Report parameter location and handle empty parameter name. Fixes #904

Author: commonsensesoftware

src/AspNet/WebApi/src/Asp.Versioning.WebApi.ApiExplorer/Description/ApiVersionParameterDescriptionContext.cs

@@ -157,6 +157,11 @@ protected virtual void UpdateUrlSegment()
     /// <param name="name">The name of the media type parameter.</param>
     protected virtual void AddMediaTypeParameter( string name )
     {
+        if ( string.IsNullOrEmpty( name ) )
+        {
+            return;
+        }
+
         var parameter = new NameValueHeaderValue( name, ApiVersion.ToString() );
 
         CloneFormattersAndAddMediaTypeParameter( parameter, ApiDescription.SupportedRequestBodyFormatters );

src/AspNet/WebApi/src/Asp.Versioning.WebApi/ApplyContentTypeVersionActionFilter.cs

@@ -3,7 +3,6 @@
 namespace Asp.Versioning;
 
 using System.Net.Http.Headers;
-using System.Web.Http;
 using System.Web.Http.Filters;
 using static Asp.Versioning.ApiVersionParameterLocation;
 

src/AspNet/WebApi/src/Asp.Versioning.WebApi/System.Web.Http/HttpConfigurationExtensions.cs

@@ -7,6 +7,7 @@ namespace System.Web.Http;
 using Asp.Versioning.Dispatcher;
 using System.Web.Http.Controllers;
 using System.Web.Http.Dispatcher;
+using static Asp.Versioning.ApiVersionParameterLocation;
 
 /// <summary>
 /// Provides extension methods for the <see cref="HttpConfiguration"/> class.
@@ -79,9 +80,16 @@ private static void AddApiVersioning( this HttpConfiguration configuration, ApiV
             configuration.Filters.Add( new ReportApiVersionsAttribute() );
         }
 
-        if ( options.ApiVersionReader.VersionsByMediaType() )
+        var reader = options.ApiVersionReader;
+
+        if ( reader.VersionsByMediaType() )
         {
-            configuration.Filters.Add( new ApplyContentTypeVersionActionFilter( options.ApiVersionReader ) );
+            var parameterName = reader.GetParameterName( MediaTypeParameter );
+
+            if ( !string.IsNullOrEmpty( parameterName ) )
+            {
+                configuration.Filters.Add( new ApplyContentTypeVersionActionFilter( reader ) );
+            }
         }
 
         configuration.Properties.AddOrUpdate( ApiVersioningOptionsKey, options, ( key, oldValue ) => options );

src/AspNetCore/WebApi/src/Asp.Versioning.Http/net6.0/Builder/IEndpointConventionBuilderExtensions.cs

@@ -10,6 +10,7 @@ namespace Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using System.Globalization;
+using System.Runtime.CompilerServices;
 using static Asp.Versioning.ApiVersionParameterLocation;
 
 /// <summary>
@@ -100,12 +101,17 @@ private static void Apply(
         if ( parameterSource.VersionsByMediaType() )
         {
             var parameterName = parameterSource.GetParameterName( MediaTypeParameter );
-            requestDelegate = EnsureRequestDelegate( requestDelegate, endpointBuilder.RequestDelegate );
-            requestDelegate = new ContentTypeApiVersionDecorator( requestDelegate, parameterName );
-            endpointBuilder.RequestDelegate = requestDelegate;
+
+            if ( !string.IsNullOrEmpty( parameterName ) )
+            {
+                requestDelegate = EnsureRequestDelegate( requestDelegate, endpointBuilder.RequestDelegate );
+                requestDelegate = new ContentTypeApiVersionDecorator( requestDelegate, parameterName );
+                endpointBuilder.RequestDelegate = requestDelegate;
+            }
         }
     }
 
+    [MethodImpl( MethodImplOptions.AggressiveInlining )]
     private static RequestDelegate EnsureRequestDelegate( RequestDelegate? current, RequestDelegate? original ) =>
         ( current ?? original ) ??
         throw new InvalidOperationException(

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

@@ -200,6 +200,11 @@ protected virtual void UpdateUrlSegment()
     /// <param name="name">The name of the media type parameter.</param>
     protected virtual void AddMediaTypeParameter( string name )
     {
+        if ( string.IsNullOrEmpty( name ) )
+        {
+            return;
+        }
+
         var requestFormats = ApiDescription.SupportedRequestFormats.ToArray();
         var responseTypes = ApiDescription.SupportedResponseTypes.ToArray();
         var parameter = $"{name}={ApiVersion}";

src/AspNetCore/WebApi/src/Asp.Versioning.Mvc/ApiVersioningMvcOptionsSetup.cs

@@ -6,6 +6,7 @@ namespace Asp.Versioning;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
 using Microsoft.Extensions.Options;
+using static Asp.Versioning.ApiVersionParameterLocation;
 
 /// <summary>
 /// Represents the API versioning configuration for ASP.NET Core <see cref="MvcOptions">MVC options</see>.
@@ -36,9 +37,16 @@ public virtual void PostConfigure( string name, MvcOptions options )
             options.Filters.AddService<ReportApiVersionsAttribute>();
         }
 
-        if ( value.ApiVersionReader.VersionsByMediaType() )
+        var reader = value.ApiVersionReader;
+
+        if ( reader.VersionsByMediaType() )
         {
-            options.Filters.AddService<ApplyContentTypeVersionActionFilter>();
+            var parameterName = reader.GetParameterName( MediaTypeParameter );
+
+            if ( !string.IsNullOrEmpty( parameterName ) )
+            {
+                options.Filters.AddService<ApplyContentTypeVersionActionFilter>();
+            }
         }
 
         var modelMetadataDetailsProviders = options.ModelMetadataDetailsProviders;

src/Common/src/Common/MediaTypeApiVersionReaderBuilder.cs

@@ -301,9 +301,16 @@ public void AddParameters( IApiVersionParameterDescriptionContext context )
                 throw new ArgumentNullException( nameof( context ) );
             }
 
-            for ( var i = 0; i < parameters.Count; i++ )
+            if ( parameters.Count == 0 )
             {
-                context.AddParameter( parameters[i], MediaTypeParameter );
+                context.AddParameter( name: string.Empty, MediaTypeParameter );
+            }
+            else
+            {
+                for ( var i = 0; i < parameters.Count; i++ )
+                {
+                    context.AddParameter( parameters[i], MediaTypeParameter );
+                }
             }
         }
 
@@ -427,7 +434,7 @@ private void Read(
                         versions.Add( result[j] );
                     }
                 }
+            }
         }
     }
-    }
 }