electron/spec/fixtures/extensions/lazy-background-page/get-background-page.js

/* global chrome */
window.completionPromise = new Promise((resolve) => {
  window.completionPromiseResolve = resolve;
});
chrome.runtime.sendMessage({ some: 'message' }, () => {
  window.completionPromiseResolve(chrome.extension.getBackgroundPage().receivedMessage);
});