public void Should_throw_ArgumentException_for_non_matching_orderitem()
{
var subject = new BuyXItemsGetYPercentOff("item-1", 3, 0.25m);
var incorrectItem = new OrderItem()
{
Identifier = "item-2", ItemCost = 10m, Quantity = 1
};
Assert.Throws <ArgumentException>(() => subject.CalculateItemPrice(incorrectItem));
}
public void When_having_exactly_x_items_the_discount_should_apply_to_all_of_them()
{
var subject = new BuyXItemsGetYPercentOff("item-1", 3, 0.25m);
var item = new OrderItem {
Identifier = "item-1", ItemCost = 10m, Quantity = 3
};
var actual = subject.CalculateItemPrice(item);
Assert.That(actual, Is.EqualTo(3 * 7.5m));
}
public void When_having_not_exact_sets_of_x_items_the_remaining_items_should_cost_full_price()
{
var subject = new BuyXItemsGetYPercentOff("item-1", 3, 0.25m);
var item = new OrderItem {
Identifier = "item-1", ItemCost = 10m, Quantity = 5
};
var actual = subject.CalculateItemPrice(item);
Assert.That(actual, Is.EqualTo(3 * 7.5m + 2 * 10m));
}