[throwaway290]

Ah, the clarity of useEffect(() => { return () => { handleUnmount() } }, [])! How did they manage to live with the ugly componentWillUnmount() { handleUnmount() } for all those years?

(By the way, don't forget that [] or it does a completely different thing that you never want.)

[yawnr]

useEffect is the biggest source of bugs in any react codebase bar none