Handle clicks outside an element

function useOnClickOutside<T extends HTMLElement>(ref: React.RefObject<T>, onOutside: () => void) {
  useEffect(() => {
    function handle(event: MouseEvent) {
      if (!ref.current || ref.current.contains(event.target as Node)) return;
      onOutside();
    }
    document.addEventListener('mousedown', handle);
    return () => document.removeEventListener('mousedown', handle);
  }, [ref, onOutside]);
}