Issue patterns-group#96 - code complete

* Added new DelegateInterceptor
* Changed LoggingInterceptor to inherit from DelegateInterceptor
* Updated test assertions to expect only one trace call for trapped error
  execution paths
* Updated ReSharper settings for "implicit scope closure"

src/Patterns/Interception/DelegateInterceptor.cs

@@ -0,0 +1,119 @@
+#region FreeBSD
+
+// Copyright (c) 2013, John Batte
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+// 
+//  * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+// 
+//  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+
+using Castle.DynamicProxy;
+
+using Patterns.ExceptionHandling;
+
+namespace Patterns.Interception
+{
+	/// <summary>
+	///    Provides an interceptor that allows its interception logic to be
+	///    injected; no-op fall-backs are used when no logic has been specified
+	///    for an interception step.
+	/// </summary>
+	public class DelegateInterceptor : IInterceptor
+	{
+		/// <summary>
+		///    Initializes a new instance of the <see cref="DelegateInterceptor" /> class.
+		/// </summary>
+		/// <param name="after">
+		///    The action to execute after proceeding. This action will not run
+		///    if the invocation throws an exception.
+		/// </param>
+		/// <param name="before">The action to execute before proceeding.</param>
+		/// <param name="condition">
+		///    The interception condition. If this condition returns <c>false</c>,
+		///    the invocation proceeds with no further interception.
+		/// </param>
+		/// <param name="finally">
+		///    The action to execute at the end of the interception, regardless of
+		///    whether or not an exception was thrown.
+		/// </param>
+		/// <param name="onError">The function to execute when an error occurs.</param>
+		public DelegateInterceptor(Action<IInvocation> after = null, Action<IInvocation> before = null,
+			Func<IInvocation, bool> condition = null, Action<IInvocation> @finally = null,
+			Func<IInvocation, Exception, ExceptionState> onError = null)
+		{
+			Initialize(after, before, condition, @finally, onError);
+		}
+
+		protected virtual Action<IInvocation> After { get; set; }
+
+		protected virtual Action<IInvocation> Before { get; set; }
+
+		protected virtual Func<IInvocation, bool> Condition { get; set; }
+
+		protected virtual Action<IInvocation> Finally { get; set; }
+
+		protected virtual Func<IInvocation, Exception, ExceptionState> OnError { get; set; }
+
+		/// <summary>
+		///    Intercepts the specified invocation.
+		/// </summary>
+		/// <param name="invocation">The invocation.</param>
+		public virtual void Intercept(IInvocation invocation)
+		{
+			if (Condition != null && !Condition(invocation))
+			{
+				invocation.Proceed();
+				return;
+			}
+
+			try
+			{
+				if (Before != null) Before(invocation);
+
+				invocation.Proceed();
+
+				if (After != null) After(invocation);
+			}
+			catch (Exception error)
+			{
+				Func<IInvocation, Exception, ExceptionState> errorHandler = OnError
+					?? ((thisCall, thisBug) => new ExceptionState(thisBug, false));
+				ExceptionState state = errorHandler(invocation, error);
+
+				if (state.IsHandled) return;
+
+				if (!ReferenceEquals(error, state.Exception) && state.Exception != null) throw state.Exception;
+
+				throw;
+			}
+			finally
+			{
+				if (Finally != null) Finally(invocation);
+			}
+		}
+
+		private void Initialize(Action<IInvocation> after, Action<IInvocation> before, Func<IInvocation, bool> condition,
+			Action<IInvocation> @finally, Func<IInvocation, Exception, ExceptionState> onError)
+		{
+			Condition = condition;
+			Before = before;
+			After = after;
+			Finally = @finally;
+			OnError = onError;
+		}
+	}
+}

src/Patterns/Logging/LoggingInterceptor.cs

@@ -28,6 +28,8 @@
 using Common.Logging;
 
 using Patterns.Collections.Strategies;
+using Patterns.ExceptionHandling;
+using Patterns.Interception;
 
 namespace Patterns.Logging
 {
@@ -36,7 +38,7 @@ namespace Patterns.Logging
 	///    uses <see cref="ILog" /> to log Trace, Debug, Info, and Error
 	///    events throughout the execution of intercepted invocations.
 	/// </summary>
-	public class LoggingInterceptor : IInterceptor
+	public class LoggingInterceptor : DelegateInterceptor
 	{
 		private const string _nullArgument = "[NULL]";
 		private const string _argumentListFormat = "({0})";
@@ -53,54 +55,74 @@ public class LoggingInterceptor : IInterceptor
 
 		private static readonly JavaScriptSerializer _jsonSerializer = new JavaScriptSerializer();
 
+		/// <summary>
+		/// Initializes a new instance of the <see cref="LoggingInterceptor"/> class.
+		/// </summary>
+		/// <param name="config">The config.</param>
+		/// <param name="logFactory">The log factory.</param>
+		public LoggingInterceptor(ILoggingConfig config, Func<Type, ILog> logFactory) : this(config, logFactory, null) {}
+
 		/// <summary>
 		/// Initializes a new instance of the <see cref="LoggingInterceptor" /> class.
 		/// </summary>
 		/// <param name="config">The config.</param>
 		/// <param name="logFactory">The log factory.</param>
-		public LoggingInterceptor(ILoggingConfig config, Func<Type, ILog> logFactory)
+		/// <param name="condition">The intercept condition.</param>
+		public LoggingInterceptor(ILoggingConfig config, Func<Type, ILog> logFactory, Func<IInvocation, bool> condition)
 		{
-			_config = config;
 			_logFactory = logFactory;
+			_config = config;
+			Initialize(condition);
 		}
 
-		/// <summary>
-		///    Intercepts the specified invocation.
-		/// </summary>
-		/// <param name="invocation">The invocation.</param>
-		public void Intercept(IInvocation invocation)
+		private void Initialize(Func<IInvocation, bool> condition)
+		{
+			Condition = condition;
+			Before = LogBefore;
+			After = LogAfter;
+			OnError = LogError;
+			Finally = LogFinally;
+		}
+
+		protected virtual void LogBefore(IInvocation invocation)
 		{
 			ILog log = _logFactory(invocation.TargetType);
 			log.Trace(handler => handler(LoggingResources.MethodStartTraceFormat, invocation.TargetType, invocation.Method.Name));
 			log.Debug(handler => handler(LoggingResources.MethodArgsDebugFormat, invocation.Method.Name, GetMethodArguments(invocation)));
+		}
 
-			try
-			{
-				invocation.Proceed();
-				log.Info(handler => handler(LoggingResources.MethodInfoFormat, invocation.Method.Name, LoggingResources.MethodInfoPass));
-			}
-			catch (Exception error)
-			{
-				log.Info(handler => handler(LoggingResources.MethodInfoFormat, invocation.Method.Name, LoggingResources.MethodInfoFail));
-				log.Error(handler => handler(LoggingResources.ExceptionErrorFormat, invocation.Method.Name, error.ToFullString()));
-				if (!_config.TrapExceptions) throw;
-			}
-
+		protected virtual void LogAfter(IInvocation invocation)
+		{
+			ILog log = _logFactory(invocation.TargetType);
+			log.Info(handler => handler(LoggingResources.MethodInfoFormat, invocation.Method.Name, LoggingResources.MethodInfoPass));
 			log.Trace(handler => handler(LoggingResources.MethodStopTraceFormat, invocation.TargetType, invocation.Method.Name));
+		}
 
+		protected virtual ExceptionState LogError(IInvocation invocation, Exception error)
+		{
+			ILog log = _logFactory(invocation.TargetType);
+			log.Info(handler => handler(LoggingResources.MethodInfoFormat, invocation.Method.Name, LoggingResources.MethodInfoFail));
+			log.Error(handler => handler(LoggingResources.ExceptionErrorFormat, invocation.Method.Name, error.ToFullString()));
+			return new ExceptionState(error, _config.TrapExceptions);
+		}
+
+		protected virtual void LogFinally(IInvocation invocation)
+		{
 			if (invocation.ReturnValue == null) return;
 
+			ILog log = _logFactory(invocation.TargetType);
+
 			object value = ConvertValueForDisplay(invocation.ReturnValue);
 			log.Debug(handler => handler(LoggingResources.MethodReturnDebugFormat, invocation.Method.Name, value));
 		}
 
-		private static string GetMethodArguments(IInvocation invocation)
+		protected static string GetMethodArguments(IInvocation invocation)
 		{
 			object[] arguments = invocation.Arguments.Select(ConvertValueForDisplay).ToArray();
 			return string.Format(_argumentListFormat, string.Join(_argumentListSeparator, arguments));
 		}
 
-		private static object ConvertValueForDisplay(object value)
+		protected static object ConvertValueForDisplay(object value)
 		{
 			if (value == null) return _nullArgument;
 

src/Patterns/Patterns.csproj

@@ -71,6 +71,7 @@
     <Compile Include="Configuration\IConfigurationSource.cs" />
     <Compile Include="ExceptionHandling\ExceptionState.cs" />
     <Compile Include="ExceptionHandling\Try.cs" />
+    <Compile Include="Interception\DelegateInterceptor.cs" />
     <Compile Include="Logging\ILoggingConfig.cs" />
     <Compile Include="Logging\LoggingConfig.cs" />
     <Compile Include="Logging\LoggingInterceptor.cs" />

src/_specs/Steps/Logging/MockVerificationSteps.cs

@@ -77,7 +77,7 @@ public void VerifyLogBrokenExecution()
 		public void VerifyLogTrappedErrorExecution()
 		{
 			Mock<ILog> mockLog = _moq.Container.Mock<ILog>();
-			mockLog.Verify(log => log.Trace(It.IsAny<Action<FormatMessageHandler>>()), Times.Exactly(2));
+			mockLog.Verify(log => log.Trace(It.IsAny<Action<FormatMessageHandler>>()), Times.Exactly(1));
 			mockLog.Verify(log => log.Debug(It.IsAny<Action<FormatMessageHandler>>()), Times.Exactly(1));
 			mockLog.Verify(log => log.Info(It.IsAny<Action<FormatMessageHandler>>()), Times.Exactly(1));
 			mockLog.Verify(log => log.Error(It.IsAny<Action<FormatMessageHandler>>()), Times.Exactly(1));

src/code-patterns-master.sln.DotSettings

@@ -1,4 +1,5 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ImplicitlyCapturedClosure/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseIsOperator_002E2/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/FilterSettingsManager/CoverageFilterXml/@EntryValue">&lt;data&gt;&lt;IncludeFilters /&gt;&lt;ExcludeFilters /&gt;&lt;/data&gt;</s:String>
 	<s:String x:Key="/Default/FilterSettingsManager/AttributeFilterXml/@EntryValue">&lt;data /&gt;</s:String></wpf:ResourceDictionary>