There seem to be no job template in integration-config to provide phpunit coverage for skins. We have achieve quite nice test coverage for WikimediaApiPortal skin, would be nice to be able to enable coverage job in CI.
Looking at mediawiki/skins.git, several MediaWiki skins do have PHPUnit tests (ls -1d */tests/phpunit):
| BlueSpiceCalumma |
| MinervaNeue |
| Vector |
| WikimediaApiPortal |