title: Accessing helpers within the model in the controller
body: <p>I am wondering why I have a helper method from a module i've mixed in with my model is throwing the NoMethodError within my controller when I try to call that models protected method. My code currently looks like this.</p>
  <pre><code>#models/my_class.rb
  
  class MyClass
    include HelperModule
      
    def self.list_payments(payments)
       new_payments = []
       payments.each do |payment|
          payment = MyClass.new.tap do |p|
             p.quality_check = quality_check(payment)
             p.amount_with_fee = calculate_fees(payment)
          end
  
          if payment.valid?
            payment.save
            new_payments &lt;&lt; payment
          end
       end
       new_payments
    end
  end
  
   #controllers/my_classes_controller
  
   class MyClassController &lt; ApplicationController
       def index
          response = Faraday.get
          unfiltered_payments = JSON.parse(response.body)[&quot;payments&quot;]
          @payments = MyClass.list_payments(unfiltered_payments)
       end
   end
  </code></pre>
  <p><code>quality_check</code> and <code>calculate_fees</code> are both within my helper module but in the controller when I call <code>MyClass.list_payments(payments)</code> I get the <code>NoMethodError</code> for both methods. I can get it to work by including the helpers within my controller and using this function as a private function within my controller, but I was trying to follow the fat model/skinny controller convention. Am I missing something here or am I okay with placing the helpers within the controller and moving this function to the controller?
  using <code>ruby 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin20]</code>, and <code>Rails 6.1.0</code></p>