public void Discount15ShouldDecreasePriceAfterTax()
{
Product product = Product.Sample;
Discount discount = new Discount(15);
AffectPriceResult result = discount.ApplyTo(product.Price);
string expected = "Discount: rate = 15%, amount = $3.04. Price: before = $20.25, after = $17.21";
Assert.AreEqual(expected, result.DescribeWith(product, discount));
}
public void NoneDiscountShouldNotAffectPrice()
{
Product product = Product.Sample;
Discount discount = Discount.None;
AffectPriceResult result = discount.ApplyTo(product.Price);
string expected = "Discount: rate = 0%, amount = $0.00. Price: before = $20.25, after = $20.25";
Assert.AreEqual(expected, result.DescribeWith(product, discount));
}
public void Tax20Discount15ShouldAffectPriceAfterTax()
{
Product product = Product.Sample;
Tax tax = new Tax(20);
AffectPriceResult taxResult = tax.ApplyTo(product.Price);
Discount discount = new Discount(15);
AffectPriceResult discountResult = discount.ApplyTo(product.Price);
Amount priceAfterAll = product.Price + taxResult.AffectedAmount - discountResult.AffectedAmount;
Assert.AreEqual("20%", tax.ToString());
Assert.AreEqual("$4.05", taxResult.AffectedAmount.ToString());
Assert.AreEqual("15%", discount.ToString());
Assert.AreEqual("$3.04", discountResult.AffectedAmount.ToString());
Assert.AreEqual("$21.26", priceAfterAll.ToString());
}