import { useEffect , useState } from "react" ; type State = Readonly < Object > ; interface Action { type : string ; } type Listener < S extends State > = ( ns : S , ps ? : S ) => void ; interface Store < S extends State , A extends Action > { dispatch : ( a : A ) => void ; getState : ( ) => S ; subscribe : ( listener : Listener < S > ) => ( ) => void ; } export default function useSelector < S extends State , A extends Action > ( store ) { const [ state , setState ] = useState ( store . getState ( ) ) ; useEffect ( ( ) => { const unsubscribe = store . subscribe ( ( ns ) => { setState ( ns ) ; } ) ; return ( ) => { unsubscribe ( ) ; } ; } , [ ] ) ; return state ; }