move forward when facing east or west.

2 files changed, 23 insertions, 1 deletions

diff --git a/lib/rover.rb b/lib/rover.rb
index 35ab1f9..90d7757 100644
--- a/lib/rover.rb
+++ b/lib/rover.rb
@@ -42,6 +42,9 @@ class East
   def turn_left
     North.new
   end
+  def forward(current_location)
+    current_location[:x] = current_location[:x]+1
+  end
 end
 class West
   def direction
@@ -53,6 +56,9 @@ class West
   def turn_left
     South.new
   end
+  def forward(current_location)
+    current_location[:x] = current_location[:x]-1
+  end
 end
 class South
   def direction
diff --git a/spec/rover_specs.rb b/spec/rover_specs.rb
index c8e5ec8..a54e2c2 100644
--- a/spec/rover_specs.rb
+++ b/spec/rover_specs.rb
@@ -73,11 +73,19 @@ describe Rover do
         @sut.heading.must_equal :north
       end
     end
+    describe "when driving forward" do
+      before do
+        @sut.move_forward(@terrain)
+      end
+      it "should increment the x coordinate on the terrain" do
+        @sut.location.must_equal({:x => 1, :y => 0})
+      end
+    end
   end
 
   describe "when facing west" do
     before do
-      @sut = create_sut :west
+      @sut = create_sut :west, 1, 0
     end
     describe "when turning right" do
       it "should face north" do
@@ -91,6 +99,14 @@ describe Rover do
         @sut.heading.must_equal :south
       end
     end
+    describe "when driving forward" do
+      before do
+        @sut.move_forward(@terrain)
+      end
+      it "should decrement the x coordinate on the terrain" do
+        @sut.location.must_equal({:x => 0, :y => 0})
+      end
+    end
   end
 
 end