In a Tycho build, ScalaTests don't run and Java-based JUnit tests don't find any Scala references

[Jens Rabe]

Despite the recommendation to use web technologies instead of RCP, I am now using RCP for my application because RCP brings a lot of stuff readily made where I would have to reinvent many wheels doing it another way, and I don't have the time to start from scratch.

I now set up a POM-less Tycho build, and have a fragment that contains some tests.

I set up the ScalaTests to run with the JUnitRunner like this:

@RunWith(classOf[JUnitRunner])
class MyTest extends FlatSpec with Matchers {

  // Test code
}

I added the respective inclusions into my pom.xml (despite it's pom-less, for tests to run, a pom.xml is needed):

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <artifactId>com.mycompany.myapp.project.model_test</artifactId>
    <packaging>eclipse-test-plugin</packaging>
    <parent>
        <groupId>com.mycompany.myapp</groupId>
        <artifactId>com.mycompany.myapp.tests</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <build>
        <plugins>
            <plugin>
                <groupId>org.eclipse.tycho</groupId>
                <artifactId>tycho-surefire-plugin</artifactId>
                <version>0.26.0</version>
                <configuration>
                <includes>**/Test*.java,**/*Test.java,**/*TestCase.java,**/Test*.scala,**/*Test.scala,**/*TestCase.scala</includes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

When I run the build, I get:

Root exception:
java.lang.RuntimeException: Unable to create test class 'com.mycompany.myapp.tests.MyTest.scala'
...
Caused by: java.lang.ClassNotFoundException: com.mycompany.myapp.tests.MyTest.scala

I can run the test from Eclipse just fine by right-clicking the test and using the appropriate option in the "Run As" menu.

When removing the Scala inclusions and adding a simple Java-based test:

import org.junit.Test;

public class FooTest {

    @Test
    public void foo() {

    }
}

this works.

However, when I try to access anything written in Scala, it cannot resolve the references.

What am I missing?

[Jens Rabe]

Since I could not get it to work, and there seems to be no one with a clue, I wrote a small JUnit runner that starts the ScalaTests and gathers the results, and so, Maven recognizes this Java-based class. It's not beautiful, but at least a workaround that works.