 
    # vendors (optional)
   validate_vendors:( config )->
-    for vname, vpath of config.vendors.javascript
+    for vname, vpath of config?.vendors?.javascript
       # skip cdn vendors or incompatible vendors
       if (/^http/m.test vpath) or (vname is 'incompatible')
         continue


  setup:( config )=>

    return unless @validate_server config
    return unless @validate_sources config
    return unless @validate_excludes config
    return unless @validate_includes config
    return unless @validate_destination config
    return unless @validate_wrappers config
    return unless @validate_vendors config

    @confs.push config



  validate_server:( config )->



  validate_wrappers:( config )->
    unless config.wrappers?
      config.wrappers = javascript: 'amd', style: 'amd'
    else
      config.wrappers.javascript ?= 'amd'
