jruby-rake-pom-snippet.xml

<plugin>
  <groupId>org.jruby.plugins</groupId>
  <artifactId>jruby-rake-plugin</artifactId>
  <executions>
    <execution>
      <id>runtests</id>
      <phase>test</phase>
      <goals><goal>rake</goal></goals>
      <configuration>
        <script>
          task :default do
            puts "tests were successful"
          end
        </script>
      </configuration>
    </execution>
  </executions>
</plugin>