dirname() is a slow function compared with __DIR__ and using
'/../'. Moodle has a large number of legacy files that are included
each time a page loads and is not able to use an autoloader as it is
functional code. This allows those required includes to perform as
best as possible in this situation.
Previously, the Check button was often shown disabled when it
could not be used (e.g. when the question was finished, or when an
interactive question was in the try-again state). Eventually we
realised it was better usability to hide it in these cases.
Note that when a teacher reviews an in-progress quiz attempt, they will
see a disabled Check button if the student doing the quiz can see the
button.
1/ type/match/tests/walkthrough_test.php - tests are failing randomly, looks like some weird randomisation is going on there - see TODOs
2/ type/multianswer/tests/upgradelibnewqe_test.php contains invalid expected value - see TODO
