NOTE

JUnit 3 based tests are deprecated since 3.4.0.

Use JUnit 5 annotations, consult javadocs for examples.

Note: This example improves the cookbook for multi-project testing.

Your Mojo should have @aggregator parameter, i.e.:

• with java annotations (maven-plugin-plugin 3.x):

@Mojo( name = "touch", aggregator = true )
public class MyMojo
    extends AbstractMojo
{
  ...
}

• or with javadoc tags:

/**
 * @goal touch
 * @aggregator
 */
public class MyMojo
    extends AbstractMojo
{
  ...
}

To test a Mojo in a multiproject area, you need to define several stubs, i.e. for the main test project and its modules.

Create Stubs

Stub for the main test project:

public class MyProjectStub
    extends MavenProjectStub
{
    /**
     * Default constructor
     */
    public MyProjectStub()
    {
        ...

        setExecutionRoot( true );
    }

    /** {@inheritDoc} */
    public MavenProject getExecutionProject()
    {
        return this;
    }
}

Stubs for the subprojects:

public class SubProject1Stub
    extends MavenProjectStub
{
    /**
     * Default constructor
     */
    public SubProject1Stub()
    {
        ...
    }
}

public class SubProject2Stub
    extends MavenProjectStub
{
    /**
     * Default constructor
     */
    public SubProject2Stub()
    {
        ...
    }
}

Configure project-to-test pom

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-my-plugin</artifactId>
        <configuration>
          ...
          <project implementation="org.apache.maven.plugin.my.stubs.MyProjectStub"/>
          <reactorProjects>
            <project implementation="org.apache.maven.plugin.my.stubs.SubProject1Stub"/>
            <project implementation="org.apache.maven.plugin.my.stubs.SubProject2Stub"/>
          </reactorProjects>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>