aspnetcore/test/MusicStore.Spa.Test/ShoppingCartTest.cs

using System.Collections.Generic;
using Microsoft.AspNet.Http;
using Microsoft.AspNet.Http.Features.Internal;
using Microsoft.AspNet.Http.Internal;
using Xunit;

namespace MusicStore.Models
{
    public class ShoppingCartTest
    {
        [Fact]
        public void GetCartId_ReturnsCartIdFromCookies()
        {
            // Arrange
            var cartId = "cartId_A";

            var httpContext = new DefaultHttpContext();
            httpContext.SetFeature<IRequestCookiesFeature>(new CookiesFeature("Session", cartId));

            var cart = new ShoppingCart(new MusicStoreContext());

            // Act
            var result = cart.GetCartId(httpContext);

            // Assert
            Assert.NotNull(result);
            Assert.Equal(cartId, result);
        }

        private class CookiesFeature : IRequestCookiesFeature
        {
            private readonly IReadableStringCollection _cookies;

            public CookiesFeature(string key, string value)
            {
                _cookies = new ReadableStringCollection(new Dictionary<string, string[]>()
                {
                    { key, new[] { value } }
                });
            }

            public IReadableStringCollection Cookies
            {
                get { return _cookies; }
            }
        }
    }
}