[FIXED] IntelliJ Junit5 Tests are not discoverable

Issue

When I am running Junit Tests, Tests are failing with below errors.

Tests are not getting discovered by Junit somehow.

/Library/Java/JavaVirtualMachines/temurin-17.jdk/Contents/Home/bin/java -ea -Didea.test.cyclic.buffer.size=1048576 -javaagent:/Applications/IntelliJ IDEA CE.app/Contents/lib/idea_rt.jar=53487:/Applications/IntelliJ IDEA CE.app/Contents/bin -Dfile.encoding=UTF-8 -classpath /Users/shubhamjain/.m2/repository/org/junit/platform/junit-platform-launcher/1.8.1/junit-platform-launcher-1.8.1.jar:/Applications/IntelliJ IDEA CE.app/Contents/lib/idea_rt.jar:/Applications/IntelliJ IDEA CE.app/Contents/plugins/junit/lib/junit5-rt.jar:/Applications/IntelliJ IDEA CE.app/Contents/plugins/junit/lib/junit-rt.jar:/Users/shubhamjain/SJ/Projects/pair-programming-exercises/graph-library/target/test-classes:/Users/shubhamjain/SJ/Projects/pair-programming-exercises/graph-library/target/classes:/Users/shubhamjain/.m2/repository/org/junit/jupiter/junit-jupiter-engine/5.8.1/junit-jupiter-engine-5.8.1.jar:/Users/shubhamjain/.m2/repository/org/junit/platform/junit-platform-engine/1.8.1/junit-platform-engine-1.8.1.jar:/Users/shubhamjain/.m2/repository/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar:/Users/shubhamjain/.m2/repository/org/junit/platform/junit-platform-commons/1.8.1/junit-platform-commons-1.8.1.jar:/Users/shubhamjain/.m2/repository/org/junit/jupiter/junit-jupiter-api/5.1.1/junit-jupiter-api-5.1.1.jar:/Users/shubhamjain/.m2/repository/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar:/Users/shubhamjain/.m2/repository/org/projectlombok/lombok/1.18.24/lombok-1.18.24.jar com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit5 com.pp.GraphTests
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:134)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:108)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:80)
    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$1.execute(IdeaTestRunner.java:38)
    at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: java.lang.NoClassDefFoundError: org/junit/jupiter/api/parallel/ExecutionMode
    at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:66)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:152)
    ... 13 more
Caused by: java.lang.ClassNotFoundException: org.junit.jupiter.api.parallel.ExecutionMode
    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)
    ... 15 more

Process finished with exit code 254

My pom.xml looks like this

<dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.24</version>
            <scope>provided</scope>
        </dependency>
</dependencies>

I am using java version 17 and this project is submodule project of a multi module java project running in intellij.

I have tried upgrading junit dependency and lower down my java version.

Solution

Replace junit-jupiter-engine with junit-jupiter.

junit-juper-engine is only a part of junit-jupiter and does not pull the everything which is relevant to run JUnit 5.

Answered By - asbachb
Answer Checked By - Pedro (JavaFixing Volunteer)