Autofac implementation for mediator pipeline

async-mediator-pipeline.cs

public class AsyncMediatorPipeline<TRequest, TResponse> : IAsyncRequestHandler<TRequest, TResponse> where TRequest : IAsyncRequest<TResponse>
    {

        private readonly IAsyncRequestHandler<TRequest, TResponse> inner;
        private readonly IAsyncPreRequestHandler<TRequest>[] preRequestHandlers;
        private readonly IAsyncPostRequestHandler<TRequest, TResponse>[] postRequestHandlers;

        public AsyncMediatorPipeline(IAsyncRequestHandler<TRequest, TResponse> inner, IAsyncPreRequestHandler<TRequest>[] preRequestHandlers, IAsyncPostRequestHandler<TRequest, TResponse>[] postRequestHandlers)
        {
            this.inner = inner;
            this.preRequestHandlers = preRequestHandlers;
            this.postRequestHandlers = postRequestHandlers;
        }

        public async Task<TResponse> Handle(TRequest message)
        {
            foreach (var preRequestHandler in preRequestHandlers)
            {
                 await preRequestHandler.Handle(message);
            }

            var result = await inner.Handle(message);

            foreach (var postRequestHandler in postRequestHandlers)
            {
                await postRequestHandler.Handle(message, result);
            }
            return result;
        }
    }

autofac-mediator-module.cs

public class MediatorModule : Module
{
    protected override void Load(ContainerBuilder builder)
    {
        builder.RegisterType<Mediator>()
            .AsImplementedInterfaces()
            .AsSelf()
            .InstancePerLifetimeScope();

        //register all pre handlers
        builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
            .As(type => type.GetInterfaces()
                .Where(interfacetype => interfacetype.IsClosedTypeOf(typeof (IAsyncPreRequestHandler<>))))
            .InstancePerLifetimeScope();

        //register all post handlers
        builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
            .As(type => type.GetInterfaces()
                .Where(interfacetype => interfacetype.IsClosedTypeOf(typeof(IAsyncPostRequestHandler<,>))))
            .InstancePerLifetimeScope();

        //register all asynchandlers
        builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
           .As(type => type.GetInterfaces()
               .Where(interfaceType => interfaceType.IsClosedTypeOf(typeof(IAsyncRequestHandler<,>)))
               .Select(interfaceType => new KeyedService("asyncRequestHandler", interfaceType)))
           .InstancePerLifetimeScope();

        //register pipeline decorators
        builder.RegisterGenericDecorator(typeof(AsyncMediatorPipeline<,>), typeof(IAsyncRequestHandler<,>), "asyncRequestHandler")
            .InstancePerLifetimeScope();
    }
}