Sub-modules failing

[kmbisset89]

Getting an error when using submodules that throws an exception.

To Reproduce
Steps to reproduce the behavior:
Use the includes keyword:
val commonModule = module {
includes(infrastructureModule, viewModels, useCases, repositories)
}

private val infrastructureModule = module {
single { CoroutineErrorCatcher(get()) }

single { DispatcherProvider(get<CoroutineErrorCatcher>().coroutineExceptionHandler) }

}

private val viewModels = module {

}

private val useCases = module {

}

private val repositories = module {

}

                                                                                                Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.List org.koin.core.module.Module.getIncludedModules()' on a null object reference

Expected behavior
Not throw exception

Koin module and version:
[e.g]: koin-core:4.0.0-RC1

[GodzerBoot]

Same issue

Not using includes() and writing all modules in the same file solved the problem, but... It's quite dirty

[kmbisset89]

@arnaudgiuliani

@OptIn(KoinInternalApi::class)
fun flatten(modules: List<Module>): Set<Module> {
    // This is actually a DFS traversal of the module graph,
    // but we're using a stack instead of recursion to avoid stack overflows and performance overhead.

    val flatten = linkedSetOf<Module>()
    // I added a filter not null to get ride of this even though it should not be possible to have a null in that list. 
    val stack = ArrayDeque(modules.asReversed().filterNotNull())

    while (stack.isNotEmpty()) {

       /* The problem is here some how it is getting a null module */

        val current = stack.removeLast()

        // If the module is already in the set, that means we've already visited it, so we can skip it.
        if (!flatten.add(current)) {
            continue
        }

        // Add all the included modules to the stack if they haven't been visited yet.
        for (module in current.includedModules) {
            if (module !in flatten) {
                stack += module
            }
        }
    }

    return flatten
}