react/shells/dev/src/backend.js

/** @flow */

import Agent from 'src/backend/agent';
import Bridge from 'src/bridge'
import { initBackend } from 'src/backend';

const bridge = new Bridge({
  listen (fn) {
    window.addEventListener('message', event => {
      fn(event.data);
    });
  },
  send (data) {
    window.parent.postMessage(data, '*')
  }
})

const agent = new Agent();
agent.addBridge(bridge);

initBackend(window.__REACT_DEVTOOLS_GLOBAL_HOOK__, agent);