     return yes
 
   validate_destination:( config )->
-    if config.destination is null
+    unless config.destination?
       msg = 'You need to inform a destination folder, check your config file.'
       return error msg
 



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

    return yes

  validate_sources:( config )->
    unless config.sources? and config.sources.length
      msg = 'You need to inform at least one source, check your config file.'
      return error msg

