Change deprecated validates_presence_of
In Validations section the example contained "validates_presence_of" which is deprecated. It should be "validates :name, presence: true"
It is not deprecated
You're right. It is still exist, but this old version is not really explained in Active Record Validations page (http://edgeguides.rubyonrails.org/active_record_validations.html). I thought, would be more consistent with the new version of validation.