cobertura-maven-plugin cannot find my groovy source code - maven

Question

I am trying to use apache-aven to produce a code-coverage report for my Java/Groovy project. Attached is the pom file:
<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>com.hal_con</groupId>
<artifactId>scheduler</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.codehaus.groovy/groovy-all -->
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-all</artifactId>
<version>2.4.8</version>
</dependency>
<!-- https://mvnrepository.com/artifact/junit/junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.gmaven</groupId>
<artifactId>gmaven-plugin</artifactId>
<version>1.5</version>
<configuration>
<providerSelection>1.8</providerSelection>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<reporting>
<plugins>
<plugin>
<!-- https://mvnrepository.com/artifact/org.codehaus.mojo/cobertura-maven-plugin -->
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>2.7</version>
</plugin>
</plugins>
</reporting>
</project>
I've tried both the following:
Adding the maven-source-plugin as suggested in: Maven + Cobertura : Unable to locate [Your Class]. Have you specified the source directory?
Adding the jxr-maven-plugin as suggested in:
maven-cobertura-plugion does not show the sources
In both cases the results were exactly the same:
Unable to locate com/hal_con/scheduler/FileParser.groovy. Have you specified the source directory?
I figure that the maven-cobertura-plugin needs to be told where to find my groovy sources, but I cannot find an example.

Answer 1

The Cobertura Maven Plugin doesn't provide a way to customize the location of the sources. By default, it then looks into the Maven standard folder, which is src/main/java. Since your Groovy classes are located inside src/main/groovy, they are not found.
There are 2 solutions depending on your project:
Add those sources to the project with the help of the build-helper-maven-plugin:add-source Mojo:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<version>3.0.0</version>
<executions>
<execution>
<goals>
<goal>add-source</goal>
</goals>
<configuration>
<sources>
<source>src/main/groovy</source>
</sources>
</configuration>
</execution>
</executions>
</plugin>
This is helpful if the project is a mixed Java / Groovy project, because you can keep the Maven defaults, and add the Groovy specific folders.
Override the source directory of Maven with
<build>
<sourceDirectory>src/main/groovy</sourceDirectory>
<!-- rest of build configuration -->
</build>
This would be convenient if the project is a pure Groovy project, without any source Java files.
With any of those two changes, running mvn clean site will generate a Cobertura report where the Groovy sources will be correctly found.