Track enabled features

Author: danielmarbach

src/NServiceBus.Core.Tests/Features/FeatureDefaultsTests.cs

@@ -42,6 +42,7 @@ protected internal override void Setup(FeatureConfigurationContext context)
     public void Init()
     {
         settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         featureFactory = new FakeFeatureFactory();
         featureSettings = new FeatureActivator(settings, featureFactory);
     }

src/NServiceBus.Core.Tests/Features/FeatureDependencyTests.cs

@@ -54,7 +54,9 @@ static IEnumerable<FeatureCombinations> FeatureCombinationsForTests
     [TestCaseSource(nameof(FeatureCombinationsForTests))]
     public void Should_only_activate_features_if_dependencies_are_met(FeatureCombinations setup)
     {
-        var featureSettings = new FeatureActivator(new SettingsHolder(), new FeatureFactory());
+        var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
+        var featureSettings = new FeatureActivator(settings, new FeatureFactory());
         var dependingFeature = setup.DependingFeature;
         featureSettings.Add(dependingFeature);
         Array.ForEach(setup.AvailableFeatures, featureSettings.Add);
@@ -79,6 +81,7 @@ public void Should_activate_upstream_dependencies_first()
         };
 
         var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
         featureSettings.Add(dependingFeature);
@@ -111,6 +114,7 @@ public void Should_activate_named_dependency_first()
         };
 
         var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
         featureSettings.Add(dependingFeature);
@@ -142,6 +146,7 @@ public void Should_not_activate_feature_when_named_dependency_disabled()
         };
 
         var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
         featureSettings.Add(dependingFeature);
@@ -179,6 +184,7 @@ public void Should_activate_all_upstream_dependencies_first()
         };
 
         var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
         featureSettings.Add(dependingFeature);
@@ -222,6 +228,7 @@ public void Should_activate_all_upstream_dependencies_when_chain_deep()
         };
 
         var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
         //the orders matter here to expose a bug
@@ -259,6 +266,7 @@ public void Should_throw_exception_when_dependency_cycle_is_found()
         };
 
         var settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
         featureSettings.Add(level1);

src/NServiceBus.Core.Tests/Features/FeatureDifferingOnlyByNamespaceTests.cs

@@ -24,6 +24,7 @@ public void Should_activate_upstream_dependencies_first()
             };
 
             var settings = new SettingsHolder();
+            settings.Set(new FeatureComponent.Settings(settings));
             var featureSettings = new FeatureActivator(settings, new FeatureFactory());
 
             featureSettings.Add(dependingFeature);

src/NServiceBus.Core.Tests/Features/FeatureSettingsTests.cs

@@ -16,6 +16,7 @@ public class FeatureSettingsTests
     public void Init()
     {
         settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         featureSettings = new FeatureActivator(settings, new FeatureFactory());
     }
 

src/NServiceBus.Core.Tests/Features/FeatureStartupTests.cs

@@ -16,6 +16,7 @@ public class FeatureStartupTests
     public void Init()
     {
         settings = new SettingsHolder();
+        settings.Set(new FeatureComponent.Settings(settings));
         feautureFactory = new FakeFeatureFactory();
         featureSettings = new FeatureActivator(settings, feautureFactory);
     }

src/NServiceBus.Core.Tests/Features/FeatureTests.cs

@@ -22,16 +22,11 @@ public void Should_be_allow_features_to_request_being_enabled_by_default()
     }
 
 
-    public class MyFeature : TestFeature
-    {
-    }
+    public class MyFeature : TestFeature;
 
 
     public class MyEnabledByDefaultFeature : TestFeature
     {
-        public MyEnabledByDefaultFeature()
-        {
-            EnableByDefault();
-        }
+        public MyEnabledByDefaultFeature() => EnableByDefault();
     }
 }

src/NServiceBus.Core/EndpointConfiguration.cs

@@ -31,6 +31,7 @@ public EndpointConfiguration(string endpointName)
         Settings.SetDefault("Transactions.DefaultTimeout", TransactionManager.DefaultTimeout);
 
         Settings.Set(new AssemblyScanningComponent.Configuration(Settings));
+        Settings.Set(new FeatureComponent.Settings(Settings));
         Settings.Set(new HostingComponent.Settings(Settings));
         Settings.Set(new TransportSeam.Settings(Settings));
         Settings.Set(new RoutingComponent.Settings(Settings));

src/NServiceBus.Core/Features/FeatureComponent.cs

@@ -3,6 +3,7 @@
 namespace NServiceBus;
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -13,9 +14,20 @@ class FeatureComponent(SettingsHolder settings)
 {
     public void RegisterFeatureEnabledStatusInSettings(HostingComponent.Configuration hostingConfiguration)
     {
+        var featureSettings = settings.Get<Settings>();
+
+        // When scanning is enabled we might find some types multiple times so we need to de-dupe them.
+        var featureTypes = new HashSet<Type>(featureSettings.Features);
+
+        // When scanning is disabled the available types might only contain explicitely added stuff.
         foreach (var type in hostingConfiguration.AvailableTypes.Where(IsFeature))
         {
-            featureActivator.Add(type.Construct<Feature>());
+            featureTypes.Add(type);
+        }
+
+        foreach (var featureType in featureTypes)
+        {
+            featureActivator.Add(featureFactory.CreateFeature(featureType));
         }
     }
 
@@ -32,5 +44,23 @@ public void Initialize(FeatureConfigurationContext featureConfigurationContext)
 
     static bool IsFeature(Type type) => typeof(Feature).IsAssignableFrom(type);
 
-    readonly FeatureActivator featureActivator = new(settings, new FeatureFactory());
+    static readonly FeatureFactory featureFactory = new();
+    readonly FeatureActivator featureActivator = new(settings, featureFactory);
+
+    public class Settings
+    {
+        readonly SettingsHolder settings;
+
+        public Settings(SettingsHolder settings)
+        {
+            this.settings = settings;
+            Features = [];
+        }
+
+        public HashSet<Type> Features
+        {
+            get => settings.Get<HashSet<Type>>("NServiceBus.Features.Features");
+            private init => settings.Set("NServiceBus.Features.Features", value);
+        }
+    }
 }

src/NServiceBus.Core/Features/SettingsExtensions.cs

@@ -27,6 +27,8 @@ public static SettingsHolder EnableFeatureByDefault(this SettingsHolder settings
     {
         ArgumentNullException.ThrowIfNull(settings);
         ArgumentNullException.ThrowIfNull(featureType);
+
+        _ = settings.Get<FeatureComponent.Settings>().Features.Add(featureType);
         settings.SetDefault(featureType.FullName, FeatureState.Enabled);
         return settings;
     }
@@ -53,6 +55,7 @@ public static bool IsFeatureEnabled(this IReadOnlySettings settings, Type featur
 
     internal static void EnableFeature(this SettingsHolder settings, Type featureType)
     {
+        _ = settings.Get<FeatureComponent.Settings>().Features.Add(featureType);
         settings.Set(featureType.FullName, FeatureState.Enabled);
     }