public void AppliedPromotionIsSetCorrectly()
{
_mockPromotionRepository.Setup(x => x.All()).Returns(GetTestPromotions());
var productC = new Product("C", 20m);
var productD = new Product("D", 15m);
_sut.AddProduct(productC);
_sut.AddProduct(productD);
var appliedPromotionInfo = _sut.ApplyPromotions();
appliedPromotionInfo.Discount.ShouldBe(5);
}