asp.net – Autofac OWIN TestServer和HttpContext

[TestClass]
public class TestBase
{
    private SimpleLifetimeScopeProvider _scopeProvider;
    private IDependencyResolver _originalResolver;
    private HttpConfiguration _configuration;
    public TestServer Server { get; private set; }

    [TestInitialize]
    public void Setup()
    {
        Server = TestServer.Create(app =>
        {
            //config webpai
            _configuration = new HttpConfiguration();
            WebApiConfig.Register(_configuration);

            // Build the container.
            var container = App_Start.IocConfig.RegisterDependencies(_configuration);
            _scopeProvider = new SimpleLifetimeScopeProvider(container);

            //set the mvc dep resolver
            var mvcResolver = new AutofacDependencyResolver(container,_scopeProvider);
            _originalResolver = DependencyResolver.Current;
            DependencyResolver.SetResolver(mvcResolver);

            //set the webapi dep resolvers
            _configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);

            app.UseAutofacMiddleware(container);
            app.UseAutofacWebApi(_configuration);
            app.UseAutofacMvc();
        });
    }

    [TestCleanup]
    public void Cleanup()
    {
        // Clean up the fake 'request' scope.
        _configuration.Dispose();
        DependencyResolver.SetResolver(_originalResolver);
        _scopeProvider.EndLifetimeScope();
        Server.Dispose();
    }
}

当一个简单的测试开始时,我得到一个ArgumentNullException“Value not not null”httpContext.如果我追溯到autofac代码,我认为它来自这个扩展方法 –

public static class AutofacMvcAppBuilderExtensions
    {
        internal static Func<HttpContextBase> CurrentHttpContext = () => new HttpContextWrapper(HttpContext.Current);

        /// <summary>
        /// Extends the Autofac lifetime scope added from the OWIN pipeline through to the MVC request lifetime scope.
        /// </summary>
        /// <param name="app">The application builder.</param>
        /// <returns>The application builder.</returns>
        [SecuritySafeCritical]
        [SuppressMessage("Microsoft.Reliability","CA2000:Dispose objects before losing scope")]
        public static IAppBuilder UseAutofacMvc(this IAppBuilder app)
        {
            return app.Use(async (context,next) =>
            {
                var lifetimeScope = context.GetAutofacLifetimeScope();
                var httpContext = CurrentHttpContext();

                if (lifetimeScope != null && httpContext != null)
                    httpContext.Items[typeof(ILifetimeScope)] = lifetimeScope;

                await next();
            });
        }
    }

在Core/Source/Autofac.Integration.Mvc.Owin/AutofacMvcAppBuilderExtensions.cs文件中.我的设置是否有问题,或者在使用IIS主机和OWIN中间件的WebApi应用程序的集成测试中使用Autofac的正确方法是什么？