ReactIdentity-test.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';

let React;
let ReactDOMClient;
let act;
let assertConsoleErrorDev;

describe('ReactIdentity', () => {
  beforeEach(() => {
    jest.resetModules();
    React = require('react');
    ReactDOMClient = require('react-dom/client');
    act = require('internal-test-utils').act;
    assertConsoleErrorDev =
      require('internal-test-utils').assertConsoleErrorDev;
  });

  it('should allow key property to express identity', async () => {
    let node;
    const Component = props => (
      <div ref={c => (node = c)}>
        <div key={props.swap ? 'banana' : 'apple'} />
        <div key={props.swap ? 'apple' : 'banana'} />
      </div>
    );

    const container = document.createElement('div');
    const root = ReactDOMClient.createRoot(container);
    await act(async () => {
      root.render(<Component />);
    });
    const origChildren = Array.from(node.childNodes);
    await act(async () => {
      root.render(<Component swap={true} />);
    });
    const newChildren = Array.from(node.childNodes);
    expect(origChildren[0]).toBe(newChildren[1]);
    expect(origChildren[1]).toBe(newChildren[0]);
  });

  it('should use composite identity', async () => {
    class Wrapper extends React.Component {
      render() {
        return <a>{this.props.children}</a>;
      }
    }

    const container = document.createElement('div');
    const root = ReactDOMClient.createRoot(container);
    let node1;
    let node2;
// ... (272 more lines)