Expose WebHostBuilderContext in UseDefaultServiceProvider (#1043)

src/Microsoft.AspNetCore.Hosting/WebHostBuilderExtensions.cs

@@ -88,10 +88,21 @@ namespace Microsoft.AspNetCore.Hosting
         /// <returns>The <see cref="IWebHostBuilder"/>.</returns>
         public static IWebHostBuilder UseDefaultServiceProvider(this IWebHostBuilder hostBuilder, Action<ServiceProviderOptions> configure)
         {
-            return hostBuilder.ConfigureServices(services =>
+            return hostBuilder.UseDefaultServiceProvider((context, options) => configure(options));
+        }
+
+        /// <summary>
+        /// Configures the default service provider
+        /// </summary>
+        /// <param name="hostBuilder">The <see cref="IWebHostBuilder"/> to configure.</param>
+        /// <param name="configure">A callback used to configure the <see cref="ServiceProviderOptions"/> for the default <see cref="IServiceProvider"/>.</param>
+        /// <returns>The <see cref="IWebHostBuilder"/>.</returns>
+        public static IWebHostBuilder UseDefaultServiceProvider(this IWebHostBuilder hostBuilder, Action<WebHostBuilderContext, ServiceProviderOptions> configure)
+        {
+            return hostBuilder.ConfigureServices((context, services) =>
             {
                 var options = new ServiceProviderOptions();
-                configure(options);
+                configure(context, options);
                 services.Replace(ServiceDescriptor.Singleton<IServiceProviderFactory<IServiceCollection>>(new DefaultServiceProviderFactory(options)));
             });
         }

test/Microsoft.AspNetCore.Hosting.Tests/WebHostBuilderTests.cs

@@ -185,6 +185,34 @@ namespace Microsoft.AspNetCore.Hosting
             Assert.Throws<InvalidOperationException>(() => hostBuilder.Build());
         }
 
+        [Fact]
+        public void ConfigureDefaultServiceProviderWithContext()
+        {
+            var configurationCallbackCalled = false;
+            var hostBuilder = new WebHostBuilder()
+                .UseServer(new TestServer())
+                .ConfigureServices(s =>
+                {
+                    s.AddTransient<ServiceD>();
+                    s.AddScoped<ServiceC>();
+                })
+                .Configure(app =>
+                {
+                    app.ApplicationServices.GetRequiredService<ServiceC>();
+                })
+                .UseDefaultServiceProvider((context, options) =>
+                {
+                    Assert.NotNull(context.HostingEnvironment);
+                    Assert.NotNull(context.Configuration);
+                    Assert.NotNull(context.LoggerFactory);
+                    configurationCallbackCalled = true;
+                    options.ValidateScopes = true;
+                });
+
+            Assert.Throws<InvalidOperationException>(() => hostBuilder.Build());
+            Assert.True(configurationCallbackCalled);
+        }
+
         [Fact]
         public void UseLoggerFactoryHonored()
         {