public void Calculate_NegativeCount_Throws()
{
var pricingRule = new PriceDropOnMinimumPricingRule("productId", 2.0m, 3, 1.0m);
pricingRule.Invoking(pr => pr.Calculate(-1)).Should().Throw <ArgumentException>();
}
public void CalculateTests(decimal price, int minimumCount, decimal priceAfter, int count, decimal total)
{
var pricingRule = new PriceDropOnMinimumPricingRule("productId", price, minimumCount, priceAfter);
pricingRule.Calculate(count).Should().Be(total);
}