👀 Views: 2 💬 Answers: 1 📅 Created: 2025-06-06

react websocket useEffect memory-leak JavaScript

I'm following best practices but I've spent hours debugging this and I tried several approaches but none seem to work. I'm working with a memory leak scenario in my React application when I establish a WebSocket connection inside a `useEffect` hook. I initialize the connection when the component mounts, but it seems that the connection isn't being closed properly when the component unmounts. This leads to multiple active WebSocket connections if the component is mounted and unmounted multiple times. Here's my code snippet: ```javascript import React, { useEffect, useState } from 'react'; const WebSocketComponent = () => { const [data, setData] = useState(null); const [socket, setSocket] = useState(null); useEffect(() => { const ws = new WebSocket('ws://example.com/socket'); setSocket(ws); ws.onmessage = (event) => { setData(event.data); }; return () => { ws.close(); }; }, []); return <div>{data}</div>; }; ``` When I check the browser's performance tools, it shows multiple WebSocket connections even after the component has been unmounted. The console doesn't throw any errors, but I'm concerned about the performance implications. I've tried adding cleanup code to close the WebSocket, but it doesn't seem to be working as expected. Is there something I'm missing? How can I ensure that the WebSocket connection is properly closed when the component unmounts? For context: I'm using Javascript on Ubuntu. The stack includes Javascript and several other technologies. Has anyone else encountered this? Could someone point me to the right documentation?