ruby on rails - Removing or overriding an ActiveRecord validation added by a superclass or mixin

Question

I'm using Clearance for authentication in my Rails application. The Clearance::User mixin adds a couple of validations to my User model, but there's one of these that I would like to remove or override. What is the best way of doing this?

The validation in question is

validates_uniqueness_of :email, :case_sensitive => false

which in itself isn't bad, but I would need to add :scope => :account_id. The problem is that if I add this to my User model

validates_uniqueness_of :email, :scope => :account_id

I get both validations, and the one Clearance adds is more restrictive than mine, so mine has no effect. I need to make sure that only mine runs. How do I do this?

Answer 1

I'd fork the GEM and add a simple check, that can then be overridden. My example uses a Concern.

Concern:

module Slugify

  extend ActiveSupport::Concern

  included do

    validates :slug, uniqueness: true, unless: :skip_uniqueness?
  end

  protected

  def skip_uniqueness?
    false
  end

end

Model:

class Category < ActiveRecord::Base
  include Slugify

  belongs_to :section

  validates :slug, uniqueness: { scope: :section_id }

  protected

  def skip_uniqueness?
    true
  end
end