[Warning: I have not looked at the way tests, nor hyphenation are
I would have thought you would need to test correct behaviour of tests with
and without at least one known hyphenation setup.
Specify that a particular hyphenation (e.g. english) must be available for
Have your tests able to enable or disable hyphenation, or make it
Have your tests test operation of particular hyphenation related test cases
with and without hyphenation, asserting that the FO results in the area
trees (or whatever) expected for that test set up.