code: def sort_js_files(js_files):
      modules = [f for f in js_files if f.endswith(MODULE_EXT)]
      mocks = [f for f in js_files if f.endswith(MOCK_EXT)]
      specs = [f for f in js_files if f.endswith(SPEC_EXT)]
      other_sources = [f for f in js_files
                       if (not f.endswith(MODULE_EXT) and
                           not f.endswith(MOCK_EXT) and
                           not f.endswith(SPEC_EXT))]
      sources = modules + other_sources
      return sources, mocks, specs