Why does TestEngine with ID 'junit-jupiter' fail to discover tests after converting project from Maven to Gradle? - maven

Question

I recently converted my Maven test project into Gradle and have been trying to get the tests to work. When I previously ran my test classes with IntelliJ, they ran perfectly, but now when I try to run them, I get an error "TestEngine with ID 'junit-jupiter' failed to discover tests". Here is the stacktrace I get:
Internal Error occurred.
org.junit.platform.commons.JUnitException: TestEngine with ID 'junit-jupiter' failed to discover tests
at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:160)
at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverSafely(EngineDiscoveryOrchestrator.java:132)
at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:107)
at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:78)
at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:110)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: org.junit.platform.commons.JUnitException: MethodSelector [className = 'tests.SampleTest', methodName = 'test', methodParameterTypes = ''] resolution failed
at org.junit.platform.launcher.listeners.discovery.AbortOnFailureLauncherDiscoveryListener.selectorProcessed(AbortOnFailureLauncherDiscoveryListener.java:39)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:103)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.run(EngineDiscoveryRequestResolution.java:83)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolver.resolve(EngineDiscoveryRequestResolver.java:113)
at org.junit.jupiter.engine.discovery.DiscoverySelectorResolver.resolveSelectors(DiscoverySelectorResolver.java:46)
at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:69)
at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:152)
... 11 more
Caused by: org.junit.platform.commons.PreconditionViolationException: Could not load class with name: tests.SampleTest
at org.junit.platform.engine.discovery.MethodSelector.lambda$lazyLoadJavaClass$0(MethodSelector.java:157)
at org.junit.platform.commons.function.Try$Failure.getOrThrow(Try.java:335)
at org.junit.platform.engine.discovery.MethodSelector.lazyLoadJavaClass(MethodSelector.java:156)
at org.junit.platform.engine.discovery.MethodSelector.getJavaClass(MethodSelector.java:135)
at org.junit.jupiter.engine.discovery.MethodSelectorResolver.resolve(MethodSelectorResolver.java:75)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.lambda$resolve$2(EngineDiscoveryRequestResolution.java:150)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1602)
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$FindOp.evaluateSequential(FindOps.java:150)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:647)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:189)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:126)
at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:92)
... 16 more
Caused by: java.lang.ClassNotFoundException: tests.SampleTest
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
at org.junit.platform.commons.util.ReflectionUtils.lambda$tryToLoadClass$9(ReflectionUtils.java:831)
at org.junit.platform.commons.function.Try.lambda$call$0(Try.java:57)
at org.junit.platform.commons.function.Try.of(Try.java:93)
at org.junit.platform.commons.function.Try.call(Try.java:57)
at org.junit.platform.commons.util.ReflectionUtils.tryToLoadClass(ReflectionUtils.java:794)
at org.junit.platform.commons.util.ReflectionUtils.tryToLoadClass(ReflectionUtils.java:750)
... 32 more
Here's the sample test class I'm using:
package tests;
import org.junit.jupiter.api.Test;
public class SampleTest {
#Test
public void test() {
System.out.println("Testing");
}
}
And here's build.gradle:
plugins {
id 'java'
id 'maven-publish'
}
repositories {
mavenCentral()
maven {
url = uri('https://repo.maven.apache.org/maven2/')
}
}
dependencies {
implementation 'org.seleniumhq.selenium:selenium-java:4.5.0'
implementation 'org.seleniumhq.selenium:selenium-api:4.5.0'
testImplementation 'org.junit.jupiter:junit-jupiter-api:5.9.0'
implementation 'com.sun.mail:javax.mail:1.6.2'
implementation 'org.apache.commons:commons-email:1.5'
testImplementation 'org.junit.jupiter:junit-jupiter:5.9.0'
}
group = 'test'
version = '1.0-SNAPSHOT'
description = 'ui-testing'
java.sourceCompatibility = JavaVersion.VERSION_1_8
publishing {
publications {
maven(MavenPublication) {
from(components.java)
}
}
}
In case it may be relevant, my project is structured like this:
project
| build.gradle
|
└───src
|
└───java
| |
| └───tests
| | SampleTest.java
|
└───resources
What could be causing this issue? Any suggestion how to resolve it?

Answer 1

Your Gradle file is missing the
useJUnitPlatform {}
configuration.
Have a look at this comprehensive sample
and on the relevant part of the JUnit documentation.