shadow-cljs handles this when resolving dependencies and then adding an alias to the ns, so basically it switches (require '[clojure.test :as t]) to (require '[cljs.test :as t])

a little different than regular CLJS but achieves the same result

https://github.com/thheller/shadow-cljs/blob/8210087d56034487758769b5b5fb0b9fec0ab569/src/main/shadow/build/resolve.clj#L525-L542

ok, so you first try the lib as is, and then try with clojure replaced with cljs

yeah the whole behavior is a bit weird since there is an actual clojure.string for example where replacing it to cljs.string would be invalid

and then there is clojure.edn which is real but kind of delegates to cljs.reader

well yeah but its just a regular ns

that's what I meant with real :)

What exactly do you mean? Can you give an example?

(for [item indexed-data]
  (cond (= (first item) 0)
    (println "First item!"))
  (cond (= (last data) item)
    (println "Last item!"))
    (item))

How do conditionals work within a for loop?

The code above is invalid because for's body can have only one expression, whereas yours have two. But conditionals works just as they do anywhere else. They're evaluated and the result is returned, becoming an element in the sequence that for returns, even if it's nil.

One exception if you use the :when keyword:

(for [x [0 1 2 3 4 5]
      :let [y (* x 3)]
      :when (even? y)]
  y)

(0 6 12)

Also keep in mind that for yields a lazy sequence, so you may want doseq if you are doing this for side effects

Okay. Thanks.