Use Express middleware before initiating web socket connection.
npm install --save express-websocketvar express = require('express');
var http = require('http');
var ws = require('ws');
var handleUpgrade = require('express-websocket');
var app = express();
var server = http.createServer(app);
var wss = new ws.Server({ noServer: true });
app.use('/websocket', function (req, res, next) {
res.websocket(function (ws) {
// Optional callback
ws.send('hello');
});
});
server.on('upgrade', handleUpgrade(app, wss));
server.listen(3000);