Refactor and reorganize message splitting

src/slack.coffee

@@ -3,6 +3,8 @@
 SlackClient = require 'slack-client'
 Util = require 'util'
 
+MAX_MESSAGE_LENGTH = 4000
+
 class SlackBot extends Adapter
   constructor: (robot) ->
     @robot = robot
@@ -107,27 +109,28 @@ class SlackBot extends Adapter
     for msg in messages
       @robot.logger.debug "Sending to #{envelope.room}: #{msg}"
 
-      # If message is greater than 4000 chars, split it into multiple msessages
-      if msg.length > 4000
+      if msg.length <= MAX_MESSAGE_LENGTH
+        channel.send msg
+
+      # If message is greater than MAX_MESSAGE_LENGTH, split it into multiple messages
+      else
         submessages = []
 
         while msg.length > 0
           # Split message at last line break, if it exists
-          chunk = msg.substring(0, 4000)
-          breakIndex = if chunk.lastIndexOf('\n') isnt -1 then chunk.lastIndexOf('\n') else 4000
+          chunk = msg.substring(0, MAX_MESSAGE_LENGTH)
+          breakIndex = chunk.lastIndexOf('\n')
+          breakIndex = MAX_MESSAGE_LENGTH if breakIndex is -1
 
           submessages.push msg.substring(0, breakIndex)
 
           # Skip char if split on line break
-          breakIndex++ if breakIndex isnt 4000
+          breakIndex++ if breakIndex isnt MAX_MESSAGE_LENGTH
 
           msg = msg.substring(breakIndex, msg.length)
 
         channel.send m for m in submessages
 
-      else
-        channel.send msg
-
   reply: (envelope, messages...) ->
     @robot.logger.debug "Sending reply"