ReactIncrementalUpdatesMinimalism-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
 * @jest-environment node
 */

'use strict';

let React;
let ReactNoop;
let act;

describe('ReactIncrementalUpdatesMinimalism', () => {
  beforeEach(() => {
    jest.resetModules();
    React = require('react');
    ReactNoop = require('react-noop-renderer');

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

  it('should render a simple component', async () => {
    function Child() {
      return <div>Hello World</div>;
    }

    function Parent() {
      return <Child />;
    }

    ReactNoop.startTrackingHostCounters();
    await act(() => ReactNoop.render(<Parent />));
    expect(ReactNoop.stopTrackingHostCounters()).toEqual({
      hostUpdateCounter: 0,
    });

    ReactNoop.startTrackingHostCounters();
    await act(() => ReactNoop.render(<Parent />));
    expect(ReactNoop.stopTrackingHostCounters()).toEqual({
      hostUpdateCounter: 1,
    });
  });

  it('should not diff referentially equal host elements', async () => {
    function Leaf(props) {
      return (
        <span>
          hello
          <b />
          {props.name}
        </span>
      );
    }

    const constEl = (
      <div>
// ... (97 more lines)