CustomHostWithTestServer.cs

namespace Microsoft.Owin.Testing.Tests
{
    using System;
    using System.Collections.Generic;
    using System.IO;
    using System.Threading.Tasks;
    using Xunit;

    public class TestServerTests
    {
        [Fact]
        public async Task HangsIndefintely()
        {
            // because task is never completed
            var testServer = TestServer.Create(builder => builder.Use(typeof(CustomOwinApp), false));
            await testServer.HttpClient.GetAsync("http://example.com/custom");
        }

        [Fact]
        public async Task ThrowsObjectDisposedException()
        {
            // because the (memory)stream is closed by the app, and the server attempts to
            // seek, ObjectDisposedException occurs.
            var testServer = TestServer.Create(builder => builder.Use(typeof(CustomOwinApp), true));
            await testServer.HttpClient.GetAsync("http://example.com/custom");
        }

        public class CustomOwinApp
        {
            private readonly Func<IDictionary<string, object>, Task> _next;
            private readonly bool _completeTheTask;

            public CustomOwinApp(Func<IDictionary<string, object>, Task> next, bool completeTheTask)
            {
                _next = next;
                _completeTheTask = completeTheTask;
            }

            public Task Invoke(IDictionary<string, object> environment)
            {
                var path = environment.Get<string>("owin.RequestPath");

                if (path == "/custom")
                {
                    var tcs = new TaskCompletionSource<int>();
                    var headers = environment.Get<IDictionary<string, string[]>>("owin.ResponseHeaders");
                    headers["Content-Type"] = new[] { "text/html" };
                    var body = environment.Get<Stream>("owin.ResponseBody");

                    using (var writer = new StreamWriter(body))
                    {
                        writer.Write("Response from the custom host2.");
                    }

                    if (_completeTheTask)
                    {
                        tcs.SetResult(0);
                    }
                    return tcs.Task;
                }

                return _next.Invoke(environment);
            }
        }
    }
}