Use Cases

[RikDriever]

I'm reviewing multiple Clean Architecture solutions and virtually all have a setup with Use Cases in the form of Interactors with a Request and a Response message.
I don't see any of that in this solution; why is that?

[ardalis]

Can you link to one so I can see an example of what you mean? This one is meant to be a solution starter kit, so it's light on features such that when you start from it, you don't have to rip a whole lot out.

[RikDriever]

Sure, for example this article https://medium.com/@stephanhoekstra/clean-architecture-in-net-8eed6c224c50 with this solution structure https://github.com/stephanhoekstra/clean-architecture

This series of blogposts is also worth looking into: https://plainionist.github.io/Implementing-Clean-Architecture-UseCases/
The image below comes from this series and is particularly interesting for this topic.

I understand this is a starter solution, but it just seemed odd to me that others see the use cases as an integral part of the architecture and you might not? The phrase "use case" is not mentioned once in your e-book either.

[ardalis]

It's true, 'use case' isn't really a term I use in this context. In my experience a use case is similar to a user story, and is captured as documentation of requirements, not part of the software domain itself. From the diagram you've provided, it seems like a use case maps to an application service. In fact, if one uses MediatR or something similar to minimize the size of one's controllers, you'll end up creating message types that could easily map to the Use Case Input Port (Request) and Use Case Output Port (Response). With the Use Case Interactor as simply the Handler in that case.

I'll check out the Medium article you linked to and respond later perhaps once I've had a chance to read it. Thanks!