Protocols with protocol conformance not respected in generated mocks

[aim2120]

I am currently unable to generate mocks for protocols with protocol conformances. Cuckoo claims to support "inheritance (grandparent methods)", but it seems this may not apply to protocols? It's not entirely clear to me whether this is a supported feature or not. Either way, it would be a desirable feature for Cuckoo to have.

Code snippet of offending code:

protocol ParentProtocol {
    func parentFunction()
}

protocol ChildProtocol: ParentProtocol {
    func childFunction()
}

In mocks generated for the above, the MockChildProtocol fails to build due to not satisfying requirements for ParentProtocol.

I've created an example Swift package here with full repro information and example code: https://github.com/aim2120/CuckooProtocolInheritanceExample

[MatyasKriz]

Hi, Cuckoo has this functionality, you made me panic that I broke it. 😄 The only pitfall is that you need to specify the parent protocols in sources as well, Cuckoo doesn't rummage through files you don't specify, so it has no idea what the parent protocol looks like.

Although such a pitfall would warrant its own warning at run-time, so that users aren't confused by this error.

[aim2120]

Ah ok! So it is intended that you copy-paste the function definitions into the "child" protocol.

It would be super cool if Cuckoo could intake a list of "reference" files in addition to source files, such that it could find the inherited protocol / superclass. That would likely be quite a feature to develop though. I'm curious how you would feel like an addition like that?

I agree, that a warning or docs clarification could help more immediately (at least for me, it wasn't clear what was/wasn't supported for this particular feature).

[MatyasKriz]

You needn't copy-paste anything, Cuckoo does this for you, but it has to know what the parent protocol looks like, there's no other way to find that out other than parsing it.

If you want to avoid generating mocks for the parent protocol, that might be a use-case that's not currently supported. In that case I'd prefer the implementation to leverage the existing exclude/regex parameter so that mocks for the types aren't generated, but their definities are still parsed and used to make sure child protocols are compilable.

[aim2120]

Got it. I see how the exclude/regex parameters could get me to what I'm looking for.

I'm still trying to think my way through the scenario where ParentProtocol and ChildProtocol are defined in separate modules. Right now, I'm resorting to copy-pasting the definitions from the parent to the child for the sake of mocks generation. The files are technically located in the same repo, but they're just not near each other (I define Cuckoofiles per module and was hoping to avoid funky relative paths). Files that aren't co-located in the same repo (e.g. different packages) would be a whole other can of worms. There's not a solution that comes immediately to mind for how Cuckoo could automatically handle those situations though (that's not rummaging through files 😅).

Tangents aside, thanks for your help! Feel free to resolve this issue, as the main concern has been addressed.