fix(jest-runner): handle test failures with circular objects (#10981)

Author: SimenB

CHANGELOG.md

@@ -41,6 +41,7 @@
 - `[jest-reporter]` Handle empty files when reporting code coverage with V8 ([#10819](https://github.com/facebook/jest/pull/10819))
 - `[jest-resolve]` Replace read-pkg-up with escalade package ([#10781](https://github.com/facebook/jest/pull/10781))
 - `[jest-resolve]` Disable `jest-pnp-resolver` for Yarn 2 ([#10847](https://github.com/facebook/jest/pull/10847))
+- `[jest-runner]` Handle test failures with circular objects ([#10981](https://github.com/facebook/jest/pull/10981))
 - `[jest-runtime]` [**BREAKING**] Do not inject `global` variable into module wrapper ([#10644](https://github.com/facebook/jest/pull/10644))
 - `[jest-runtime]` [**BREAKING**] remove long-deprecated `jest.addMatchers`, `jest.resetModuleRegistry`, and `jest.runTimersToTime` ([#9853](https://github.com/facebook/jest/pull/9853))
 - `[jest-runtime]` Fix stack overflow and promise deadlock when importing mutual dependant ES module ([#10892](https://github.com/facebook/jest/pull/10892))

e2e/__tests__/__snapshots__/circularInequality.test.ts.snap

@@ -0,0 +1,53 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`handles circular inequality properly 1`] = `
+FAIL __tests__/test-1.js
+  ● test
+
+    expect(received).toEqual(expected) // deep equality
+
+    - Expected  - 1
+    + Received  + 3
+
+    - Object {}
+    + Object {
+    +   "ref": [Circular],
+    + }
+
+      3 |   foo.ref = foo;
+      4 |
+    > 5 |   expect(foo).toEqual({});
+        |               ^
+      6 | });
+
+      at Object.toEqual (__tests__/test-1.js:5:15)
+
+FAIL __tests__/test-2.js
+  ● test
+
+    expect(received).toEqual(expected) // deep equality
+
+    - Expected  - 1
+    + Received  + 3
+
+    - Object {}
+    + Object {
+    +   "ref": [Circular],
+    + }
+
+      3 |   foo.ref = foo;
+      4 |
+    > 5 |   expect(foo).toEqual({});
+        |               ^
+      6 | });
+
+      at Object.toEqual (__tests__/test-2.js:5:15)
+`;
+
+exports[`handles circular inequality properly 2`] = `
+Test Suites: 2 failed, 2 total
+Tests:       2 failed, 2 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites.
+`;

e2e/__tests__/circularInequality.test.ts

@@ -0,0 +1,58 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {tmpdir} from 'os';
+import * as path from 'path';
+import {wrap} from 'jest-snapshot-serializer-raw';
+import {
+  cleanup,
+  createEmptyPackage,
+  extractSortedSummary,
+  writeFiles,
+} from '../Utils';
+import {runContinuous} from '../runJest';
+
+const tempDir = path.resolve(tmpdir(), 'circular-inequality-test');
+
+beforeEach(() => {
+  createEmptyPackage(tempDir);
+});
+
+afterEach(() => {
+  cleanup(tempDir);
+});
+
+test('handles circular inequality properly', async () => {
+  const testFileContent = `
+    it('test', () => {
+      const foo = {};
+      foo.ref = foo;
+
+      expect(foo).toEqual({});
+    });
+  `;
+
+  writeFiles(tempDir, {
+    '__tests__/test-1.js': testFileContent,
+    '__tests__/test-2.js': testFileContent,
+  });
+
+  const {end, waitUntil} = runContinuous(
+    tempDir,
+    ['--no-watchman', '--watch-all'],
+    // timeout in case the `waitUntil` below doesn't fire
+    {stripAnsi: true, timeout: 5000},
+  );
+
+  await waitUntil(({stderr}) => stderr.includes('Ran all test suites.'));
+
+  const {stderr} = await end();
+
+  const {summary, rest} = extractSortedSummary(stderr);
+  expect(wrap(rest)).toMatchSnapshot();
+  expect(wrap(summary)).toMatchSnapshot();
+});

packages/jest-runner/src/index.ts

@@ -166,7 +166,12 @@ export default class TestRunner {
 
     const worker = new Worker(TEST_WORKER_PATH, {
       exposedMethods: ['worker'],
-      forkOptions: {stdio: 'pipe'},
+      forkOptions: {
+        // use advanced serialization in order to transfer objects with circular references
+        // @ts-expect-error: option does not exist on the node 10 types
+        serialization: 'advanced',
+        stdio: 'pipe',
+      },
       maxRetries: 3,
       numWorkers: this._globalConfig.maxWorkers,
       setupArgs: [