jUnit 5 can't find tests

Question

I know this has been questionned few times now but i'm running out of ideas.

sept. 07, 2023 3:57:06 PM org.junit.platform.launcher.core.DefaultLauncher handleThrowable
WARNING: TestEngine with ID 'junit-jupiter' failed to discover tests
java.lang.NoClassDefFoundError: org/junit/platform/engine/support/discovery/SelectorResolver
    at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:69)
    at org.junit.platform.launcher.core.DefaultLauncher.discoverEngineRoot(DefaultLauncher.java:168)
    at org.junit.platform.launcher.core.DefaultLauncher.discoverRoot(DefaultLauncher.java:155)
    at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:120)
    at org.apache.maven.surefire.junitplatform.TestPlanScannerFilter.accept(TestPlanScannerFilter.java:56)
    at org.apache.maven.surefire.util.DefaultScanResult.applyFilter(DefaultScanResult.java:102)
    at org.apache.maven.surefire.junitplatform.JUnitPlatformProvider.scanClasspath(JUnitPlatformProvider.java:143)
    at org.apache.maven.surefire.junitplatform.JUnitPlatformProvider.invoke(JUnitPlatformProvider.java:124)
    at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:384)
    at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:345)
    at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:126)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:418)
Caused by: java.lang.ClassNotFoundException: org.junit.platform.engine.support.discovery.SelectorResolver
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 12 more

This is the message I got with jUnit 5. He can't find any tests (have over 800).

My pom seems correct :

<dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <version>5.10.0</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-engine</artifactId>
      <version>5.10.0</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-params</artifactId>
      <version>5.10.0</version>
      <scope>test</scope>
    </dependency>

<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-surefire-plugin</artifactId>
   <version>2.22.2</version>
</plugin>

My tests are well named :

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class AttestationIdentiteCallParamsTest {

    @Test
    void testAttestationIdentiteCallParams() {
}

Executing my test from intelliJ and CMD with java 11.

mvn clean install

200 times

It just never works. Ideas ? Thanks

Answer 1

To run Junit Jupiter tests it's best is to use the junit-bom for all the needed artifact dependencies.

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.junit</groupId>
        <artifactId>junit-bom</artifactId>
        <version>5.10.0</version>
        <scope>import</scope>
        <type>pom</type>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <dependencies>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-engine</artifactId>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-params</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

Also use most recent version of maven-surefire-plugin

  <build>
    <pluginManagement>
      <plugins>
        ...
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>3.1.2</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-failsafe-plugin</artifactId>
          <version>3.1.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
     ..
  </build>

If you combine JUnit 4 and JUnit Jupiter (aka JUnit 5) test in the same project you have to use the junit-vintage-engine like this:

 <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.junit</groupId>
        <artifactId>junit-bom</artifactId>
        <version>5.10.0</version>
        <scope>import</scope>
        <type>pom</type>
      </dependency>
      <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13.2</version>
      </dependency>
    </dependencies>
  </dependencyManagement>


  <dependencies>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-engine</artifactId>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.vintage</groupId>
      <artifactId>junit-vintage-engine</artifactId>
      <scope>test</scope>
    </dependency>
    ..
  </dependencies>

That would result mean to run your JUnit 4 tests via JUnit 5 Vintage engine.