Mutation observers on Facebook

observer.js

var observer = new MutationObserver(records => {
  for (var record of records) {
    for (var node of record.addedNodes) {
      // TODO: do something with the node
    }
  }
})
// TODO: is there a cleaner way to do this?
var hookMeUp = () => {
  var feed = document.querySelector('#stream_pagelet > :last-child > div')
  if (feed) observer.observe(feed, {childList: true})
  else setTimeout(hookMeUp, 100)
}
hookMeUp()