feat: add support for snapshot matchers in concurrent tests (#14139)

Author: dmitri-gb

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### Features
 
+- `[jest-circus, jest-snapshot]` Add support for snapshot matchers in concurrent tests ([#14139](https://github.com/jestjs/jest/pull/14139))
 - `[jest-cli]` Include type definitions to generated config files ([#14078](https://github.com/facebook/jest/pull/14078))
 - `[jest-snapshot]` Support arrays as property matchers ([#14025](https://github.com/facebook/jest/pull/14025))
 - `[jest-core, jest-circus, jest-reporter, jest-runner]` Added support for reporting about start individual test cases using jest-circus ([#14174](https://github.com/jestjs/jest/pull/14174))

e2e/__tests__/snapshot-concurrent.test.ts

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {skipSuiteOnJasmine} from '@jest/test-utils';
+import runJest from '../runJest';
+
+skipSuiteOnJasmine();
+
+test('Snapshots get correct names in concurrent tests', () => {
+  const result = runJest('snapshot-concurrent', ['--ci']);
+  expect(result.exitCode).toBe(0);
+});

e2e/snapshot-concurrent/__tests__/__snapshots__/works.test.js.snap

@@ -0,0 +1,29 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`A a 1`] = `"Aa1"`;
+
+exports[`A a 2`] = `"Aa2"`;
+
+exports[`A b 1`] = `"Ab1"`;
+
+exports[`A b 2`] = `"Ab2"`;
+
+exports[`A c 1`] = `"Ac1"`;
+
+exports[`A c 2`] = `"Ac2"`;
+
+exports[`A d 1`] = `"Ad1"`;
+
+exports[`A d 2`] = `"Ad2"`;
+
+exports[`B 1`] = `"B1"`;
+
+exports[`B 2`] = `"B2"`;
+
+exports[`C 1`] = `"C1"`;
+
+exports[`C 2`] = `"C2"`;
+
+exports[`D 1`] = `"D1"`;
+
+exports[`D 2`] = `"D2"`;

e2e/snapshot-concurrent/__tests__/works.test.js

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+'use strict';
+
+const sleep = ms => new Promise(r => setTimeout(r, ms));
+
+describe('A', () => {
+  it.concurrent('a', async () => {
+    await sleep(100);
+    expect('Aa1').toMatchSnapshot();
+    expect('Aa2').toMatchSnapshot();
+  });
+
+  it.concurrent('b', async () => {
+    await sleep(10);
+    expect('Ab1').toMatchSnapshot();
+    expect('Ab2').toMatchSnapshot();
+  });
+
+  it.concurrent('c', async () => {
+    expect('Ac1').toMatchSnapshot();
+    expect('Ac2').toMatchSnapshot();
+  });
+
+  it('d', () => {
+    expect('Ad1').toMatchSnapshot();
+    expect('Ad2').toMatchSnapshot();
+  });
+});
+
+it.concurrent('B', async () => {
+  await sleep(10);
+  expect('B1').toMatchSnapshot();
+  expect('B2').toMatchSnapshot();
+});
+
+it('C', () => {
+  expect('C1').toMatchSnapshot();
+  expect('C2').toMatchSnapshot();
+});
+
+it.concurrent('D', async () => {
+  expect('D1').toMatchSnapshot();
+  expect('D2').toMatchSnapshot();
+});

e2e/snapshot-concurrent/package.json

@@ -0,0 +1,5 @@
+{
+  "jest": {
+    "testEnvironment": "node"
+  }
+}

packages/expect/package.json

@@ -20,6 +20,7 @@
   },
   "dependencies": {
     "@jest/expect-utils": "workspace:^",
+    "@types/node": "*",
     "jest-get-type": "workspace:^",
     "jest-matcher-utils": "workspace:^",
     "jest-message-util": "workspace:^",

packages/expect/src/types.ts

@@ -6,6 +6,7 @@
  *
  */
 
+import type {AsyncLocalStorage} from 'async_hooks';
 import type {EqualsFunction, Tester} from '@jest/expect-utils';
 import type * as jestMatcherUtils from 'jest-matcher-utils';
 import {INTERNAL_MATCHER_FLAG} from './jestMatchersObject';
@@ -57,6 +58,7 @@ export interface MatcherUtils {
 
 export interface MatcherState {
   assertionCalls: number;
+  currentConcurrentTestName?: AsyncLocalStorage<string>;
   currentTestName?: string;
   error?: Error;
   expand?: boolean;

packages/jest-circus/src/run.ts

@@ -5,7 +5,9 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {AsyncLocalStorage} from 'async_hooks';
 import pLimit = require('p-limit');
+import {jestExpect} from '@jest/expect';
 import type {Circus} from '@jest/types';
 import shuffleArray, {RandomNumberGenerator, rngBuilder} from './shuffleArray';
 import {dispatch, getState} from './state';
@@ -19,6 +21,10 @@ import {
   makeRunResult,
 } from './utils';
 
+type ConcurrentTestEntry = Omit<Circus.TestEntry, 'fn'> & {
+  fn: Circus.ConcurrentTestFn;
+};
+
 const run = async (): Promise<Circus.RunResult> => {
   const {rootDescribeBlock, seed, randomize} = getState();
   const rng = randomize ? rngBuilder(seed) : undefined;
@@ -49,20 +55,8 @@ const _runTestsForDescribeBlock = async (
 
   if (isRootBlock) {
     const concurrentTests = collectConcurrentTests(describeBlock);
-    const mutex = pLimit(getState().maxConcurrency);
-    for (const test of concurrentTests) {
-      try {
-        const promise = mutex(test.fn);
-        // Avoid triggering the uncaught promise rejection handler in case the
-        // test errors before being awaited on.
-        // eslint-disable-next-line @typescript-eslint/no-empty-function
-        promise.catch(() => {});
-        test.fn = () => promise;
-      } catch (err) {
-        test.fn = () => {
-          throw err;
-        };
-      }
+    if (concurrentTests.length > 0) {
+      startTestsConcurrently(concurrentTests);
     }
   }
 
@@ -120,7 +114,7 @@ const _runTestsForDescribeBlock = async (
 
 function collectConcurrentTests(
   describeBlock: Circus.DescribeBlock,
-): Array<Omit<Circus.TestEntry, 'fn'> & {fn: Circus.ConcurrentTestFn}> {
+): Array<ConcurrentTestEntry> {
   if (describeBlock.mode === 'skip') {
     return [];
   }
@@ -135,13 +129,33 @@ function collectConcurrentTests(
           child.mode === 'skip' ||
           (hasFocusedTests && child.mode !== 'only') ||
           (testNamePattern && !testNamePattern.test(getTestID(child)));
-        return skip
-          ? []
-          : [child as Circus.TestEntry & {fn: Circus.ConcurrentTestFn}];
+        return skip ? [] : [child as ConcurrentTestEntry];
     }
   });
 }
 
+function startTestsConcurrently(concurrentTests: Array<ConcurrentTestEntry>) {
+  const mutex = pLimit(getState().maxConcurrency);
+  const testNameStorage = new AsyncLocalStorage<string>();
+  jestExpect.setState({currentConcurrentTestName: testNameStorage});
+  for (const test of concurrentTests) {
+    try {
+      const promise = testNameStorage.run(getTestID(test), () =>
+        mutex(test.fn),
+      );
+      // Avoid triggering the uncaught promise rejection handler in case the
+      // test fails before being awaited on.
+      // eslint-disable-next-line @typescript-eslint/no-empty-function
+      promise.catch(() => {});
+      test.fn = () => promise;
+    } catch (err) {
+      test.fn = () => {
+        throw err;
+      };
+    }
+  }
+}
+
 const _runTest = async (
   test: Circus.TestEntry,
   parentSkipped: boolean,

packages/jest-snapshot/src/index.ts

@@ -279,7 +279,9 @@ const _toMatchSnapshot = (config: MatchSnapshotConfig) => {
 
   context.dontThrow && context.dontThrow();
 
-  const {currentTestName, isNot, snapshotState} = context;
+  const {currentConcurrentTestName, isNot, snapshotState} = context;
+  const currentTestName =
+    currentConcurrentTestName?.getStore() ?? context.currentTestName;
 
   if (isNot) {
     throw new Error(

yarn.lock

@@ -9697,6 +9697,7 @@ __metadata:
     "@jest/expect-utils": "workspace:^"
     "@jest/test-utils": "workspace:^"
     "@tsd/typescript": ^5.0.4
+    "@types/node": "*"
     chalk: ^4.0.0
     immutable: ^4.0.0
     jest-get-type: "workspace:^"