ws library for WebSocket server in Node.js - Mini Project: Build & Apply

Basic WebSocket Server with ws Library

📖 Scenario: You want to create a simple WebSocket server that can accept connections from clients and send messages back and forth.This is useful for real-time chat apps, live notifications, or games.

🎯 Goal: Build a WebSocket server using the ws library in Node.js that listens on port 8080, accepts client connections, and sends a welcome message.

📋 What You'll Learn

Create a WebSocket server using the ws library

Listen on port 8080

Send a welcome message to each client when they connect

Log connection and message events to the console

💡 Why This Matters

🌍 Real World

WebSocket servers enable real-time communication for chat apps, live updates, multiplayer games, and collaborative tools.

💼 Career

Understanding how to build WebSocket servers is valuable for backend developers working on interactive web applications and real-time data streaming.

1

Install and import the ws library

Create a constant called WebSocketServer by requiring the ws library.

Node.js

# Your code here

Need a hint?

Use require('ws').Server to get the WebSocketServer class.

2

Create the WebSocket server on port 8080

Create a constant called wss and assign it a new WebSocketServer instance that listens on port 8080.

Node.js

const WebSocketServer = require('ws').Server;
# Your code here

Need a hint?

Use new WebSocketServer({ port: 8080 }) to create the server.

3

Add connection event listener

Use wss.on('connection', (ws) => { ... }) to listen for new client connections. Inside the callback, send the message 'Welcome to the server!' to the connected client using ws.send().

Node.js

const WebSocketServer = require('ws').Server;
const wss = new WebSocketServer({ port: 8080 });
# Your code here

Need a hint?

Use wss.on('connection', (ws) => { ws.send('Welcome to the server!'); }).

4

Log connection and message events

Inside the connection event callback, add a console.log to print 'Client connected'. Also, add a listener on ws for the 'message' event that logs Received: plus the message content.

Node.js

const WebSocketServer = require('ws').Server;
const wss = new WebSocketServer({ port: 8080 });
wss.on('connection', (ws) => {
    ws.send('Welcome to the server!');
    # Your code here
});

Need a hint?

Use console.log('Client connected') and ws.on('message', (message) => { console.log('Received: ' + message); }).