Feature: React custom hook - useDepEffect

[yairEO]

useDepEffect (use dependency effect)

Runs a useEffect only when the dependency array changes and not on initial mount.
(see related stackoverflow discussion)

Instead of manually using a ref to know when the component mounted:

const isMountedRef = useRef();

useEffect(() => {
  if (isMountedRef.current)
	document.title = `You clicked ${count} times`;

  isMountedRef = true;
}, [count]); 

Use the custom hook (much shorter):

useDepEffect(() => {
  document.title = `You clicked ${count} times`;
}, [count]); // Only re-run the effect if count changes