Are tests (files under `src/test` in a Maven project) considered to be located in a different module...

# language-proposals

[David Kubecka]

Are tests (files under src/test in a Maven project) considered to be located in a different module than src/main ? Otherwise I cannot explain why I'm getting the Smart cast to 'Long' is impossible, because 'XXX' is a public API property declared in different module error in a single-module project.

[dmitriy.novozhilov]

Yes, they are different modules (but with friend relation, so you can use internals from main module in tests)
From compiler point of view module is a single compilation unit -- smallest bunch of sources, which are compiled together
In gradle terminology compiler modules are mapped to gradle sourcesets

[David Kubecka]

Hmm, and couldn't they be friends also with respect to smart casts? 🙂

[David Kubecka]

I know there is https://youtrack.jetbrains.com/issue/KT-50534/Consider-relaxing-smart-cast-requirements-for-classes-from-different-modules-but-in-the-same-project. Should I mention this case there or is there a more specific issue for that?

[dmitriy.novozhilov]

Actually yes, because test and main are always compiled together

[dmitriy.novozhilov]

It's better to create new issue and mention it in KT-50534
Your case is much smaller and safer (from language point of view), so it possible can be implemented separately from KT-50534

[David Kubecka]

Ok, will do

[David Kubecka]

I guess I should also create an issue to a related problem that there's a mismatch between what kotlinc and IDEA build system think. IDEA thinks that the smart cast is actually performed in my case.

[dmitriy.novozhilov]

Interesting
It worth for another ticket, indeed

[David Kubecka]

Could this ^ perhaps mean that for IDEA tests and main actually constitute a single module?

[dmitriy.novozhilov]

Definitely not (otherwise you'll be able to see test classes in the main module)
Most likely there is a bug in some module structure representation passed from IDE to the checker which reports this error

[David Kubecka]

Btw what's the relation of this IDE checker to the kotlin compiler? I thought that they are actually same, or rather that IDE checker relies on what compiler reports. If that's so how come that such bugs are even possible?

[dmitriy.novozhilov]

This checker is implemented deeply in the compiler
IDE just shows errors found by the compiler

[dmitriy.novozhilov]

You can easily check in IDE from where any warning/error was reported from compiler or from IDE by enabling internal mode
When it enabled you will see internal diagnostic name in pop-up with message if this diagnostic was reported by compiler

[dmitriy.novozhilov]

^first one from ide, second one from compiler

[David Kubecka]

I didn't know about the internal mode. Thanks!

[David Kubecka]

Anyway, I still don't understand how could it be that IDE "missed" that message from the compiler (about impossible smartcast)

[dmitriy.novozhilov]

BTW you can also add -Xrender-internal-diagnostic-names compiler flag to render those names during build too if you want

[dmitriy.novozhilov]

Anyway, I still don't understand how could it be that IDE "missed" that message from the compiler (about impossible smartcast)

IDE don't loose it. It's compiler for some reason don't report it based on configuration and data passed to it from IDE

[David Kubecka]

Ah, ok. So to which project I should report this second issue exactly? IDEA or kotlin?

[dmitriy.novozhilov]

Kotlin Intellij IDEA Plugin (KTIJ)

[David Kubecka]

you will see internal diagnostic name in pop-up with message if this diagnostic was reported by compiler

How can I actually see which error is coming from where? 🙂 Do compiler errors have the square brackets prefix?

[dmitriy.novozhilov]

Yes, that's the difference