Has anyone had luck with writing a kotlin subplugin with Gradle's TestKit? They don't seem to be hap...

# gradle

[Justin Ryan]

Has anyone had luck with writing a kotlin subplugin with Gradle's TestKit? They don't seem to be happy together, because of the ServiceLoader logic that SubpluginEnvironment does with class loaders. I see that even Kotlin's tests don't use TestKit. 😞 I'd love to have a TestKit based test for a compiler plugin I'm writing.

[eskatos]

TestKit might create some classloading issues when using runner.withDebug(true), it should not cause trouble when not using that

[snowe]

what is the difference between a plugin and subplugin?

[eskatos]

it’s not a Gradle thing
the Kotlin Gradle Plugin has a notion of “sub plugin”

[Justin Ryan]

Subplugins is a Kotlin gradle plugin concept. It wants to load the compiler plugins, and it uses a ServiceLoader to do it. Then uses the Subplugins to tied the configuration in the Gradle plugin to the corresponding compiler plugin.

[snowe]

I see.

[snowe]

woah... I just googled something completely unrelated and found you and your name as the main answer on an SO post @Justin Ryan 😂

[snowe]

spoopy

[Justin Ryan]

I've only got online one SO post, so that is quite a coincidence. 🙂

[snowe]

https://stackoverflow.com/questions/21190230/how-can-plugin-programmatically-configure-maven-publish-publishing-and-allow-bui/27066692

[snowe]

so crazy haha

[Justin Ryan]

@eskatos I concur that debug changes things. When I run without debug, I get identical behavior though, as in it never sees my subplugin. It could be for another reason, but it's suspicious.

[eskatos]

it is suspicious
fwiw, TestKit without withDebug just runs a regular Gradle daemon

[eskatos]

ah, but there’s also withPluginClasspath that does a nasty trick to get the plugin under development in the classloader hierarchy

[eskatos]

what you could try is automate publishing your plugin to a local repository and then reference that repository in your builds under test, to really mimic real world conditions

[eskatos]

if you have a reproducer for the issue with withPluginClasspath, could you please open an issue on gradle/gradle?

[Justin Ryan]

Thanks @eskatos. I remember the days of publishing to a local repo for testing. I'll give it a try to unblock myself.

For an issue, there's a few pieces involved. I'll see if I can pair down the minimal project I'm working with: https://github.com/quidryan/debuglog/blob/plugin-unit-tests/gradle-plugin/src/test/kotlin/debuglog/DebugLogGradlePluginTest.kt

It's from a small addition to @kevinmost’s debuglog example project.