index.js

var express = require('express');
var app = express();
var server = require('http').Server(app);
var io = require('socket.io')(server);

var rooms = 0;

app.use(express.static('.'));

app.get('/', function (req, res) {
    res.sendFile(__dirname + '/game.html');
});

io.on('connection', function (socket) {
    /**
     * Create a new game room and notify the creator of game.
     */
    socket.on('createGame', function (data) {
        socket.join('room-' + ++rooms);
        socket.emit('newGame', {
            name: data.name,
            room: 'room-' + rooms
        });
    });

    /**
     * Connect the Player 2 to the room he requested. Show error if room full.
     */
    socket.on('joinGame', function (data) {
        var room = io.nsps['/'].adapter.rooms[data.room];
        if (room && room.length == 1) {
            socket.join(data.room);
            console.log("pass");
            socket.to(data.room).emit("joined", {
                name: data.name,
                id: room
            });
        } else {
            socket.to(room).emit('err', {
                message: 'Sorry, The room is full!'
            });
        }
    });

    /**
     * Handle the turn played by either player and notify the other.
     */
    socket.on('played', function (data) {
        socket.broadcast.to(data.room).emit('turnPlayed', {
            tile: data.tile,
            index: data.index
        });
    });

    /**
     * Notify the players about the victor.
     */
    socket.on('gameEnded', function (data) {
        socket.broadcast.to(data.room).emit('gameEnd', data);
    });
});

server.on('listening', function () {
    console.log('ok, server is running');
});

server.listen(3000);