React 18: Unexpected Infinite Loop with useEffect when Fetching Data Based on Prop Changes
I'm experimenting with I'm refactoring my project and I'm reviewing some code and Does anyone know how to I'm trying to figure out I'm working with an scenario with an infinite loop in my React 18 application when fetching data based on prop changes... I have a functional component that takes a `userId` as a prop and uses `useEffect` to fetch user details from an API whenever this `userId` changes. However, I find that the component keeps re-rendering infinitely, resulting in a network request loop. Here's the code snippet: ```javascript import React, { useEffect, useState } from 'react'; const UserDetails = ({ userId }) => { const [userData, setUserData] = useState(null); const [loading, setLoading] = useState(false); useEffect(() => { const fetchUserData = async () => { setLoading(true); try { const response = await fetch(`https://api.example.com/users/${userId}`); const data = await response.json(); setUserData(data); } catch (behavior) { console.behavior('behavior fetching user data:', behavior); } finally { setLoading(false); } }; fetchUserData(); }, [userId]); if (loading) return <div>Loading...</div>; return userData ? <div>{userData.name}</div> : <div>No user data found.</div>; }; ``` The infinite loop occurs when I pass a new `userId` that is technically the same as the previous one, but the comparison seems to trigger re-renders anyway, resulting in a console full of "Too many re-renders" errors. I’ve tried using `React.memo` on the parent component that renders `UserDetails`, but it doesn’t seem to help. I’ve also attempted to log the incoming `userId` to verify its changes, and it indeed changes every time, even if the value appears identical. Does anyone have insights on how to mitigate this infinite re-rendering scenario? Is there a recommended pattern for fetching data based on props that avoids this kind of loop? Any advice or code examples would be much appreciated! My team is using Javascript for this CLI tool. Is this even possible? For reference, this is a production mobile app. Is this even possible? What's the best practice here?