Function onInsert

testing/iframe.js:599–610

* Returns a promise for when an element has been added to the given * window. This is for use in tests to wait until after the * attachment of an element to the DOM should have been registered. * @param {!Window} win * @return {!Promise }

(win)

 * @return {!Promise<undefined>}
 */
function onInsert(win) {
  return new Promise((resolve) => {
    const observer = new win.MutationObserver(() => {
      observer.disconnect();
      resolve();
    });
    observer.observe(win.document.documentElement, {
      childList: true,
      subtree: true,
    });
  });
}

/**
 * Takes a HTML document that is pointing to unminified JS and HTML binaries and