Question

I’m working on a Rails app with two-factor authentication. The User model in this app has an attribute, two_factor_phone_number. I have the model validating that this attribute is present before the model can be saved.

To make sure the phone number is saved in a proper format, I’ve created a custom attribute assignment method that looks like this:

def two_factor_phone_number=(num)
  num.gsub!(/\D/, '') if num.is_a?(String)
  self[:two_factor_phone_number] = num.to_i
end

I’m doing some acceptance testing, and I’ve discovered that if this method is in the model, the ActiveRecord validation is ignored/skipped and a new model can be created without a two_factor_phone_number set.

The model code looks like this:

class User < ActiveRecord::Base
  devise :database_authenticatable, :registerable, :confirmable,
        :recoverable, :rememberable, :trackable, :validatable,
        :lockable

  attr_accessible :email, :password, :password_confirmation, :remember_me,
                  :first_name, :last_name, :two_factor_phone_number

  validates :first_name,              presence: true
  validates :last_name,               presence: true
  validates :two_factor_phone_number, presence: true

  # Removes all non-digit characters from a phone number and saves it
  #
  # num - the number to be saved
  #
  # Returns the digit-only phone number
    def two_factor_phone_number=(num)
      num.gsub!(/\D/, '') if num.is_a?(String)
      self[:two_factor_phone_number] = num.to_i
    end
end

Answer 1

You could add a format validation:

validates :two_factor_phone_number, :format => { :with => /[0-9]/,
:message => "Only digits allowed" }

and/or create another method to set this attribute and call it before validation

before_validation :update_phone_format

def update_phone_format
 ...
end