I'm guessing you can extract some private function checking whether the form at point is function-like. I assume that would be useful for other things down the road.

I've done a small refactoring in this PR and extracted some helper functions, such asclojure-ts--search-list-form-at-point orclojure-ts--list-node-sym-text orclojure-ts--parent-until (which I wish was part oftreesit.el). This particular regexp and the following query is very unlikely going to be used anywhere else, it's too specific. If I extracted it to a function I would have to give it a name that indicates that it returns a node that represents a construct to which an arity could be added. We can always extract it if we need it in other place.