UnusedPrivateMember - [invoke]: False positive: Used by public member function

[hfhbd]

Expected Behavior

no issue

Observed Behavior

UnusedPrivateMember - [invoke] at /Users/philipwedemann/invokeFalsePositive/src/main/kotlin/Test.kt:2:5

Steps to Reproduce

./gradlew detekt

object Test {
    private operator fun invoke(i: Int): Int = i

    fun answer() = Test(1)
}

val answer = Test.answer()

See also the attached reproducer project

Context

I adopt the code style from kotlinx.coroutines, which uses this constructor like function to emulate a constructor for an interface:

interface MutableStateFlow { }
fun MutableStateFlow(initValue: t) { }

Using this code style for the invoke function and combine it with objects results into some kind of namespaces.

Your Environment

• Version of detekt used: 1.19
• Version of Gradle used: 7.3.3
• Gradle scan link (add --scan option when running the gradle task): https://scans.gradle.com/s/rhwzv6cdovkwe
• Operating System and version: macOS 12.1
• Link to your project (if it's a public repository):
  invokeFalsePositive.zip

[BraisGabin]

Related with #4242.

[BraisGabin]

@hfhbd your issue I think that it will be solved by #4441 because you aren't using type solving. But I'll keep this open because we have the same issue with type solving too.

I reproduced that issue with this test:

        it("does not report used invoke operator - #4435") {
            val code = """
                object Test {
                    private operator fun invoke(i: Int): Int = i
                
                    fun answer() = Test(1)
                }

                val answer = Test.answer()
            """
            assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
        }

[github-actions]

This issue is stale because it has been open 90 days with no activity. Please comment or this will be closed in 7 days.

[github-actions]

This issue was closed because it has been stalled for 7 days with no activity.

[chao2zhang]

@BraisGabin Is the stance that we should acknowledge such degradation of UnusedPrivateMember with type resolution?

[atulgpt]

Hi @BraisGabin, this is also blocked for my project. I have created a PR for the fix at #5717