Warnings during JVM tests

[CherryPerry]

Looks like caused by

@Ignore
class SingleToSingleTestsImpl

But they still run properly, I tried to fail check in SingleToSingleTestsImpl and test failed as expected.

https://github.com/badoo/Reaktive/actions/runs/4393344710/jobs/7693685167#step:7:1659

Unable to load JUnit4 runner to calculate Ignored test cases
java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
	at org.gradle.api.internal.tasks.testing.junit.AllExceptIgnoredTestRunnerBuilder$FallbackJUnit4Builder.runnerForClass(AllExceptIgnoredTestRunnerBuilder.java:55)
	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:70)
	at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:37)
	at org.gradle.api.internal.tasks.testing.junit.IgnoredTestDescriptorProvider.getAllDescriptions(IgnoredTestDescriptorProvider.java:31)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestEventAdapter.processIgnoredClass(JUnitTestEventAdapter.java:140)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestEventAdapter.testIgnored(JUnitTestEventAdapter.java:129)
	at org.junit.runner.notification.SynchronizedRunListener.testIgnored(SynchronizedRunListener.java:108)
	at org.junit.runner.notification.RunNotifier$8.notifyListener(RunNotifier.java:209)
	at org.junit.runner.notification.RunNotifier$SafeNotifier.run(RunNotifier.java:72)
	at org.junit.runner.notification.RunNotifier.fireTestIgnored(RunNotifier.java:206)
	at org.junit.internal.builders.IgnoredClassRunner.run(IgnoredClassRunner.java:16)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:108)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:57)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:39)
	at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:52)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
	at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker$2.run(TestWorker.java:176)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60)
	at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:113)
	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:65)
	at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
	at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)

[arkivanov]

Nice! Perhaps, we could make ignored classes abstract and add a factory function with the same name?

fun SingleToSingleTests(...): SingleToSingleTests =
    object : SingleToSingleTestsImpl(...) {}

private abstract class SingleToSingleTestsImpl(...) {
...
}

Maybe even abstract wouldn't needed if the class is private.

[arkivanov]

The solution I described should work, though there is a new warning now in Kotlin 1.9.20, for every test method. Filed https://youtrack.jetbrains.com/issue/KT-63132.