This might have an obvious answer, but I've been having trouble running the ORES extension's maintenance classes under PHPUnit. My first pass was nearly working, but it emitted output. I found a MaintenanceTest class under mediawiki-core/tests/phpunit/maintenance, which does the output filtering and so on, but isn't appropriate as a base class because it includes its own tests.
If what I'm looking for doesn't exist, I'd be happy to split the maintenance testing framework from the tests themselves, please let me know.