CheckoutKata/CheckoutKataTests/CheckoutTests.cs

using System.Collections.Generic;
using CheckoutKata;
using FluentAssertions;
using Xunit;

namespace CheckoutKataTests
{
	public class CheckoutTests
	{
		private class Products : IProducts
		{
			private readonly Dictionary<string, Product> _products = new Dictionary<string, Product> {
				{"A", new SpecialPriceProduct(50, 130, 3)},
				{"B", new SpecialPriceProduct(30, 45, 2)},
				{"C", new Product(20)}
			};
			public Product GetBySKU(string sku) => _products[sku];
		}

		[Fact]
		public void Scan_WithOneProductCosting50_GetTotalPriceReturns50()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("A");
			checkout.GetTotalPrice().Should().Be(50);
		}

		[Fact]
		public void Scan_WithTwoProductsCosting50_GetTotalPriceReturns100()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("A");
			checkout.Scan("A");
			checkout.GetTotalPrice().Should().Be(100);
		}

		[Fact]
		public void Scan_WithThreeSpecialPriceProductsCosting50_GetTotalPriceReturns130()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("A");
			checkout.Scan("A");
			checkout.Scan("A");
			checkout.GetTotalPrice().Should().Be(130);
		}

		[Fact]
		public void Scan_WithOneProductCosting30_GetTotalPriceReturns30()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("B");
			checkout.GetTotalPrice().Should().Be(30);
		}

		[Fact]
		public void Scan_WithTwoSpecialPriceProductsCosting30_GetTotalPriceReturns45()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("B");
			checkout.Scan("B");
			checkout.GetTotalPrice().Should().Be(45);
		}

		[Fact]
		public void Scan_WithThreeSpecialPriceProductsCosting30_GetTotalPriceReturns75()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("B");
			checkout.Scan("B");
			checkout.Scan("B");
			checkout.GetTotalPrice().Should().Be(75);
		}

		[Fact]
		public void Scan_WithOneProductCosting20_GetTotalPriceReturns20()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("C");
			checkout.GetTotalPrice().Should().Be(20);
		}

		[Fact]
		public void Scan_WithTwoProductsCosting20_GetTotalPriceReturns40()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("C");
			checkout.Scan("C");
			checkout.GetTotalPrice().Should().Be(40);
		}

		[Fact]
		public void Scan_WithThreeDifferentProductsCosting50_GetTotalPriceReturns95()
		{
			var checkout = new Checkout(new Products());
			checkout.Scan("B");
			checkout.Scan("A");
			checkout.Scan("B");
			checkout.GetTotalPrice().Should().Be(95);
		}
	}
}