👀 Views: 4490 💬 Answers: 1 📅 Created: 2025-06-07

react memory-leaks useEffect performance JavaScript

I'm building a feature where I'm performance testing and I'm facing a memory leak issue in my React application that becomes apparent as the component tree grows in complexity. The application is built using React 17 and has several components that subscribe to various events, particularly using the `useEffect` hook for adding event listeners. For instance, in one of my components, I have the following code: ```javascript import React, { useEffect } from 'react'; const MyComponent = () => { useEffect(() => { const handleResize = () => { console.log('Window resized!'); }; window.addEventListener('resize', handleResize); return () => { window.removeEventListener('resize', handleResize); }; }, []); return <div>Resize the window!</div>; }; export default MyComponent; ``` While I make sure to clean up the event listeners, I've noticed that over time, the memory usage of the application increases significantly, especially when navigating between different components within a SPA. I also tried using the React Developer Tools to check for potential memory leaks, and it shows that the listeners may not be getting removed properly, despite my cleanup function. I am also using a Redux store and `useSelector` to manage global state, which has become quite extensive. I’m concerned that there might be a deeper issue with how I manage state or how components are rendered. I've tried various approaches, such as optimizing the `useEffect` dependencies and even running a profiling session in Chrome, but the memory leak persists. Is there a best practice or pattern specifically for handling event listeners in React applications with large component trees? How can I ensure that these listeners are indeed cleaned up and to prevent memory leaks effectively? Any insights or suggestions would be greatly appreciated! I've been using Javascript for about a year now. I'm working in a Ubuntu 22.04 environment. Thanks, I really appreciate it!