JaCoCo & Kotlin: Coverage on Generated Code

JaCoCo works flawlessly with Kotlin. Except when it reports lines not covered on generated code 😡. Fortunately there’s a fix already in place.

Update 08/26: JaCoCo 0.8.2 has now officially been released 👏 No need to use the 0.8.2-SNAPSHOT anymore.

What!? I didn’t even write those functions! There’s no way I’m writing tests for them. I’m pretty sure the compiler knows what it’s doing…

Good news is that this has been fixed in the latest JaCoCo release (thanks to goodwink). Bad news is that 0.8.2 is not out yet 😞

If you are like me, and can’t wait to get this working, you can use the SNAPSHOT version of JaCoCo making this changes on your build.gradle:

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repositories {
  …
  maven("https://oss.sonatype.org/content/repositories/snapshots")
}

jacoco {
  toolVersion = "0.8.2-SNAPSHOT"
}

(I’m using Gradle with Kotlin DSL in this example)

Now you can finally take your Kotlin coverage to 100% without having to write tests for component1() and component2().