Noticed I was writing the same thing in multiple places and created a macro, #'aff-test-pairs, to spit out that thing. Tweaked a couple of tests to use the aff-test pairs macro.
Wrote a test for #'aff-dissect-itunes-url, fixed a bug that it revealed in the function (a group in the main regex was capturing and it should have been a non-capturing group). Sensing a pattern here.