To be honest, I also usually just hope I get it right the first time and Jenkins doesn't embarrass me... ;) (hey, it's a great time saver when it works).
When I do need to test locally, it's very helpful to run individual test cases instead of the whole suite and just pretend the other failures don't exist:
https://www.mediawiki.org/wiki/Manual:PHP_unit_testing/Running_the_unit_test...