cljs.repl.node/repl-env*

(defn repl-env* [options]
  (let [{:keys [host port path debug-port]}
        (merge
          {:host "localhost"
           :port (+ 49000 (rand-int 10000))}
          options)]
    (assoc
      (NodeEnv. host port path
        (atom nil) (atom nil) (atom {:listeners 0}))
      :debug-port debug-port)))