Handling Memory Leaks in a React App with Event Listeners on Scroll Events
Quick question that's been bugging me - I can't seem to get I'm currently facing an issue with memory leaks in my React application when setting up event listeners for scroll events. I'm using React 17 and have implemented a component that loads additional content on scrolling to the bottom. The component uses `useEffect` to add an event listener on mount, but I'm not sure how to properly clean it up. I wrote the following code: ```javascript import React, { useEffect, useState } from 'react'; const InfiniteScroll = () => { const [items, setItems] = useState([]); const loadMoreItems = () => { // Simulate fetching data setItems(prevItems => [...prevItems, ...Array.from({ length: 10 }, (_, i) => `Item ${prevItems.length + i + 1}`)]); }; useEffect(() => { const handleScroll = () => { if (window.innerHeight + document.documentElement.scrollTop !== document.documentElement.offsetHeight) return; loadMoreItems(); }; window.addEventListener('scroll', handleScroll); return () => { window.removeEventListener('scroll', handleScroll); }; }, []); return <div>{items.map(item => <div key={item}>{item}</div>)}</div>; }; export default InfiniteScroll; ``` While testing it, I noticed that my app's performance degraded significantly after several scrolls, and the browser console showed warnings about potential memory leaks. I suspect that the event listener might still be active after the component unmounts, even though I added a cleanup function. I've tried adding console logs in both the event handler and the cleanup function, and I see that the cleanup function does execute when the component unmounts, but the memory usage continues to rise. Is there something fundamental I'm missing or any best practices for managing scroll events in React to avoid memory leaks? Any insights would be greatly appreciated! For reference, this is a production service. What am I doing wrong?