With ClojureScript 1.10.238, if you call .apply with over 21 arguments on a function that has been instrumented with cljs.spec.test.alpha/instrument, you will get an error about invalid arity. This problem does not occur with ClojureScript 1.9.954.
Regular apply works as expected.
See CLJS-364 & CLJS-365
Some of these are (commented out) but added in the patch for the apply test suit:
Ah great, thanks for the tests.
Revisiting this now that I'm working on CLJS-2761, why do we need to support `.apply`? I don't think this was ever promised.