has anyone else seen this issue when trying to test a plugin with test kit, and the plugin uses clas...

# gradle

[wakingrufus]

has anyone else seen this issue when trying to test a plugin with test kit, and the plugin uses classes from the kotlin plugin?

* What went wrong:
java.lang.NoClassDefFoundError: org/jetbrains/kotlin/gradle/dsl/KotlinProjectExtension
> org/jetbrains/kotlin/gradle/dsl/KotlinProjectExtension

[wakingrufus]

and the test script looks like

plugins {
   kotlin("jvm") version("1.8.0")
   id("my.plugin")
}

[mbonnin]

Maybe you need withPluginClasspath() or so?

[wakingrufus]

i do have that

[mbonnin]

As a side note, I usually prefer publishing the plugin to a local maven repository and reuse that from the test project

[wakingrufus]

i do not have a dependency on the kotlin plugin in my plugin b/c in me experience, it causes issues downstream such as

Class 'kotlin.reflect.KClass' was compiled with an incompatible version of Kotlin. The binary version of its metadata is 1.6.0, expected version is 1.4.1.

[mbonnin]

Typically the Kotlin Gradle Plugin should be a compileOnly dependency so maybe withPluginClasspath() doesn't load it, I don't know

[wakingrufus]

yeah, this probalem came up when i switch the dep from implementation to compileOnly

[wakingrufus]

maybe there is a better way to solve that other issue above. i found that when an old kotlin plugin is transitively brought in, the com[iler is expecting that language version even if i add kotlin("jvm") version("1.6.0") in the build script

[mbonnin]

expected version is 1.4.1.

That's Gradle forcing you on 1.4

[mbonnin]

See https://handstandsam.com/2022/04/13/using-the-kotlin-dsl-gradle-plugin-forces-kotlin-1-4-compatibility/

[mbonnin]

TLDR: use compileOnly and do not use withPluginClassPath

[mbonnin]

Just make your test task depends on publishAllPublicationToSomeLocalMavenRepository

[mbonnin]

We're doing it here

[wakingrufus]

thanks for the help. this helped me understand what was going on

[wakingrufus]

i solved it a different way though

[wakingrufus]

i added the dependency

compileOnly(gradleTestKit())

then configured

tasks.withType<PluginUnderTestMetadata> {
        pluginClasspath.from(project.sourceSets.getByName("main").compileClasspath)
    }