Add ability to mix in delegate (types) to proxies

CHANGELOG.md

@@ -6,6 +6,7 @@ Enhancements:
 - Added trace logging level below Debug; maps to Trace in log4net/NLog, and Verbose in Serilog (@pi3k14, #404)
 - Recognize read-only parameters by the `In` modreq (@zvirja, #406)
 - DictionaryAdapter: Exposed GetAdapter overloads with NameValueCollection parameter in .NET Standard (@rzontar, #423)
+- Ability to add delegate mixins to proxies using `ProxyGenerationOptions.AddDelegate[Type]Mixin`. You can bind to the mixed-in `Invoke` methods on the proxy using `ProxyUtil.CreateDelegateToMixin`. (@stakx, #436)
 - New `IInvocation.CaptureProceedInfo()` method to enable better implementations of asynchronous interceptors (@stakx, #439)
 
 Deprecations:

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

@@ -0,0 +1,311 @@
+// Copyright 2004-2010 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 System.Reflection;
+
+	using NUnit.Framework;
+
+	[TestFixture]
+	public class DelegateMixinTestCase  : BasePEVerifyTestCase
+	{
+		[Test]
+		public void ProxyGenerationOptions_AddDelegateTypeMixin_when_given_null_throws_ArgumentNullException()
+		{
+			var options = new ProxyGenerationOptions();
+			Assert.Throws<ArgumentNullException>(() => options.AddDelegateTypeMixin(null));
+		}
+
+		[Test]
+		public void ProxyGenerationOptions_AddDelegateTypeMixin_when_given_non_delegate_type_throws_ArgumentException()
+		{
+			var options = new ProxyGenerationOptions();
+			Assert.Throws<ArgumentException>(() => options.AddDelegateTypeMixin(typeof(Exception)));
+		}
+
+		[Test]
+		public void ProxyGenerationOptions_AddDelegateTypeMixin_when_given_delegate_type_succeeds()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+		}
+
+		[Test]
+		public void ProxyGenerationOptions_AddDelegateMixin_when_given_null_throws_ArgumentNullException()
+		{
+			var options = new ProxyGenerationOptions();
+			Assert.Throws<ArgumentNullException>(() => options.AddDelegateMixin(null));
+		}
+
+		[Test]
+		public void ProxyGenerationOptions_AddDelegateMixin_when_given_delegate_succeeds()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateMixin(new Action(() => { }));
+		}
+
+
+		[Test]
+		public void ProxyGenerator_CreateClassProxy_can_create_delegate_proxy_without_target()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+			var _ = new Interceptor();
+			var proxy = generator.CreateClassProxy(typeof(object), options, _);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithoutTarget_can_create_delegate_proxy_without_target()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+			var _ = new Interceptor();
+			var proxy = generator.CreateInterfaceProxyWithoutTarget(typeof(IComparable), options, _);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithTarget_can_create_delegate_proxy_without_target()
+		{
+			var target = new Target();
+
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+			var _ = new Interceptor();
+			var proxy = generator.CreateInterfaceProxyWithTarget(typeof(IComparable), target, options, _);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateClassProxy_can_create_callable_delegate_proxy_without_target()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+
+			var interceptor = new Interceptor();
+
+			var proxy = generator.CreateClassProxy(typeof(object), options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			action.Invoke();
+			Assert.AreSame(typeof(Action).GetTypeInfo().GetMethod("Invoke"), interceptor.LastInvocation.Method);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithoutTarget_can_create_callable_delegate_proxy_without_target()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+
+			var interceptor = new Interceptor();
+
+			var proxy = generator.CreateInterfaceProxyWithoutTarget(typeof(IComparable), options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			action.Invoke();
+			Assert.AreSame(typeof(Action).GetTypeInfo().GetMethod("Invoke"), interceptor.LastInvocation.Method);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithTarget_can_create_callable_delegate_proxy_without_target()
+		{
+			var target = new Target();
+
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+
+			var interceptor = new Interceptor();
+
+			var proxy = generator.CreateInterfaceProxyWithTarget(typeof(IComparable), target, options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			action.Invoke();
+			Assert.AreSame(typeof(Action).GetTypeInfo().GetMethod("Invoke"), interceptor.LastInvocation.Method);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateClassProxy_cannot_proceed_to_delegate_type_mixin()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+
+			var interceptor = new Interceptor(shouldProceed: true);
+
+			var proxy = generator.CreateClassProxy(typeof(object), options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			Assert.Throws<NotImplementedException>(() => action.Invoke());
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithoutTarget_cannot_proceed_to_delegate_type_mixin()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+
+			var interceptor = new Interceptor(shouldProceed: true);
+
+			var proxy = generator.CreateInterfaceProxyWithoutTarget(typeof(IComparable), options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			Assert.Throws<NotImplementedException>(() => action.Invoke());
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithTarget_cannot_proceed_to_delegate_type_mixin()
+		{
+			var target = new Target();
+
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+
+			var interceptor = new Interceptor(shouldProceed: true);
+
+			var proxy = generator.CreateInterfaceProxyWithTarget(typeof(IComparable), target, options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			Assert.Throws<NotImplementedException>(() => action.Invoke());
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateClassProxy_can_proceed_to_delegate_mixin()
+		{
+			var target = new Target();
+
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateMixin(new Action(target.Method));
+
+			var interceptor = new Interceptor(shouldProceed: true);
+
+			var proxy = generator.CreateClassProxy(typeof(object), options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			action.Invoke();
+			Assert.True(target.MethodInvoked);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithoutTarget_can_proceed_to_delegate_mixin()
+		{
+			var target = new Target();
+
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateMixin(new Action(target.Method));
+
+			var interceptor = new Interceptor(shouldProceed: true);
+
+			var proxy = generator.CreateInterfaceProxyWithoutTarget(typeof(IComparable), options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			action.Invoke();
+			Assert.True(target.MethodInvoked);
+		}
+
+		[Test]
+		public void ProxyGenerator_CreateInterfaceProxyWithTarget_can_proceed_to_delegate_mixin()
+		{
+			var target = new Target();
+
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateMixin(new Action(target.Method));
+
+			var interceptor = new Interceptor(shouldProceed: true);
+
+			var proxy = generator.CreateInterfaceProxyWithTarget(typeof(IComparable), target, options, interceptor);
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+
+			action.Invoke();
+			Assert.True(target.MethodInvoked);
+		}
+
+		[Test]
+		public void Can_mixin_several_different_delegate_types_simultaneously()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Action));
+			options.AddDelegateTypeMixin(typeof(Action<int>));
+
+			var interceptor = new Interceptor();
+
+			var proxy = generator.CreateClassProxy(typeof(object), options, interceptor);
+
+			var action = ProxyUtil.CreateDelegateToMixin<Action>(proxy);
+			Assert.NotNull(action);
+			action.Invoke();
+
+			var intAction = ProxyUtil.CreateDelegateToMixin<Action<int>>(proxy);
+			Assert.NotNull(action);
+			intAction.Invoke(42);
+		}
+
+		[Test]
+		public void Cannot_mixin_several_delegate_types_with_same_signature()
+		{
+			var options = new ProxyGenerationOptions();
+			options.AddDelegateTypeMixin(typeof(Func<Exception, bool>));
+			options.AddDelegateTypeMixin(typeof(Predicate<Exception>));
+			Assert.Throws<InvalidMixinConfigurationException>(() => options.Initialize());
+
+		}
+
+		[Serializable]
+		public sealed class Target : IComparable
+		{
+			public bool CompareToInvoked { get; set; }
+
+			public bool MethodInvoked { get; set; }
+
+			public int CompareTo(object obj)
+			{
+				CompareToInvoked = true;
+				return 123;
+			}
+
+			public void Method()
+			{
+				MethodInvoked = true;
+			}
+		}
+
+		private sealed class Interceptor : IInterceptor
+		{
+			private readonly bool shouldProceed;
+
+			public Interceptor(bool shouldProceed = false)
+			{
+				this.shouldProceed = shouldProceed;
+			}
+
+			public IInvocation LastInvocation { get; set; }
+
+			public void Intercept(IInvocation invocation)
+			{
+				LastInvocation = invocation;
+				if (shouldProceed)
+				{
+					invocation.Proceed();
+				}
+			}
+		}
+	}
+}