public void DecreaseScoreByOne(int currentScore)
{
var sut = new TennisPlayer(currentScore);
sut.DecreaseScore();
var expectedScore = (TennisScore)(currentScore - 1);
Assert.AreEqual(expectedScore, sut.GetScore());
}
public void ThrowExceptionWhenInvalidScoreIsDecremented()
{
var sut = new TennisPlayer();
Assert.Throws <IndexOutOfRangeException>(() => sut.DecreaseScore());
}
