doubles_UI_tests.rb

describe 'UI' do

  context 'player move messages' do
    before :each do
      board   = double('board')
      @ui     = UI.new(board)
      @player = double('player', :marker => 'X' )
    end

    describe '#first_move_message' do
      it "prints a message with the player's marker" do
        printed = capture_stdout { @ui.first_move_message(@player) }
        printed.should include("Player 'X'")
      end
    end

    describe '#next_move_message' do
      it "prints a message with the player's marker" do
        printed = capture_stdout { @ui.next_move_message(@player) }
        printed.should include("Player 'X'")
      end
    end

    describe '#winning_game_message' do
      it "prints a message with the player's marker" do
        printed = capture_stdout { @ui.winning_game_message(@player) }
        printed.should include("Player 'X'")
      end
    end
  ...
end