public void Buy3MilksGet4thFreeRule_IsApplicable_ShouldReturn_Correctly()
{
List <IBasketItem> basketItems = null;
var rule = new Buy3MilksGet4thFreeRule();
Assert.IsFalse(rule.IsApplicable(basketItems));
basketItems = new List <IBasketItem>();
Assert.IsFalse(rule.IsApplicable(basketItems));
var milk = new Product()
{
Name = "Milk",
Price = 1.15
};
basketItems.Add(new BasketItem(milk, 1));
Assert.IsFalse(rule.IsApplicable(basketItems));
basketItems[0].Quantity++;
Assert.IsFalse(rule.IsApplicable(basketItems));
basketItems[0].Quantity++;
Assert.IsFalse(rule.IsApplicable(basketItems));
basketItems[0].Quantity++;
Assert.IsTrue(rule.IsApplicable(basketItems));
}
public void Buy3MilksGet4thFreeRule_ApplyDiscount_ShouldApply_Correctly()
{
List <IBasketItem> basketItems = null;
var rule = new Buy3MilksGet4thFreeRule();
Assert.AreEqual(0, rule.ApplyDiscount(basketItems));
basketItems = new List <IBasketItem>();
Assert.AreEqual(0, rule.ApplyDiscount(basketItems));
var milk = new Product()
{
Name = "Milk",
Price = 1.15
};
basketItems.Add(new BasketItem(milk, 1));
Assert.AreEqual(0, rule.ApplyDiscount(basketItems));
basketItems[0].Quantity++;
Assert.AreEqual(0, rule.ApplyDiscount(basketItems));
basketItems[0].Quantity++;
Assert.AreEqual(0, rule.ApplyDiscount(basketItems));
basketItems[0].Quantity++;
Assert.AreEqual(1.15, rule.ApplyDiscount(basketItems));
}