Adding LoggingBehavior

Directory.Packages.props

@@ -1,9 +1,11 @@
 <Project>
   <ItemGroup>
+    <PackageVersion Include="Ardalis.GuardClauses" Version="4.1.1" />
     <PackageVersion Include="Ardalis.Specification" Version="7.0.0" />
     <PackageVersion Include="coverlet.collector" Version="3.2.0" />
     <PackageVersion Include="FluentAssertions" Version="6.11.0" />
     <PackageVersion Include="MediatR" Version="12.1.1" />
+    <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="7.0.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
     <PackageVersion Include="Moq" Version="4.18.4" />
     <PackageVersion Include="xunit" Version="2.4.2" />

src/Ardalis.SharedKernel/Ardalis.SharedKernel.csproj

@@ -13,9 +13,9 @@
     <RepositoryUrl>https://github.com/ardalis/Ardalis.SharedKernel</RepositoryUrl>
     <PackageTags>DDD;Shared Kernel;SharedKernel;Domain-Driven Design;Repository;Specification;ValueObject;Value Object;Ardalis;Clean;Clean Architecture;Clean Architecture Template</PackageTags>
     <PackageIcon>icon.png</PackageIcon>
-    <Version>1.2.0</Version>
+    <Version>1.3.0</Version>
     <PackageReleaseNotes>
-      * Add Commands, Queries, and Handler interfaces
+      * Adding LoggingBehavior
     </PackageReleaseNotes>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
@@ -24,8 +24,10 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Ardalis.GuardClauses" />
     <PackageReference Include="Ardalis.Specification" />
     <PackageReference Include="MediatR" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" />
   </ItemGroup>
 
   <ItemGroup>

src/Ardalis.SharedKernel/LoggingBehavior.cs

@@ -0,0 +1,63 @@
+using System.Diagnostics;
+using System.Reflection;
+using Ardalis.GuardClauses;
+using MediatR;
+using Microsoft.Extensions.Logging;
+
+namespace Ardalis.SharedKernel;
+
+/// <summary>
+/// Adds logging for all requests in MediatR pipeline.
+/// Configure by adding the service with a scoped lifetime
+/// 
+/// Example for Autofac:
+/// builder
+///   .RegisterType&lt;Mediator&gt;()
+///   .As&lt;IMediator&gt;()
+///   .InstancePerLifetimeScope();
+///
+/// builder
+///   .RegisterGeneric(typeof(LoggingBehavior&lt;,&gt;))
+///      .As(typeof(IPipelineBehavior&lt;,&gt;))
+///   .InstancePerLifetimeScope();
+///
+/// </summary>
+/// <typeparam name="TRequest"></typeparam>
+/// <typeparam name="TResponse"></typeparam>
+public class LoggingBehavior<TRequest, TResponse> : IPipelineBehavior<TRequest, TResponse>
+  where TRequest : IRequest<TResponse>
+{
+  private readonly ILogger<Mediator> _logger;
+
+  public LoggingBehavior(ILogger<Mediator> logger)
+  {
+    _logger = logger;
+  }
+
+  public async Task<TResponse> Handle(TRequest request, RequestHandlerDelegate<TResponse> next, CancellationToken cancellationToken)
+  {
+    Guard.Against.Null(request);
+    if (_logger.IsEnabled(LogLevel.Information))
+    {
+      _logger.LogInformation("Handling {RequestName}", typeof(TRequest).Name);
+
+      // Reflection! Could be a performance concern
+      Type myType = request.GetType();
+      IList<PropertyInfo> props = new List<PropertyInfo>(myType.GetProperties());
+      foreach (PropertyInfo prop in props)
+      {
+        object? propValue = prop?.GetValue(request, null);
+        _logger.LogInformation("Property {Property} : {@Value}", prop?.Name, propValue);
+      }
+    }
+
+    var sw = Stopwatch.StartNew();
+
+    var response = await next();
+
+    _logger.LogInformation("Handled {RequestName} with {Response} in {ms} ms", typeof(TRequest).Name, response, sw.ElapsedMilliseconds);
+    sw.Stop();
+    return response;
+  }
+}
+

src/Ardalis.SharedKernel/MediatRDomainEventDispatcher.cs

@@ -1,4 +1,5 @@
-using MediatR;
+using System;
+using MediatR;
 
 namespace Ardalis.SharedKernel;
 
@@ -24,3 +25,4 @@ public async Task DispatchAndClearEvents(IEnumerable<EntityBase> entitiesWithEve
     }
   }
 }
+