Clover-for-Ant allows to specify custom test patterns - based on file names, class signatures and method signatures. This allows to integrate with test frameworks different than JUnit/TestNG/Spock.
<testsources> <testclass> <testmethod/> </testclass> </testsources>
Clover Maven Plugin does not have this option. Create an equivalent for clover:setup/instrument/instrument-test goals.
Challenge: test sources are currently based on Maven's source roots, so maybe we could use them, but still have file inclusion/exclusion filter? If not, try to implement testclass/testmethod at least.