Fix build, address feedback, and remove Readers from trim tests

Author: captainsafia

src/Microsoft.OpenApi/Any/OpenApiAnyCloneHelper.cs

@@ -50,7 +50,7 @@ public static IOpenApiAny CloneFromCopyConstructor(IOpenApiAny obj)
                     var pi = ci.GetParameters();
                     if (pi.Length == 1 && pi[0].ParameterType == typeof(T))
                     {
-                        return (IOpenApiAny)ci.Invoke([obj]);
+                        return (T)ci.Invoke([obj]);
                     }
                 }
             }

src/Microsoft.OpenApi/Extensions/EnumExtensions.cs

@@ -23,6 +23,7 @@ public static class EnumExtensions
         /// <returns>
         /// The attribute of the specified type or null.
         /// </returns>
+        [Obsolete("GetAttributeOfType<T> is deprecated and will be removed in a future release.")]
         [RequiresUnreferencedCode("GetAttributeOfType is not trim-compatible. Recommended to use native AoT-friendly type-specific overloads of GetDisplayName instead.")]
         public static T GetAttributeOfType<T>(this Enum enumValue) where T : Attribute
         {

src/Microsoft.OpenApi/Validations/ValidationRuleSet.cs

@@ -185,12 +185,13 @@ IEnumerator IEnumerable.GetEnumerator()
         private static ValidationRuleSet BuildDefaultRuleSet()
         {
             var ruleSet = new ValidationRuleSet();
+            var validationRuleType = typeof(ValidationRule);
 
             var ruleTypeProperties = GetValidationRuleTypes();
 
             foreach (var property in ruleTypeProperties)
             {
-                if (!typeof(ValidationRule).IsAssignableFrom(property.PropertyType))
+                if (!validationRuleType.IsAssignableFrom(property.PropertyType))
                 {
                     continue;
                 }

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -24,7 +24,7 @@ namespace Microsoft.OpenApi.Any
         public OpenApiAnyCloneHelper() { }
         [System.Obsolete("Use native AoT-friendly generic overload of CloneFromCopyConstructor instead.")]
         public static Microsoft.OpenApi.Any.IOpenApiAny CloneFromCopyConstructor(Microsoft.OpenApi.Any.IOpenApiAny obj) { }
-        public static Microsoft.OpenApi.Any.IOpenApiAny CloneFromCopyConstructor<T>(T obj)
+        public static T CloneFromCopyConstructor<T>(T obj)
             where T : Microsoft.OpenApi.Any.IOpenApiAny { }
     }
     public class OpenApiArray : System.Collections.Generic.List<Microsoft.OpenApi.Any.IOpenApiAny>, Microsoft.OpenApi.Any.IOpenApiAny, Microsoft.OpenApi.Interfaces.IOpenApiElement, Microsoft.OpenApi.Interfaces.IOpenApiExtension
@@ -249,6 +249,7 @@ namespace Microsoft.OpenApi.Extensions
 {
     public static class EnumExtensions
     {
+        [System.Obsolete("GetAttributeOfType<T> is deprecated and will be removed in a future release.")]
         public static T GetAttributeOfType<T>(this System.Enum enumValue)
             where T : System.Attribute { }
         public static string GetDisplayName(this Microsoft.OpenApi.Models.ParameterLocation parameterLocation) { }

test/Microsoft.OpenApi.Trimming.Tests/Microsoft.OpenApi.Trimming.Tests.csproj

@@ -15,9 +15,4 @@
     <TrimmerRootAssembly Include="Microsoft.OpenApi" />
   </ItemGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\..\src\Microsoft.OpenApi.Readers\Microsoft.OpenApi.Readers.csproj" />
-    <TrimmerRootAssembly Include="Microsoft.OpenApi.Readers" />
-  </ItemGroup>
-
 </Project>