Add ConfigureAspNetCoreDefaults

MetaPackages.sln

@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26412.1
+VisualStudioVersion = 15.0.26507.0
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{ED834E68-51C3-4ADE-ACC8-6BA6D4207C09}"
 EndProject
@@ -46,6 +46,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TrimDeps", "tools\TrimDeps\
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DependencyInjectionApp", "test\TestSites\DependencyInjectionApp\DependencyInjectionApp.csproj", "{65FE2E38-4529-4C93-A7B0-CF12DD7A70C3}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Tests", "test\Microsoft.AspNetCore.Tests\Microsoft.AspNetCore.Tests.csproj", "{914D3FAD-8B94-4353-B24F-B264F675481C}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -100,6 +102,10 @@ Global
 		{65FE2E38-4529-4C93-A7B0-CF12DD7A70C3}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{65FE2E38-4529-4C93-A7B0-CF12DD7A70C3}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{65FE2E38-4529-4C93-A7B0-CF12DD7A70C3}.Release|Any CPU.Build.0 = Release|Any CPU
+		{914D3FAD-8B94-4353-B24F-B264F675481C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{914D3FAD-8B94-4353-B24F-B264F675481C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{914D3FAD-8B94-4353-B24F-B264F675481C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{914D3FAD-8B94-4353-B24F-B264F675481C}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -118,7 +124,7 @@ Global
 		{AE4216BF-D471-471B-82F3-6B6D004F7D17} = {ED834E68-51C3-4ADE-ACC8-6BA6D4207C09}
 		{302400A0-98BB-4C04-88D4-C32DC2D4B945} = {ED834E68-51C3-4ADE-ACC8-6BA6D4207C09}
 		{67E4C92F-6D12-4C52-BB79-B8D11BFC6B82} = {ED834E68-51C3-4ADE-ACC8-6BA6D4207C09}
-		{302400A0-98BB-4C04-88D4-C32DC2D4B945} = {ED834E68-51C3-4ADE-ACC8-6BA6D4207C09}
 		{65FE2E38-4529-4C93-A7B0-CF12DD7A70C3} = {EC22261D-0DE1-47DE-8F7C-072675D6F5B4}
+		{914D3FAD-8B94-4353-B24F-B264F675481C} = {9E49B5B9-9E72-42FB-B684-90CA1B1BCF9C}
 	EndGlobalSection
 EndGlobal

src/Microsoft.AspNetCore/AspNetCoreExtensions.cs

@@ -0,0 +1,32 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Options.Infrastructure;
+
+namespace Microsoft.AspNetCore
+{
+    /// <summary>
+    /// Exposes extension method for establishing configuration defaults.
+    /// </summary>
+    public static class AspNetCoreExtensions
+    {
+        /// <summary>
+        /// Allows features to do some default setup for their options, i.e. binding against the default configuration.
+        /// </summary>
+        /// <param name="services">The <see cref="IServiceCollection"/> to modify.</param>
+        /// <returns>The service collection.</returns>
+        public static IServiceCollection ConfigureAspNetCoreDefaults(this IServiceCollection services)
+        {
+            services.AddTransient(typeof(IConfigureOptions<>), typeof(ConfigureDefaults<>));
+            services.AddTransient(typeof(IConfigureNamedOptions<>), typeof(ConfigureDefaults<>));
+            return services;
+        }
+    }
+}

src/Microsoft.AspNetCore/WebHost.cs

@@ -13,6 +13,7 @@ using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Options.Infrastructure;
 
 namespace Microsoft.AspNetCore
 {
@@ -124,6 +125,7 @@ namespace Microsoft.AspNetCore
         ///     load <see cref="IConfiguration"/> from environment variables,
         ///     configures the <see cref="ILoggerFactory"/> to log to the console and debug output,
         ///     enables IIS integration,
+        ///     enables the ability for frameworks to bind their options to their default configuration sections,
         ///     and adds the developer exception page when <see cref="IHostingEnvironment.EnvironmentName"/> is 'Development'
         /// </remarks>
         /// <returns>The initialized <see cref="IWebHostBuilder"/>.</returns>
@@ -143,6 +145,7 @@ namespace Microsoft.AspNetCore
         ///     load <see cref="IConfiguration"/> from supplied command line args,
         ///     configures the <see cref="ILoggerFactory"/> to log to the console and debug output,
         ///     enables IIS integration,
+        ///     enables the ability for frameworks to bind their options to their default configuration sections,
         ///     and adds the developer exception page when <see cref="IHostingEnvironment.EnvironmentName"/> is 'Development'
         /// </remarks>
         /// <param name="args">The command line args.</param>
@@ -189,6 +192,7 @@ namespace Microsoft.AspNetCore
                 .ConfigureServices(services =>
                 {
                     services.AddTransient<IConfigureOptions<KestrelServerOptions>, KestrelServerOptionsSetup>();
+                    services.ConfigureAspNetCoreDefaults();
                 });
 
             return builder;

test/Microsoft.AspNetCore.Tests/ConfigurationTests.cs

@@ -0,0 +1,68 @@
+// Copyright (c) .NET Foundation. All rights reserved. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Options.Infrastructure;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Tests
+{
+    public class ConfigurationTests
+    {
+        private class TestOptions
+        {
+              public string Message { get; set; }
+        }
+      
+        private class ConfigureTestDefault : ConfigureDefaultOptions<TestOptions>
+        {
+            public ConfigureTestDefault(IConfiguration config) :
+                base(options => config.GetSection("Test").Bind(options))
+            { }
+        }
+
+        [Fact]
+        public void ConfigureAspNetCoreDefaultsEnablesBindAgainstDefaultConfig()
+        {
+            var dic = new Dictionary<string, string>
+            {
+                { "Test:Message", "yadayada"}
+            };
+            var configurationBuilder = new ConfigurationBuilder();
+            configurationBuilder.AddInMemoryCollection(dic);
+            var config = configurationBuilder.Build();
+            var services = new ServiceCollection()
+                .AddSingleton<IConfiguration>(config)
+                .AddOptions()
+                .AddTransient<ConfigureDefaultOptions<TestOptions>, ConfigureTestDefault>()
+                .ConfigureAspNetCoreDefaults();
+            var sp = services.BuildServiceProvider();
+
+            var options = sp.GetRequiredService<IOptions<TestOptions>>().Value;
+            Assert.Equal("yadayada", options.Message);
+        }
+
+        [Fact]
+        public void DefaultConfigIgnoredWithoutConfigureAspNetCoreDefaults()
+        {
+            var dic = new Dictionary<string, string>
+            {
+                { "Test:Message", "yadayada"}
+            };
+            var configurationBuilder = new ConfigurationBuilder();
+            configurationBuilder.AddInMemoryCollection(dic);
+            var config = configurationBuilder.Build();
+            var services = new ServiceCollection()
+                .AddSingleton<IConfiguration>(config)
+                .AddOptions()
+                .AddTransient<ConfigureDefaultOptions<TestOptions>, ConfigureTestDefault>();
+            var sp = services.BuildServiceProvider();
+
+            var options = sp.GetRequiredService<IOptions<TestOptions>>().Value;
+            Assert.Null(options.Message);
+        }
+
+    }
+}

test/Microsoft.AspNetCore.Tests/Microsoft.AspNetCore.Tests.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <Import Project="..\..\build\common.props" />
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Microsoft.AspNetCore.All\Microsoft.AspNetCore.All.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
+    <PackageReference Include="Moq" Version="$(MoqVersion)" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="$(XunitVersion)" />
+    <PackageReference Include="xunit" Version="$(XunitVersion)" />
+  </ItemGroup>
+
+</Project>