Those tests either just check that an exception is NOT thrown or are
there to check dependencies for other tests. Newer phpunits mark all
tests as risky that have no assertion.

The filter passed by the user manager is called 'grps' not 'group'

This is a feature that was present in the old authmysql plugin. It
allows administrators to specify an SQL string that is used for explicit
password checking instead of letting DokuWiki compare the hashes. This
is useful where application implement their own salt/hashing thing.

This comes with a test case for the MyBB forum software. Dump kindly
provided by William Kitchen

This allows for more fine control over what the abilities are,
depending on the parameters used within the configured sql string.