Use documentables helper method within specs and document model.

app/helpers/documentables_helper.rb

@@ -16,4 +16,10 @@ module DocumentablesHelper
     documentable.class.accepted_content_types
   end
 
+  def humanized_accepted_content_types(documentable)
+    documentable.class.accepted_content_types
+                .collect{ |content_type| content_type.split("/").last }
+                .join(", ")
+  end
+
 end

app/models/document.rb

@@ -1,5 +1,6 @@
 class Document < ActiveRecord::Base
   include DocumentsHelper
+  include DocumentablesHelper
   has_attached_file :attachment
 
   belongs_to :user
@@ -21,16 +22,16 @@ class Document < ActiveRecord::Base
        attachment_file_size > documentable.class.max_file_size
       errors[:attachment] = I18n.t("documents.errors.messages.in_between",
                                     min: "0 Bytes",
-                                    max: "#{bytesToMeg(documentable.class.max_file_size)} MB")
+                                    max: "#{max_file_size(documentable)} MB")
     end
   end
 
   def validate_attachment_content_type
     if documentable.present? &&
-       !documentable.class.accepted_content_types.include?(attachment_content_type)
+       !accepted_content_types(documentable).include?(attachment_content_type)
       errors[:attachment] = I18n.t("documents.errors.messages.wrong_content_type",
                                     content_type: attachment_content_type,
-                                    accepted_content_types: documentable.class.accepted_content_types.join(", "))
+                                    accepted_content_types: humanized_accepted_content_types(documentable))
     end
   end
 

app/views/documents/new.html.erb

@@ -10,9 +10,18 @@
     <span class="icon-documents float-right"></span>
     <h2><%= t("documents.recommendations_title") %></h2>
     <ul class="recommendations">
-      <li><%= t("documents.recommendation_one_html", max_documents_allowed: @document.documentable.class.max_documents_allowed) %></li>
+      <li>
-      <li><%= t("documents.recommendation_two_html", accepted_content_types: @document.documentable.class.accepted_content_types.join(", ")) %></li>
+        <%= t "documents.recommendation_one_html",
-      <li><%= t("documents.recommendation_three_html", max_file_size: bytesToMeg(@document.documentable.class.max_file_size)) %></li>
+                max_documents_allowed: max_documents_allowed(@document.documentable) %>
+      </li>
+      <li>
+        <%= t "documents.recommendation_two_html",
+              accepted_content_types: humanized_accepted_content_types(@document.documentable) %>
+      </li>
+      <li>
+        <%= t "documents.recommendation_three_html",
+              max_file_size: max_file_size(@document.documentable) %>
+      </li>
     </ul>
   </div>
 </div>

spec/shared/features/documentable.rb

@@ -1,12 +1,13 @@
 shared_examples "documentable" do |documentable_factory_name, documentable_path, documentable_path_arguments|
   include ActionView::Helpers
   include DocumentsHelper
+  include DocumentablesHelper
 
   let!(:administrator)          { create(:user) }
   let!(:user)                   { create(:user) }
   let!(:arguments)              { {} }
   let!(:documentable)           { create(documentable_factory_name, author: user) }
-  let!(:documentable_dom_name)  { documentable_factory_name.gsub('_', '-') }
+  let!(:documentable_dom_name)  { documentable_factory_name.parameterize }
 
   before do
     create(:administrator, user: administrator)
@@ -157,9 +158,9 @@ shared_examples "documentable" do |documentable_factory_name, documentable_path,
                               documentable_id: documentable.id,
                               from: send(documentable_path, arguments))
 
-      expect(page).to have_content "You can upload up to a maximum of #{documentable.class.max_documents_allowed} documents."
+      expect(page).to have_content "You can upload up to a maximum of #{max_file_size(documentable)} documents."
-      expect(page).to have_content "You can upload #{documentable.class.accepted_content_types.join(", ")} files."
+      expect(page).to have_content "You can upload #{humanized_accepted_content_types(documentable)} files."
-      expect(page).to have_content "You can upload files up to #{bytesToMeg(documentable.class.max_file_size)} MB."
+      expect(page).to have_content "You can upload files up to #{max_file_size(documentable)} MB."
     end
 
   end

spec/shared/models/document_validations.rb

@@ -3,6 +3,7 @@ shared_examples "document validations" do |documentable_factory|
   include DocumentablesHelper
 
   let!(:document)               { build(:document, documentable_factory.to_sym) }
+  let!(:documentable)           { document.documentable }
   let!(:maxfilesize)            { max_file_size(document.documentable) }
   let!(:acceptedcontenttypes)   { accepted_content_types(document.documentable) }