RocketChat/Rocket.Chat

import type { MutableRefObject, Ref, RefCallback } from 'react';
import { useCallback } from 'react';

const isRefCallback = <T>(x: unknown): x is RefCallback<T> => typeof x === 'function';
const isMutableRefObject = <T>(x: unknown): x is MutableRefObject<T> => typeof x === 'object';

/**
 * Merges multiple refs into a single ref callback.
 * it was not meant to be used with in any different place than MessageBox
 *
 * @param refs The refs to merge.
 * @returns The merged ref callback.
 */
export const useMessageComposerMergedRefs = <T>(...refs: Ref<T>[]): RefCallback<T> => {
    return useCallback((refValue: T) => {
        refs.filter(Boolean).forEach((ref) => {
            if (isRefCallback<T>(ref)) {
                ref(refValue);
                return;
            }

            if (isMutableRefObject<T>(ref)) {
                ref.current = refValue;
            }
        });
        // eslint-disable-next-line react-hooks/exhaustive-deps
    }, refs);
};