Support Explicit Nested Scopes for improved hierarchy and Lifecycle-Safety

[oungsi2000]

Hi, I’m currently working on a project using Koin and wanted to share an idea regarding how scopes are handled.
Currently, implementing nested scopes in Koin often relies on managing scope keys and lifecycles manually, as shown below:

val myModule = module {
    scope(named("session_scope")) {
        scoped { UserSession() }
    }
    scope(named("task_scope")) {
        scoped { (parentSession: UserSession) -> 
            TaskProcessor(parentSession) 
        }
    }
}

While Koin’s dynamic graph creation (especially in Android) is convenient, it can sometimes be implicit and lead to unintended behavior. I personally prefer a more explicit graph definition, similar to Dagger or Metro, where the hierarchy is strictly defined.

val myModule = module {
    scope(named("session_scope")) {
        scoped { UserSession() }
        
        // Nesting the scope definition directly
        scope(named("task_scope")) {
            scoped { (parentSession: UserSession) -> 
                TaskProcessor(parentSession) 
            }
        }
    }
}

I have implemented a simple library that demonstrates this concept of explicit nesting:
https://github.com/Mole-Labs/mole-di

I’d love to hear your thoughts on this approach. Do you think this direction aligns with Koin’s roadmap, or are there specific architectural reasons for keeping the current flat scope definition?

Looking forward to your feedback!