When using JUnit5, I got a warning: "ClassNotFoundException: org.junit.platform.engine.support.filter.ExclusionReasonConsumingFilter"

Question

I'm trying to use JUnit5.
First, I added dependencies to maven project:

<dependencies>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>5.3.0</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.junit.platform</groupId>
        <artifactId>junit-platform-runner</artifactId>
        <version>1.3.0</version>
        <scope>test</scope>
    </dependency>
</dependencies>

Then, I created a test:

package com.example.multicurrency;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class JunitTests {
    @Test
    void testAssertTrue() {
        assertTrue(false);
    }
}

After that, I run the test. The following is what I have got:

org.junit.platform.launcher.core.DefaultLauncher handleThrowable
warning: TestEngine with ID 'junit-vintage' failed to discover tests
java.lang.NoClassDefFoundError: org/junit/platform/engine/support/filter/ExclusionReasonConsumingFilter
Caused by: java.lang.ClassNotFoundException: org.junit.platform.engine.support.filter.ExclusionReasonConsumingFilter

org.opentest4j.AssertionFailedError: 
Expected :<true> 
Actual   :<false>

The result was what I expected. But the warning confused me. What does the warning mean?

Answer 1

Use version 5.3.x of the junit-jupiter-engine for now with Surefire 2.22.2.

<dependencies>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>5.3.2</version>
        <scope>test</scope>
    </dependency>
</dependencies>

Seems like you're struck by https://issues.apache.org/jira/browse/SUREFIRE-1564 which describes a known issue that Surefire 2.22.0 internally stays on version 1.2.0 for all junit-platfrom-xyz artifacts.

You should also give Surefire 3.x a try - afaik, it is compatible with all versions of JUnit: https://maven.apache.org/surefire/maven-surefire-plugin/