Register built-in filter by default (#287)

* register built-in filter first & target on main branch

* remove internal keyword

* resolve comments

* improve the way to register targeting context accessor

* fix typo

* adjust the way to register targeting context accessor & update testcases

* fix typo

* move WithTargeting to FeatureManagementBuilderExtension

Author: zhiyuanliang-ms

src/Microsoft.FeatureManagement/FeatureManagementBuilder.cs

@@ -37,7 +37,7 @@ public IFeatureManagementBuilder AddFeatureFilter<T>() where T : IFeatureFilterM
 
             if (!Services.Any(descriptor => descriptor.ServiceType == serviceType && descriptor.ImplementationType == implementationType))
             {
-                Services.AddSingleton(typeof(IFeatureFilterMetadata), typeof(T));
+                Services.AddSingleton(serviceType, implementationType);
             }
 
             return this;

src/Microsoft.FeatureManagement/FeatureManagementBuilderExtensions.cs

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.FeatureManagement.FeatureFilters;
+
+namespace Microsoft.FeatureManagement
+{
+    /// <summary>
+    /// Extensions used to add feature management functionality.
+    /// </summary>
+    public static class FeatureManagementBuilderExtensions
+    {
+        /// <summary>
+        /// Adds an <see cref="ITargetingContextAccessor"/> to be used for targeting and registers the targeting filter to the feature management system.
+        /// </summary>
+        /// <param name="builder">The <see cref="IFeatureManagementBuilder"/> used to customize feature management functionality.</param>
+        /// <returns>A <see cref="IFeatureManagementBuilder"/> that can be used to customize feature management functionality.</returns>
+        public static IFeatureManagementBuilder WithTargeting<T>(this IFeatureManagementBuilder builder) where T : ITargetingContextAccessor
+        {
+            builder.Services.TryAddSingleton(typeof(ITargetingContextAccessor), typeof(T));
+
+            builder.AddFeatureFilter<TargetingFilter>();
+
+            return builder;
+        }
+    }
+}

src/Microsoft.FeatureManagement/ServiceCollectionExtensions.cs

@@ -5,6 +5,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Logging;
+using Microsoft.FeatureManagement.FeatureFilters;
 using System;
 
 namespace Microsoft.FeatureManagement
@@ -15,7 +16,7 @@ namespace Microsoft.FeatureManagement
     public static class ServiceCollectionExtensions
     {
         /// <summary>
-        /// Adds required feature management services.
+        /// Adds required feature management services and built-in feature filters.
         /// </summary>
         /// <param name="services">The service collection that feature management services are added to.</param>
         /// <returns>A <see cref="IFeatureManagementBuilder"/> that can be used to customize feature management functionality.</returns>
@@ -33,7 +34,17 @@ public static IFeatureManagementBuilder AddFeatureManagement(this IServiceCollec
 
             services.AddScoped<IFeatureManagerSnapshot, FeatureManagerSnapshot>();
 
-            return new FeatureManagementBuilder(services);
+            var builder = new FeatureManagementBuilder(services);
+            
+            //
+            // Add built-in feature filters
+            builder.AddFeatureFilter<PercentageFilter>();
+
+            builder.AddFeatureFilter<TimeWindowFilter>();
+
+            builder.AddFeatureFilter<ContextualTargetingFilter>();
+
+            return builder;
         }
 
         /// <summary>

tests/Tests.FeatureManagement/FeatureManagement.cs

@@ -86,7 +86,7 @@ public async Task ReadsOnlyFeatureManagementSection()
         }
 
         [Fact]
-        public async Task AllowDuplicatedFilterAlias()
+        public async Task AllowsDuplicatedFilterAlias()
         {
             const string duplicatedFilterName = "DuplicatedFilterName";
 
@@ -101,8 +101,7 @@ public async Task AllowDuplicatedFilterAlias()
                 .AddFeatureManagement()
                 .AddFeatureFilter<DuplicatedAliasFeatureFilter1>()
                 .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithAccountContext>()
-                .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithDummyContext1>()
-                .AddFeatureFilter<PercentageFilter>();
+                .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithDummyContext1>();
 
             ServiceProvider serviceProvider = services.BuildServiceProvider();
 
@@ -127,8 +126,7 @@ public async Task AllowDuplicatedFilterAlias()
             services
                 .AddSingleton(config)
                 .AddFeatureManagement()
-                .AddFeatureFilter<DuplicatedAliasFeatureFilter1>()
-                .AddFeatureFilter<PercentageFilter>();
+                .AddFeatureFilter<DuplicatedAliasFeatureFilter1>();
 
             serviceProvider = services.BuildServiceProvider();
 
@@ -142,8 +140,7 @@ public async Task AllowDuplicatedFilterAlias()
                 .AddSingleton(config)
                 .AddFeatureManagement()
                 .AddFeatureFilter<DuplicatedAliasFeatureFilter1>()
-                .AddFeatureFilter<DuplicatedAliasFeatureFilter2>()
-                .AddFeatureFilter<PercentageFilter>();
+                .AddFeatureFilter<DuplicatedAliasFeatureFilter2>();
 
             serviceProvider = services.BuildServiceProvider();
 
@@ -163,8 +160,7 @@ public async Task AllowDuplicatedFilterAlias()
                 .AddSingleton(config)
                 .AddFeatureManagement()
                 .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithDummyContext1>()
-                .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithDummyContext2>()
-                .AddFeatureFilter<PercentageFilter>();
+                .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithDummyContext2>();
 
             serviceProvider = services.BuildServiceProvider();
 
@@ -183,8 +179,7 @@ public async Task AllowDuplicatedFilterAlias()
             services
                 .AddSingleton(config)
                 .AddFeatureManagement()
-                .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithAccountContext>()
-                .AddFeatureFilter<PercentageFilter>();
+                .AddFeatureFilter<ContextualDuplicatedAliasFeatureFilterWithAccountContext>();
 
             serviceProvider = services.BuildServiceProvider();
 
@@ -246,8 +241,7 @@ public async Task TimeWindow()
             var serviceCollection = new ServiceCollection();
 
             serviceCollection.AddSingleton(config)
-                .AddFeatureManagement()
-                .AddFeatureFilter<TimeWindowFilter>();
+                .AddFeatureManagement();
 
             ServiceProvider provider = serviceCollection.BuildServiceProvider();
 
@@ -272,8 +266,7 @@ public async Task Percentage()
             var serviceCollection = new ServiceCollection();
 
             serviceCollection.AddSingleton(config)
-                .AddFeatureManagement()
-                .AddFeatureFilter<PercentageFilter>();
+                .AddFeatureManagement();
 
             ServiceProvider provider = serviceCollection.BuildServiceProvider();
 
@@ -307,8 +300,7 @@ public async Task Targeting()
 
             services
                 .AddSingleton(config)
-                .AddFeatureManagement()
-                .AddFeatureFilter<ContextualTargetingFilter>();
+                .AddFeatureManagement();
 
             ServiceProvider serviceProvider = services.BuildServiceProvider();
 
@@ -374,7 +366,7 @@ public async Task TargetingAccessor()
             services
                 .AddSingleton(config)
                 .AddFeatureManagement()
-                .AddFeatureFilter<TargetingFilter>();
+                .WithTargeting<OnDemandTargetingContextAccessor>();
 
             ServiceProvider serviceProvider = services.BuildServiceProvider();