👀 Views: 80 💬 Answers: 1 📅 Created: 2025-06-11

react websocket useeffect JavaScript

I'm currently working on a React 18 application that establishes a WebSocket connection to receive real-time updates from a server. I've implemented the connection within a `useEffect` hook, but I'm seeing some unexpected behavior where the connection continues even after the component unmounts, leading to memory leaks and multiple listeners being created. Here’s the relevant part of my code: ```javascript import React, { useEffect, useState } from 'react'; const WebSocketComponent = () => { const [messages, setMessages] = useState([]); let socket; useEffect(() => { socket = new WebSocket('wss://example.com/socket'); socket.onmessage = (event) => { setMessages((prevMessages) => [...prevMessages, event.data]); }; return () => { socket.close(); // Attempting to close the connection }; }, []); return ( <div> <h2>Messages</h2> <ul> {messages.map((msg, index) => ( <li key={index}>{msg}</li> ))} </ul> </div> ); }; ``` The question is that when I navigate away from this component, the WebSocket connection does not seem to close as expected. I’ve added the cleanup function to the `useEffect`, but I still notice multiple instances of listeners when I navigate back to the component, which results in duplicate messages being displayed. I also checked the browser’s performance tab, and it shows that the WebSocket connection still exists even after unmounting the component. I've tried using the `useRef` hook to store the socket instance, but the scenario continues. Am I missing something in the cleanup process, or is there another best practice for handling WebSocket connections in React? Any insights would be greatly appreciated! I'm using Javascript 3.11 in this project. I appreciate any insights!