Code clean up

Author: Chris Martinez

src/AspNetCore/WebApi/src/Asp.Versioning.Http/ApiVersioningFeature.cs

@@ -5,6 +5,7 @@ namespace Asp.Versioning;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using System.Globalization;
+using System.Runtime.CompilerServices;
 
 /// <summary>
 /// Represents the API versioning feature.
@@ -33,11 +34,10 @@ public IReadOnlyList<string> RawRequestedApiVersions
         {
             if ( rawApiVersions is null )
             {
-                var reader =
-                    context.RequestServices.GetService<IApiVersionReader>() ??
-                    ApiVersionReader.Combine(
-                        new QueryStringApiVersionReader(),
-                        new UrlSegmentApiVersionReader() );
+                var reader = context.RequestServices.GetService<IApiVersionReader>()
+                             ?? ApiVersionReader.Combine(
+                                 new QueryStringApiVersionReader(),
+                                 new UrlSegmentApiVersionReader() );
 
                 rawApiVersions = reader.Read( context.Request );
             }
@@ -58,11 +58,7 @@ public string? RawRequestedApiVersion
             {
                 0 => default,
                 1 => values[0],
-#pragma warning disable CA1065 // Do not raise exceptions in unexpected locations; existing behavior via IApiVersionReader.Read
-                _ => throw new AmbiguousApiVersionException(
-                        string.Format( CultureInfo.CurrentCulture, CommonSR.MultipleDifferentApiVersionsRequested, string.Join( ", ", values ) ),
-                        values ),
-#pragma warning restore CA1065
+                _ => throw NewAmbiguousApiVersionException( values ),
             };
         }
         set
@@ -88,7 +84,8 @@ public ApiVersion? RequestedApiVersion
                 return apiVersion;
             }
 
-            var parser = context.RequestServices.GetRequiredService<IApiVersionParser>();
+            var parser = context.RequestServices.GetService<IApiVersionParser>()
+                         ?? ApiVersionParser.Default;
 
             try
             {
@@ -105,10 +102,20 @@ public ApiVersion? RequestedApiVersion
         {
             apiVersion = value;
 
-            if ( apiVersion is not null && ( rawApiVersions is null || rawApiVersions.Count == 0 ) )
+            if ( apiVersion is not null &&
+               ( rawApiVersions is null || rawApiVersions.Count == 0 ) )
             {
                 rawApiVersions = new[] { apiVersion.ToString() };
             }
         }
     }
+
+    [MethodImpl( MethodImplOptions.AggressiveInlining )]
+    private static AmbiguousApiVersionException NewAmbiguousApiVersionException( IReadOnlyList<string> values ) =>
+        new(
+            string.Format(
+                CultureInfo.CurrentCulture,
+                CommonSR.MultipleDifferentApiVersionsRequested,
+                string.Join( ", ", values.ToArray(), 0, values.Count ) ),
+            values );
 }