Kotlin: call on the result of an unqualified helper (repository().m()) resolves to a same-named decoy in another package #2805

Version: codegraph 1.6.2 (darwin-arm64), fresh codegraph init -y .

Related: #750 / #752 fixed Foo.factory().bar() for Kotlin. This is the neighbouring shape where the factory is an unqualified call (a same-class private helper, implicit this), plus its local-variable form. The helper declares its return type explicitly, so the information #752 relies on is there.

Repro

// src/main/kotlin/demo/domain/Repo.kt
package demo.domain

interface Repo {
    fun pending(id: Long): Int
}

// src/main/kotlin/demo/data/RealRepo.kt
package demo.data

import demo.domain.Repo

class RealRepo : Repo {
    override fun pending(id: Long): Int = 1
}

// src/test/kotlin/demo/testutil/FakeRepo.kt
package demo.testutil

import demo.domain.Repo

class FakeRepo : Repo {
    override fun pending(id: Long): Int = 2
}

// src/test/kotlin/demo/data/RealRepoTest.kt
package demo.data

class RealRepoTest {
    private fun repository(): RealRepo = RealRepo()

    fun viaConstructor() {
        val repo = RealRepo()
        repo.pending(1)
    }

    fun viaHelperLocal() {
        val repo = repository()
        repo.pending(1)
    }

    fun viaHelperChain() {
        repository().pending(1)
    }
}

codegraph init -y . && codegraph callees <fn>:

• The wrong edge needs the decoy in a different package. With all three classes in one package, both helper calls land on the interface method instead (imprecise, but not wrong).
• Same results with the calls inside a lambda (runTest { … }), for / if blocks, a block-bodied helper, and suspend functions.

Impact

callers RealRepo::pending misses the helper-based call sites, and callers FakeRepo::pending gains a call it never receives. So impact / affected on a repository implementation under-reports its tests and points at the fake. This is the common Android test setup: a private repository() builder in the test class, and a shared fake in a testutil package.

In a larger private Kotlin codebase (~1.1k Kotlin files) the local-variable form went further: val repo = repository(); for (…) { repo.m(…) } inside runTest { } produced no calls edge to m at all (the test's callees listed repository but not m). I couldn't reduce that variant: the toy project above resolves it to the interface. Treat it as an extra data point.

Expected

Infer the receiver type from the helper's declared return type for unqualified calls and for val x = helper() locals, the same way it already works for Foo.factory() (#752) and constructor-initialised locals. Per #750's invariant, when the type can't be validated, emit no edge rather than one to a same-named method on an unrelated class.

Happy to turn the repro into a fixture PR if that helps.