server.js

var express = require('express');
var app = express();
var http = require('http').createServer(app);
var io = require('socket.io').listen(http);
var port = 3000;
var RateLimiter = require('limiter').RateLimiter;
var limiter = new RateLimiter(1, 50, true); // fire CB immediately

// serve any file out of the current directory
app.use(express.static(__dirname));

// serve the index.html file by default
app.get('/', function(req, res) {
  res.sendfile(__dirname + '/index.html');
});


var warriors = [
  { id: 1, name: 'Chuck Norris', wins: 0, image: 'assets/images/chuck-norris.jpg' },
  { id: 2, name: 'Mr. T', wins: 0, image: 'assets/images/mr-t.jpg' },
  { id: 3, name: 'Darth Vader', wins: 0, image: 'assets/images/darth-vader.jpg' },
  { id: 4, name: 'Rocky Balboa', wins: 0, image: 'assets/images/rocky-balboa.jpg' },
  { id: 5, name: 'T2000', wins: 0, image: 'assets/images/t2000.jpg' },
  { id: 6, name: 'Nitro', wins: 0, image: 'assets/images/nitro.jpg' }
];

io.on('connection', function(socket) {
  console.log('new client connected');
  socket.emit('init', warriors);

  socket.on('warriorSelection', function(selectedId) {

    // limit the incoming events to help prevent hacking
    limiter.removeTokens(1, function(err, remainingRequests) {
      // disconnect malicious users
      if (remainingRequests < 0) {
        socket.emit('tooManyRequests');
        socket.disconnect('unauthorized');
      }
      // otherwise, process the incoming request
      else {
        console.log('warriorSelection', selectedId);
        var newWarriors = warriors.map(function(warrior) {
          if (warrior.id === selectedId) warrior.wins++;
          return warrior;
        });
        io.sockets.emit('allWarriorsData', newWarriors);
        warriors = newWarriors;
      }
    });

  });

});


// start the http server at port defined above
http.listen(port, function() {
  console.log("Server up and running on port:" + port);
});