UndocumentedPublicClass false positive for inner types

[jcornaz]

Expected Behavior

Given the following source code:

private class MyClass {
  object MyInnerObject
}

I don't expect the UndocumentedPublicClass to be reported because MyClass is private.

Yes MyInnerObject is not explicitly marked private. But being an inner type of a private one, makes MyInnerObject effectively private.

Observed Behavior

Given the snippet above and the rule UndocumentedPublicClass activated:

  UndocumentedPublicClass:
    active: true
    searchInInnerObject: true

A UndocumentedPublicClass issue is reported, saying that MyInnerObject is public and undocumented.

Steps to Reproduce

The snippets above should be enough to reproduce the issue.

Context

I added a private class with inner types and got the mentioned false-positive reported by detekt.

Your Environment

• Version of detekt used: 1.7.4
• Version of Gradle used: 6.3
• Operating System and version: Linux 5.5.13

[BraisGabin]

I think that we don't even need searchInInnerObject that object should never be flagged.

[schalkms]

Thanks for reporting this.
The rule doesn't take nested classes into account at the moment.
Following code should be flagged, however, since the nested and outer class(es) are public.

class Outer(val i: Int) {
    // must be documented
    class Nested(val s: String) {
    }
}

[jcornaz]

@schalkms

The rule doesn't take nested classes into account at the moment.

Mmmh. Yes they do... There is even explicit config for it.

The documentation says:

By default this rule also searches for nested and inner classes and objects. This default behavior can be changed with the configuration options of this rule.

And, yes your example should and is flagged. As far as I can see, that works as expected.

The problem is only when the outer class is not public.