socket-queue.js

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var port = process.env.PORT || 3000;

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

let queue = [];

io.on('connection', function(socket){
  socket.on('chat message', function(msg){
  	console.log(socket.id);
    io.emit('chat message', msg);
  });

  socket.join("Toilet");

  socket.on('book', function(msg){
  	queue.push(socket.id);
    socket.emit('book', queue.length);
  });

  socket.on('done', function(msg){
  	queue = queue.filter(id => id !== socket.id)
  	console.log(queue);
    io.to('Toilet').emit('done', {});
  });
});

http.listen(port, function(){
  console.log('listening on *:' + port);
});