How can I view clover coverage against code that has changed?

[Matt Hlavaty]

In my maven project, I want to view the clover coverage against code that has changed in my snapshot since the last released version.

Is there a way to accomplish this?

[Marek Parfianowicz]

If you would like to perform a logical or arithmetical operation (such as XOR or subtraction) on coverage data from two different builds, then unfortunately such feature is not available right now. A feature request is reported here https://jira.atlassian.com/browse/CLOV-1024.

[Marek Parfianowicz]

If you want to limit your HTML report to contain classes which have been modified since a previous build (using information from a VCS such as git or hg), then you'd have to build such query on your own and next pass list of files to the <clover-report> task (see <fileset> + <testsources> options).

As you are using Maven, you would have to prepare an Ant file with such a custom <clover-report> task and use the reportDescriptor option. Check Creating custom reports for more details.

See also: https://answers.atlassian.com/questions/86543 question.

[Marek Parfianowicz]

If you want to just see for which classes code coverage changed the most, then you can simply generate a historical report, which looks like this. In order to have it in Maven, you have to use the clover2:save-history goal together with the clover2:clover and a generateHistorical=true option.