Refactor DI so that IApiVersionDescriptionProviderFactory creates IApiVersionDescriptionProvider in all paths and can be the single source of replacement

Author: commonsensesoftware

src/AspNetCore/WebApi/src/Asp.Versioning.Mvc.ApiExplorer/ApiVersionDescriptionProviderFactory.cs

@@ -1,33 +1,27 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 
-#pragma warning disable SA1135 // Using directives should be qualified
-#pragma warning disable SA1200 // Using directives should be placed correctly
-
-using Asp.Versioning;
-using Asp.Versioning.ApiExplorer;
-using Microsoft.Extensions.Options;
+#pragma warning disable CA1812 // Avoid uninstantiated internal classes
 
 namespace Microsoft.AspNetCore.Builder;
 
+using Asp.Versioning;
+using Asp.Versioning.ApiExplorer;
 using Microsoft.AspNetCore.Routing;
-using Activator = Func<IEnumerable<IApiVersionMetadataCollationProvider>, ISunsetPolicyManager, IOptions<ApiExplorerOptions>, IApiVersionDescriptionProvider>;
+using Microsoft.Extensions.Options;
 
 internal sealed class ApiVersionDescriptionProviderFactory : IApiVersionDescriptionProviderFactory
 {
     private readonly ISunsetPolicyManager sunsetPolicyManager;
     private readonly IApiVersionMetadataCollationProvider[] providers;
     private readonly IEndpointInspector endpointInspector;
     private readonly IOptions<ApiExplorerOptions> options;
-    private readonly Activator activator;
 
     public ApiVersionDescriptionProviderFactory(
-        Activator activator,
         ISunsetPolicyManager sunsetPolicyManager,
         IEnumerable<IApiVersionMetadataCollationProvider> providers,
         IEndpointInspector endpointInspector,
         IOptions<ApiExplorerOptions> options )
     {
-        this.activator = activator;
         this.sunsetPolicyManager = sunsetPolicyManager;
         this.providers = providers.ToArray();
         this.endpointInspector = endpointInspector;
@@ -43,6 +37,6 @@ public IApiVersionDescriptionProvider Create( EndpointDataSource endpointDataSou
 
         collators.AddRange( providers );
 
-        return activator( collators, sunsetPolicyManager, options );
+        return new DefaultApiVersionDescriptionProvider( collators, sunsetPolicyManager, options );
     }
 }

src/AspNetCore/WebApi/src/Asp.Versioning.Mvc.ApiExplorer/DependencyInjection/IApiVersioningBuilderExtensions.cs

@@ -5,13 +5,11 @@ namespace Microsoft.Extensions.DependencyInjection;
 using Asp.Versioning;
 using Asp.Versioning.ApiExplorer;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.ApiExplorer;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
-using Microsoft.Extensions.Primitives;
 using static ServiceDescriptor;
 
 /// <summary>
@@ -54,54 +52,17 @@ private static void AddApiExplorerServices( IApiVersioningBuilder builder )
 
         services.AddMvcCore().AddApiExplorer();
         services.TryAddSingleton<IOptionsFactory<ApiExplorerOptions>, ApiExplorerOptionsFactory<ApiExplorerOptions>>();
-        services.TryAddTransient( ResolveApiVersionDescriptionProviderFactory );
-        services.TryAddSingleton( ResolveApiVersionDescriptionProvider );
+        services.TryAddTransient<IApiVersionDescriptionProviderFactory, ApiVersionDescriptionProviderFactory>();
+        services.TryAddSingleton( static sp => sp.GetRequiredService<IApiVersionDescriptionProviderFactory>().Create() );
 
         // use internal constructor until ASP.NET Core fixes their bug
         // BUG: https://github.com/dotnet/aspnetcore/issues/41773
         services.TryAddEnumerable(
             Transient<IApiDescriptionProvider, VersionedApiDescriptionProvider>(
-                sp => new(
+                static sp => new(
                     sp.GetRequiredService<ISunsetPolicyManager>(),
                     sp.GetRequiredService<IModelMetadataProvider>(),
                     sp.GetRequiredService<IInlineConstraintResolver>(),
                     sp.GetRequiredService<IOptions<ApiExplorerOptions>>() ) ) );
     }
-
-    private static IApiVersionDescriptionProviderFactory ResolveApiVersionDescriptionProviderFactory( IServiceProvider serviceProvider )
-    {
-        var sunsetPolicyManager = serviceProvider.GetRequiredService<ISunsetPolicyManager>();
-        var providers = serviceProvider.GetServices<IApiVersionMetadataCollationProvider>();
-        var inspector = serviceProvider.GetRequiredService<IEndpointInspector>();
-        var options = serviceProvider.GetRequiredService<IOptions<ApiExplorerOptions>>();
-
-        return new ApiVersionDescriptionProviderFactory(
-            NewDefaultProvider,
-            sunsetPolicyManager,
-            providers,
-            inspector,
-            options );
-
-        static DefaultApiVersionDescriptionProvider NewDefaultProvider(
-            IEnumerable<IApiVersionMetadataCollationProvider> providers,
-            ISunsetPolicyManager sunsetPolicyManager,
-            IOptions<ApiExplorerOptions> apiExplorerOptions ) =>
-            new( providers, sunsetPolicyManager, apiExplorerOptions );
-    }
-
-    private static IApiVersionDescriptionProvider ResolveApiVersionDescriptionProvider( IServiceProvider serviceProvider )
-    {
-        var factory = serviceProvider.GetRequiredService<IApiVersionDescriptionProviderFactory>();
-        var endpointDataSource = new EmptyEndpointDataSource();
-        return factory.Create( endpointDataSource );
-    }
-
-    private sealed class EmptyEndpointDataSource : EndpointDataSource
-    {
-        public override IReadOnlyList<Endpoint> Endpoints => Array.Empty<Endpoint>();
-
-        public override IChangeToken GetChangeToken() => new CancellationChangeToken( CancellationToken.None );
-
-        public override IReadOnlyList<Endpoint> GetGroupedEndpoints( RouteGroupContext context ) => Array.Empty<Endpoint>();
-    }
 }