Javascript async interop between callbacks/promises and channels

async-apply.cljs

(ns service.async
  (:require-macros [cljs.core.async.macros :as a])
  (:require [cljs.core.async :as a]))

(defn <cb [f & args]
  (let [out (a/chan)]
    (apply f (conj (into [] args) #(a/close! out)))
    out))

(defn <promise [f & args]
  (let [out  (a/chan)
        done (fn [& _] (a/close! out))]

    (.then (apply f args) done done)

    out))