Patch jest/runner/testWorker.js to fix compatibility issues and more

Readme.md

Fix env in jest tests

• testing-library / issues / The current testing environment is not configured to support act(...) with vitest and React 18
• jsdom / ReferenceError: AggregateError is not defined
• structuredClone is not defined (todo: issue?)
• Allow to use native nodejs require (not jest version of it)
• Allow to use nodejs versions of timers setTimeout, setImmediate, queueMicrotask etc (not a jest/sinon version of it even if FakeTimers is on)
• Allow to use nodejs versions of URL, Blob, Buffer etc

How to use

• Run patch_node_modules_jest_runner_testWorker.js on postistall
• or use patch-package to write a similar solution (you need to inject require('../<relative_path>/../jestProcess_onCreate.js') to jest-runner/build/testWorker.js).

Limitation

Script patch_node_modules_jest_runner_testWorker.js was tested only for [email protected]. To support other versions you may needed to update it.

jestProcess_onCreate.js

'use strict';

// This file will be hack-patched to `jest-runner/build/testWorker.js` in `patch_node_modules_jest_runner_testWorker.js`

// Polyfills if you need it
require('./polyfills/jscore');

const vm = require('node:vm');

const { createContext } = vm;
const nodejsSetTimeout = globalThis.setTimeout;
const nodejsClearTimeout = globalThis.clearTimeout;
const nodejsSetInterval = globalThis.setInterval;
const nodejsClearInterval = globalThis.clearInterval;
const nodejsSetImmediate = globalThis.setImmediate;
const nodejsClearImmediate = globalThis.clearImmediate;
const nodejsQueueMicrotask = globalThis.queueMicrotask;
const nodejsRequire = require;
const nodejsConsole = console;
const nodejsBuffer = Buffer;
const nodejs_structuredClone = typeof structuredClone === 'function'
  ? structuredClone
  : void 0
;

const { URL: nodeWebURL } = require('node:url');
const { Blob: nodeWebBlob } = require('node:buffer');

vm.createContext = function(context) {
  if (!context) {
    context = {};
  }

  /**
   * Temporary solution for issue [jsdom / ReferenceError: AggregateError is not defined]{@link https://github.com/jsdom/jsdom/issues/3205}
   */
  if (!context.AggregateError) {
    // this could be from polyfill or from native nodejs support
    if (typeof AggregateError === 'function') {
      // eslint-disable-next-line no-undef
      context.AggregateError = AggregateError;  
    }
    else {
      context.AggregateError = Error;  
    }
  }

  /*
  Use it like this to create native require function:
  ```
  const nativeNode_require = nodejsRequire('node:module').createRequire(__filename);
  ```
  */
  // link to real nodejs require, to use it in tests.
  context.nodejsRequire = nodejsRequire;
  context.nodejsConsole = nodejsConsole;
  context.nodejsSetTimeout = nodejsSetTimeout;
  context.nodejsClearTimeout = nodejsClearTimeout;
  context.nodejsSetInterval = nodejsSetInterval;
  context.nodejsClearInterval = nodejsClearInterval;
  context.nodejsSetImmediate = nodejsSetImmediate;
  context.nodejsClearImmediate = nodejsClearImmediate;
  context.nodejsQueueMicrotask = nodejsQueueMicrotask;
  context.nodeWebURL = nodeWebURL;
  context.nodeWebBlob = nodeWebBlob;
  context.nodejsBuffer = nodejsBuffer;

  if (!context.structuredClone && nodejs_structuredClone) {
    context.structuredClone = nodejs_structuredClone;
  }

  if (globalThis["IS_REACT_ACT_ENVIRONMENT"] && context["IS_REACT_ACT_ENVIRONMENT"] == null) {
    /**
     * * [How to Upgrade to React 18 / Configuring Your Testing Environment](https://react.dev/blog/2022/03/08/react-18-upgrade-guide#configuring-your-testing-environment)
     * * [React / Test Utilities / act()](https://legacy.reactjs.org/docs/test-utils.html#act)
     * * [testing-library / issues / The current testing environment is not configured to support act(...) with vitest and React 18](https://github.com/testing-library/react-testing-library/issues/1061)
     */
    context["IS_REACT_ACT_ENVIRONMENT"] = true;
  }

  return createContext(context);
};

patch_node_modules_jest_runner_testWorker.js

'use strict';

const path = require("node:path");
const fs = require("node:fs");

// link to injected file
const jestProcess_onCreate_path = require.resolve('./jestProcess_onCreate.js');

// Use this fir debugging: `node patch_node_modules_jest_runner_testWorker.js`
if (require.main.filename === __filename) {
  patch_node_modules_jest_runner_testWorker();
}

/**
 * Patch jest: jest-runner/build/testWorker.js.
 *
 * For example: `[email protected]`. To support other versions you __may__ needed to update `require.resolve()` bellow.
 */
function patch_node_modules_jest_runner_testWorker() {
  try {
    /**
     * Path of file: '/node_modules/jest/build/jest.js'
     */
    const jest_path = require.resolve('jest');
    /** Path of file: '/node_modules/@jest/core/build/jest.js' */
    const jest_core_path = require.resolve('@jest/core', { paths: [ jest_path ] });
    /**
     * Path of file: '/node_modules/jest-runner/build/index.js'
     */
    const jest_runner_path = require.resolve('jest-runner', { paths: [ jest_path, jest_core_path ] });
    /**
     * Path of file: '/node_modules/jest-runner/build/testWorker.js'
     */
    const jest_runner_testWorker_path = path.join(path.dirname(jest_runner_path), 'testWorker.js');
    /**
     * Normalize '\\' to '/' for Windows.
     */
    const jestProcess_onCreate_relative_path = path.relative(path.dirname(jest_runner_path), jestProcess_onCreate_path);

    {
      const content = String(fs.readFileSync(jest_runner_testWorker_path));
      const old_value = 'async function worker({config, globalConfig, path, context}) {';
      const new_value_start = `async function worker({config, globalConfig, path, context}) {// -INJECTION_START-`;
      const new_value_content = `\nrequire('${jestProcess_onCreate_relative_path.replace(/\\/g, '/')}')`;
      const new_value_end = `\n// -INJECTION_START-\n`;
      const new_value = new_value_start + new_value_content + new_value_end;

      if (!content.includes(old_value)) {
        // noinspection ExceptionCaughtLocallyJS
        throw new Error(`Can't PATH "jest-runner" testWorker.js: original script changed. Can't find "${old_value}".`);
      }

      /** @type {string | undefined} */
      let newContent;

      // never was
      if (!content.includes(new_value_start)) {
        newContent = content.replace(old_value, new_value);
      }
      else {
        // Path to jestProcess_onCreate_relative_path may be changed
        if (!content.includes(new_value)) {
          const startIndex = content.indexOf(new_value_start);
          const endIndex = content.indexOf(new_value_end);

          if (startIndex === -1 || endIndex === -1) {
            // noinspection ExceptionCaughtLocallyJS
            throw new Error(`Can't PATH "jest-runner" testWorker.js! Something wrong with patched script ${JSON.stringify({ startIndex, endIndex })}`);
          }

          newContent = content.substring(0, startIndex) + new_value + content.substring(endIndex + new_value_end.length);
        }
      }

      if (newContent) {
        fs.writeFileSync(jest_runner_testWorker_path, newContent);
      }
    }
  }
  catch (err) {
    console.warn(`"${patch_node_modules_jest_runner_testWorker.name}": done with error:`, err);
  }
}

module.exports = {
  patch_node_modules_jest_runner_testWorker,
};