Anybody got an example of a Kotest test for a gradle plugin

Question

Anybody got an example of a Kotest test for a gradle plugin in kotlin using GradleRunner that works I m trying for the first time and getting this exception ```Caused by org gradle testkit runner InvalidPluginMetadataException Test runtime classpath does not contain plugin metadata file plugin under test metadata properties at org gradle testkit runner internal PluginUnderTestMetadataReading readImplementationClasspath PluginUnderTestMetadataReading java 44 at org gradle testkit runner internal PluginUnderTestMetadataReading readImplementationClasspath PluginUnderTestMetadataReading java 37 at org gradle testkit runner internal DefaultGradleRunner withPluginClasspath DefaultGradleRunner java 162 ``` I ve seen old posts about people seeing this specific error and this plugin is supposed to help with an issue in IDEA ``` com palantir idea test fix version 0 1 0 ``` but it doesn t help me I didn t look into it so don t know what specifically this is doing Anyway was hoping someone else has this working slightly smiling face Thanks in advance for any info In case it s useful here s the snippet causing the above error ``` val gradleRunner = GradleRunner create withPluginClasspath withProjectDir testProjectDir root withTestKitDir testProjectDir newFolder ```

sam · Answer

Are you trying to test a gradle plugin itself

Skolson5903 · Answer

Yup have one with a few tasks and can debug loading it with a kotest no problem But running a gradle build to actually test results of the tasks executed during a build requires the Gradle runner Which is when I hit this thing

sam · Answer

It s a pretty niche use case so not sure if anyone will have had experience in here with it

sam · Answer

It does look like the classpath isn t being set properly

Skolson5903 · Answer

Cool was worth a shot

sam · Answer

how are you executing the tests via the plugin or via the gradle window

sam · Answer

Skolson5903 · Answer

Plugin so far The nice thing about the Gradle runner test is it essentially sets up a test project on the fly I d have to set up a separate project using the plugin to run gradle tasks that way takes a little work

sam · Answer

When I write my gradle plugin I install to local then have another project that uses that plugin from local

sam · Answer

Is that what this gradle runner thing is meant to save doing

Skolson5903 · Answer

Yeah that s probably what I ll do tomorrow too

Skolson5903 · Answer

Yup It sets up a test on the fly then let s you run tasks from test code using the runner and verify results

Skolson5903 · Answer

Part of the code you haven t seen him the test makes the test project and writes out a build gradle with whatever the test needs

sam · Answer

that s clever

sam · Answer

There s probably some class path trickery that our plugin isn t doing right

Skolson5903 · Answer

Yeah the runner has that usePluginClasspath call to ensure the test gradle run can see the test classpath Evidently that palantir plugin has some workaround for a bug feature in IDEA that causes this error Tomorrow I m gonna dig into what it s trying to do and see if I can tell what s needed

MiSikora · Answer

I have Kotest tests with GradleRunner here <https github com MiSikora Laboratory tree master library gradle plugin src test java io mehow laboratory gradle>

MiSikora · Answer

Maybe it ll help

Skolson5903 · Answer

Awesome thanks I ll check it out Are you using Idea or Android Studio or something else to run tests

MiSikora · Answer

I mostly work with AS but it should work with Idea as well Or just from the console

Skolson5903 · Answer

Thanks Did you ever see the plugin under test metadata properties error Or did it just work on yours

MiSikora · Answer

I had some trouble but I don t remember any specifics I set it up couple of months ago

Skolson5903 · Answer

What JDK are you using

MiSikora · Answer

At the time of writing I used 1 8 but now I m on 14

Skolson5903 · Answer

Cool I m on 14 too so that s evidently not it slightly smiling face Thanks for your help

MiSikora · Answer

Did you try to clone my project and run tests

Skolson5903 · Answer

Not yet still tinkering with setting up mine using yours as a template but so far still get the same error After I finish trying stuff I ll do that just to see if it s specific to my environment and not my project

Skolson5903 · Answer

FWIW I found a post in StackOverflow for this problem and their fix seems to work I had to translate from groovy to kotlin and ended up adding this to my build gradle kts Michal don t know why your project didn t need this so still trying to figure this out ```val fixIdeaPluginClasspath = tasks create fixIdeaPluginClasspath doFirst tasks pluginUnderTestMetadata configure val ideaClassesPath = project buildDir toPath resolveSibling out resolve production toFile val newClasspath = pluginClasspath toMutableList newClasspath add 0 ideaClassesPath pluginClasspath setFrom newClasspath tasks getByName pluginUnderTestMetadata mustRunAfter fixIdeaPluginClasspath fun org gradle plugins ide idea model IdeaProject settings block ProjectSettings gt Unit = this settings as ExtensionAware extensions configure block fun ProjectSettings taskTriggers block org jetbrains gradle ext TaskTriggersConfig gt Unit = this taskTriggers as ExtensionAware extensions configure taskTriggers block idea project settings taskTriggers beforeBuild fixIdeaPluginClasspath tasks pluginUnderTestMetadata ```