public void Given_FourMilk_WhenBuyThreeMilksGetOneFree_ReturnOnePointOneFive()
{
var testData = new List <Product>
{
new Product
{
PriceInPounds = 1.15m,
DisplayName = "Milk",
Quantity = 4,
Id = Product.MilkId
}
};
var result = _offerService.BuyThreeMilksGetOneFree(testData);
Assert.AreEqual(1.15m, result);
}