Merge pull request #828 from jbogard/consolidate-registration

Consolidate registration to single configuration object and optimize registration

samples/MediatR.Examples.AspNetCore/Program.cs

@@ -22,7 +22,10 @@ private static IMediator BuildMediator(WrappingWriter writer)
 
  services.AddSingleton<TextWriter>(writer);
 
- services.AddMediatR(typeof(Ping), typeof(Sing));
+ services.AddMediatR(cfg =>
+ {
+ cfg.RegisterServicesFromAssemblies(typeof(Ping).Assembly, typeof(Sing).Assembly);
+ });
 
  services.AddScoped(typeof(IStreamRequestHandler<Sing, Song>), typeof(SingHandler));
 

src/MediatR/MicrosoftExtensionsDI/MediatrServiceConfiguration.cs

@@ -1,48 +1,63 @@
 using System;
+using System.Collections.Generic;
+using System.Reflection;
 using MediatR;
 
 namespace Microsoft.Extensions.DependencyInjection;
 
 public class MediatRServiceConfiguration
 {
- public Func<Type, bool> TypeEvaluator { get; private set; } = t => true;
- public Type MediatorImplementationType { get; private set; }
- public ServiceLifetime Lifetime { get; private set; }
+ public Func<Type, bool> TypeEvaluator { get; set; } = t => true;
+ public Type MediatorImplementationType { get; set; } = typeof(Mediator);
+ public ServiceLifetime Lifetime { get; set; } = ServiceLifetime.Transient;
  public RequestExceptionActionProcessorStrategy RequestExceptionActionProcessorStrategy { get; set; }
+ = RequestExceptionActionProcessorStrategy.ApplyForUnhandledExceptions;
 
- public MediatRServiceConfiguration()
- {
- MediatorImplementationType = typeof(Mediator);
- Lifetime = ServiceLifetime.Transient;
- }
+ internal List<Assembly> AssembliesToRegister { get; } = new();
 
- public MediatRServiceConfiguration Using<TMediator>() where TMediator : IMediator
- {
- MediatorImplementationType = typeof(TMediator);
- return this;
- }
+ public List<ServiceDescriptor> BehaviorsToRegister { get; } = new();
+
+ public MediatRServiceConfiguration RegisterServicesFromAssemblyContaining<T>()
+ => RegisterServicesFromAssemblyContaining(typeof(T));
+
+ public MediatRServiceConfiguration RegisterServicesFromAssemblyContaining(Type type)
+ => RegisterServicesFromAssembly(type.Assembly);
 
- public MediatRServiceConfiguration AsSingleton()
+ public MediatRServiceConfiguration RegisterServicesFromAssembly(Assembly assembly)
  {
- Lifetime = ServiceLifetime.Singleton;
+ AssembliesToRegister.Add(assembly);
+
  return this;
  }
 
- public MediatRServiceConfiguration AsScoped()
+ public MediatRServiceConfiguration RegisterServicesFromAssemblies(
+ params Assembly[] assemblies)
  {
- Lifetime = ServiceLifetime.Scoped;
+ AssembliesToRegister.AddRange(assemblies);
+
  return this;
  }
 
- public MediatRServiceConfiguration AsTransient()
+ public MediatRServiceConfiguration AddBehavior<TServiceType, TImplementationType>(
+ ServiceLifetime serviceLifetime = ServiceLifetime.Transient) =>
+ AddBehavior(typeof(TServiceType), typeof(TImplementationType), serviceLifetime);
+
+ public MediatRServiceConfiguration AddBehavior(
+ Type serviceType,
+ Type implementationType,
+ ServiceLifetime serviceLifetime = ServiceLifetime.Transient)
  {
- Lifetime = ServiceLifetime.Transient;
+ BehaviorsToRegister.Add(new ServiceDescriptor(serviceType, implementationType, serviceLifetime));
+
  return this;
  }
 
- public MediatRServiceConfiguration WithEvaluator(Func<Type, bool> evaluator)
+ public MediatRServiceConfiguration AddOpenBehavior(Type openBehaviorType, ServiceLifetime serviceLifetime = ServiceLifetime.Transient)
  {
- TypeEvaluator = evaluator;
+ var serviceType = typeof(IPipelineBehavior<,>);
+
+ BehaviorsToRegister.Add(new ServiceDescriptor(serviceType, openBehaviorType, serviceLifetime));
+
  return this;
  }
 }

src/MediatR/MicrosoftExtensionsDI/ServiceCollectionExtensions.cs

@@ -23,71 +23,24 @@ public static class ServiceCollectionExtensions
  /// Registers handlers and mediator types from the specified assemblies
  /// </summary>
  /// <param name="services">Service collection</param>
- /// <param name="assemblies">Assemblies to scan</param> 
- /// <returns>Service collection</returns>
- public static IServiceCollection AddMediatR(this IServiceCollection services, params Assembly[] assemblies)
- => services.AddMediatR(assemblies, configuration: null);
-
- /// <summary>
- /// Registers handlers and mediator types from the specified assemblies
- /// </summary>
- /// <param name="services">Service collection</param>
- /// <param name="assemblies">Assemblies to scan</param>
- /// <param name="configuration">The action used to configure the options</param>
- /// <returns>Service collection</returns>
- public static IServiceCollection AddMediatR(this IServiceCollection services, Action<MediatRServiceConfiguration>? configuration, params Assembly[] assemblies)
- => services.AddMediatR(assemblies, configuration);
-
- /// <summary>
- /// Registers handlers and mediator types from the specified assemblies
- /// </summary>
- /// <param name="services">Service collection</param>
- /// <param name="assemblies">Assemblies to scan</param>
  /// <param name="configuration">The action used to configure the options</param>
  /// <returns>Service collection</returns>
- public static IServiceCollection AddMediatR(this IServiceCollection services, IEnumerable<Assembly> assemblies, Action<MediatRServiceConfiguration>? configuration)
+ public static IServiceCollection AddMediatR(this IServiceCollection services, 
+ Action<MediatRServiceConfiguration> configuration)
  {
- if (!assemblies.Any())
+ var serviceConfig = new MediatRServiceConfiguration();
+
+ configuration.Invoke(serviceConfig);
+
+ if (!serviceConfig.AssembliesToRegister.Any())
  {
  throw new ArgumentException("No assemblies found to scan. Supply at least one assembly to scan for handlers.");
  }
- var serviceConfig = new MediatRServiceConfiguration();
 
- configuration?.Invoke(serviceConfig);
+ ServiceRegistrar.AddMediatRClasses(services, serviceConfig);
 
  ServiceRegistrar.AddRequiredServices(services, serviceConfig);
 
- ServiceRegistrar.AddMediatRClasses(services, assemblies, serviceConfig);
-
  return services;
  }
-
- /// <summary>
- /// Registers handlers and mediator types from the assemblies that contain the specified types
- /// </summary>
- /// <param name="services"></param>
- /// <param name="handlerAssemblyMarkerTypes"></param> 
- /// <returns>Service collection</returns>
- public static IServiceCollection AddMediatR(this IServiceCollection services, params Type[] handlerAssemblyMarkerTypes)
- => services.AddMediatR(handlerAssemblyMarkerTypes, configuration: null);
-
- /// <summary>
- /// Registers handlers and mediator types from the assemblies that contain the specified types
- /// </summary>
- /// <param name="services"></param>
- /// <param name="handlerAssemblyMarkerTypes"></param>
- /// <param name="configuration">The action used to configure the options</param>
- /// <returns>Service collection</returns>
- public static IServiceCollection AddMediatR(this IServiceCollection services, Action<MediatRServiceConfiguration>? configuration, params Type[] handlerAssemblyMarkerTypes)
- => services.AddMediatR(handlerAssemblyMarkerTypes, configuration);
-
- /// <summary>
- /// Registers handlers and mediator types from the assemblies that contain the specified types
- /// </summary>
- /// <param name="services"></param>
- /// <param name="handlerAssemblyMarkerTypes"></param>
- /// <param name="configuration">The action used to configure the options</param>
- /// <returns>Service collection</returns>
- public static IServiceCollection AddMediatR(this IServiceCollection services, IEnumerable<Type> handlerAssemblyMarkerTypes, Action<MediatRServiceConfiguration>? configuration)
- => services.AddMediatR(handlerAssemblyMarkerTypes.Select(t => t.GetTypeInfo().Assembly), configuration);
 }

src/MediatR/Pipeline/RequestExceptionHandlerState.cs

@@ -12,7 +12,7 @@ public class RequestExceptionHandlerState<TResponse>
  public bool Handled { get; private set; }
 
  /// <summary>
- /// The response that is returned if <see cref="Handled"/> is  <code>true</code>.
+ /// The response that is returned if <see cref="Handled"/> is <code>true</code>.
  /// </summary>
  public TResponse? Response { get; private set; }
 

src/MediatR/Registration/ServiceRegistrar.cs

@@ -10,9 +10,9 @@ namespace MediatR.Registration;
 
 public static class ServiceRegistrar
 {
- public static void AddMediatRClasses(IServiceCollection services, IEnumerable<Assembly> assembliesToScan, MediatRServiceConfiguration configuration)
+ public static void AddMediatRClasses(IServiceCollection services, MediatRServiceConfiguration configuration)
  {
- assembliesToScan = assembliesToScan.Distinct().ToArray();
+ var assembliesToScan = configuration.AssembliesToRegister.Distinct().ToArray();
 
  ConnectImplementationsToTypesClosing(typeof(IRequestHandler<,>), services, assembliesToScan, false, configuration);
  ConnectImplementationsToTypesClosing(typeof(INotificationHandler<>), services, assembliesToScan, true, configuration);
@@ -217,20 +217,53 @@ public static void AddRequiredServices(IServiceCollection services, MediatRServi
  services.TryAdd(new ServiceDescriptor(typeof(ISender), sp => sp.GetRequiredService<IMediator>(), serviceConfiguration.Lifetime));
  services.TryAdd(new ServiceDescriptor(typeof(IPublisher), sp => sp.GetRequiredService<IMediator>(), serviceConfiguration.Lifetime));
 
- // Use TryAddTransientExact (see below), we dó want to register our Pre/Post processor behavior, even if (a more concrete)
+ foreach (var serviceDescriptor in serviceConfiguration.BehaviorsToRegister)
+ {
+ services.Add(serviceDescriptor);
+ }
+
+ // Use TryAddTransientExact (see below), we do want to register our Pre/Post processor behavior, even if (a more concrete)
  // registration for IPipelineBehavior<,> already exists. But only once.
- services.TryAddTransientExact(typeof(IPipelineBehavior<,>), typeof(RequestPreProcessorBehavior<,>));
- services.TryAddTransientExact(typeof(IPipelineBehavior<,>), typeof(RequestPostProcessorBehavior<,>));
+ RegisterBehaviorIfImplementationsExist(services, typeof(RequestPreProcessorBehavior<,>),
+ typeof(IRequestPreProcessor<>));
+ RegisterBehaviorIfImplementationsExist(services, typeof(RequestPostProcessorBehavior<,>),
+ typeof(IRequestPostProcessor<,>));
 
- if (serviceConfiguration.RequestExceptionActionProcessorStrategy == RequestExceptionActionProcessorStrategy.ApplyForUnhandledExceptions)
+ if (serviceConfiguration.RequestExceptionActionProcessorStrategy ==
+ RequestExceptionActionProcessorStrategy.ApplyForUnhandledExceptions)
  {
- services.TryAddTransientExact(typeof(IPipelineBehavior<,>), typeof(RequestExceptionActionProcessorBehavior<,>));
- services.TryAddTransientExact(typeof(IPipelineBehavior<,>), typeof(RequestExceptionProcessorBehavior<,>));
+ RegisterBehaviorIfImplementationsExist(services, typeof(RequestExceptionActionProcessorBehavior<,>),
+ typeof(IRequestExceptionAction<,>));
+ RegisterBehaviorIfImplementationsExist(services, typeof(RequestExceptionProcessorBehavior<,>),
+ typeof(IRequestExceptionHandler<,,>));
  }
  else
  {
- services.TryAddTransientExact(typeof(IPipelineBehavior<,>), typeof(RequestExceptionProcessorBehavior<,>));
- services.TryAddTransientExact(typeof(IPipelineBehavior<,>), typeof(RequestExceptionActionProcessorBehavior<,>));
+ RegisterBehaviorIfImplementationsExist(services, typeof(RequestExceptionProcessorBehavior<,>),
+ typeof(IRequestExceptionHandler<,,>));
+ RegisterBehaviorIfImplementationsExist(services, typeof(RequestExceptionActionProcessorBehavior<,>),
+ typeof(IRequestExceptionAction<,>));
+ }
+ }
+
+ private static void RegisterBehaviorIfImplementationsExist(
+ IServiceCollection services,
+ Type behaviorType,
+ Type subBehaviorType
+ )
+ {
+ var hasAnyRegistrationsOfSubBehaviorType = services
+ .Select(service => service.ImplementationType)
+ .Where(type => type != null)
+ .SelectMany(type => type!.GetInterfaces())
+ .Where(type => type.IsGenericType)
+ .Select(type => type.GetGenericTypeDefinition())
+ .Where(type => type != null)
+ .Any(type => type == subBehaviorType);
+
+ if (hasAnyRegistrationsOfSubBehaviorType)
+ {
+ services.TryAddTransientExact(typeof(IPipelineBehavior<,>), behaviorType);
  }
  }
 

test/MediatR.Benchmarks/Benchmarks.cs

@@ -20,7 +20,7 @@ public void GlobalSetup()
 
  services.AddSingleton(TextWriter.Null);
 
- services.AddMediatR(typeof(Ping));
+ services.AddMediatR(cfg => cfg.RegisterServicesFromAssemblyContaining(typeof(Ping)));
 
  services.AddScoped(typeof(IPipelineBehavior<,>), typeof(GenericPipelineBehavior<,>));
  services.AddScoped(typeof(IRequestPreProcessor<>), typeof(GenericRequestPreProcessor<>));

test/MediatR.Tests/MicrosoftExtensionsDI/AssemblyResolutionTests.cs

@@ -16,7 +16,7 @@ public AssemblyResolutionTests()
  {
  IServiceCollection services = new ServiceCollection();
  services.AddSingleton(new Logger());
- services.AddMediatR(typeof(Ping).GetTypeInfo().Assembly);
+ services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly));
  _provider = services.BuildServiceProvider();
  }
 
@@ -55,7 +55,7 @@ public void ShouldRequireAtLeastOneAssembly()
  {
  var services = new ServiceCollection();
 
- Action registration = () => services.AddMediatR(new Type[0]);
+ Action registration = () => services.AddMediatR(_ => {});
 
  registration.ShouldThrow<ArgumentException>();
  }

test/MediatR.Tests/MicrosoftExtensionsDI/CustomMediatorTests.cs

@@ -15,7 +15,11 @@ public CustomMediatorTests()
  {
  IServiceCollection services = new ServiceCollection();
  services.AddSingleton(new Logger());
- services.AddMediatR(cfg => cfg.Using<MyCustomMediator>(), typeof(CustomMediatorTests));
+ services.AddMediatR(cfg =>
+ {
+ cfg.MediatorImplementationType = typeof(MyCustomMediator);
+ cfg.RegisterServicesFromAssemblyContaining(typeof(CustomMediatorTests));
+ });
  _provider = services.BuildServiceProvider();
  }
 
@@ -43,10 +47,14 @@ public void Can_Call_AddMediatr_multiple_times()
  {
  IServiceCollection services = new ServiceCollection();
  services.AddSingleton(new Logger());
- services.AddMediatR(cfg => cfg.Using<MyCustomMediator>(), typeof(CustomMediatorTests));
+ services.AddMediatR(cfg =>
+ {
+ cfg.MediatorImplementationType = typeof(MyCustomMediator);
+ cfg.RegisterServicesFromAssemblyContaining(typeof(CustomMediatorTests));
+ });
 
  // Call AddMediatr again, this should NOT override our custom mediatr (With MS DI, last registration wins)
- services.AddMediatR(typeof(CustomMediatorTests));
+ services.AddMediatR(cfg => cfg.RegisterServicesFromAssemblyContaining(typeof(CustomMediatorTests)));
 
  var provider = services.BuildServiceProvider();
  var mediator = provider.GetRequiredService<IMediator>();

test/MediatR.Tests/MicrosoftExtensionsDI/DerivingRequestsTests.cs

@@ -15,7 +15,7 @@ public DerivingRequestsTests()
  {
  IServiceCollection services = new ServiceCollection();
  services.AddSingleton(new Logger());
- services.AddMediatR(typeof(Ping));
+ services.AddMediatR(cfg => cfg.RegisterServicesFromAssemblyContaining(typeof(Ping)));
  _provider = services.BuildServiceProvider();
  _mediator = _provider.GetRequiredService<IMediator>();
  }

test/MediatR.Tests/MicrosoftExtensionsDI/DuplicateAssemblyResolutionTests.cs

@@ -15,7 +15,7 @@ public DuplicateAssemblyResolutionTests()
  {
  IServiceCollection services = new ServiceCollection();
  services.AddSingleton(new Logger());
- services.AddMediatR(typeof(Ping), typeof(Ping));
+ services.AddMediatR(cfg => cfg.RegisterServicesFromAssemblies(typeof(Ping).Assembly, typeof(Ping).Assembly));
  _provider = services.BuildServiceProvider();
  }
 

test/MediatR.Tests/MicrosoftExtensionsDI/PipeLineMultiCallToConstructorTest.cs

@@ -81,7 +81,7 @@ public async Task Should_not_call_constructor_multiple_times_when_using_a_pipeli
 
  services.AddSingleton(output);
  services.AddTransient(typeof(IPipelineBehavior<,>), typeof(ConstructorTestBehavior<,>));
- services.AddMediatR(typeof(Ping).GetTypeInfo().Assembly);
+ services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly));
  var provider = services.BuildServiceProvider();
 
  var mediator = provider.GetRequiredService<IMediator>();