React hook to click outside a ref

useOnClickOutside.js

// Hook
function useOnClickOutside(ref, handler) {
  useEffect(() => {
    const listener = event => {
      if (!ref.current || ref.current.contains(event.target)) {
        return;
      }
      handler(event);
    };
    document.addEventListener("mousedown", listener);
    document.addEventListener("touchstart", listener);
    return () => {
      document.removeEventListener("mousedown", listener);
      document.removeEventListener("touchstart", listener);
    };
  }, [ref, handler]);
}