React State implementation guide After Fetch Call - Need guide with Race Conditions
I'm building a feature where I'm experiencing an scenario in my React application where the state does not seem to update correctly after making an asynchronous fetch call... I'm using React 18 and handling state with the `useState` and `useEffect` hooks. The fetch call is meant to retrieve user data from an API endpoint, but sometimes the state reflects stale data due to what I suspect may be a race condition. Here's a simplified version of my code: ```javascript import React, { useEffect, useState } from 'react'; const UserProfile = () => { const [user, setUser] = useState(null); useEffect(() => { const fetchUserData = async () => { const response = await fetch('https://api.example.com/user'); const data = await response.json(); setUser(data); }; fetchUserData(); }, []); return <div>{user ? `Hello, ${user.name}` : 'Loading...'}</div>; }; export default UserProfile; ``` The question arises when the component re-renders rapidly, such as when the user navigates quickly between different pages. In those cases, the state seems to get exploring on the previous user data instead of updating to the latest fetched data. Sometimes I even see the behavior in the console: `Uncaught (in promise) TypeError: want to read properties of null (reading 'name')` when the fetch call takes too long, and the component tries to access the `name` property before `user` is set. I've tried adding a cleanup function inside the `useEffect` to cancel the fetch call, but that didn't seem to resolve the scenario. I also considered using a local variable to store the fetched data temporarily before updating the state, but Iām not sure how to implement this correctly. Any insights on how I can ensure my state updates reliably in this scenario, or whether there are better practices to follow when making fetch calls in React? I'm working with Javascript in a Docker container on CentOS. Is there a simpler solution I'm overlooking? I'm working on a web app that needs to handle this.