispatcher._reporters.length).toBe(0);
 });
 
-test('.addReporter() .removeReporter()', () => {
-  const scheduler = new TestScheduler({}, {});
+test('.addReporter() .removeReporter()', async () => {
+  const scheduler = await createTestScheduler({}, {});
   const reporter = new SummaryReporter();
   scheduler.addReporter(reporter);
   expect(scheduler._dispatcher._reporters).toContain(reporter);
@@ -84,7 +84,7 @@ test('.addReporter() .removeReporter()', () => {
 });
 
 test('schedule tests run in parallel per default', async () => {
-  const scheduler = new TestScheduler({}, {});
+  const scheduler = await createTestScheduler({}, {});
   const test = {
     context: {
       config: makeProjectConfig({
@@ -107,7 +107,7 @@ test('schedule tests run in parallel per default', async () => {
 });
 
 test('schedule tests run in serial if the runner flags them', async () => {
-  const scheduler = new TestScheduler({}, {});
+  const scheduler = await createTestScheduler({}, {});
   const test = {
     context: {
       config: makeProjectConfig({
@@ -130,7 +130,7 @@ test('schedule tests run in serial if the runner flags them', async () => {
 });
 
 test('should bail after `n` failures', async () => {
-  const scheduler = new TestScheduler({bail: 2}, {});
+  const scheduler = await createTestScheduler({bail: 2}, {});
   const test = {
     context: {
       config: makeProjectConfig({
@@ -162,7 +162,7 @@ test('should bail after `n` failures', async () => {
 });
 
 test('should not bail if less than `n` failures', async () => {
-  const scheduler = new TestScheduler({bail: 2}, {});
+  const scheduler = await createTestScheduler({bail: 2}, {});
   const test = {
     context: {
       config: makeProjectConfig({
@@ -194,7 +194,7 @@ test('should not bail if less than `n` failures', async () => {
 });
 
 test('should set runInBand to run in serial', async () => {
-  const scheduler = new TestScheduler({}, {});
+  const scheduler = await createTestScheduler({}, {});
   const test = {
     context: {
       config: makeProjectConfig({
@@ -220,7 +220,7 @@ test('should set runInBand to run in serial', async () => {
 });
 
 test('should set runInBand to not run in serial', async () => {
-  const scheduler = new TestScheduler({}, {});
+  const scheduler = await createTestScheduler({}, {});
   const test = {
     context: {
       config: makeProjectConfig({

packages/jest-core/src/jest.ts

@@ -6,7 +6,7 @@
  */
 
 export {default as SearchSource} from './SearchSource';
-export {default as TestScheduler} from './TestScheduler';
+export {createTestScheduler} from './TestScheduler';
 export {default as TestWatcher} from './TestWatcher';
 export {runCLI} from './cli';
 export {default as getVersion} from './version';

packages/jest-core/src/runJest.ts

@@ -24,7 +24,7 @@ import {requireOrImportModule, tryRealpath} from 'jest-util';
 import {JestHook, JestHookEmitter} from 'jest-watcher';
 import type FailedTestsCache from './FailedTestsCache';
 import SearchSource from './SearchSource';
-import TestScheduler, {TestSchedulerContext} from './TestScheduler';
+import {TestSchedulerContext, createTestScheduler} from './TestScheduler';
 import type TestWatcher from './TestWatcher';
 import collectNodeHandles, {HandleCollectionResult} from './collectHandles';
 import getNoTestsFoundMessage from './getNoTestsFoundMessage';
@@ -268,11 +268,13 @@ export default async function runJest({
     }
   }
 
-  const results = await new TestScheduler(
+  const scheduler = await createTestScheduler(
     globalConfig,
     {startRun},
     testSchedulerContext,
-  ).scheduleTests(allTests, testWatcher);
+  );
+
+  const results = await scheduler.scheduleTests(allTests, testWatcher);
 
   await sequencer.cacheResults(allTests, results);
 

packages/jest/src/jest.ts

@@ -7,8 +7,8 @@
 
 export {
   SearchSource,
-  TestScheduler,
   TestWatcher,
+  createTestScheduler,
   getVersion,
   runCLI,
 } from '@jest/core';