NoNameShadowing false positive in kotlin-dsl

[eygraber]

I've been getting NoNameShadowing violations in a project that uses kotlin-dsl where the name being shadowed is implicit lambda parameter 'it'. I think it might be because of the lambda getting converted into an Action because there's no other it in scope.

public fun Project.registerDetektTask(
  name: String,
  sourceSet: KotlinSourceSet
): TaskProvider<Detekt> = tasks.register("detekt${name.capitalize()}", Detekt::class.java) {
  val detekt = detekt
  detekt.basePath?.let { basePath = it } // NoNameShadowing
}

[BraisGabin]

I assume that the lambda of register has a parameter it and that's the issue. Can that be the case?

[eygraber]

I believe it does, but I think kotlin-dsl applies a compiler plugin that converts it into a lambda with receiver. So there is no it and the compiler won't let you assign a name to the parameter (because it doesn't exist anymore).

[BraisGabin]

I see the problem... But I don't think detekt should take care of this strange behaviour were a compiler plugin is involved. If those functions would annotated with something we could use that to ignore them but that's not the case here.

I think that here you should use a @Suppress or write it like this:

  detekt.basePath?.let { b -> basePath = b } // NoNameShadowing

[eygraber]

I ended up specifying a name to get rid of the violation, but it could be annoying if there was a lot of them.

If detekt used a compiler plugin, would it make it easier to avoid this issue (or would it solve it outright)?

[BraisGabin]

I imagine that with a compiler plugin this could be spotted.

Closing for the reasons I wrote before.

[TWiStErRob]

+2

I had the same issue with a different rules: just throwing my case here to maybe help the case of getting support for this in some form. I encountered two weird reports, one from Deprecated and another from NestedScopeFunctions. Only the Deprecated case is detailed here, as it was a bigger WTF. The below code is only focusing on the problem, other parts removed, also copied some context from external classes near the code for more visibility:

(😅 It's really meta to be having a problem with setting up Detekt Gradle plugin and getting reports from Detekt on it.)

[eygraber]

Ran into this again with Deprecation and NoNameShadowing in a different projects that had a lot of violations. Was very annoying to address.

[BraisGabin]

#5492 should fix this issue (or at least give us the option to fix it). And I understand that this is annoying but we are facing a limitation on our current engine. That's the reason of #5492.

[eygraber]

Very excited for that. I'm ready to test 😅