webrtc-web: Not correctly checking number of clients in room (step-04)

In step-04/index.js the server checks how many clients are in the room by calling

var numClients = io.sockets.sockets.length;
log('Room ' + room + ' now has ' + numClients + ' client(s)');

However this returns undefined, as well as doesn’t actually try and check for the given room.

A proposed fix:

var clientsInRoom = io.nsps['/'].adapter.rooms[room];
var numClients = clientsInRoom === undefined ? 0 : Object.keys(clientsInRoom).length;

Or if you also want to upgrade to socket v1.4

var clientsInRoom = io.nsps['/'].adapter.rooms[room];
var numClients = clientsInRoom === undefined ? 0 : Object.keys(clientsInRoom.sockets).length;

A full fix + some small cleans up 😃 would look like

var clientsInRoom = io.nsps['/'].adapter.rooms[room];
var numClients = clientsInRoom === undefined ? 0 : Object.keys(clientsInRoom).
// socket.io 1.4.8
var numClients = clientsInRoom === undefined ? 0 : Object.keys(clientsInRoom.sockets).length;

// max two clients
if (numClients === 2) {
  socket.emit('full', room);
  return;
}

log('Room ' + room + ' now has ' + (numClients + 1) + ' client(s)');

if (numClients === 0) {
  socket.join(room);
  log('Client ID ' + socket.id + ' created room ' + room);
  socket.emit('created', room, socket.id);

} else {
  log('Client ID ' + socket.id + ' joined room ' + room);
  io.sockets.in(room).emit('join', room);
  socket.join(room);
  socket.emit('joined', room, socket.id);
  io.sockets.in(room).emit('ready');
}

See: https://github.com/AlexRobinson-/webrtc-web/blob/fix-check-room-clients/step-04/index.js