Send a message on invite commands when the user doesn't exist or is a…

…lready in the channel

packages/rocketchat-slashcommands-invite/invite.coffee

@@ -22,10 +22,22 @@ else
 			user = Meteor.users.findOne({ username: username })
 
 			if not user?
+				RocketChat.Notifications.notifyUser Meteor.userId(), 'message', {
+					_id: Random.id()
+					rid: item.rid
+					ts: new Date
+					msg: "No user exists by the name of `#{username}`."#TODO: Make this a language setting
+				}
 				return
 
 			# cancel if the user is already in this room
 			if RocketChat.models.Rooms.findOneByIdContainigUsername(item.rid, user.username)?
+				RocketChat.Notifications.notifyUser Meteor.userId(), 'message', {
+					_id: Random.id()
+					rid: item.rid
+					ts: new Date
+					msg: "`#{username}` is already in here."#TODO: Make this a language setting
+				}
 				return
 
 			Meteor.runAsUser user._id, ->