Question: instead of converting the tests to new api, would it be more beneficial to test both? testNewAPI() / testOldAPI()
No need to do this. The correct backwards-compatibility of the new API is checked separately by the extra test in
It is enough if you remove all next() methods, add incrementToken() and make the above mentioned changes to make the token streams final where possible (see the comment of Michael Busch above – which is the "howto" for the conversion).
The testy should only test the new API, but until they are also converted, the old tests should also still work (because of the backwards-compatibility layer). Be sure to apply
LUCENE-1693 which does not change anything in contrib before starting to create a patch to have the newest API. Hopefully Michael has committed 1693 tomorrow.
LUCENE-1460_core.txt is already in LUCENE-1693 as it is part of core token streams.