Function createStore

zustand-test/src/myZustand.js:3–40

(createState)

import { useSyncExternalStore } from "react";

const createStore = (createState) => {
    let state;
    const listeners = new Set();
  
    const setState = (partial, replace) => {
      const nextState = typeof partial === 'function' ? partial(state) : partial

      if (!Object.is(nextState, state)) {
        const previousState = state;

        if(!replace) {
            state = (typeof nextState !== 'object' || nextState === null)
                ? nextState
                : Object.assign({}, state, nextState);
        } else {
            state = nextState;
        }
        listeners.forEach((listener) => listener(state, previousState));
      }
    }
  
    const getState = () => state;
  
    const subscribe= (listener) => {
      listeners.add(listener)
      return () => listeners.delete(listener)
    }
  
    const destroy= () => {
      listeners.clear()
    }
  
    const api = { setState, getState, subscribe, destroy }

    state = createState(setState, getState, api)

    return api
}

function useStore(api, selector) {
    function getState() {