Gradle: Converting a copy task from groovy to kotlin gradle script - kotlin

Question

I am stuck with converting a groovy gradle script to kotlin script. I am trying to use pf4j in my project and have started converting their example build.gradle to .gradle.kts. Example can be found here: https://github.com/pf4j/pf4j/blob/master/demo_gradle/plugins/build.gradle
Since I got stuck I am trying it just for one plugin right now, however their example is applying the task to all subprojects. So be aware of the difference.
So I tried to replace their build example with the following gradle.kts file:
val pluginClass: String by project
val pluginId: String by project
val pluginProvider: String by project
val version: String by project
val pf4jVersion: String by project
dependencies {
implementation(project(":api"))
implementation("org.pf4j:pf4j:${pf4jVersion}")
annotationProcessor("org.pf4j:pf4j:${pf4jVersion}")
}
val buildPluginArchive = task("plugin", Jar::class) {
manifest {
attributes["Plugin-Class"] = pluginClass
attributes["Plugin-Id"] = pluginId
attributes["Plugin-Version"] = version
attributes["Plugin-Provider"] = pluginProvider
}
archiveBaseName.set("plugin-${pluginId}")
into("classes") {
from(sourceSets.main.get().output)
}
dependsOn(configurations.runtimeClasspath)
into("lib") {
from({
configurations.runtimeClasspath.get().filter { it.name.endsWith("jar") }.map { zipTree(it) }
})
}
archiveExtension.set("zip")
}
tasks {
"build" {
dependsOn(buildPluginArchive)
}
}
And it works and generates a zip, but the contents do not match the original. Firstly the lib folder does not only contain jar files, but also a folder structure (and more important a META-INF folder with MANIFEST.MF file that confuses the plugin loader). And it is missing the MANIFEST.MF in the classes/META-INF folder.
I suspect the issue being somwhere with this configuration in the original build.gradle:
into('classes') {
with jar
}
I just could not find any meaningful documentation about what "with jar" actually does or how to replicate the behavior in gradle.kts.
How can I get the same output as the demo with a gradle.kts configuration?

Answer 1

I just could not find any meaningful documentation about what "with jar" actually does
with is a method from the Jar task type. See the method details section of the Jar task, scroll to the bottom and you'll find information the with method. It's signature is:
CopySpec with(CopySpec... sourceSpecs)
Now if you were to look at the API documentation for Jar, you'll see that with actually comes from CopySpec which Jar implements thanks to its super class.
The jar part in with jar is referring to the task named jar which is created by the Java plugin.
With all of that said, a more idiomatic approach for the with part would be:
tasks {
val plugin by registering(Jar::class) {
into("classes") {
with(jar.get())
}
}
build {
dependsOn(plugin)
}
}