3 files changed, 56 insertions, 9 deletions
diff --git a/lux-lein/src/leiningen/lux.clj b/lux-lein/src/leiningen/lux.clj
index 6b2268d70..4902d048f 100644
--- a/lux-lein/src/leiningen/lux.clj
+++ b/lux-lein/src/leiningen/lux.clj
@@ -8,7 +8,8 @@
             [leiningen.core.classpath :as classpath]
             (leiningen.lux [builder :as &builder]
                            [test :as &test]
-                           [repl :as &repl])))
+                           [repl :as &repl]
+                           [watch :as &watch])))
 
 ;; [Exports]
 (defn lux [project & args]
@@ -22,6 +23,14 @@
     "repl"
     (&repl/repl project)
 
+    "watch"
+    (case (second args)
+      "build"
+      (&watch/watch #(&builder/build project) project)
+
+      "test"
+      (&watch/watch #(&test/test project) project))
+
     ;; default...
-    (println "Commands available: build, test, repl"))
+    (println "Commands available: (watch) build, (watch) test, repl"))
   )
diff --git a/lux-lein/src/leiningen/lux/utils.clj b/lux-lein/src/leiningen/lux/utils.clj
index 70d203865..6419e9de8 100644
--- a/lux-lein/src/leiningen/lux/utils.clj
+++ b/lux-lein/src/leiningen/lux/utils.clj
@@ -86,11 +86,8 @@
         (when line
           (println line)
           (recur (.readLine std-out))))
-      (loop [had-error? false
-             line (.readLine std-err)]
-        (if line
-          (do (println line)
-            (recur true (.readLine std-err)))
-          (when had-error?
-            (System/exit 1))))
+      (loop [line (.readLine std-err)]
+        (when line
+          (println line)
+          (recur (.readLine std-err))))
       (println post))))
diff --git a/lux-lein/src/leiningen/lux/watch.clj b/lux-lein/src/leiningen/lux/watch.clj
new file mode 100644
index 000000000..d9cae9075
--- /dev/null
+++ b/lux-lein/src/leiningen/lux/watch.clj
@@ -0,0 +1,41 @@
+;;  Copyright (c) Eduardo Julian. All rights reserved.
+;;  This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+;;  If a copy of the MPL was not distributed with this file,
+;;  You can obtain one at http://mozilla.org/MPL/2.0/.
+
+(ns leiningen.lux.watch
+  (:require [leiningen.core.classpath :as classpath])
+  (:import (java.io File)
+           (java.nio.file FileSystems
+                          Path
+                          WatchEvent$Kind
+                          StandardWatchEventKinds
+                          WatchService
+                          WatchKey)))
+
+(defn ^:private file-tree [path]
+  (let [dir (new File path)]
+    (if (and (.exists dir)
+             (.isDirectory dir))
+      (->> (.listFiles dir) (mapcat (comp file-tree #(.getAbsolutePath ^File %))) (cons path))
+      (list))))
+
+(defn watch [action project]
+  (let [fs (FileSystems/getDefault)
+        ^WatchService watcher (.newWatchService fs)
+        dirs-to-watch (->> (concat (get project :test-paths (list))
+                                   (get project :source-paths (list)))
+                           (mapcat file-tree)
+                           (map #(.getPath fs % (into-array String []))))
+        _ (doseq [^Path dir dirs-to-watch]
+            (.register dir watcher (into-array WatchEvent$Kind [StandardWatchEventKinds/ENTRY_MODIFY])))]
+    (do (action)
+      (loop []
+        (do (when-let [^WatchKey key (.poll watcher)]
+              (when (.isValid key)
+                (.pollEvents key)
+                (.reset key)
+                (action)))
+          (Thread/sleep 1000)
+          (recur))))
+    ))