Feature: Initial attempt at the exercise.

train.rb

@@ -1,15 +1,35 @@
 class Conductor
 
-	attr_reader :engineer
+  attr_reader :engineer
+	attr_reader :message_board
 
-	def initialize(engineer)
-		@engineer = engineer
+	def initialize(message_board, engineer)
+    @engineer = engineer
+		@message_board = message_board
 	end
 
 	def see_danger_coming!
-		engineer.slow_down!
+		message_board.send_message(engineer.slow_down!)
 	end
 end
 
 class Engineer
-end
+
+  attr_reader :message_board
+
+  def initialize(message_board)
+    @message_board = message_board
+  end
+
+  def avert_danger!
+    message_board.confirm_slow_down
+  end
+end
+
+class MessageBoard
+
+  def send_message(message)
+    message
+  end
+
+end

train_spec.rb

@@ -2,12 +2,29 @@
 require './train'
 describe Conductor do
 
-	let(:engineer) { Engineer.new }
-	let(:conductor) { Conductor.new(engineer)}
-
-	it "should tell the engineer to slow down" do
-		engineer.should_receive(:slow_down!)
-		conductor.see_danger_coming!
-	end
-
-end
+	let(:message_board) { MessageBoard.new()}
+  let(:engineer) { Engineer.new (message_board)}
+  let(:conductor) { Conductor.new(message_board,engineer)}
+
+  it "sees trouble and tells the engineer to slow down via the message board" do
+    engineer.should_receive(:slow_down!)
+    conductor.see_danger_coming!
+  end
+end
+
+describe Engineer do
+
+  let(:message_board) { MessageBoard.new()}
+  let(:engineer) { Engineer.new (message_board)}
+  let(:conductor) { Conductor.new(message_board,engineer)}
+
+  it "receives the slows down message" do
+    engineer.should_receive(:slow_down!)
+    conductor.see_danger_coming!
+  end
+
+  it "replies back with the confirmation message via the message board" do
+    message_board.should_receive(:confirm_slow_down)
+    engineer.avert_danger!
+  end
+end