Merge pull request #69 from GavinDmello/master

presence module for aedes

README.md

@@ -329,6 +329,17 @@ specifying a `messageId` will send suback to the client.
 
 Disconnects the client
 
+-------------------------------------------------------
+<a name="clientpresence"></a>
+### client presence
+
+You can subscribe on the following $SYS topics to get client presence
+
+ - `$SYS/+/new/clients` - Will inform about new clients connections
+ - `$SYS/+/disconnect/clients` - Will inform about client disconnections
+The payload will contain the clientId of the connected/disconnected client
+
+
 <a name="todo"></a>
 ## Todo
 

aedes.js

@@ -270,6 +270,10 @@ Aedes.prototype.unregisterClient = function (client) {
   this.connectedClients--
   delete this.clients[client.id]
   this.emit('clientDisconnect', client)
+  this.publish({
+    topic: '$SYS/' + this.id + '/disconnect/clients',
+    payload: new Buffer(client.id, 'utf8')
+  }, noop)
 }
 
 function closeClient (client, cb) {

test/client-pub-sub.js

@@ -320,3 +320,55 @@ test('subscribe a client programmatically with full packet', function (t) {
     t.deepEqual(packet, expected, 'packet matches')
   })
 })
+
+test('get message when client connects', function (t) {
+  t.plan(2)
+  var client1 = 'gav'
+  var broker = aedes()
+
+  broker.on('client', function (client) {
+    client.subscribe({
+      subscriptions: [{
+        topic: '$SYS/+/new/clients',
+        qos: 0
+      }]
+    }, function (err) {
+      t.error(err, 'no error')
+    })
+  })
+
+  var s1 = connect(setup(broker), { clientId: client1 })
+
+  s1.outStream.on('data', function (packet) {
+    t.equal(client1, packet.payload.toString())
+  })
+})
+
+test('get message when client disconnects', function (t) {
+  t.plan(2)
+  var client1 = 'gav'
+  var client2 = 'friend'
+  var broker = aedes()
+
+  broker.on('client', function (client) {
+    if (client.id === client1) {
+      client.subscribe({
+        subscriptions: [{
+          topic: '$SYS/+/disconnect/clients',
+          qos: 0
+        }]
+      }, function (err) {
+        t.error(err, 'no error')
+      })
+    } else {
+      client.close()
+    }
+  })
+
+  var s1 = connect(setup(broker), { clientId: client1 })
+  connect(setup(broker), { clientId: client2 })
+
+  s1.outStream.on('data', function (packet) {
+    t.equal(client2, packet.payload.toString())
+  })
+})

test/qos2.js

@@ -129,9 +129,11 @@ test('call published method with client with QoS 2', function (t) {
   }
 
   broker.published = function (packet, client, cb) {
-    t.ok(client, 'client must be passed to published method')
-
-    cb()
+    // Client is null for all server publishes
+    if (packet.topic.split('/')[0] !== '$SYS') {
+      t.ok(client, 'client must be passed to published method')
+      cb()
+    }
   }
 
   subscribe(t, subscriber, 'hello', 2, function () {