Make services registered in ConfigureServices work in Configure

- Added a test

#114

src/Microsoft.AspNet.Hosting/Startup/StartupLoader.cs

@@ -57,6 +57,7 @@ namespace Microsoft.AspNet.Hosting.Startup
 
         private object Invoke(MethodInfo methodInfo, object instance, IApplicationBuilder builder, IServiceCollection services = null)
         {
+            var serviceProvider = builder?.ApplicationServices ?? _services;
             var parameterInfos = methodInfo.GetParameters();
             var parameters = new object[parameterInfos.Length];
             for (var index = 0; index != parameterInfos.Length; ++index)
@@ -74,7 +75,7 @@ namespace Microsoft.AspNet.Hosting.Startup
                 {
                     try
                     {
-                        parameters[index] = _services.GetRequiredService(parameterInfo.ParameterType);
+                        parameters[index] = serviceProvider.GetRequiredService(parameterInfo.ParameterType);
                     }
                     catch (Exception)
                     {

test/Microsoft.AspNet.Hosting.Tests/Fakes/StartupWithConfigureServices.cs

@@ -0,0 +1,35 @@
+using System;
+using Microsoft.AspNet.Builder;
+using Microsoft.Framework.DependencyInjection;
+
+namespace Microsoft.AspNet.Hosting.Fakes
+{
+    public class StartupWithConfigureServices
+    {
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddSingleton<IFoo, Foo>();
+        }
+
+        public void Configure(IApplicationBuilder app, IFoo foo)
+        {
+            foo.Bar();
+        }
+
+        public interface IFoo
+        {
+            bool Invoked { get; }
+            void Bar();
+        }
+
+        public class Foo : IFoo
+        {
+            public bool Invoked { get; private set; }
+
+            public void Bar()
+            {
+                Invoked = true;
+            }
+        }
+    }
+}

test/Microsoft.AspNet.Hosting.Tests/StartupManagerTests.cs

@@ -111,6 +111,23 @@ namespace Microsoft.AspNet.Hosting.Tests
             Assert.True(ex.Message.Contains("ConfigureBoom or Configure method not found"));
         }
 
+        [Fact]
+        public void StartupClassWithConfigureServicesShouldMakeServiceAvailableInConfigure()
+        {
+            var serviceCollection = HostingServices.Create();
+            var services = serviceCollection.BuildServiceProvider();
+            var manager = services.GetRequiredService<IStartupManager>();
+
+            var app = new ApplicationBuilder(services);
+
+            var startup = manager.LoadStartup("Microsoft.AspNet.Hosting.Tests", "WithConfigureServices");
+
+            startup.Invoke(app);
+
+            var foo = app.ApplicationServices.GetRequiredService<StartupWithConfigureServices.IFoo>();
+            Assert.True(foo.Invoked);
+        }
+
         public void ConfigurationMethodCalled(object instance)
         {
             _configurationMethodCalledList.Add(instance);