ReactInterleavedUpdates-test.js — react Source File

Source Code

let React;
let ReactNoop;
let Scheduler;
let startTransition;
let useState;
let useEffect;
let act;
let assertLog;
let waitFor;
let waitForPaint;

describe('ReactInterleavedUpdates', () => {
  beforeEach(() => {
    jest.resetModules();

    React = require('react');
    ReactNoop = require('react-noop-renderer');
    Scheduler = require('scheduler');
    act = require('internal-test-utils').act;
    startTransition = React.startTransition;
    useState = React.useState;
    useEffect = React.useEffect;

    const InternalTestUtils = require('internal-test-utils');
    assertLog = InternalTestUtils.assertLog;
    waitFor = InternalTestUtils.waitFor;
    waitForPaint = InternalTestUtils.waitForPaint;
  });

  function Text({text}) {
    Scheduler.log(text);
    return text;
  }

  it('update during an interleaved event is not processed during the current render', async () => {
    const updaters = [];

    function Child() {
      const [state, setState] = useState(0);
      useEffect(() => {
        updaters.push(setState);
      }, []);
      return <Text text={state} />;
    }

    function updateChildren(value) {
      for (let i = 0; i < updaters.length; i++) {
        const setState = updaters[i];
        setState(value);
      }
    }

    const root = ReactNoop.createRoot();

    await act(() => {
      root.render(
        <>
          <Child />
          <Child />
          <Child />
// ... (77 more lines)