AtomicFUTransformerBase doesn't delete the destination directory before copying files. If any of the source files are deleted, the destination will still contain the deleted files.

Solution

AtomicFUTransformerBase should delete destinationDirectory before the task executes.

Steps to reproduce

I have a Kotlin Gradle project that uses Atomicfu plugin.

The project has a single test in src/main/kotlin.

When I run ./gradlew check I see a single passing test.

I delete the test in src/main/kotlin.

When I re-run check I still see a single passing test. This is unexpected. The test should not run, because it was deleted.

I run ./gradlew clean, then ./gradlew check. I now see no tests, as expected.

Workaround

As a workaround the AtomicFU tasks can be modified to clear the destination directory before each execution:

tasks.withType<kotlinx.atomicfu.plugin.gradle.AtomicFUTransformTask>().configureEach {
    doFirst("clear stale files") {
        destinationDirectory.get().asFile.deleteRecursively()
    }
}