emit client errors like unauthorized (#204)

* emit client errors like unauthorized

* move messages to the top

lib/handlers/connect.js

@@ -22,6 +22,15 @@ var connectActions = [
   emptyQueue
 ]
 
+var errorMessages = [
+  '',
+  'unacceptable protocol version',
+  'identifier rejected',
+  'Server unavailable',
+  'bad user name or password',
+  'not authorized'
+]
+
 function handleConnect (client, packet, done) {
   client.connected = true
   client.clean = packet.clean
@@ -60,28 +69,35 @@ function authenticate (arg, done) {
     negate)
 
   function negate (err, successful) {
+    var errCode
     if (!err && successful) {
       client.broker.registerClient(client)
       return done()
     } else if (err) {
       if (err.returnCode && (err.returnCode >= 1 && err.returnCode <= 3)) {
+        errCode = err.returnCode
         write(client, {
           cmd: 'connack',
           returnCode: err.returnCode
         }, client.close.bind(client, done))
       } else {
         // If errorCode is 4 or not a number
+        errCode = 4
         write(client, {
           cmd: 'connack',
           returnCode: 4
         }, client.close.bind(client, done))
       }
     } else {
+      errCode = 5
       write(client, {
         cmd: 'connack',
         returnCode: 5
       }, client.close.bind(client, done))
     }
+    var error = new Error(errorMessages[errCode])
+    error.errorCode = errCode
+    client.broker.emit('clientError', client, error)
   }
 }