useStateThen.js

import {useRef, useState, useCallback, useEffect} from 'react';

function useStateThen(initialValue) {
  const p = useRef(null);
  const [value, setValue] = useState(initialValue);
  const wrappedSetValue = useCallback((...args) => {
    return new Promise(resolve => {
      p.current = resolve;
      setValue(...args);
    });
  }, [setValue]);

  useEffect(() => {
    if (p.current) {
      p.current(value);
      p.current = null;
    }
  }, [value]);

  return [value, wrappedSetValue];
}