proxy.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
 */
/* global chrome */

'use strict';

function injectProxy({target}: {target: any}) {
  // Firefox's behaviour for injecting this content script can be unpredictable
  // While navigating the history, some content scripts might not be re-injected and still be alive
  if (!window.__REACT_DEVTOOLS_PROXY_INJECTED__) {
    window.__REACT_DEVTOOLS_PROXY_INJECTED__ = true;

    connectPort();
    sayHelloToBackendManager();

    // The backend waits to install the global hook until notified by the content script.
    // In the event of a page reload, the content script might be loaded before the backend manager is injected.
    // Because of this we need to poll the backend manager until it has been initialized.
    const intervalID: IntervalID = setInterval(() => {
      if (backendInitialized) {
        clearInterval(intervalID);
      } else {
        sayHelloToBackendManager();
      }
    }, 500);
  }
}

window.addEventListener('pagereveal', injectProxy);
// For backwards compat with browsers not implementing `pagereveal` which is a fairly new event.
window.addEventListener('pageshow', injectProxy);

window.addEventListener('pagehide', function ({target}) {
  if (target !== window.document) {
    return;
  }

  delete window.__REACT_DEVTOOLS_PROXY_INJECTED__;
});

let port = null;
let backendInitialized: boolean = false;

function sayHelloToBackendManager() {
  window.postMessage(
    {
      source: 'react-devtools-content-script',
      hello: true,
    },
    '*',
  );
}

function handleMessageFromDevtools(message: any) {
// ... (106 more lines)