Add callback support to SlackBot::{send,reply}

src/bot.coffee

@@ -2,6 +2,7 @@
 {SlackTextMessage, ReactionMessage, PresenceMessage}                              = require "./message"
 SlackClient                                                                       = require "./client"
 pkg                                                                               = require "../package"
+Promise = require("bluebird");
 
 class SlackBot extends Adapter
 
@@ -80,10 +81,14 @@ class SlackBot extends Adapter
   # @param {...(string|Object)} messages - fully documented in SlackClient
   ###
   send: (envelope, messages...) ->
-    # TODO: if the sender is interested in the completion, the last item in `messages` will be a function
-    for message in messages
+    callback = ->
+    if typeof(messages[messages.length - 1]) == 'function'
+      callback = messages.pop()
+    messagePromises = messages.map (message) =>
+      return Promise.resolve() if typeof(message) is 'function'
       # NOTE: perhaps do envelope manipulation here instead of in the client (separation of concerns)
       @client.send(envelope, message) unless message is ""
+    Promise.all(messagePromises).then(callback.bind(null, null), callback)
 
   ###*
   # Hubot is replying to a Slack message
@@ -92,12 +97,16 @@ class SlackBot extends Adapter
   # @param {...(string|Object)} messages - fully documented in SlackClient
   ###
   reply: (envelope, messages...) ->
-    # TODO: if the sender is interested in the completion, the last item in `messages` will be a function
-    for message in messages
+    callback = ->
+    if typeof(messages[messages.length - 1]) == 'function'
+      callback = messages.pop()
+    messagePromises = messages.map (message) =>
+      return Promise.resolve() if typeof(message) is 'function'
       if message isnt ""
         # TODO: channel prefix matching should be removed
         message = "<@#{envelope.user.id}>: #{message}" unless envelope.room[0] is "D"
         @client.send envelope, message
+    Promise.all(messagePromises).then(callback.bind(null, null), callback)
 
   ###*
   # Hubot is setting the Slack conversation topic

test/bot.coffee

@@ -106,6 +106,10 @@ describe 'Send Messages', ->
     @stubs._dmmsg.should.eql 'message'
     @stubs._room.should.eql @stubs.user.id
 
+  it 'Should send a message with a callback', (done) ->
+    @slackbot.send {room: @stubs.channel.id}, 'message', done
+    @stubs._sendCount.should.equal 1
+    @stubs._msg.should.equal 'message'
 
 describe 'Client sending message', ->
   it 'Should append as_user = true', ->
@@ -136,6 +140,11 @@ describe 'Reply to Messages', ->
     @stubs._sendCount.should.equal 1
     @stubs._dmmsg.should.equal "message"
 
+  it 'Should call the callback', (done) ->
+    @slackbot.reply {user: @stubs.user, room: @stubs.channel.id}, 'message', done
+    @stubs._sendCount.should.equal 1
+    @stubs._msg.should.equal "<@#{@stubs.user.id}>: message"
+
 describe 'Setting the channel topic', ->
 
   it 'Should set the topic in channels', (done) ->