import { RefObject, useEffect, useMemo, useState } from 'react'; export default function useIsVisible( ref: RefObject< HTMLElement >, options?: IntersectionObserverInit ) { const [ isIntersecting, setIntersecting ] = useState< boolean | undefined >( undefined ); const observer = useMemo( () => { if ( typeof window === 'undefined' ) { return; } return new IntersectionObserver( ( [ entry ] ) => setIntersecting( entry.isIntersecting ), options ); }, [ options ] ); useEffect( () => { if ( ref && ref.current ) { observer?.observe( ref.current ); } return () => observer?.disconnect(); }, [ observer, ref ] ); return isIntersecting; }