(() => {
  if (!['localhost', '127.0.0.1'].includes(location.hostname)) return;
  const events = new EventSource('http://127.0.0.1:8588/events');
  let revision;
  const refresh = (event) => {
    const next = JSON.parse(event.data).revision;
    if (revision && revision !== next) location.reload();
    revision = next;
  };
  events.addEventListener('ready', refresh);
  events.addEventListener('update', refresh);
})();