Hello everybody, I want to test code that calls a ...

# mockk

[maxmello]

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?

[robin]

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.

[robin]

I've actually built myself an extension function that does exactly that:

inline infix fun <reified T> MockKStubScope<T, T>.returnsArgument(n: Int): MockKAdditionalAnswerScope<T, T> =
    this answers { invocation.args[n] as T }

[robin]

Called like:

every { repo.save(any()) } returnsArgument 0

[oleksiyp]

Nice extension

[oleksiyp]

I would expect slot stuff to be working actually

[oleksiyp]

Added https://github.com/mockk/mockk/issues/194

[oleksiyp]

https://github.com/mockk/mockk/issues/195

[oleksiyp]

(please don't expect it to happen fast. I spend one weekend to fix stuff in mockk per 4-6 weeks)

[maxmello]

Thank you both for the answers, very cool!