react-native-web/dist/vendor/react-native/Utilities/useMergeRefs.js.flow

React Native for Web

/**
 * 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
 * @format
 */

import { useCallback } from 'react';
type CallbackRef<T> = (T) => mixed;
type ObjectRef<T> = {
  current: T,
  ...
};
type Ref<T> = CallbackRef<T> | ObjectRef<T>;

/**
 * Constructs a new ref that forwards new values to each of the given refs. The
 * given refs will always be invoked in the order that they are supplied.
 *
 * WARNING: A known problem of merging refs using this approach is that if any
 * of the given refs change, the returned callback ref will also be changed. If
 * the returned callback ref is supplied as a `ref` to a React element, this may
 * lead to problems with the given refs being invoked more times than desired.
 */
declare export default function useMergeRefs<T>(...refs: $ReadOnlyArray<?Ref<T>>): CallbackRef<T>;