// Copyright 2017-2020 @polkadot/react-hooks authors & contributors
// This software may be modified and distributed under the terms
// of the Apache-2.0 license. See the LICENSE file for details.

import { useEffect, useRef } from 'react';

export type MountedRef = React.MutableRefObject<boolean>;

export default function useIsMountedRef (): MountedRef {
  const isMounted = useRef(false);

  useEffect((): () => void => {
    isMounted.current = true;

    return (): void => {
      isMounted.current = false;
    };
  }, []);

  return isMounted;
}