department-of-veterans-affairs/vets-website

import { useEffect, useRef } from 'react';

/**
 * Custom hook pulled from https://overreacted.io/making-setinterval-declarative-with-react-hooks/
 * @param {*} callback
 * @param {*} delay
 */

function useInterval(callback, delay) {
  const savedCallback = useRef();

  // Remember the latest callback.
  useEffect(
    () => {
      savedCallback.current = callback;
    },
    [callback],
  );

  // Set up the interval.
  useEffect(
    () => {
      function tick() {
        savedCallback.current();
      }
      if (delay !== null) {
        const id = setInterval(tick, delay);
        return () => clearInterval(id);
      }
      return null;
    },
    [delay],
  );
}

export default useInterval;