Spring Spring Boot 4.0.0-RC1: JUnit test discovery fails depending on a test name

Hello!

I am using Spring Boot 4.0.0-RC1 + JUnit 6 + Kotlin 2.2.21 + Gradle 8.14.3

I created a simple class that generates a positive integer:

@Service
class RandomService {

    suspend fun getRandomPositiveInt(): Int {
        delay(1_000)
        return Random.nextInt(from = 1, until = Int.MAX_VALUE)
    }

}

Then I created a test for the RandomService class:

@SpringBootTest
class RandomServiceTest1(
    @Autowired private val randomService: RandomService,
) {

    @Test
    suspend fun `check getRandomPositiveInt`() {
        val result = randomService.getRandomPositiveInt()
        assertTrue { result > 0 }
    }

}

And when I try to run the test, the following problem occurs:

Click to see a full error

org.junit.platform.launcher.core.DiscoveryIssueException: TestEngine with ID 'junit-jupiter' encountered a critical issue during test discovery:

(1) [ERROR] ClassSelector [className = 'io.sultazat.demo.service.RandomServiceTest1', classLoader = jdk.internal.loader.ClassLoaders$AppClassLoader@2c854dc5] resolution failed
    Source: ClassSource [className = 'io.sultazat.demo.service.RandomServiceTest1', filePosition = null]
            at io.sultazat.demo.service.RandomServiceTest1.<no-method>(SourceFile:0)
    Cause: org.junit.platform.commons.PreconditionViolationException: Failed to get Kotlin function for method: static java.lang.Object io.sultazat.demo.service.RandomServiceTest1.check getRandomPositiveInt$suspendImpl(io.sultazat.demo.service.RandomServiceTest1,kotlin.coroutines.Continuation)
    at org.junit.platform.commons.util.Preconditions.condition(Preconditions.java:339)
    at org.junit.platform.commons.util.Preconditions.notNull(Preconditions.java:74)
    at org.junit.platform.commons.util.KotlinSuspendingFunctionUtils.getKotlinFunction(KotlinSuspendingFunctionUtils.java:112)
    at org.junit.platform.commons.util.KotlinSuspendingFunctionUtils.getReturnType(KotlinSuspendingFunctionUtils.java:43)
    at org.junit.platform.commons.util.KotlinReflectionUtils.getKotlinSuspendingFunctionReturnType(KotlinReflectionUtils.java:127)
    at org.junit.jupiter.engine.support.MethodReflectionUtils.getReturnType(MethodReflectionUtils.java:31)
    at org.junit.jupiter.engine.discovery.predicates.IsTestableMethod.lambda$hasVoidReturnType$0(IsTestableMethod.java:68)
    at org.junit.platform.engine.support.discovery.DiscoveryIssueReporter.lambda$createReportingCondition$0(DiscoveryIssueReporter.java:121)
    at org.junit.platform.engine.support.discovery.DiscoveryIssueReporter$Condition.lambda$and$0(DiscoveryIssueReporter.java:171)
    at org.junit.jupiter.engine.discovery.predicates.IsTestableMethod.test(IsTestableMethod.java:49)
    at org.junit.jupiter.engine.discovery.predicates.IsTestMethod.test(IsTestMethod.java:24)
    at org.junit.jupiter.engine.discovery.predicates.IsTestableMethod.test(IsTestableMethod.java:32)
    at java.base/java.util.function.Predicate.lambda$or$2(Predicate.java:101)
    at java.base/java.util.function.Predicate.lambda$or$2(Predicate.java:101)
    at org.junit.platform.commons.util.ReflectionUtils.findMethod(ReflectionUtils.java:1513)
    at org.junit.platform.commons.util.ReflectionUtils.isMethodPresent(ReflectionUtils.java:1379)
    at org.junit.jupiter.engine.discovery.predicates.TestClassPredicates.hasTestOrTestFactoryOrTestTemplateMethods(TestClassPredicates.java:107)
    at org.junit.jupiter.engine.discovery.predicates.TestClassPredicates.looksLikeIntendedTestClass(TestClassPredicates.java:82)
    at org.junit.jupiter.engine.discovery.predicates.TestClassPredicates.looksLikeIntendedTestClass(TestClassPredicates.java:76)
    at org.junit.jupiter.engine.discovery.ClassSelectorResolver.isAcceptedStandaloneTestClass(ClassSelectorResolver.java:114)
    at org.junit.jupiter.engine.discovery.ClassSelectorResolver.resolveStandaloneTestClass(ClassSelectorResolver.java:105)
    at org.junit.jupiter.engine.discovery.ClassSelectorResolver.resolve(ClassSelectorResolver.java:101)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.lambda$resolve$0(EngineDiscoveryRequestResolution.java:137)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
    at java.base/java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1685)
    at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:129)
    at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:527)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:513)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
    at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:150)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:647)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:191)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:128)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:94)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.run(EngineDiscoveryRequestResolution.java:85)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolver.resolve(EngineDiscoveryRequestResolver.java:150)
    at org.junit.jupiter.engine.discovery.DiscoverySelectorResolver.resolveSelectors(DiscoverySelectorResolver.java:62)
    at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:74)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:195)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverSafely(EngineDiscoveryOrchestrator.java:174)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:119)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:84)
    at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:119)
    at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$1(DefaultLauncher.java:112)
    at java.base/java.util.Optional.orElseGet(Optional.java:364)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:109)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:93)
    at org.junit.platform.launcher.core.DelegatingLauncher.execute(DelegatingLauncher.java:48)
    at org.junit.platform.launcher.core.InterceptingLauncher.lambda$execute$0(InterceptingLauncher.java:41)
    at org.junit.platform.launcher.core.ClasspathAlignmentCheckingLauncherInterceptor.intercept(ClasspathAlignmentCheckingLauncherInterceptor.java:25)
    at org.junit.platform.launcher.core.InterceptingLauncher.execute(InterceptingLauncher.java:40)
    at org.junit.platform.launcher.core.DelegatingLauncher.execute(DelegatingLauncher.java:48)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:124)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:99)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:94)
    at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:63)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at java.base/java.lang.reflect.Method.invoke(Method.java:580)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
    at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
    at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:92)
    at jdk.proxy1/jdk.proxy1.$Proxy4.stop(Unknown Source)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker$3.run(TestWorker.java:200)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:132)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:103)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:63)
    at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
    at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:122)
    at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:72)
    at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
    at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)

If I change a name of the test, it works:

@Test
suspend fun `check int`() {
    val result = randomService.getRandomPositiveInt()
    assertTrue { result > 0 }
}

Some extra examples that work: - suspend fun `check check`() - suspend fun check_check() - suspend fun `check again`() - suspend fun `check 1`() - suspend fun `test int`() - suspend fun `test getRandomPositiveInt`() - suspend fun `check check check 1`() - suspend fun `check check check 20000000`() - suspend fun `trying super long test name hello how are you int`()

Some extra examples that do not work: - suspend fun `check getRandomPositiveInt`() - suspend fun `check check check`() - suspend fun `trying super long test name hello how are you`() - suspend fun `check generator`() - suspend fun check_getRandomPositiveInt() - suspend fun check_check_check()

If I create unit tests for RandomService, then I don't have the issue anymore:

class RandomServiceTest2 {

    private val randomService = RandomService()

    @Test
    suspend fun `check int`() {
        val result = randomService.getRandomPositiveInt()
        assertTrue { result > 0 }
    }

    @Test
    suspend fun `check getRandomPositiveInt`() {
        val result = randomService.getRandomPositiveInt()
        assertTrue { result > 0 }
    }

}

I created a small demo project with a source code: https://github.com/sultazat/junit6-kotlin-issue