core.async Promise.all equivalent attempt

promiseall.cljs

    (go (println (<! (a/into [] (a/merge (map original-image-dimensions (:items @app-state)))))))

(defn original-image-dimensions [item]
  (let [sub clojure.string/replace
        image_url (sub (:large_default_image_url item) #"large" "original")
        img (js/Image.)
        out (chan)]
    (aset img "onload" (fn [] (this-as image
                                       (put! out {:height (.-height image)
                                                  :width (.-width image)})
                                       (a/close! out))))
    (aset img "src" image_url)
    out))