Add failing test for generic by-ref parameter constrained to Enum

This triggers a `ArgumentException`: "Cannot create an instance of
`TEnum` because `Type.ContainsGenericParameters` is true."

Author: stakx

src/Castle.Core.Tests/DynamicProxy.Tests/GenInterfaces/IHaveGenericMethodWithEnumConstraint.cs

@@ -0,0 +1,23 @@
+// Copyright 2004-2023 Castle Project - http://www.castleproject.org/
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+namespace Castle.DynamicProxy.Tests.GenInterfaces
+{
+	using System;
+
+	public interface IHaveGenericMethodWithEnumConstraint
+	{
+		void Method<TEnum>(out TEnum result) where TEnum : Enum;
+	}
+}

src/Castle.Core.Tests/DynamicProxy.Tests/GenericConstraintsTestCase.cs

@@ -33,6 +33,12 @@ public void Generic_type_generic_method_with_struct_base_Method_base_Type_constr
 			CreateProxyFor<IConstraint_Method1IsTypeStructAndMethod2<object>>();
 		}
 
+		[Test]
+		public void Non_generic_type_generic_method_with_by_ref_parameter_type_constrained_to_Enum()
+		{
+			CreateProxyFor<IHaveGenericMethodWithEnumConstraint>();
+		}
+
 
 		private T CreateProxyFor<T>(params IInterceptor[] interceptors) where T : class
 		{