JaCoCo Agent Override

[wakawaka54]

I'm working through JaCoCo support with this tool and I did have quite a bit of trouble with the JaCoCo Agent resolution logic. In the internal builds in my company we provide the JaCoCo dependencies in a custom manner.

This logic here expects the dependency name to be "org.jacoco.agent" https://github.com/Kotlin/kotlinx-kover/blob/main/src/main/kotlin/kotlinx/kover/engines/jacoco/JacocoAgent.kt#L20 . The problem I couldn't find a good way to manually provide an agent jar that would work resolve properly here.

I had to do this:

class JacocoAgentDependency(collection: FileCollectionInternal) : DefaultSelfResolvingDependency(collection) {
    override fun getName(): String = "org.jacoco.agent"
}

val koverJacocoConfig = project.configurations.getByName("JacocoKoverConfig")

val jacocoAgentJar: File = // my custom agent jar //

koverJacocoConfig.withDependencies {
    val fileCollectionFactory: FileCollectionFactory = serviceOf()
    add(JacocoAgentDependency(fileCollectionFactory.fixed(jacocoAgentJar)))
}

[shanshin]

Hi,
may you clarify, you are using a fork of the JaCoCo?

[wakawaka54]

Uhhh technically no. But I think a good way to think about this request is that if I have the JaCoCo Agent JAR located locally within the same project, I'd want to configure Kover to just use that JaCoCo Agent rather than trying to implicitly resolve it.

This might also be better served by allowing some customization into the Kover engine adapters, potentially allowing me to register my own engine, etc.

[shanshin]

Unfortunately, you can't just replace the agent jar file - for the plugin to work correctly, it must be compatible with the classpath of reports.
Also, the plugin must be modified so that the build cache supports custom agents.
Making an adapter for custom coverage engines is a good idea, but it was not included in the short-term plans.

As a workaround, you may try to use a fork of the JaCoCo, publish it to a local Maven repository.

[shanshin]

Resolved in 0.7.0-Alpha