async issue

events.cljs

(reg-event-fx
  :firebase/listen
  (fn [{:keys [db] :as cofx} event]
    (let [user              (:user db)
          firebase-database (:firebase-database db)]

      ; fetch user (core.async version)
      (take! (-> firebase-database
                 (.ref)
                 (m/get-in [:user user])
                 (ma/deref<))
             #(println "took:" %))

      ; fetch user (sync version)
      (let [promise (-> firebase-database
                        (.ref)
                        (m/get-in [:user user])
                        (m/deref #(println %)))]
        (.then promise
               #(println "success:" %)
               #(println "failed:" %)))

      ; if users exists...
      ; TODO


      ;then setup listening to both all users updates + user updates
      (println "Listen to firebase update for user:" user "db=" db "cofx=" cofx)
      (let [
            allusers-unsubscribe-fn (listen-firebase firebase-database :firebase-allusers-updated)
            user-unsubscribe-fn     (listen-firebase firebase-database :firebase-user-updated user)]
        {:db       (assoc db :firebase-unsubscribe-allusers-fn allusers-unsubscribe-fn
                             :firebase-unsubscribe-user-fn user-unsubscribe-fn)
         :dispatch [:firebase/listen-successful]}))))

repl.clj

(take! (-> firebase-database
                 (.ref)
                 (m/get-in [:user user])
                 (ma/deref<))
             #(println "took:" %))
took: {:friends true, :personal-data {:salary 1700, :salary-basis year, :salary-payment-rate 13}}
=> nil
(let [promise (-> firebase-database
                        (.ref)
                        (m/get-in [:user user])
                        (m/deref #(println %)))]
        (.then promise
               #(println "success:" %)
               #(println "failed:" %)))
{:friends true, :personal-data {:salary 1700, :salary-basis year, :salary-payment-rate 13}}
=> #object[Promise [object Object]]
success: #object[V [object Object]]

Grosso modo j'aimerai que à la ligne 25 du premier fichier, je puis récupérer la valeur qui a été fetchée en asynchrone...