fix default :output-dir logic for Node.js REPL

add precondition to cljs.util/output-directory

Author: swannodette

src/clj/cljs/repl/node.clj

@@ -81,7 +81,7 @@
   ([repl-env] (setup repl-env nil))
   ([repl-env opts]
     (let [opts (merge {:output-dir ".cljs_node_repl"} opts)
-          output-dir (io/file (util/output-directory (:output-dir opts)))
+          output-dir (io/file (util/output-directory opts))
           _    (.mkdirs output-dir)
           of   (io/file output-dir "node_repl.js")
           _   (spit of

src/clj/cljs/util.clj

@@ -82,7 +82,8 @@
 (defn output-directory
   ([opts] (output-directory opts "out"))
   ([opts default]
-    (or (:output-dir opts) default)))
+   {:pre [(or (nil? opts) (map? opts))]}
+   (or (:output-dir opts) default)))
 
 (defn file? [f]
   (instance? File f))