Feature filter parameter object

src/Microsoft.FeatureManagement/FeatureFilterConfiguration.cs

@@ -20,5 +20,13 @@ public class FeatureFilterConfiguration
         /// Configurable parameters that can change across instances of a feature filter.
         /// </summary>
         public IConfiguration Parameters { get; set; } = new ConfigurationRoot(new List<IConfigurationProvider>());
+
+        /// <summary>
+        /// A strongly-typed parameter object that can be used as an alternative to <see cref="Parameters"/>.
+        /// Custom <see cref="IFeatureDefinitionProvider"/> implementations can populate this property directly
+        /// instead of constructing an <see cref="IConfiguration"/> instance.
+        /// When set, feature filters should prefer this over <see cref="Parameters"/>.
+        /// </summary>
+        public object ParameterObject { get; set; }
     }
 }

src/Microsoft.FeatureManagement/FeatureFilterEvaluationContext.cs

@@ -21,6 +21,12 @@ public class FeatureFilterEvaluationContext
         /// </summary>
         public IConfiguration Parameters { get; set; }
 
+        /// <summary>
+        /// A strongly-typed parameter object, if any, provided by a custom <see cref="IFeatureDefinitionProvider"/>.
+        /// When set, feature filters should prefer this over <see cref="Parameters"/>.
+        /// </summary>
+        public object ParameterObject { get; set; }
+
         /// <summary>
         /// A settings object, if any, that has been pre-bound from <see cref="Parameters"/>.
         /// The settings are made available for <see cref="IFeatureFilter"/>s that implement <see cref="IFilterParametersBinder"/>.

src/Microsoft.FeatureManagement/FeatureFilters/PercentageFilter.cs

@@ -50,8 +50,10 @@ public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
             }
 
             //
-            // Check if prebound settings available, otherwise bind from parameters.
-            PercentageFilterSettings settings = (PercentageFilterSettings)context.Settings ?? (PercentageFilterSettings)BindParameters(context.Parameters);
+            // Check if ParameterObject available (takes precedence), then prebound settings, otherwise bind from parameters.
+            PercentageFilterSettings settings = context.ParameterObject != null
+                ? (PercentageFilterSettings)context.ParameterObject
+                : (PercentageFilterSettings)context.Settings ?? (PercentageFilterSettings)BindParameters(context.Parameters);
 
             bool result = true;
 

src/Microsoft.FeatureManagement/FeatureFilters/TimeWindowFilter.cs

@@ -71,8 +71,10 @@ public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
             }
 
             //
-            // Check if prebound settings available, otherwise bind from parameters.
-            TimeWindowFilterSettings settings = (TimeWindowFilterSettings)context.Settings ?? (TimeWindowFilterSettings)BindParameters(context.Parameters);
+            // Check if ParameterObject available (takes precedence), then prebound settings, otherwise bind from parameters.
+            TimeWindowFilterSettings settings = context.ParameterObject != null
+                ? (TimeWindowFilterSettings)context.ParameterObject
+                : (TimeWindowFilterSettings)context.Settings ?? (TimeWindowFilterSettings)BindParameters(context.Parameters);
 
             DateTimeOffset now = SystemClock?.GetUtcNow() ?? DateTimeOffset.UtcNow;
 

src/Microsoft.FeatureManagement/FeatureManager.cs

@@ -498,6 +498,7 @@ private async ValueTask<bool> IsEnabledAsync<TContext>(FeatureDefinition feature
                     {
                         FeatureName = featureDefinition.Name,
                         Parameters = featureFilterConfiguration.Parameters,
+                        ParameterObject = featureFilterConfiguration.ParameterObject,
                         CancellationToken = cancellationToken
                     };
 

src/Microsoft.FeatureManagement/Targeting/ContextualTargetingFilter.cs

@@ -68,8 +68,10 @@ public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context, ITargeti
             }
 
             //
-            // Check if prebound settings available, otherwise bind from parameters.
-            TargetingFilterSettings settings = (TargetingFilterSettings)context.Settings ?? (TargetingFilterSettings)BindParameters(context.Parameters);
+            // Check if ParameterObject available (takes precedence), then prebound settings, otherwise bind from parameters.
+            TargetingFilterSettings settings = context.ParameterObject != null
+                ? (TargetingFilterSettings)context.ParameterObject
+                : (TargetingFilterSettings)context.Settings ?? (TargetingFilterSettings)BindParameters(context.Parameters);
 
             return Task.FromResult(TargetingEvaluator.IsTargeted(targetingContext, settings, _options.IgnoreCase, context.FeatureName));
         }

tests/Tests.FeatureManagement/FeatureManagementTest.cs

@@ -1051,6 +1051,124 @@ public async Task BindsFeatureFlagSettings()
 
             Assert.True(called);
         }
+
+        [Fact]
+        public async Task UsesParameterObject()
+        {
+            var parameterObject = new object();
+
+            FeatureFilterConfiguration testFilterConfiguration = new FeatureFilterConfiguration
+            {
+                Name = "Test",
+                ParameterObject = parameterObject
+            };
+
+            var services = new ServiceCollection();
+
+            var definitionProvider = new InMemoryFeatureDefinitionProvider(
+                new FeatureDefinition[]
+                {
+                    new FeatureDefinition
+                    {
+                        Name = Features.ConditionalFeature,
+                        EnabledFor = new List<FeatureFilterConfiguration>()
+                        {
+                            testFilterConfiguration
+                        }
+                    }
+                });
+
+            services.AddSingleton<IFeatureDefinitionProvider>(definitionProvider)
+                    .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build())
+                    .AddFeatureManagement()
+                    .AddFeatureFilter<TestFilter>();
+
+            ServiceProvider serviceProvider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = serviceProvider.GetRequiredService<IFeatureManager>();
+
+            IEnumerable<IFeatureFilterMetadata> featureFilters = serviceProvider.GetRequiredService<IEnumerable<IFeatureFilterMetadata>>();
+
+            TestFilter testFeatureFilter = (TestFilter)featureFilters.First(f => f is TestFilter);
+
+            testFeatureFilter.Callback = (evaluationContext) =>
+            {
+                //
+                // When ParameterObject is set, it should be available on the context
+                // so custom filters can use it with their own precedence logic.
+                Assert.Same(parameterObject, evaluationContext.ParameterObject);
+
+                return Task.FromResult(true);
+            };
+
+            bool result = await featureManager.IsEnabledAsync(Features.ConditionalFeature);
+
+            Assert.True(result);
+        }
+
+        [Fact]
+        public async Task ParameterObjectFallsBackToParametersWhenNull()
+        {
+            FeatureFilterConfiguration testFilterConfiguration = new FeatureFilterConfiguration
+            {
+                Name = "Test",
+                ParameterObject = null
+            };
+
+            var services = new ServiceCollection();
+
+            var definitionProvider = new InMemoryFeatureDefinitionProvider(
+                new FeatureDefinition[]
+                {
+                    new FeatureDefinition
+                    {
+                        Name = Features.ConditionalFeature,
+                        EnabledFor = new List<FeatureFilterConfiguration>()
+                        {
+                            testFilterConfiguration
+                        }
+                    }
+                });
+
+            services.AddSingleton<IFeatureDefinitionProvider>(definitionProvider)
+                    .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build())
+                    .AddFeatureManagement()
+                    .AddFeatureFilter<TestFilter>();
+
+            ServiceProvider serviceProvider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = serviceProvider.GetRequiredService<IFeatureManager>();
+
+            IEnumerable<IFeatureFilterMetadata> featureFilters = serviceProvider.GetRequiredService<IEnumerable<IFeatureFilterMetadata>>();
+
+            TestFilter testFeatureFilter = (TestFilter)featureFilters.First(f => f is TestFilter);
+
+            bool binderCalled = false;
+
+            testFeatureFilter.ParametersBinderCallback = (parameters) =>
+            {
+                binderCalled = true;
+
+                return parameters;
+            };
+
+            testFeatureFilter.Callback = (evaluationContext) =>
+            {
+                //
+                // When ParameterObject is null, Settings should be populated
+                // by IFilterParametersBinder as usual.
+                Assert.Null(evaluationContext.ParameterObject);
+                Assert.NotNull(evaluationContext.Settings);
+
+                return Task.FromResult(true);
+            };
+
+            bool result = await featureManager.IsEnabledAsync(Features.ConditionalFeature);
+
+            Assert.True(result);
+
+            Assert.True(binderCalled);
+        }
     }
 
     public class FeatureManagementBuiltInFeatureFilterTest
@@ -1671,6 +1789,142 @@ public async Task CustomFilterContextualTargetingWithNullSetting()
 
             Assert.True(await featureManager.IsEnabledAsync("CustomFilterFeature"));
         }
+
+        [Fact]
+        public async Task PercentageFilterUsesParameterObject()
+        {
+            var services = new ServiceCollection();
+
+            var definitionProvider = new InMemoryFeatureDefinitionProvider(
+                new FeatureDefinition[]
+                {
+                    new FeatureDefinition
+                    {
+                        Name = "PercentageFeature",
+                        EnabledFor = new List<FeatureFilterConfiguration>()
+                        {
+                            new FeatureFilterConfiguration
+                            {
+                                Name = "Microsoft.Percentage",
+                                ParameterObject = new PercentageFilterSettings { Value = 100 }
+                            }
+                        }
+                    }
+                });
+
+            services.AddSingleton<IFeatureDefinitionProvider>(definitionProvider)
+                    .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build())
+                    .AddFeatureManagement();
+
+            ServiceProvider serviceProvider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = serviceProvider.GetRequiredService<IFeatureManager>();
+
+            Assert.True(await featureManager.IsEnabledAsync("PercentageFeature"));
+        }
+
+        [Fact]
+        public async Task TimeWindowFilterUsesParameterObject()
+        {
+            var services = new ServiceCollection();
+
+            var definitionProvider = new InMemoryFeatureDefinitionProvider(
+                new FeatureDefinition[]
+                {
+                    new FeatureDefinition
+                    {
+                        Name = "TimeWindowFeature",
+                        EnabledFor = new List<FeatureFilterConfiguration>()
+                        {
+                            new FeatureFilterConfiguration
+                            {
+                                Name = "Microsoft.TimeWindow",
+                                ParameterObject = new TimeWindowFilterSettings
+                                {
+                                    Start = DateTimeOffset.UtcNow.AddDays(-1),
+                                    End = DateTimeOffset.UtcNow.AddDays(1)
+                                }
+                            }
+                        }
+                    }
+                });
+
+            services.AddSingleton<IFeatureDefinitionProvider>(definitionProvider)
+                    .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build())
+                    .AddFeatureManagement();
+
+            ServiceProvider serviceProvider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = serviceProvider.GetRequiredService<IFeatureManager>();
+
+            Assert.True(await featureManager.IsEnabledAsync("TimeWindowFeature"));
+        }
+
+        [Fact]
+        public async Task PercentageFilterThrowsOnInvalidParameterObjectType()
+        {
+            var services = new ServiceCollection();
+
+            var definitionProvider = new InMemoryFeatureDefinitionProvider(
+                new FeatureDefinition[]
+                {
+                    new FeatureDefinition
+                    {
+                        Name = "BadFeature",
+                        EnabledFor = new List<FeatureFilterConfiguration>()
+                        {
+                            new FeatureFilterConfiguration
+                            {
+                                Name = "Microsoft.Percentage",
+                                ParameterObject = "wrong type"
+                            }
+                        }
+                    }
+                });
+
+            services.AddSingleton<IFeatureDefinitionProvider>(definitionProvider)
+                    .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build())
+                    .AddFeatureManagement();
+
+            ServiceProvider serviceProvider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = serviceProvider.GetRequiredService<IFeatureManager>();
+
+            await Assert.ThrowsAsync<InvalidCastException>(() => featureManager.IsEnabledAsync("BadFeature"));
+        }
+
+        [Fact]
+        public async Task TimeWindowFilterThrowsOnInvalidParameterObjectType()
+        {
+            var services = new ServiceCollection();
+
+            var definitionProvider = new InMemoryFeatureDefinitionProvider(
+                new FeatureDefinition[]
+                {
+                    new FeatureDefinition
+                    {
+                        Name = "BadFeature",
+                        EnabledFor = new List<FeatureFilterConfiguration>()
+                        {
+                            new FeatureFilterConfiguration
+                            {
+                                Name = "Microsoft.TimeWindow",
+                                ParameterObject = 42
+                            }
+                        }
+                    }
+                });
+
+            services.AddSingleton<IFeatureDefinitionProvider>(definitionProvider)
+                    .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build())
+                    .AddFeatureManagement();
+
+            ServiceProvider serviceProvider = services.BuildServiceProvider();
+
+            IFeatureManager featureManager = serviceProvider.GetRequiredService<IFeatureManager>();
+
+            await Assert.ThrowsAsync<InvalidCastException>(() => featureManager.IsEnabledAsync("BadFeature"));
+        }
     }
 
     public class FeatureManagementVariantTest