Let Rails handle Voucher type building

app/controllers/admin/vouchers_controller.rb

@@ -9,20 +9,9 @@ module Admin
     end
 
     def create
-      # In the scenario where you get an error when trying to create a percentage voucher, we'll
-      # now have percentage rate voucher instanciated. Hence why we check for both params type
-      voucher_type = params.dig(:voucher, :voucher_type)
-
-      # The use of "safe_constantize" here will trigger a Brakeman error, it can safely be ignored
-      # as it's a false positive : https://github.com/openfoodfoundation/openfoodnetwork/pull/10821
-      if Voucher::TYPES.include?(voucher_type)
-        @voucher = voucher_type.safe_constantize.create(
-          permitted_resource_params.merge(enterprise: @enterprise)
-        )
-      else
-        @voucher.errors.add(:type)
-        return render_error
-      end
+      @voucher = Voucher.new(
+        permitted_resource_params.merge(enterprise: @enterprise)
+      )
 
       if @voucher.save
         flash[:success] = I18n.t(:successfully_created, resource: "Voucher")
@@ -30,6 +19,9 @@ module Admin
       else
         render_error
       end
+    rescue ActiveRecord::SubclassNotFound
+      @voucher.errors.add(:type)
+      render_error
     end
 
     private
@@ -47,7 +39,7 @@ module Admin
     end
 
     def permitted_resource_params
-      params.require(:voucher).permit(:code, :amount)
+      params.require(:voucher).permit(:code, :amount, :type)
     end
   end
 end

app/views/admin/vouchers/new.html.haml

@@ -17,9 +17,9 @@
             = f.text_field :code, class: 'fullwidth'
         .row
           .alpha.four.columns
-            = f.label :voucher_type, t('.voucher_type')
+            = f.label :type, t('.voucher_type')
           .omega.eight.columns
-            = f.select :voucher_type, options_for_select(Voucher::TYPES.map { |type| [t(".#{type.demodulize.underscore}"), type] }, @voucher.class.to_s)
+            = f.select :type, options_for_select(Voucher::TYPES.map { |type| [t(".#{type.demodulize.underscore}"), type] }, @voucher.class.to_s)
         .row
           .alpha.four.columns
             = f.label :amount, t('.voucher_amount')

spec/requests/admin/vouchers_controller_spec.rb

@@ -29,7 +29,7 @@ describe Admin::VouchersController, type: :request do
         voucher: {
           code: code,
           amount: amount,
-          voucher_type: type
+          type: type
         }
       }
     end
@@ -55,7 +55,7 @@ describe Admin::VouchersController, type: :request do
           voucher: {
             code: code,
             amount: amount,
-            voucher_type: type
+            type: type
           }
         }
       end