ReactStrictMode-test.internal.js — react Source File

Source Code

/**
 * 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.
 *
 * @emails react-core
 */

'use strict';

describe('ReactStrictMode', () => {
  let React;
  let ReactDOMClient;
  let act;

  beforeEach(() => {
    jest.resetModules();
    React = require('react');
    ReactDOMClient = require('react-dom/client');

    act = require('internal-test-utils').act;
  });

  describe('levels', () => {
    let log;

    beforeEach(() => {
      log = [];
    });

    function Component({label}) {
      React.useEffect(() => {
        log.push(`${label}: useEffect mount`);
        return () => log.push(`${label}: useEffect unmount`);
      });

      React.useLayoutEffect(() => {
        log.push(`${label}: useLayoutEffect mount`);
        return () => log.push(`${label}: useLayoutEffect unmount`);
      });

      log.push(`${label}: render`);

      return null;
    }

    it('should default to not strict', async () => {
      await act(() => {
        const container = document.createElement('div');
        const root = ReactDOMClient.createRoot(container);
        root.render(<Component label="A" />);
      });

      expect(log).toEqual([
        'A: render',
        'A: useLayoutEffect mount',
        'A: useEffect mount',
      ]);
    });
// ... (113 more lines)