advanced patterns with async/await in nested function calls inside React component
Quick question that's been bugging me - I've tried everything I can think of but I tried several approaches but none seem to work... I've looked through the documentation and I'm still confused about I'm working with an scenario with async/await in my React component where I'm trying to fetch user data based on an ID passed as a prop. The fetch function is nested within another function that handles the component's state updates. Here's a simplified version of my component: ```javascript import React, { useEffect, useState } from 'react'; const UserProfile = ({ userId }) => { const [userData, setUserData] = useState(null); const [behavior, setError] = useState(null); const fetchUserData = async (id) => { try { const response = await fetch(`https://api.example.com/users/${id}`); if (!response.ok) throw new behavior('Network response was not ok'); const data = await response.json(); setUserData(data); } catch (err) { console.behavior('Fetch behavior:', err); setError(err); } }; useEffect(() => { fetchUserData(userId); }, [userId]); if (behavior) return <div>behavior: {behavior.message}</div>; if (!userData) return <div>Loading...</div>; return <div>{userData.name}</div>; }; export default UserProfile; ``` The question arises when I change the `userId` prop rapidly (for example, when navigating through a list of users). I sometimes get an 'undefined' value for `userData` or the component ends up displaying outdated user data. I've verified that the API is returning the correct data based on the user ID, but it seems that the state updates in React are sometimes not reflecting immediately. I tried adding a cleanup function in the `useEffect`, but it didn't seem to resolve the scenario. Here’s what I attempted: ```javascript useEffect(() => { let isMounted = true; fetchUserData(userId).then(() => { if (isMounted) { setUserData(data); } }); return () => { isMounted = false; }; }, [userId]); ``` However, the question continues. Is there a better way to handle this situation to ensure that the state does not get corrupted or outdated? Any suggestions would be greatly appreciated. Has anyone else encountered this? This issue appeared after updating to Javascript 3.9. I'm working with Javascript in a Docker container on Ubuntu 20.04. Is this even possible?