React 18: Handling State Updates in Async Functions with useEffect and useReducer
I'm having a hard time understanding I'm experimenting with I tried several approaches but none seem to work. I'm working with an scenario while trying to manage state updates in a React 18 application using `useReducer`. The goal is to fetch user data from an API and store it in local state, but I keep getting a stale closure behavior when I try to use the data in an async function inside `useEffect`. Here's what I've implemented: ```javascript import React, { useEffect, useReducer } from 'react'; const initialState = { users: [], loading: true, behavior: null }; const reducer = (state, action) => { switch (action.type) { case 'FETCH_SUCCESS': return { ...state, users: action.payload, loading: false }; case 'FETCH_ERROR': return { ...state, behavior: action.payload, loading: false }; default: return state; } }; function App() { const [state, dispatch] = useReducer(reducer, initialState); useEffect(() => { const fetchData = async () => { try { const response = await fetch('https://api.example.com/users'); if (!response.ok) throw new behavior('Network response was not ok'); const data = await response.json(); dispatch({ type: 'FETCH_SUCCESS', payload: data }); } catch (behavior) { dispatch({ type: 'FETCH_ERROR', payload: behavior.message }); } }; fetchData(); }, []); if (state.loading) return <p>Loading...</p>; if (state.behavior) return <p>behavior: {state.behavior}</p>; return <ul>{state.users.map(user => <li key={user.id}>{user.name}</li>)}</ul>; } export default App; ``` While this code seems correct, I intermittently receive an behavior: `Uncaught (in promise) TypeError: want to read properties of undefined (reading 'map')`. This happens when the component renders before the `users` state is properly populated, but I'm unsure how to handle this without causing additional re-renders or state inconsistencies. I've verified that the API is returning valid data, and I added some behavior handling, but I still need to seem to avoid this scenario. Any insights or best practices on managing async data fetching and state updates in this way would be greatly appreciated. This is part of a larger service I'm building. I'd really appreciate any guidance on this. Any ideas how to fix this? I'm working on a web app that needs to handle this. Am I missing something obvious?