Compare type member names case-sensitively

CHANGELOG.md

@@ -11,6 +11,7 @@ Enhancements:
 Bugfixes:
 - `InvalidProgramException` when proxying `MemoryStream` with .NET 7 (@stakx, #651)
 - `invocation.MethodInvocationTarget` throws `ArgumentNullException` for default interface method (@stakx, #684)
+- `DynamicProxyException` ("duplicate element") when type to proxy contains members whose names differ only in case (@stakx, #691)
 
 Deprecations:
 - .NET Core 2.1, .NET Core 3.1, .NET 6, and mono tests

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

@@ -0,0 +1,103 @@
+// Copyright 2004-2025 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
+{
+	using System;
+
+	using Castle.DynamicProxy.Tests.Interceptors;
+
+	using NUnit.Framework;
+
+	[TestFixture]
+	public class CaseSensitivityTestCase : BasePEVerifyTestCase
+	{
+		[TestCase(typeof(IDifferentlyCasedEvents))]
+		[TestCase(typeof(IDifferentlyCasedMethods))]
+		[TestCase(typeof(IDifferentlyCasedProperties))]
+		public void Can_proxy_type_with_differently_cased_members(Type interfaceTypeToProxy)
+		{
+			_ = generator.CreateInterfaceProxyWithoutTarget(interfaceTypeToProxy);
+		}
+
+		[Test]
+		public void Can_distinguish_differently_cased_events_during_interception()
+		{
+			var interceptor = new KeepDataInterceptor();
+			var proxy = generator.CreateInterfaceProxyWithoutTarget<IDifferentlyCasedEvents>(interceptor);
+
+			proxy.Abc += delegate { };
+			Assert.AreEqual("add_Abc", interceptor.Invocation.Method.Name);
+
+			proxy.aBc += delegate { };
+			Assert.AreEqual("add_aBc", interceptor.Invocation.Method.Name);
+
+			proxy.abC += delegate { };
+			Assert.AreEqual("add_abC", interceptor.Invocation.Method.Name);
+		}
+
+		[Test]
+		public void Can_distinguish_differently_cased_methods_during_interception()
+		{
+			var interceptor = new KeepDataInterceptor();
+			var proxy = generator.CreateInterfaceProxyWithoutTarget<IDifferentlyCasedMethods>(interceptor);
+
+			proxy.Abc();
+			Assert.AreEqual("Abc", interceptor.Invocation.Method.Name);
+
+			proxy.aBc();
+			Assert.AreEqual("aBc", interceptor.Invocation.Method.Name);
+
+			proxy.abC();
+			Assert.AreEqual("abC", interceptor.Invocation.Method.Name);
+		}
+
+		[Test]
+		public void Can_distinguish_differently_cased_properties_during_interception()
+		{
+			var interceptor = new KeepDataInterceptor();
+			var proxy = generator.CreateInterfaceProxyWithoutTarget<IDifferentlyCasedProperties>(interceptor);
+
+			_ = proxy.Abc;
+			Assert.AreEqual("get_Abc", interceptor.Invocation.Method.Name);
+
+			_ = proxy.aBc;
+			Assert.AreEqual("get_aBc", interceptor.Invocation.Method.Name);
+
+			_ = proxy.abC;
+			Assert.AreEqual("get_abC", interceptor.Invocation.Method.Name);
+		}
+
+		public interface IDifferentlyCasedEvents
+		{
+			event EventHandler Abc;
+			event EventHandler aBc;
+			event EventHandler abC;
+		}
+
+		public interface IDifferentlyCasedMethods
+		{
+			void Abc();
+			void aBc();
+			void abC();
+		}
+
+		public interface IDifferentlyCasedProperties
+		{
+			object Abc { get; }
+			object aBc { get; }
+			object abC { get; }
+		}
+	}
+}

src/Castle.Core/DynamicProxy/Generators/Emitters/ClassEmitter.cs

@@ -34,7 +34,7 @@
 		private readonly List<EventEmitter> events;
 
 		private readonly IDictionary<string, FieldReference> fields =
-			new Dictionary<string, FieldReference>(StringComparer.OrdinalIgnoreCase);
+			new Dictionary<string, FieldReference>(StringComparer.Ordinal);
 
 		private readonly List<MethodEmitter> methods;
 
@@ -44,7 +44,7 @@
 		private GenericTypeParameterBuilder[] genericTypeParams;
 
 		internal const TypeAttributes DefaultTypeAttributes =
 			TypeAttributes.Public | TypeAttributes.Class | TypeAttributes.Serializable;
 
 		public ClassEmitter(TypeBuilder typeBuilder)
 		{
@@ -195,7 +195,7 @@
 
 			if (!serializable)
 			{
 				atts |= FieldAttributes.NotSerialized;
 			}
 
 			return CreateField(name, fieldType, atts);

src/Castle.Core/DynamicProxy/Generators/MetaEvent.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2025 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.
@@ -128,7 +128,7 @@ public bool Equals(MetaEvent other)
 				return true;
 			}
 
-			if (!StringComparer.OrdinalIgnoreCase.Equals(Name, other.Name))
+			if (!StringComparer.Ordinal.Equals(Name, other.Name))
 			{
 				return false;
 			}

src/Castle.Core/DynamicProxy/Generators/MetaMethod.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2025 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.
@@ -61,7 +61,7 @@ public bool Equals(MetaMethod other)
 				return true;
 			}
 
-			if (!StringComparer.OrdinalIgnoreCase.Equals(Name, other.Name))
+			if (!StringComparer.Ordinal.Equals(Name, other.Name))
 			{
 				return false;
 			}

src/Castle.Core/DynamicProxy/Generators/MetaProperty.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2025 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.
@@ -159,7 +159,7 @@ public bool Equals(MetaProperty other)
 				return true;
 			}
 
-			if (!StringComparer.OrdinalIgnoreCase.Equals(Name, other.Name))
+			if (!StringComparer.Ordinal.Equals(Name, other.Name))
 			{
 				return false;
 			}

src/Castle.Core/DynamicProxy/Internal/TypeUtil.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2025 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.
@@ -139,7 +139,7 @@
 		internal static bool HasAnyOverridableDefaultImplementations(this Type interfaceType)
 		{
 			Debug.Assert(interfaceType != null);
 			Debug.Assert(interfaceType.IsInterface);
 
 			var cache = hasAnyOverridableDefaultImplementationsCache;
 			lock (cache)
@@ -195,12 +195,12 @@
 
 		internal static bool IsGetType(this MethodInfo methodInfo)
 		{
-			return methodInfo.DeclaringType == typeof(object) && string.Equals("GetType", methodInfo.Name, StringComparison.OrdinalIgnoreCase);
+			return methodInfo.DeclaringType == typeof(object) && string.Equals("GetType", methodInfo.Name, StringComparison.Ordinal);
 		}
 
 		internal static bool IsMemberwiseClone(this MethodInfo methodInfo)
 		{
-			return methodInfo.DeclaringType == typeof(object) && string.Equals("MemberwiseClone", methodInfo.Name, StringComparison.OrdinalIgnoreCase);
+			return methodInfo.DeclaringType == typeof(object) && string.Equals("MemberwiseClone", methodInfo.Name, StringComparison.Ordinal);
 		}
 
 		internal static void SetStaticField(this Type type, string fieldName, BindingFlags additionalFlags, object? value)
@@ -252,7 +252,7 @@
 		{
 			var sortedMembers = new MemberInfo[members.Length];
 			Array.Copy(members, sortedMembers, members.Length);
-			Array.Sort(sortedMembers, (l, r) => string.Compare(l.Name, r.Name, StringComparison.OrdinalIgnoreCase));
+			Array.Sort(sortedMembers, (l, r) => string.Compare(l.Name, r.Name, StringComparison.Ordinal));
 			return sortedMembers;
 		}