add NewSlot attribute

Author: huoshan12345

src/AspectCore.Core/Utils/ProxyGeneratorUtils.cs

@@ -441,17 +441,22 @@ internal static MethodBuilder DefineClassMethod(MethodInfo method, Type implType
 
                 if (method.Attributes.HasFlag(MethodAttributes.Public))
                 {
-                    attributes = attributes | MethodAttributes.Public;
+                    attributes |= MethodAttributes.Public;
                 }
 
                 if (method.Attributes.HasFlag(MethodAttributes.Family))
                 {
-                    attributes = attributes | MethodAttributes.Family;
+                    attributes |= MethodAttributes.Family;
                 }
 
                 if (method.Attributes.HasFlag(MethodAttributes.FamORAssem))
                 {
-                    attributes = attributes | MethodAttributes.FamORAssem;
+                    attributes |= MethodAttributes.FamORAssem;
+                }
+
+                if (method.Attributes.HasFlag(MethodAttributes.NewSlot))
+                {
+                    attributes |= MethodAttributes.NewSlot;
                 }
 
                 var methodBuilder = DefineMethod(method, method.Name, attributes, implType, typeDesc);
@@ -470,6 +475,9 @@ private static MethodBuilder DefineMethod(MethodInfo method, string name, Method
                 //inherit targetMethod's attribute
                 foreach (var customAttributeData in method.CustomAttributes)
                 {
+                    if (customAttributeData.AttributeType.Name == "PreserveBaseOverridesAttribute")
+                        continue; // Skip PreserveBaseOverridesAttribute as it is not needed in dynamic proxy generation.
+
                     methodBuilder.SetCustomAttribute(CustomAttributeBuilderUtils.DefineCustomAttribute(customAttributeData));
                 }
 

tests/AspectCore.Tests/DynamicProxy/CovariantReturnTypesTests.cs

@@ -1,4 +1,5 @@
-using AspectCore.DynamicProxy;
+using System.Reflection;
+using AspectCore.DynamicProxy;
 using Xunit;
 
 namespace AspectCore.Tests.DynamicProxy;
@@ -13,8 +14,8 @@ public interface IService
 
     public class Service : IService
     {
-        public virtual object Method() => nameof(Service);
-        public virtual object Property { get; } = nameof(Service);
+        public virtual object Method() => new();
+        public virtual object Property { get; } = new();
     }
 
     public class CovariantReturnsService : Service