public void GivenListOfItems_WhenItemssAreValid_ReturnsTotalCostWithDiscounts()
{
//arrange
var listOfItems = TestVariables.GetFakeListOfItems();
Decimal totalApplePriceInList = listOfItems.Where(x => x.ItemName.ToLower() == "apple").Sum(y => y.ItemPrice);
Decimal totalOrangePriceInList = listOfItems.Where(x => x.ItemName.ToLower() == "orange").Sum(y => y.ItemPrice);
var appleDiscountPercent = 0.5M;
var orangeDiscountPercent = 2M / 3M;
var totalPriceInLIst = listOfItems.Sum(x => x.ItemPrice);
var totalDiscountedPrice = totalPriceInLIst - ((totalApplePriceInList * appleDiscountPercent) + (totalOrangePriceInList * orangeDiscountPercent));
var sut = new Checkout();
//act
var result = Decimal.Round(sut.CalculateTotalPriceAndApplyDiscounts(listOfItems), 2);
//Assert
Assert.Equal(Decimal.Round(totalDiscountedPrice, 2), result);
}