gradle kotlin DSL scala & idea

Question

How can I set

idea {
    targetVersion = "13"
}

and

sourceCompatibility = 1.8

from the scala plugin https://docs.gradle.org/current/userguide/scala_plugin.html when building using the gradle kotlin dsl?

Answer 1

Setting the target version of IDEA is a simple copy-paste:

build.gradle:

idea {
    targetVersion = "13"
}

build.gradle.kts:

idea {
    targetVersion = "13"
}

Setting the sourceCompatibility is a bit trickier:

build.gradle:

sourceCompatibility = 1.8

build.gradle.kts:

 tasks.withType<ScalaCompile> {
     sourceCompatibility = "1.8"
 }

Do note however, that the Gradle Scala plugin docs state that the sourceCompatibility option is basically a no-op. The compatible Java version is determined by the Scala compiler, where 2.11.x targets Java 1.6, and 2.12.x targets Java 1.8