Handling Race Conditions in a React Component with Concurrent API Calls to Update State
Quick question that's been bugging me - This might be a silly question, but I'm working with a race condition in my React component where I make multiple API calls to fetch user data and settings simultaneously... I’m using `useEffect` to trigger these calls based on a user ID, but sometimes the state updates overlap, leading to inconsistent UI behavior. The function is structured like this: ```javascript import React, { useEffect, useState } from 'react'; const UserProfile = ({ userId }) => { const [userData, setUserData] = useState(null); const [userSettings, setUserSettings] = useState(null); useEffect(() => { const fetchUserData = async () => { const response = await fetch(`/api/users/${userId}`); const data = await response.json(); setUserData(data); }; const fetchUserSettings = async () => { const response = await fetch(`/api/users/${userId}/settings`); const settings = await response.json(); setUserSettings(settings); }; fetchUserData(); fetchUserSettings(); }, [userId]); if (!userData || !userSettings) return <div>Loading...</div>; return ( <div> <h1>{userData.name}</h1> <p>Settings: {JSON.stringify(userSettings)}</p> </div> ); }; ``` The scenario arises when `fetchUserData` and `fetchUserSettings` return at different times. If `fetchUserSettings` resolves after an updated `userData`, it could display stale or incorrect information. I’ve tried using an `AbortController` to cancel the previous fetch calls when `userId` changes, but I’m still working with inconsistencies. Here’s the adjusted fetch function with the abort logic: ```javascript useEffect(() => { const controller = new AbortController(); const signal = controller.signal; const fetchUserData = async () => { try { const response = await fetch(`/api/users/${userId}`, { signal }); const data = await response.json(); setUserData(data); } catch (err) { if (err.name === 'AbortError') return; console.behavior('Fetch user data failed', err); } }; const fetchUserSettings = async () => { try { const response = await fetch(`/api/users/${userId}/settings`, { signal }); const settings = await response.json(); setUserSettings(settings); } catch (err) { if (err.name === 'AbortError') return; console.behavior('Fetch user settings failed', err); } }; fetchUserData(); fetchUserSettings(); return () => { controller.abort(); }; }, [userId]); ``` However, I'm still seeing instances where the UI reflects outdated data. Is there a better way to handle these concurrent calls to ensure the latest responses are the only ones that update the state? Any help on managing this more effectively would be appreciated! This is my first time working with Javascript 3.10. Has anyone else encountered this? I'm using Javascript 3.9 in this project. What's the correct way to implement this?