import { useState } from 'react'; import { IHookStateInitAction, IHookStateSetAction, resolveHookState } from '../misc/hookState'; import useEffectOnce from '../useEffectOnce'; import useIsomorphicLayoutEffect from '../useIsomorphicLayoutEffect'; export function createGlobalState( initialState: IHookStateInitAction ): () => [S, (state: IHookStateSetAction) => void]; export function createGlobalState(): () => [ S, (state: IHookStateSetAction) => void ]; export function createGlobalState(initialState?: S) { const store: { state: S; setState: (state: IHookStateSetAction) => void; setters: any[]; } = { state: initialState instanceof Function ? initialState() : initialState, setState(nextState: IHookStateSetAction) { store.state = resolveHookState(nextState, store.state); store.setters.forEach((setter) => setter(store.state)); }, setters: [], }; return () => { const [globalState, stateSetter] = useState(store.state); useEffectOnce(() => () => { store.setters = store.setters.filter((setter) => setter !== stateSetter); }); useIsomorphicLayoutEffect(() => { if (!store.setters.includes(stateSetter)) { store.setters.push(stateSetter); } }); return [globalState, store.setState]; }; } export default createGlobalState;