profilerChangeDescriptions-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.
 *
 * @flow
 */

import {getVersionedRenderImplementation} from './utils';

describe('Profiler change descriptions', () => {
  let React;
  let store;
  let utils;

  beforeEach(() => {
    utils = require('./utils');
    utils.beforeEachProfiling();

    store = global.store;
    store.collapseNodesByDefault = false;
    store.recordChangeDescriptions = true;

    React = require('react');
  });

  const {render} = getVersionedRenderImplementation();

  // @reactVersion >=18.0
  it('should identify useContext as the cause for a re-render', () => {
    const Context = React.createContext(0);

    function Child() {
      const context = React.useContext(Context);
      return context;
    }

    function areEqual() {
      return true;
    }

    const MemoizedChild = React.memo(Child, areEqual);
    const ForwardRefChild = React.forwardRef(
      function RefForwardingComponent(props, ref) {
        return <Child />;
      },
    );

    let forceUpdate = null;

    const App = function App() {
      const [val, dispatch] = React.useReducer(x => x + 1, 0);

      forceUpdate = dispatch;

      return (
        <Context.Provider value={val}>
          <Child />
          <MemoizedChild />
// ... (91 more lines)