public void GetDiscount_throws_null_argument_exception_when_passed_null_object()
{
// Arrrange
var offer = new FreeMilkOffer();
// Assert
Assert.Throws <ArgumentNullException>(() => offer.GetDiscount(null));
}
public void GetDiscount_returns_correct_dicscount_amount(int milkCount, decimal expected)
{
// Arrange
var offer = new FreeMilkOffer();
var items = new List <IProduct>();
for (int i = 0; i < milkCount; i++)
{
items.Add(new Milk());
}
// Act
var result = offer.GetDiscount(items);
// Assert
Assert.Equal(expected, result);
}
