cljs_spec_cheat_sheet.md

Mutli-arity function definitions:

You use the "regex" functions. s/? Will say "0 or 1 of this" - so in the spec below 0 or 1 offsets is required.

(s/fdef create
        :args (s/cat
                :character ::character
                :offset (s/? ::offset))
        :ret ::invader)

Return Values

Are not checked without test.check.