Eclipse No tests found using JUnit 5 caused by NoClassDefFoundError for LauncherFactory

Question

The problem

Whenever I run my projects JUnit test (using JUnit 5 with Java 9 and Eclipse Oxygen 1.a) I encounter the problem that eclipse can\'t find any tests.

Answer 1

Since it's not possible to post code blocks into comments here's the POM template I am using in projects requiring JUnit 5. This allows to build and "Run as JUnit Test" in Eclipse and building the project with plain Maven.

<project
    xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>group</groupId>
    <artifactId>project</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>project name</name>

    <dependencyManagement>
      <dependencies>
        <dependency>
        <groupId>org.junit</groupId>
        <artifactId>junit-bom</artifactId>
        <version>5.3.1</version>
        <type>pom</type>
        <scope>import</scope>
        </dependency>
      </dependencies>
    </dependencyManagement>

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

      <dependency>
        <groupId>org.junit.platform</groupId>
        <artifactId>junit-platform-launcher</artifactId>
        <scope>test</scope>
      </dependency>

      <dependency>
        <!-- only required when using parameterized tests -->
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-params</artifactId>
        <scope>test</scope>
      </dependency>
    </dependencies>
</project>

You can see that now you only have to update the version in one place if you want to update JUnit. Also the platform version number does not need to appear (in a compatible version) anywhere in your POM, it's automatically managed via the junit-bom import.

Answer 2

Following Andrii Karaivanskyi's answer here's the Maven POM declaration:

<properties>
    ...
    <junit-jupiter.version>5.2.0</junit-jupiter.version>
    <junit-platform.version>1.2.0</junit-platform.version>
    ...
</properties>

<dependencies>
    ...
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>${junit-jupiter.version}</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.junit.platform</groupId>
        <artifactId>junit-platform-launcher</artifactId>
        <version>${junit-platform.version}</version>
        <scope>test</scope>
    </dependency>
    ...
</dependencies>

UPDATE

As per comment by Alexander Wessel you can use org.junit:junit-bom as described in his answer to question Eclipse No tests found using JUnit 5 caused by NoClassDefFoundError for LauncherFactory.

Answer 3

you should know that :

@Before from junit4 goes with @Test : "import org.junit.Test"

AND

@BeforeEach from Junit5 goes with : "import org.junit.jupiter.api.Test"

so make sure you are using the imports from the same version of Junit , otherwise it w'ont Work I guess.

Answer 4

Just added my Test.class via eclipse menu and worked. Right click to project -> New -> Other -> JUnit -> JUnit Test Case

Answer 5

Answers so far did not adress the problem of sharing code with other people who don't necessarily use Eclipse. Here is one proposition. The key is to use a maven profile to solve the Eclipse Case.

It assumes you have defined a property junit5.version in your pom like:

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <junit5.version>5.1.1</junit5.version>
</properties>

then in the profiles section add the following:

<profiles>
    <profile>
        <id>eclipse</id>
        <dependencies>
            <dependency>
                <groupId>org.junit.jupiter</groupId>
                <artifactId>junit-jupiter-engine</artifactId>
            </dependency>
            <dependency>
                <groupId>org.junit.platform</groupId>
                <artifactId>junit-platform-launcher</artifactId>
            </dependency>
        </dependencies>
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.junit.jupiter</groupId>
                    <artifactId>junit-jupiter-engine</artifactId>
                    <version>${junit5.version}</version>
                    <scope>test</scope>
                </dependency>
                <dependency>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-launcher</artifactId>
                    <version>1.1.1</version>
                    <scope>test</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    </profile>
</profiles>

All you have to do after this is to select the profile in your local Eclipse: Right click on your project and select Maven > Select Maven Profiles... (or hit Ctrl + Alt + P), and then check the "eclipse" profile we just created.

With that you are done. Your Eclipse will run Junit 5 tests as expected, but the configuration you added won't pollute other builds or other IDE

Answer 6

Adding this maven dependency with JUnit Jupiter (v.5.5.1) solves the issue.

<dependency>
    <groupId>org.junit.platform</groupId>
    <artifactId>junit-platform-launcher</artifactId>
    <version>1.5.1</version>
    <scope>test</scope>
</dependency>