StructureMap does not see types in ASP.NET Core .NET5

Question

I am creating sample project based on DDD.

1. I created SharedKernel project where I have my class for DomainEvents

    public static class DomainEvents
    {
        public static IContainer Container { get; set; }

        static DomainEvents()
        {
            Container = StructureMap.Container.For<GenericTypesScanning>();
        }

        public static void Raise<T>(T args) where T : IDomainEvent
        {
            foreach (var handler in Container.GetAllInstances<IHandle<T>>())
            {
                handler.Handle(args);
            }
        }
     }

and this is class GenericTypesScanning

    public class GenericTypesScanning : Registry
    {
        public GenericTypesScanning()
        {
            Scan(scan =>
            {
                // 1. Declare which assemblies to scan
                scan.Assembly("MyLib");

                // 2. Built in registration conventions
                scan.AddAllTypesOf(typeof(IHandle<>));
                scan.WithDefaultConventions();

            });          

        }
    }

2. In MyLib project I have class AppointmentConfirmedEvent and handler for this event:

    public class EmailConfirmationHandler: IHandle<AppointmentConfirmedEvent>
    {
        public void Handle(AppointmentConfirmedEvent appointmentConfirmedEvent)
        {
            // TBD
        }
    }

3. I have temporary rest api controller where I wanted to check if everything is correctly registered and I am doing this:

    [Route("api/[controller]")]
    [ApiController]
    public class ValuesController : ControllerBase
    {
        // GET: api/<ValuesController>
        [HttpGet]
        public IEnumerable<string> Get()
        {                        
            var appointmentConfirmedEvent = new AppointmentConfirmedEvent();
            DomainEvents.Raise(appointmentConfirmedEvent);

            return new string[] { "value1", "value2" };
        }
    }

but when DomainEvents.Raise is called the event is not handled because internal call Container.GetAllInstances<IHandle<T>>() returns empty array.

I did analogous example with Console app and there everything works fine. Any idea why it does not work in case of ASP.NET Core .NET 5 project?

-Jacek

Answer 1

The AddAllTypesOf() method does not work with open generics. See the ConnectImplementationsToTypesClosing() method in the StructureMap docs: http://structuremap.github.io/generics/

And just a reminder, StructureMap is no longer supported. Moreover, 2.6.4.1 was the "haunted" version of StructureMap that was admittedly buggy.