register built-in filter first & target on main branch

src/Microsoft.FeatureManagement/EmptyTargetingContextAccessor.cs

@@ -0,0 +1,23 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.FeatureManagement.FeatureFilters;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace Microsoft.FeatureManagement
+{
+    internal class EmptyTargetingContextAccessor : ITargetingContextAccessor
+    {
+        public ValueTask<TargetingContext> GetContextAsync()
+        {
+            TargetingContext targetingContext = new TargetingContext
+            {
+                UserId = "",
+                Groups = new List<string>()
+            };
+
+            return new ValueTask<TargetingContext>(targetingContext);
+        }
+    }
+}

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
@@ -33,7 +34,17 @@ public static IFeatureManagementBuilder AddFeatureManagement(this IServiceCollec
 
             services.AddScoped<IFeatureManagerSnapshot, FeatureManagerSnapshot>();
 
-            return new FeatureManagementBuilder(services);
+            services.TryAddSingleton<ITargetingContextAccessor, EmptyTargetingContextAccessor>();
+
+            var builder = new FeatureManagementBuilder(services);
+
+            builder.AddFeatureFilter<PercentageFilter>();
+
+            builder.AddFeatureFilter<TimeWindowFilter>();
+
+            builder.AddFeatureFilter<TargetingFilter>();
+
+            return builder;
         }
 
         /// <summary>