Adds edge case for EvaluateAsync call that doesn't use context from FeatureManager (#246) (#247)

* Adds edge case for EvaluateAsync call that doesn't use context from FeatureManager

Author: rossgrambo

src/Microsoft.FeatureManagement.AspNetCore/Microsoft.FeatureManagement.AspNetCore.csproj

@@ -5,7 +5,7 @@
   <PropertyGroup>
     <MajorVersion>2</MajorVersion>
     <MinorVersion>6</MinorVersion>
-    <PatchVersion>0</PatchVersion>
+    <PatchVersion>1</PatchVersion>
   </PropertyGroup>
 
   <Import Project="..\..\build\Versioning.props" />

src/Microsoft.FeatureManagement/FeatureFilters/PercentageFilter.cs

@@ -43,7 +43,9 @@ public object BindParameters(IConfiguration filterParameters)
         /// <returns>True if the feature is enabled, false otherwise.</returns>
         public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
         {
-            PercentageFilterSettings settings = (PercentageFilterSettings)context.Settings;
+            //
+            // Check if prebound settings available, otherwise bind from parameters.
+            PercentageFilterSettings settings = (PercentageFilterSettings)context.Settings ?? (PercentageFilterSettings)BindParameters(context.Parameters);
 
             bool result = true;
 

src/Microsoft.FeatureManagement/FeatureFilters/TimeWindowFilter.cs

@@ -43,7 +43,9 @@ public object BindParameters(IConfiguration filterParameters)
         /// <returns>True if the feature is enabled, false otherwise.</returns>
         public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
         {
-            TimeWindowFilterSettings settings = (TimeWindowFilterSettings)context.Settings;
+            //
+            // Check if prebound settings available, otherwise bind from parameters.
+            TimeWindowFilterSettings settings = (TimeWindowFilterSettings)context.Settings ?? (TimeWindowFilterSettings)BindParameters(context.Parameters);
 
             DateTimeOffset now = DateTimeOffset.UtcNow;
 

src/Microsoft.FeatureManagement/Microsoft.FeatureManagement.csproj

@@ -5,7 +5,7 @@
   <PropertyGroup>
     <MajorVersion>2</MajorVersion>
     <MinorVersion>6</MinorVersion>
-    <PatchVersion>0</PatchVersion>
+    <PatchVersion>1</PatchVersion>
   </PropertyGroup>
 
   <Import Project="..\..\build\Versioning.props" />

src/Microsoft.FeatureManagement/Targeting/ContextualTargetingFilter.cs

@@ -66,7 +66,9 @@ public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context, ITargeti
                 throw new ArgumentNullException(nameof(targetingContext));
             }
 
-            TargetingFilterSettings settings = (TargetingFilterSettings)context.Settings;
+            //
+            // Check if prebound settings available, otherwise bind from parameters.
+            TargetingFilterSettings settings = (TargetingFilterSettings)context.Settings ?? (TargetingFilterSettings)BindParameters(context.Parameters);
 
             if (!TryValidateSettings(settings, out string paramName, out string message))
             {

tests/Tests.FeatureManagement/CustomTargetingFilter.cs

@@ -0,0 +1,32 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Microsoft.FeatureManagement;
+using Microsoft.FeatureManagement.FeatureFilters;
+using System;
+using System.Threading.Tasks;
+
+namespace Tests.FeatureManagement
+{
+    [FilterAlias(Alias)]
+    class CustomTargetingFilter : IFeatureFilter
+    {
+        private const string Alias = "CustomTargetingFilter";
+        private readonly ContextualTargetingFilter _contextualFilter;
+
+        public CustomTargetingFilter(IOptions<TargetingEvaluationOptions> options, ILoggerFactory loggerFactory)
+        {
+            _contextualFilter = new ContextualTargetingFilter(options, loggerFactory);
+        }
+
+        public Func<FeatureFilterEvaluationContext, Task<bool>> Callback { get; set; }
+
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
+        {
+            return _contextualFilter.EvaluateAsync(context, new TargetingContext(){ UserId = "Jeff" });
+        }
+    }
+}

tests/Tests.FeatureManagement/FeatureManagement.cs

@@ -171,7 +171,29 @@ public async Task GatesFeatures()
             Assert.Equal(HttpStatusCode.NotFound, gateAllResponse.StatusCode);
             Assert.Equal(HttpStatusCode.NotFound, gateAnyResponse.StatusCode);
         }
-        
+
+        [Fact]
+        public async Task CustomFilterContextualTargetingWithNullSetting()
+        {
+            IConfiguration config = new ConfigurationBuilder().AddJsonFile("appsettings.json").Build();
+
+            ServiceCollection services = new ServiceCollection();
+            
+            var targetingContextAccessor = new OnDemandTargetingContextAccessor();
+            services.AddSingleton<ITargetingContextAccessor>(targetingContextAccessor);
+
+            services
+                .AddSingleton(config)
+                .AddFeatureManagement()
+                .AddFeatureFilter<CustomTargetingFilter>();
+
+            ServiceProvider provider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = provider.GetRequiredService<IFeatureManager>();
+
+            Assert.True(await featureManager.IsEnabledAsync("CustomFilterFeature"));
+        }
+
         [Fact]
         public async Task GatesRazorPageFeatures()
         {

tests/Tests.FeatureManagement/appsettings.json

@@ -70,6 +70,20 @@
         }
       ]
     },
+    "CustomFilterFeature": {
+      "EnabledFor": [
+        {
+          "Name": "CustomTargetingFilter",
+          "Parameters": {
+            "Audience": {
+              "Users": [
+                "Jeff"
+              ]
+            }
+          }
+        }
+      ]
+    },
     "ConditionalFeature": {
       "EnabledFor": [
         {