Himera - Compile CLJS in a custom namespace

gistfile1.clj

;; Handler
(ns ttmachines.server.views.repl-service ...)
...
(defpage [:post "/compile"] {:keys [expr cljs-ns] :or {cljs-ns "cljs.user"}}
    (let [cljs-ns (symbol cljs-ns)]
      (try
          (generate-repl-response (cljs/compilation expr :cljs-ns cljs-ns))
          (catch RuntimeException e
              (generate-repl-response {:result nil} 400)))))

;; Service
(ns himera.server.cljs
  (:require [cljs.compiler :as comp])
  (:require [himera.server.setup :as setup])
  (:import [java.io PushbackReader BufferedReader StringReader]
           [clojure.lang ISeq]))

(declare exp)

(defn build [action locals expr & {:keys [opt pp] :or {opt :simple pp false}}]
  {:result
   (let [env {:ns (@comp/namespaces comp/*cljs-ns*)
              :uses #{'cljs.core}
              :context :expr
              :locals locals}]
     (with-redefs [comp/get-expander exp]
       (action env expr)))
 :status 200})

(defn compilation [expr & {:keys [cljs-ns]}] 
  (binding [comp/*cljs-ns* cljs-ns]
    (build
      #(comp/emits (comp/analyze % %2))
      (setup/load-core-names)
      expr)))

;; privates

(defn- exp [sym env]
  (let [mvar
        (when-not (or (-> env :locals sym)        ;locals hide macros
                      (-> env :ns :excludes sym))
          (if-let [nstr (namespace sym)]
            (when-let [ns (cond
                           (= "clojure.core" nstr) (find-ns 'cljs.core)
                           (.contains nstr ".") (find-ns (symbol nstr))
                           :else
                           (-> env :ns :requires-macros (get (symbol nstr))))]
              (.findInternedVar ^clojure.lang.Namespace ns (symbol (name sym))))
            (if-let [nsym (-> env :ns :uses-macros sym)]
              (.findInternedVar ^clojure.lang.Namespace (find-ns nsym) sym)
              (.findInternedVar ^clojure.lang.Namespace (find-ns 'cljs.core) sym))))]
    (println [sym mvar])
    (let [sym (symbol (.getName sym))]
      (when (and mvar (or (setup/clojure-macros sym) (setup/cljs-macros sym)))
        @mvar))))