import { useEffect, useRef } from 'react' export const useUserChannel = (): BroadcastChannel | null => { const channelRef = useRef(null) if (channelRef.current === null && 'BroadcastChannel' in window) { channelRef.current = new BroadcastChannel('user') } useEffect(() => { return () => channelRef.current?.close() }, []) return channelRef.current }