text: var express = require('express');
  var http = require('http');
  var app = express();
  var server = http.createServer(app);
  
  var io = require('socket.io')(server);
  var Redis = require('ioredis');
  var redis = new Redis();
  
  redis.subscribe('test-channel');
  
  redis.on('message', function (channel, message) {
      console.log('Message received');
      console.log(message);
  });
  
  io.on('connection', function (socket) {
      var room;
  
      socket.on('join', function (data) {
          room = data.room;
  
          socket.join(room);
          if (room in io.sockets.adapter.rooms) {
              io.sockets.in(room).emit('clients', {clientsNum: io.sockets.adapter.rooms[room].length});
          }
      });
  
      socket.on('disconnect', function () {
          if (room && room in io.sockets.adapter.rooms) {
              io.sockets.in(room).emit('clients', {clientsNum: io.sockets.adapter.rooms[room].length});
          }
      });
  });
  
  app.get('/', function (req, res) {
      res.send('Hello World!');
  });
  
  server.listen(3000, function () {
      console.log('Example app listening on port 3000!');
  });
  