How to configure every Kotlin project in Gradle multi-project build?
You can reference the Kotlin plugin by its id
instead of its type, as follows:
allprojects {
plugins.withType(JavaPlugin) {
// All the stuff that all Java sub-projects have in common
// ...
}
plugins.withId("org.jetbrains.kotlin.jvm") {
// All the stuff that all Kotlin sub-projects have in common
// ...
}
}
For Java plugin it's easer and you can use plugins.withType
, as it's a "core" Gradle plugin, and the JavaPlugin
class can be used as it's part of the Gradle Default Imports ( import org.gradle.api.plugins.*
)
The kotlin plugin being applied is actually not KotlinPlugin
but KotlinPluginWrapper
. Also it's necessary to use the canonical name to find the type.
plugins.withType(org.jetbrains.kotlin.gradle.plugin.KotlinPluginWrapper) {
// All the stuff that all Kotlin sub-projects have in common
...
}
To catch all wrapper implementations, KotlinBasePluginWrapper
could be used as well.
One solution is to start to use a custom plugin for your project. This is exactly what the AndroidX team did
import org.gradle.api.Plugin
import org.gradle.api.Project
import org.jetbrains.kotlin.gradle.plugin.KotlinBasePluginWrapper
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
class MyPlugin : Plugin<Project> {
override fun apply(project: Project) {
project.plugins.all {
when (it) {
...
is KotlinBasePluginWrapper -> {
project.tasks.withType(KotlinCompile::class.java).configureEach { compile ->
compile.kotlinOptions.allWarningsAsErrors = true
compile.kotlinOptions.jvmTarget = "1.8"
}
}
}
}
}
You'll need to setup all the boiler plate to get this setup, but the long term payoff is high.
Read more
https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-master-dev/buildSrc/src/main/kotlin/androidx/build/AndroidXPlugin.kt#186
https://www.youtube.com/watch?v=sQC9-Rj2yLI&feature=youtu.be&t=429