Multi-module JaCoCo report

coverage.groovy

// Runs a combined JaCoCo report across all modules in the reactor
// Output is placed in the root project's output directory

def root = session.topLevelProject
def modules = session.projectDependencyGraph.sortedProjects
  .findAll { it != project && it.packaging != 'pom' }

if (!modules.empty) {
  def jacoco = groovy.xml.NamespaceBuilder.newInstance(ant, 'antlib:org.jacoco.ant')
  jacoco.report {
    executiondata {
      modules.collect { ant.fileset(file: new File(it.build.directory, "jacoco.exec")) }
    }
    structure(name: "Combined coverage") {
      classfiles {
        modules.collect { ant.fileset(dir: it.build.outputDirectory) }
      }
      sourcefiles {
        modules.collectMany { it.compileSourceRoots.collect { ant.fileset(dir: it) } }
      }
    }
    html(destdir: new File(root.build.directory, "jacoco"))
  }
}