import { useEffect, useRef } from "react"; import useIsomorphicLayoutEffect from "./use-isomorphic-layout-effect"; function useInterval(callback: () => void, delay: number | null) { const savedCallback = useRef(callback); // Remember the latest callback if it changes. useIsomorphicLayoutEffect(() => { savedCallback.current = callback; }, [callback]); // Set up the interval. useEffect(() => { // Don't schedule if no delay is specified. // Note: 0 is a valid value for delay. if (!delay && delay !== 0) { return; } const id = setInterval(() => savedCallback.current(), delay); return () => clearInterval(id); }, [delay]); } export default useInterval;