const getInitialTweets = () => [...document.querySelectorAll('.js-stream-item')]
const nonchrono = e => {
  for (typ of ['follower', 'promoted', 'heartBadge']) {
    if (e.querySelector(`.context .Icon--${typ}`)) {
      return true;
    }
  }
  return false;
}
const decorate = e => e.style.border = "10px solid red";
const remove = e => e.remove();
const handler = decorate;
const processTweets = tweets => tweets.filter(nonchrono).forEach(handler);
const createTweetObserver = () => {
  return new MutationObserver(mut => processTweets([...mut[0].addedNodes]))
}
const attachTweetObserver = observer => {
  const config = { attributes: false, childList: true, subtree: false };
  const target = document.querySelector('ol.js-navigable-stream')
  observer.observe(target, config)
}
const attachDocObserver = (tweetObserver) => {
  const config = { attributes: true, childList: false, subtree: false };
  const handler = mut => {
    tweetObserver.disconnect();
    if (mut[0].target.classList.contains('route-home')) {
      processTweets(getInitialTweets());
      attachTweetObserver(tweetObserver);
    }
  }
  const observer = new MutationObserver(handler);
  observer.observe(document.getElementById('doc'), config);
}
const tweetObserver = createTweetObserver();
processTweets(getInitialTweets());
attachTweetObserver(tweetObserver);
attachDocObserver(tweetObserver);