Mocking HttpClient

AlwaysReturns.cs

using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;

namespace DotUpgrade.Test
{
	class AlwaysReturns : HttpMessageHandler
	{
		readonly HttpStatusCode StatusCode;

		public AlwaysReturns(HttpStatusCode statusCode)
		{
			StatusCode = statusCode;
		}

		protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
			=> Task.FromResult(new HttpResponseMessage(StatusCode));
	}
}

SampleTests.cs

using System.Net;
using System.Net.Http;
using Xunit;

namespace DotUpgrade.Test
{
	public class SampleTests
	{
		[Fact]
		public void Should_Return_Indicated_Code()
		{
			var httpClient = new HttpClient(new AlwaysReturns(HttpStatusCode.Conflict));
			var response = httpClient.GetAsync("http://www.google.com").Result;
			Assert.Equal(HttpStatusCode.Conflict, response.StatusCode);
		}
	}
}