Only add the xmodule.coffee file once per class, and put it before all other coffeescript files

common/lib/xmodule/xmodule/x_module.py

@@ -45,17 +45,13 @@ class HTMLSnippet(object):
         # cdodge: We've moved the xmodule.coffee script from an outside directory into the xmodule area of common
         # this means we need to make sure that all xmodules include this dependency which had been previously implicitly
         # fulfilled in a different area of code
-        js = cls.js
+        coffee = cls.js.setdefault('coffee', [])
+        fragment = resource_string(__name__, 'js/src/xmodule.coffee')
 
-        if js is None:
-            js = {}
+        if fragment not in coffee:
+            coffee.insert(0, fragment)
 
-        if 'coffee' not in js:
-            js['coffee'] = []
-
-        js['coffee'].append(resource_string(__name__, 'js/src/xmodule.coffee'))
-
-        return js
+        return cls.js
 
     @classmethod
     def get_css(cls):