👀 Views: 63 💬 Answers: 1 📅 Created: 2025-08-20

react hooks memory-leak javascript

I'm testing a new approach and Hey everyone, I'm running into an issue that's driving me crazy... I'm working with a memory leak warning in my React application when navigating away from a component that uses the `useEffect` hook. The effect sets up a WebSocket connection to receive real-time updates. However, when the component unmounts, it seems that the cleanup function isn't being called as expected. Here's the code snippet: ```javascript import React, { useEffect } from 'react'; const RealTimeComponent = () => { useEffect(() => { const socket = new WebSocket('wss://example.com/socket'); socket.onmessage = (event) => { console.log('Message from server ', event.data); }; return () => { socket.close(); console.log('WebSocket closed'); }; }, []); return <div>Real-time updates here!</div>; }; export default RealTimeComponent; ``` I expect the cleanup function to be called when the component unmounts, but I still see the warning in the console indicating that there are memory leaks. I've tried adding dependencies to the `useEffect` hook and also tried using a `ref` to store the `WebSocket` instance, but nothing seems to solve the scenario. The warning message I receive is: "Warning: need to perform a React state update on an unmounted component." It happens when the `socket.onmessage` callback tries to execute after the component has been removed from the DOM. Am I missing something in how to properly handle the cleanup for the WebSocket, or is there a different approach I should take? I'm using React 17.0.2. Thanks for any help you can provide! I'm using Javascript LTS in this project. Am I approaching this the right way?