I've also added/plagiarized rainbow's tests to the repo: https://github.com/arclanguage/anarki/commit/68be3c0f4d. Joys of the perl artistic license.
There's still a couple of syntax tests that are failing, likely because of test harness issues. And I'd like to unify all the different tests into a single framework. For future work..
Update 43 minutes later: it turns out rainbow's ssyntax precedence rules were different. Perhaps anarki changed at some point. Those tests are now fixed.