Add DataAnnotations based validation

Options.sln

@@ -37,6 +37,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		version.xml = version.xml
 	EndProjectSection
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Extensions.Options.DataAnnotations", "src\Microsoft.Extensions.Options.DataAnnotations\Microsoft.Extensions.Options.DataAnnotations.csproj", "{D0EB1487-D9E9-4C58-A907-BCD595993251}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -55,6 +57,10 @@ Global
 		{BA4EF3CE-1829-4E0E-8281-BD503FF8A682}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BA4EF3CE-1829-4E0E-8281-BD503FF8A682}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BA4EF3CE-1829-4E0E-8281-BD503FF8A682}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D0EB1487-D9E9-4C58-A907-BCD595993251}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D0EB1487-D9E9-4C58-A907-BCD595993251}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D0EB1487-D9E9-4C58-A907-BCD595993251}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D0EB1487-D9E9-4C58-A907-BCD595993251}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -63,6 +69,7 @@ Global
 		{16BADE2F-1184-4518-8A70-B68A19D0805B} = {0A4664A0-CB48-4338-A6B7-02E28DF62CBA}
 		{6ACF4BAB-2F09-4DA6-B273-27E4282865EB} = {10221BD9-FD19-4809-B680-7628CB87926B}
 		{BA4EF3CE-1829-4E0E-8281-BD503FF8A682} = {10221BD9-FD19-4809-B680-7628CB87926B}
+		{D0EB1487-D9E9-4C58-A907-BCD595993251} = {10221BD9-FD19-4809-B680-7628CB87926B}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {A4D0BBDB-82DD-4B7E-981F-E6B90F3850B6}

build/dependencies.props

@@ -13,6 +13,7 @@
     <MicrosoftNETCoreApp21PackageVersion>2.1.2</MicrosoftNETCoreApp21PackageVersion>
     <MicrosoftNETCoreApp22PackageVersion>2.2.0-preview1-26618-02</MicrosoftNETCoreApp22PackageVersion>
     <MicrosoftNETTestSdkPackageVersion>15.6.1</MicrosoftNETTestSdkPackageVersion>
+    <SystemComponentModelAnnotationsPackageVersion>4.6.0-preview1-26617-01</SystemComponentModelAnnotationsPackageVersion>
     <NETStandardLibrary20PackageVersion>2.0.3</NETStandardLibrary20PackageVersion>
     <XunitPackageVersion>2.3.1</XunitPackageVersion>
     <XunitRunnerVisualStudioPackageVersion>2.4.0</XunitRunnerVisualStudioPackageVersion>

src/Microsoft.Extensions.Options.ConfigurationExtensions/ConfigurationChangeTokenSource.cs

@@ -37,6 +37,9 @@ public ConfigurationChangeTokenSource(string name, IConfiguration config)
             Name = name ?? Options.DefaultName;
         }
 
+        /// <summary>
+        /// The name of the option instance being changed.
+        /// </summary>
         public string Name { get; }
 
         /// <summary>

src/Microsoft.Extensions.Options.ConfigurationExtensions/Microsoft.Extensions.Options.ConfigurationExtensions.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Description>Provides additional configuration specific functionality related to Options.</Description>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <NoWarn>$(NoWarn);CS1591</NoWarn>
+    <NoWarn>$(NoWarn)</NoWarn>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageTags>aspnetcore;configuration;options</PackageTags>
   </PropertyGroup>

src/Microsoft.Extensions.Options.DataAnnotations/DataAnnotationValidateOptions.cs

@@ -0,0 +1,61 @@
+// 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 System.ComponentModel.DataAnnotations;
+using System.Linq;
+
+namespace Microsoft.Extensions.Options
+{
+    /// <summary>
+    /// Implementation of <see cref="IValidateOptions{TOptions}"/> that uses DataAnnotation's <see cref="Validator"/> for validation.
+    /// </summary>
+    /// <typeparam name="TOptions">The instance being validated.</typeparam>
+    public class DataAnnotationValidateOptions<TOptions> : IValidateOptions<TOptions> where TOptions : class
+    {
+        /// <summary>
+        /// Constructor.
+        /// </summary>
+        /// <param name="name"></param>
+        public DataAnnotationValidateOptions(string name)
+        {
+            Name = name;
+        }
+
+        /// <summary>
+        /// The options name.
+        /// </summary>
+        public string Name { get; }
+
+        /// <summary>
+        /// Validates a specific named options instance (or all when name is null).
+        /// </summary>
+        /// <param name="name">The name of the options instance being validated.</param>
+        /// <param name="options">The options instance.</param>
+        /// <returns>The <see cref="ValidateOptionsResult"/> result.</returns>
+        public ValidateOptionsResult Validate(string name, TOptions options)
+        {
+            // Null name is used to configure all named options.
+            if (Name == null || name == Name)
+            {
+                var validationResults = new List<ValidationResult>();
+                if (Validator.TryValidateObject(options,
+                    new ValidationContext(options, serviceProvider: null, items: null), 
+                    validationResults, 
+                    validateAllProperties: true))
+                {
+                    return ValidateOptionsResult.Success;
+                }
+
+                return ValidateOptionsResult.Fail(String.Join(Environment.NewLine,
+                    validationResults.Select(r => "DataAnnotation validation failed for members " +
+                        String.Join(", ", r.MemberNames) +
+                        " with the error '" + r.ErrorMessage + "'.")));
+            }
+
+            // Ignored if not validating this instance.
+            return ValidateOptionsResult.Skip;
+        }
+    }
+}

src/Microsoft.Extensions.Options.DataAnnotations/Microsoft.Extensions.Options.DataAnnotations.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <Description>Provides additional DataAnnotations specific functionality related to Options.</Description>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <NoWarn>$(NoWarn)</NoWarn>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <PackageTags>aspnetcore;validation;options</PackageTags>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Microsoft.Extensions.Options\Microsoft.Extensions.Options.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="$(MicrosoftExtensionsDependencyInjectionAbstractionsPackageVersion)" />
+    <PackageReference Include="System.ComponentModel.Annotations" Version="$(SystemComponentModelAnnotationsPackageVersion)" />
+  </ItemGroup>
+
+</Project>

src/Microsoft.Extensions.Options.DataAnnotations/OptionsBuilderDataAnnotationsExtensions.cs

@@ -0,0 +1,25 @@
+// 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 Microsoft.Extensions.Options;
+
+namespace Microsoft.Extensions.DependencyInjection
+{
+    /// <summary>
+    /// Extension methods for adding configuration related options services to the DI container via <see cref="OptionsBuilder{TOptions}"/>.
+    /// </summary>
+    public static class OptionsBuilderDataAnnotationsExtensions
+    {
+        /// <summary>
+        /// Register this options instance for validation of its DataAnnotations.
+        /// </summary>
+        /// <typeparam name="TOptions">The options type to be configured.</typeparam>
+        /// <param name="optionsBuilder">The options builder to add the services to.</param>
+        /// <returns>The <see cref="OptionsBuilder{TOptions}"/> so that additional calls can be chained.</returns>
+        public static OptionsBuilder<TOptions> ValidateDataAnnotations<TOptions>(this OptionsBuilder<TOptions> optionsBuilder) where TOptions : class
+        {
+            optionsBuilder.Services.AddSingleton<IValidateOptions<TOptions>>(new DataAnnotationValidateOptions<TOptions>(optionsBuilder.Name));
+            return optionsBuilder;
+        }
+    }
+}

src/Microsoft.Extensions.Options.DataAnnotations/baseline.netcore.json

@@ -0,0 +1,2 @@
+{
+}

src/Microsoft.Extensions.Options/ConfigureNamedOptions.cs

@@ -35,8 +35,8 @@ public ConfigureNamedOptions(string name, Action<TOptions> action)
         /// <summary>
         /// Invokes the registered configure Action if the name matches.
         /// </summary>
-        /// <param name="name"></param>
-        /// <param name="options"></param>
+        /// <param name="name">The name of the options instance being configured.</param>
+        /// <param name="options">The options instance to configure.</param>
         public virtual void Configure(string name, TOptions options)
         {
             if (options == null)
@@ -51,6 +51,10 @@ public virtual void Configure(string name, TOptions options)
             }
         }
 
+        /// <summary>
+        /// Invoked to configure a TOptions instance with the <see cref="Options.DefaultName"/>.
+        /// </summary>
+        /// <param name="options">The options instance to configure.</param>
         public void Configure(TOptions options) => Configure(Options.DefaultName, options);
     }
 
@@ -86,8 +90,16 @@ public ConfigureNamedOptions(string name, TDep dependency, Action<TOptions, TDep
         /// </summary>
         public Action<TOptions, TDep> Action { get; }
 
+        /// <summary>
+        /// The dependency.
+        /// </summary>
         public TDep Dependency { get; }
 
+        /// <summary>
+        /// Invokes the registered configure Action if the name matches.
+        /// </summary>
+        /// <param name="name">The name of the options instance being configured.</param>
+        /// <param name="options">The options instance to configure.</param>
         public virtual void Configure(string name, TOptions options)
         {
             if (options == null)
@@ -102,6 +114,10 @@ public virtual void Configure(string name, TOptions options)
             }
         }
 
+        /// <summary>
+        /// Invoked to configure a TOptions instance with the <see cref="Options.DefaultName"/>.
+        /// </summary>
+        /// <param name="options">The options instance to configure.</param>
         public void Configure(TOptions options) => Configure(Options.DefaultName, options);
     }
 
@@ -141,10 +157,21 @@ public ConfigureNamedOptions(string name, TDep1 dependency, TDep2 dependency2, A
         /// </summary>
         public Action<TOptions, TDep1, TDep2> Action { get; }
 
+        /// <summary>
+        /// The first dependency.
+        /// </summary>
         public TDep1 Dependency1 { get; }
 
+        /// <summary>
+        /// The second dependency.
+        /// </summary>
         public TDep2 Dependency2 { get; }
 
+        /// <summary>
+        /// Invokes the registered configure Action if the name matches.
+        /// </summary>
+        /// <param name="name">The name of the options instance being configured.</param>
+        /// <param name="options">The options instance to configure.</param>
         public virtual void Configure(string name, TOptions options)
         {
             if (options == null)
@@ -159,6 +186,10 @@ public virtual void Configure(string name, TOptions options)
             }
         }
 
+        /// <summary>
+        /// Invoked to configure a TOptions instance with the <see cref="Options.DefaultName"/>.
+        /// </summary>
+        /// <param name="options">The options instance to configure.</param>
         public void Configure(TOptions options) => Configure(Options.DefaultName, options);
     }
 
@@ -202,13 +233,26 @@ public ConfigureNamedOptions(string name, TDep1 dependency, TDep2 dependency2, T
         /// </summary>
         public Action<TOptions, TDep1, TDep2, TDep3> Action { get; }
 
+        /// <summary>
+        /// The first dependency.
+        /// </summary>
         public TDep1 Dependency1 { get; }
 
+        /// <summary>
+        /// The second dependency.
+        /// </summary>
         public TDep2 Dependency2 { get; }
 
+        /// <summary>
+        /// The third dependency.
+        /// </summary>
         public TDep3 Dependency3 { get; }
 
-
+        /// <summary>
+        /// Invokes the registered configure Action if the name matches.
+        /// </summary>
+        /// <param name="name">The name of the options instance being configured.</param>
+        /// <param name="options">The options instance to configure.</param>
         public virtual void Configure(string name, TOptions options)
         {
             if (options == null)
@@ -223,6 +267,10 @@ public virtual void Configure(string name, TOptions options)
             }
         }
 
+        /// <summary>
+        /// Invoked to configure a TOptions instance with the <see cref="Options.DefaultName"/>.
+        /// </summary>
+        /// <param name="options">The options instance to configure.</param>
         public void Configure(TOptions options) => Configure(Options.DefaultName, options);
     }
 
@@ -270,15 +318,31 @@ public ConfigureNamedOptions(string name, TDep1 dependency1, TDep2 dependency2,
         /// </summary>
         public Action<TOptions, TDep1, TDep2, TDep3, TDep4> Action { get; }
 
+        /// <summary>
+        /// The first dependency.
+        /// </summary>
         public TDep1 Dependency1 { get; }
 
+        /// <summary>
+        /// The second dependency.
+        /// </summary>
         public TDep2 Dependency2 { get; }
 
+        /// <summary>
+        /// The third dependency.
+        /// </summary>
         public TDep3 Dependency3 { get; }
 
+        /// <summary>
+        /// The fourth dependency.
+        /// </summary>
         public TDep4 Dependency4 { get; }
 
-
+        /// <summary>
+        /// Invokes the registered configure Action if the name matches.
+        /// </summary>
+        /// <param name="name">The name of the options instance being configured.</param>
+        /// <param name="options">The options instance to configure.</param>
         public virtual void Configure(string name, TOptions options)
         {
             if (options == null)
@@ -293,6 +357,10 @@ public virtual void Configure(string name, TOptions options)
             }
         }
 
+        /// <summary>
+        /// Invoked to configure a TOptions instance with the <see cref="Options.DefaultName"/>.
+        /// </summary>
+        /// <param name="options">The options instance to configure.</param>
         public void Configure(TOptions options) => Configure(Options.DefaultName, options);
     }
 
@@ -344,17 +412,36 @@ public ConfigureNamedOptions(string name, TDep1 dependency1, TDep2 dependency2,
         /// </summary>
         public Action<TOptions, TDep1, TDep2, TDep3, TDep4, TDep5> Action { get; }
 
+        /// <summary>
+        /// The first dependency.
+        /// </summary>
         public TDep1 Dependency1 { get; }
 
+        /// <summary>
+        /// The second dependency.
+        /// </summary>
         public TDep2 Dependency2 { get; }
 
+        /// <summary>
+        /// The third dependency.
+        /// </summary>
         public TDep3 Dependency3 { get; }
 
+        /// <summary>
+        /// The fourth dependency.
+        /// </summary>
         public TDep4 Dependency4 { get; }
 
+        /// <summary>
+        /// The fifth dependency.
+        /// </summary>
         public TDep5 Dependency5 { get; }
 
-
+        /// <summary>
+        /// Invokes the registered configure Action if the name matches.
+        /// </summary>
+        /// <param name="name">The name of the options instance being configured.</param>
+        /// <param name="options">The options instance to configure.</param>
         public virtual void Configure(string name, TOptions options)
         {
             if (options == null)
@@ -369,7 +456,10 @@ public virtual void Configure(string name, TOptions options)
             }
         }
 
+        /// <summary>
+        /// Invoked to configure a TOptions instance with the <see cref="Options.DefaultName"/>.
+        /// </summary>
+        /// <param name="options">The options instance to configure.</param>
         public void Configure(TOptions options) => Configure(Options.DefaultName, options);
     }
-
 }

src/Microsoft.Extensions.Options/IOptions.cs

@@ -10,7 +10,7 @@ namespace Microsoft.Extensions.Options
     public interface IOptions<out TOptions> where TOptions : class, new()
     {
         /// <summary>
-        /// The default configured TOptions instance, equivalent to Get(string.Empty).
+        /// The default configured TOptions instance
         /// </summary>
         TOptions Value { get; }
     }