One additional thing we should add to our XMPPong game is the ability for clients to discover it. Recall that a DISCO#info request to the server will list the features that the room supports.

To do that, let’s but a handler in that recognizes when a DISCO request is being sent:

  socket.on('xmpp.discover.client', handleDisco)

You can place that right next to socket.on(‘xmpp.chat.message, handleMessage).

Now, we’ll implement the handleDisco function, which will send the identity of this client and the features it supports:

  function handleDisco(data) {
    socket.send(
      'xmpp.discover.client',
      {
        to: data.from,
        id: data.id,
        features: [
          { kind: 'identity', type: 'text', name: 'XMPPong', 
            category: 'chat' },
          { kind: 'feature', var: 'http://jabber.org/protocol/chat' }
        ]
      },
      function(error, data) { console...