[pitest-maven] report-aggregate fails due to test dependencies

I run pitmp on my whole project to generate reports for each module. Then I run pitest-maven report-aggregate on a reporting module (dedicated module that has dependencies to all other modules). I get the following error:

[ERROR] Failed to execute goal org.pitest:pitest-maven:1.4.8:report-aggregate (merge-pitest-reports) on project reporting: An error has occurred in PIT Test Report report generation.: /home/---/.m2/repository/commons-beanutils/commons-beanutils/1.9.3/commons-beanutils-1.9.3.jar is not a directory -> [Help 1]

I tried to understand why this is happening so I ran maven in debug mode and debugged pitest-maven. Here is the code that seems wrong to me (in AbstractPitAggregationReportMojo class):

  private List<File> getCompiledDirs(final MavenProject project)
      throws Exception {
    final List<String> sourceRoots = new ArrayList<>();
    for (final Object artifactObj : FCollection
        .filter(project.getPluginArtifactMap().values(), new DependencyFilter(
            new PluginServices(this.getClass().getClassLoader())))) {

      final Artifact artifact = (Artifact) artifactObj;
      sourceRoots.add(artifact.getFile().getAbsolutePath());
    }
    return convertToRootDirs(project.getTestClasspathElements(),
        Arrays.asList(project.getBuild().getOutputDirectory(),
            project.getBuild().getTestOutputDirectory()),
        sourceRoots);
  }

The call to project.getTestClasspathElements() returns the list of test sources but also the list of dependencies. Then in ReportAggregator, the method addCompiledCodeDirectory calls validateDirectory with this code:

    private void validateDirectory(final File directory) {
      if (directory == null) {
        throw new IllegalArgumentException("directory is null");
      }
      // For this method, a non existing directory is valid.
      // It probably needs some special treatment later, but it shouldn't prevent the aggregator to be built.
      if (directory.exists() && !directory.isDirectory()) {
        throw new IllegalArgumentException(directory.getAbsolutePath() + " is not a directory");
      }
    }

It fails here due to dependencies that are jars and not folders.

I think the issue comes from use of getTestClasspathElements(). If you want only directories, it should be getTestCompileSourceRoots() instead.

[aurelien-baudet]

Waiting for @hcoles to merge it

[hcoles]

@dan323 as per my comment on the PR, happy to merge if someone can resolve the conflicts and confirm that it works.