Hi! Our team using 3 types of jacoco reports in our projects

• integration tests coverage
• unit tests coverage
• it+unit coverage

We used jacoco ant tasks for merging/aggregating job for a while but ended up with this patch: https://gist.github.com/4491163

Configuration example

<configuration>

  <!-- data files to merge -->
  <dataFiles>
    <dataFile>${jacoco.exec.it}</dataFile>
    <dataFile>${jacoco.exec.unit}</dataFile>
  </dataFiles>

  <!-- fail on missing data file from list -->
  <strict>false</strict>

  <!-- skip report generating for each module in 
       multimodule environment -->
  <skipModule>true</skipModule>

  <!-- ...and aggregate all module reports in superpom porject -->
  <aggregate>true</aggregate>
</configuration>

This patch does fallback to old behavior till no data passed to <dataFiles/>.

Anyway patch is rough enough and there is no tests yet... So any modifications are welcome!

Also it would be nice if we could combine this patch with patch from #12.