Cacher is the code snippet organizer for pro developers

const connection$ = new Observable((observer) => {
  const { effectiveType } = navigator.connection;
  observer.next(effectiveType);

  const onConnectionChange = () => {
    const { effectiveType } = navigator.connection;
    observer.next(effectiveType);
  }

  navigator.connection.addEventListener('change', onConnectionChange)

  return () => {
    navigator.connection.removeEventListener('change', onConnectionChange);
    observer.complete();
  }
});