Set default values recoursive

defaults_recoursive.coffee

_mergeDefaults = (item, defaultValues...)->
  for defaultValue in defaultValues
    for key, value of defaultValue
      if not item[key]
        item[key] = value
        
      else if typeof value is 'object' and typeof value.length is 'undefined'
        item[key] = _mergeDefaults(item[key], value)
  
  return item

# call
_mergeDefaults {a: 1, b: {c: 2, d:3}}, {a: 5, b: {t: 8}}, {d: 1} # => a: 1, b: {c: 2, d: 3, t: 8}, d: 1