jestjs · G-Rath · May 28, 2021 · Sep 29, 2021 · Dec 19, 2021 · Dec 19, 2021
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,7 @@
 - `[jest-resolver]` [**BREAKING**] Add support for `package.json` `exports` ([11961](https://github.com/facebook/jest/pull/11961))
 - `[@jes/schemas]` New module for JSON schemas for Jest's config ([#12384](https://github.com/facebook/jest/pull/12384))
 - `[jest-worker]` [**BREAKING**] Allow only absolute `workerPath` ([#12343](https://github.com/facebook/jest/pull/12343))
+- `[jest-worker]` Support serializing complex objects ([#11467](https://github.com/facebook/jest/pull/11467))
 
 ### Fixes
 

diff --git a/e2e/__tests__/circularInequality.test.ts b/e2e/__tests__/circularInequality.test.ts
@@ -25,7 +25,7 @@ afterEach(() => {
   cleanup(tempDir);
 });
 
-test.skip('handles circular inequality properly', async () => {
+test('handles circular inequality properly', async () => {
   const testFileContent = `
     it('test', () => {
       const foo = {};

diff --git a/e2e/__tests__/complexItemsInErrors.ts b/e2e/__tests__/complexItemsInErrors.ts
@@ -58,7 +58,7 @@ test('handles functions that close over outside variables', async () => {
   expect(rest).toMatchSnapshot();
 });
 
-test.skip('handles errors with BigInt', async () => {
+test('handles errors with BigInt', async () => {
   const testFileContent = `
     test('dummy', () => {
       expect(1n).toEqual(2n);

diff --git a/packages/jest-worker/src/workers/ChildProcessWorker.ts b/packages/jest-worker/src/workers/ChildProcessWorker.ts
@@ -23,6 +23,7 @@ import {
   WorkerInterface,
   WorkerOptions,
 } from '../types';
+import {deserialize} from './utils';
 
 const SIGNAL_BASE_EXIT_CODE = 128;
 const SIGKILL_EXIT_CODE = SIGNAL_BASE_EXIT_CODE + 9;
@@ -164,7 +165,7 @@ export default class ChildProcessWorker implements WorkerInterface {
 
     switch (response[0]) {
       case PARENT_MESSAGE_OK:
-        this._onProcessEnd(null, response[1]);
+        this._onProcessEnd(null, deserialize(response));
         break;
 
       case PARENT_MESSAGE_CLIENT_ERROR:
@@ -197,7 +198,7 @@ export default class ChildProcessWorker implements WorkerInterface {
         this._onProcessEnd(error, null);
         break;
       case PARENT_MESSAGE_CUSTOM:
-        this._onCustomMessage(response[1]);
+        this._onCustomMessage(deserialize(response));
         break;
       default:
         throw new TypeError('Unexpected response from worker: ' + response[0]);

diff --git a/packages/jest-worker/src/workers/NodeThreadsWorker.ts b/packages/jest-worker/src/workers/NodeThreadsWorker.ts
@@ -22,6 +22,7 @@ import {
   WorkerInterface,
   WorkerOptions,
 } from '../types';
+import {deserialize} from './utils';
 
 export default class ExperimentalWorker implements WorkerInterface {
   private _worker!: Worker;
@@ -131,7 +132,7 @@ export default class ExperimentalWorker implements WorkerInterface {
 
     switch (response[0]) {
       case PARENT_MESSAGE_OK:
-        this._onProcessEnd(null, response[1]);
+        this._onProcessEnd(null, deserialize(response));
         break;
 
       case PARENT_MESSAGE_CLIENT_ERROR:
@@ -165,7 +166,7 @@ export default class ExperimentalWorker implements WorkerInterface {
         this._onProcessEnd(error, null);
         break;
       case PARENT_MESSAGE_CUSTOM:
-        this._onCustomMessage(response[1]);
+        this._onCustomMessage(deserialize(response));
         break;
       default:
         throw new TypeError('Unexpected response from worker: ' + response[0]);

diff --git a/packages/jest-worker/src/workers/__tests__/processChild.test.js b/packages/jest-worker/src/workers/__tests__/processChild.test.js
@@ -14,6 +14,7 @@ const processSend = process.send;
 const uninitializedParam = {};
 const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
 
+import {serialize} from 'v8';
 import {
   CHILD_MESSAGE_CALL,
   CHILD_MESSAGE_END,
@@ -177,7 +178,10 @@ it('returns results immediately when function is synchronous', () => {
     [],
   ]);
 
-  expect(process.send.mock.calls[0][0]).toEqual([PARENT_MESSAGE_OK, 1989]);
+  expect(process.send.mock.calls[0][0]).toEqual([
+    PARENT_MESSAGE_OK,
+    {serializedMessage: serialize(1989)},
+  ]);
 
   process.emit('message', [
     CHILD_MESSAGE_CALL,
@@ -258,7 +262,10 @@ it('returns results when it gets resolved if function is asynchronous', async ()
 
   await sleep(10);
 
-  expect(process.send.mock.calls[0][0]).toEqual([PARENT_MESSAGE_OK, 1989]);
+  expect(process.send.mock.calls[0][0]).toEqual([
+    PARENT_MESSAGE_OK,
+    {serializedMessage: serialize(1989)},
+  ]);
 
   process.emit('message', [
     CHILD_MESSAGE_CALL,
@@ -294,7 +301,10 @@ it('calls the main module if the method call is "default"', () => {
     [],
   ]);
 
-  expect(process.send.mock.calls[0][0]).toEqual([PARENT_MESSAGE_OK, 12345]);
+  expect(process.send.mock.calls[0][0]).toEqual([
+    PARENT_MESSAGE_OK,
+    {serializedMessage: serialize(12345)},
+  ]);
 });
 
 it('calls the main export if the method call is "default" and it is a Babel transpiled one', () => {
@@ -311,7 +321,10 @@ it('calls the main export if the method call is "default" and it is a Babel tran
     [],
   ]);
 
-  expect(process.send.mock.calls[0][0]).toEqual([PARENT_MESSAGE_OK, 67890]);
+  expect(process.send.mock.calls[0][0]).toEqual([
+    PARENT_MESSAGE_OK,
+    {serializedMessage: serialize(67890)},
+  ]);
 });
 
 it('removes the message listener on END message', () => {

diff --git a/packages/jest-worker/src/workers/__tests__/threadChild.test.js b/packages/jest-worker/src/workers/__tests__/threadChild.test.js
@@ -24,6 +24,7 @@ const mockExtendedError = new ReferenceError('Booo extended');
 const uninitializedParam = {};
 const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
 
+import {serialize} from 'v8';
 import {
   CHILD_MESSAGE_CALL,
   CHILD_MESSAGE_END,
@@ -201,7 +202,7 @@ it('returns results immediately when function is synchronous', () => {
 
   expect(thread.postMessage.mock.calls[0][0]).toEqual([
     PARENT_MESSAGE_OK,
-    1989,
+    {serializedMessage: serialize(1989)},
   ]);
 
   thread.emit('message', [
@@ -287,7 +288,7 @@ it('returns results when it gets resolved if function is asynchronous', async ()
 
   expect(thread.postMessage.mock.calls[0][0]).toEqual([
     PARENT_MESSAGE_OK,
-    1989,
+    {serializedMessage: serialize(1989)},
   ]);
 
   thread.emit('message', [
@@ -326,7 +327,7 @@ it('calls the main module if the method call is "default"', () => {
 
   expect(thread.postMessage.mock.calls[0][0]).toEqual([
     PARENT_MESSAGE_OK,
-    12345,
+    {serializedMessage: serialize(12345)},
   ]);
 });
 
@@ -346,7 +347,7 @@ it('calls the main export if the method call is "default" and it is a Babel tran
 
   expect(thread.postMessage.mock.calls[0][0]).toEqual([
     PARENT_MESSAGE_OK,
-    67890,
+    {serializedMessage: serialize(67890)},
   ]);
 });
 

diff --git a/packages/jest-worker/src/workers/messageParent.ts b/packages/jest-worker/src/workers/messageParent.ts
@@ -7,6 +7,7 @@
 
 import {isMainThread, parentPort} from 'worker_threads';
 import {PARENT_MESSAGE_CUSTOM} from '../types';
+import {serialize} from './utils';
 
 export default function messageParent(
   message: unknown,
@@ -15,7 +16,7 @@ export default function messageParent(
   if (!isMainThread && parentPort != null) {
     parentPort.postMessage([PARENT_MESSAGE_CUSTOM, message]);
   } else if (typeof parentProcess.send === 'function') {
-    parentProcess.send([PARENT_MESSAGE_CUSTOM, message]);
+    parentProcess.send([PARENT_MESSAGE_CUSTOM, serialize(message)]);
   } else {
     throw new Error('"messageParent" can only be used inside a worker');
   }

diff --git a/packages/jest-worker/src/workers/processChild.ts b/packages/jest-worker/src/workers/processChild.ts
@@ -17,6 +17,7 @@ import {
   PARENT_MESSAGE_OK,
   PARENT_MESSAGE_SETUP_ERROR,
 } from '../types';
+import {serialize} from './utils';
 
 let file: string | null = null;
 let setupArgs: Array<unknown> = [];
@@ -65,7 +66,7 @@ function reportSuccess(result: unknown) {
     throw new Error('Child can only be used on a forked process');
   }
 
-  process.send([PARENT_MESSAGE_OK, result]);
+  process.send([PARENT_MESSAGE_OK, serialize(result)]);
 }
 
 function reportClientError(error: Error) {

diff --git a/packages/jest-worker/src/workers/threadChild.ts b/packages/jest-worker/src/workers/threadChild.ts
@@ -18,6 +18,7 @@ import {
   PARENT_MESSAGE_OK,
   PARENT_MESSAGE_SETUP_ERROR,
 } from '../types';
+import {serialize} from './utils';
 
 let file: string | null = null;
 let setupArgs: Array<unknown> = [];
@@ -67,7 +68,7 @@ function reportSuccess(result: unknown) {
     throw new Error('Child can only be used on a forked process');
   }
 
-  parentPort!.postMessage([PARENT_MESSAGE_OK, result]);
+  parentPort!.postMessage([PARENT_MESSAGE_OK, serialize(result)]);
 }
 
 function reportClientError(error: Error) {

diff --git a/packages/jest-worker/src/workers/utils.ts b/packages/jest-worker/src/workers/utils.ts
@@ -0,0 +1,27 @@
+/**
+ * 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 * as v8 from 'v8';
+
+type SerializedMessage = {serializedMessage: Buffer};
+type WorkerResponse = Array<unknown> | [unknown, SerializedMessage];
+
+export const serialize = (message: unknown): SerializedMessage => {
+  return {serializedMessage: v8.serialize(message)};
+};
+
+function hasSerializedMessage(obj: unknown): obj is SerializedMessage {
+  return obj != null && typeof obj === 'object' && 'serializedMessage' in obj;
+}
+
+export const deserialize = ([, re]: WorkerResponse): unknown => {
+  if (hasSerializedMessage(re)) {
+    return v8.deserialize(Buffer.from(re.serializedMessage));
+  }
+
+  return re;
+};