Something weird happens with static-fns true

In some cases, we end up using call

Look I discovered something weird with static-fns true Look here http://app.klipse.tech/?cljs_in=(defn%20foo%20%5B%5D%20%3Afoo)%0A%0A(defn%20bar%0A%20%20(%5B%5D%20%3Abar)%0A%20%20(%5Bx%5D%20x))%0A%0A%0A(foo)%0A(bar)%0A(bar%20%3Amy-bar)%0A%0A(def%20f%20foo)%0A(def%20g%20bar)%0A(f)%0A(g)%0A%0A&static-fns=true

is transpiled to

(f)` becomes (cljs.user.f.cljs$core$IFn$_invoke$arity$0 ? cljs.user.f.cljs$core$IFn$_invoke$arity$0() : cljs.user.f.call(null));

At run time, it will be cljs.user.f.call(null))

Because cljs.user.f.cljs$core$IFn$_invoke$arity$0 is undefined

while (g) will be cljs.user.g.cljs$core$IFn$_invoke$arity$0()

It’s related to this part of the compiler code https://github.com/clojure/clojurescript/blob/master/src/main/clojure/cljs/compiler.cljc#L1008-L1013

@viebel: that’s how it’s supposed to work, I talked about this behavior the other day

it’s an optimization for higher order function calls where it’s not possible to know the arity statically

FWIW, I revised the else branch to look like f "(" (comma-sep args) "))” and it works in this particular case and for the compiler unit tests (in other words, it blindly makes a static call if the desired arity is not found). Perhaps the assumption that it is a non-multi-arity function misses corner cases though, and even though :static-fns true is enabled, it is safer to dynamically dispatch.