update karma config

config/ng-test.conf.js

@@ -27,9 +27,16 @@ module.exports = function(config) {
       'app/assets/javascripts/admin/util.js.erb'
     ],
 
+    preprocessors: {
+      '**/*.coffee': ['coffee']
+    },
+
     coffeePreprocessor: {
       options: {
         sourceMap: true
+      },
+      transformPath: function(path) {
+        return path.replace(/\.coffee$/, '.js');
       }
     },