Hello everybody, I want to test code that calls a repository, which I have mocked. I want the

repository.save(entity)

method to just return whatever is passed into it. I thought that

Slot

would be the correct way of doing this, but …

val slot = slot<Entity>()
every { repository.save(capture(slot)) } answers { slot.captured }

… does not work, because the slot.captured is lateinit and not initialized during initialization of the mocks. Am I missing something or is this not possible with mockK?

It's possible, but not with caputure slots. You can do smth like this:

every { repo.save(any()) } answers { invocation.args[n] as XYZ }

where XYZ is the type of the argument passed in.

Nice extension

Thank you both for the answers, very cool!