Wednesday 17 October 2012

Tennis Kata - My Solution

Intentional practice is something that is strongly advocated at the company I work for.  What we do as intentional practice changes from time to time, but over the last few months we have spent a fair bit of time solving and resolving various kata's.

Here is what I eventually ended up with after numerous runs of the Tennis Kata.

Firstly, the code:

    
    public class Game
    {
        private readonly Point _servicePoint = new Point();
        private readonly Point _receiverPoint = new Point();

        public string Score
        {
            get
            {
                if (_servicePoint.ToString().Equals(Point.FORTY) 
                   && (_receiverPoint.ToString().Equals(Point.FORTY)))
                {
                    return "DEUCE";
                }
                return string.Format("{0}-{1}", _servicePoint, _receiverPoint);
            }
        }

        public void ScoreToService()
        {
            _servicePoint.Score(_receiverPoint);
        }

        public void ScoreToReceiver()
        {
            _receiverPoint.Score(_servicePoint);
        }
    }
 
    public class Point
    {
        public const string LOVE = "0";
        public const string FIFTEEN = "15";
        public const string THIRTY = "30";
        public const string FORTY = "40";
        public const string GAME = "GAME";
        public const string ADVANTAGE = "ADV";

        private string _score = LOVE;
        private Dictionary> _pointMap;

        public Point()
        {
            BuildPointMap();
        }

        public override string ToString()
        {
            return _score;
        }

        public void Score(Point opponentPoint)
        {
            _pointMap[_score].Invoke(opponentPoint);
        }

        private void BuildPointMap()
        {
            _pointMap = new Dictionary>
            {
               {Point.LOVE, o => { _score = Point.FIFTEEN; }},
               {Point.FIFTEEN, o => { _score = Point.THIRTY; }},
               {Point.THIRTY, o => { _score = Point.FORTY; }},
               {
                  Point.FORTY, o =>
                  {
                     if (o.ToString().Equals(Point.FORTY))
                     {
                        _score = ADVANTAGE;
                     }
                     else
                     {
                        _score = o.ToString().Equals(Point.ADVANTAGE) 
                                                             ? FORTY 
                                                             : GAME;
                     }
                  }
               },
               {Point.ADVANTAGE, o => { _score = GAME; }},
               {Point.GAME, o => 
                 { 
                  throw new ApplicationException("Game already completed!"); 
                 }
               }
            };
        }
    }

And the tests:
    
    [TestFixture]
    public class TestGame
    {
        [Test]
        public void NewGame_ShouldSetScore_0_0()
        {
            //---------------Set up test pack-------------------
            //---------------Assert Precondition----------------

            //---------------Execute Test ----------------------
            var game = new Game();

            //---------------Test Result -----------------------
            Assert.IsNotNull(game);
            Assert.AreEqual("0-0", game.Score);
        }

        [Test]
        public void ScoreToService_When_0_0_ShouldSetScore_15_0()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            //---------------Assert Precondition----------------
            Assert.AreEqual("0-0", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToService();
            //---------------Test Result -----------------------
            Assert.AreEqual("15-0", game.Score);
        }

        [Test]
        public void ScoreToReceiver_When_0_0_ShouldSetScore_0_15()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            //---------------Assert Precondition----------------
            Assert.AreEqual("0-0", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToReceiver();
            //---------------Test Result -----------------------
            Assert.AreEqual("0-15", game.Score);
        }

        [Test]
        public void ScoreToReceiver_When_15_15_ShouldSetScore_15_30()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            game.ScoreToService();
            game.ScoreToReceiver();
            //---------------Assert Precondition----------------
            Assert.AreEqual("15-15", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToReceiver();
            //---------------Test Result -----------------------
            Assert.AreEqual("15-30", game.Score);
        }

        [Test]
        public void ScoreToService_When_40_15_ShouldSetScore_GAME_15()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            game.ScoreToService();
            game.ScoreToService();
            game.ScoreToService();
            game.ScoreToReceiver();
            //---------------Assert Precondition----------------
            Assert.AreEqual("40-15", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToService();
            //---------------Test Result -----------------------
            Assert.AreEqual("GAME-15", game.Score);
        }

        [Test]
        public void ScoreToService_When_30_40_ShouldSetScore_DEUCE()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            game.ScoreToService();
            game.ScoreToService();
            game.ScoreToReceiver();
            game.ScoreToReceiver();
            game.ScoreToReceiver();
            //---------------Assert Precondition----------------
            Assert.AreEqual("30-40", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToService();
            //---------------Test Result -----------------------
            Assert.AreEqual("DEUCE", game.Score);
        }

        [Test]
        public void ScoreToService_When_DEUCE_ShouldSetScore_ADV_40()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            game.ScoreToService();
            game.ScoreToService();
            game.ScoreToService();

            game.ScoreToReceiver();
            game.ScoreToReceiver();
            game.ScoreToReceiver();
            //---------------Assert Precondition----------------
            Assert.AreEqual("DEUCE", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToService();
            //---------------Test Result -----------------------
            Assert.AreEqual("ADV-40", game.Score);
        }

        [Test]
        public void ScoreToReceiver_When_40_ADV_ShouldSetScore_40_GAME()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            game.ScoreToService();
            game.ScoreToService();
            game.ScoreToService();

            game.ScoreToReceiver();
            game.ScoreToReceiver();
            game.ScoreToReceiver();
            game.ScoreToReceiver();
            //---------------Assert Precondition----------------
            Assert.AreEqual("40-ADV", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToReceiver();
            //---------------Test Result -----------------------
            Assert.AreEqual("40-GAME", game.Score);
        }

        [Test]
        public void ScoreToReceiver_When_DEUCE_ShouldSetScore_40_ADV()
        {
            //---------------Set up test pack-------------------
            var game = new Game();
            game.ScoreToService();
            game.ScoreToService();
            game.ScoreToService();

            game.ScoreToReceiver();
            game.ScoreToReceiver();
            game.ScoreToReceiver();
            //---------------Assert Precondition----------------
            Assert.AreEqual("DEUCE", game.Score);

            //---------------Execute Test ----------------------
            game.ScoreToReceiver();
            //---------------Test Result -----------------------
            Assert.AreEqual("40-ADV", game.Score);
        }
    }

 
    [TestFixture]
    public class TestPoint
    {
        // ReSharper disable InconsistentNaming
        [Test]
        public void NewPoint_ShouldSetToString_0()
        {
            //---------------Set up test pack-------------------
            //---------------Assert Precondition----------------
            //---------------Execute Test ----------------------
            var point = new Point();
            //---------------Test Result -----------------------
            Assert.IsNotNull(point);
            Assert.AreEqual(Point.LOVE, point.ToString());
        }

        [Test]
        public void Score_When_0_ShouldSetToString_15()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.LOVE, point.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(new Point());
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.FIFTEEN, point.ToString());
        }

        [Test]
        public void Score_When_15_ShouldSetToString_30()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            point.Score(new Point());
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.FIFTEEN, point.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(new Point());
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.THIRTY, point.ToString());
        }

        [Test]
        public void Score_When_30_ShouldSetToString_40()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            point.Score(new Point());
            point.Score(new Point());
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.THIRTY, point.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(new Point());
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.FORTY, point.ToString());
        }

        [Test]
        public void Score_When_40_ShouldSetToString_GAME()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            point.Score(new Point());
            point.Score(new Point());
            point.Score(new Point());
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.FORTY, point.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(new Point());
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.GAME, point.ToString());
        }

        [Test]
        public void Score_When_40_40_ShouldSetToString_ADV()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            var opponentPoint = new Point();
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.FORTY, point.ToString(), "PRE CONDITION");
            Assert.AreEqual(Point.FORTY, opponentPoint.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(opponentPoint);
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.ADVANTAGE, point.ToString());
        }

        [Test]
        public void Score_When_40_ADV_ShouldSetToString_40()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            var opponentPoint = new Point();
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.FORTY, point.ToString(), "PRE CONDITION");
            Assert.AreEqual(Point.ADVANTAGE, opponentPoint.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(opponentPoint);
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.FORTY, point.ToString());
        }

        [Test]
        public void Score_When_ADV_40_ShouldSetToString_GAME()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            var opponentPoint = new Point();
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            opponentPoint.Score(point);
            point.Score(opponentPoint);
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.ADVANTAGE, point.ToString(), "PRE CONDITION");
            Assert.AreEqual(Point.FORTY, opponentPoint.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            point.Score(opponentPoint);
            //---------------Test Result -----------------------
            Assert.AreEqual(Point.GAME, point.ToString());
        }

        [Test]
        public void Score_When_GAME_0_ShouldError()
        {
            //---------------Set up test pack-------------------
            var point = new Point();
            var opponentPoint = new Point();
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            point.Score(opponentPoint);
            //---------------Assert Precondition----------------
            Assert.AreEqual(Point.GAME, point.ToString(), "PRE CONDITION");
            //---------------Execute Test ----------------------
            var ex = Assert.Throws(() => point.Score(opponentPoint));
            //---------------Test Result -----------------------
            StringAssert.Contains("Game already completed!", ex.Message);
        }
    }