Choose open edge as a last resort

lib/board.rb

@@ -19,6 +19,14 @@ def open_spaces
       @spaces.select { |space| space.open? }
     end
 
+    def open_edge_spaces
+      open_spaces.select { |space| space.edge? }
+    end
+
+    def edge_spaces
+      @spaces.select { |space| space.edge? }
+    end
+
     def open_corner_spaces
       open_spaces.select { |space| space.corner? }
     end

lib/player.rb

@@ -21,6 +21,7 @@ def move
       space ||= center
       space ||= opposite_corner
       space ||= corner
+      space ||= edge
       space
     end
 
@@ -55,5 +56,9 @@ def opposite_corner
     def corner
       @board.open_corner_spaces.first
     end
+
+    def edge
+      @board.open_edge_spaces.first
+    end
   end
 end

spec/player_spec.rb

@@ -310,5 +310,15 @@ module TicTacToe
         player.move.row_and_column.should eql "0 0"
       end
     end
+
+    context "edge" do
+      it "chooses the first available edge" do
+        player = Player.new("X", [ ["X", "O", "X"],
+                                   ["O", "X", "_"],
+                                   ["O", "X", "O"] ])
+
+        player.move.row_and_column.should eql "1 2"
+      end
+    end
   end
 end