public void Process_WhenValidProductsListEntered()
{
double applePrice = 1.25;
double biscuitPrice = 4.25;
double cheesePrice = 1.00;
double dairyMilkPrice = 0.75;
_applePromoProcessor.Setup(p => p.Apply(3, applePrice)).Returns(3.00);
_applePromoProcessor.Setup(p => p.Apply(1, applePrice)).Returns(1.25);
_biscuitPromoProcessor.Setup(p => p.Apply(2, biscuitPrice)).Returns(8.50);
_biscuitPromoProcessor.Setup(p => p.Apply(1, biscuitPrice)).Returns(4.25);
_cheesePromoProcessor.Setup(p => p.Apply(1, cheesePrice)).Returns(1.00);
_cheesePromoProcessor.Setup(p => p.Apply(7, cheesePrice)).Returns(6.00);
_dairyMilkPromoProcessor.Setup(p => p.Apply(1, dairyMilkPrice)).Returns(0.75);
var posService = new PosService(_portfolio, _applePromoProcessor.Object, _biscuitPromoProcessor.Object,
_cheesePromoProcessor.Object, _dairyMilkPromoProcessor.Object);
var totalPrice = posService.Process("ABCDABA");
Assert.Equal(13.25, totalPrice);
totalPrice = posService.Process("CCCCCCC");
Assert.Equal(6.00, totalPrice);
totalPrice = posService.Process("ABCD");
Assert.Equal(7.25, totalPrice);
}