react-relay/relay-hooks/useIsMountedRef.js.flow

A framework for building GraphQL-driven React applications.

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow strict-local
 * @format
 * @oncall relay
 */

'use strict';

const {useEffect, useRef} = require('react');

hook useIsMountedRef(): {current: boolean} {
  const isMountedRef = useRef(true);

  useEffect(() => {
    isMountedRef.current = true;
    return () => {
      isMountedRef.current = false;
    };
  }, []);

  return isMountedRef;
}

module.exports = useIsMountedRef;