CLDC-4174: add validation that new value is different

app/models/validations/sales/financial_validations.rb

@@ -139,6 +139,24 @@ module Validations::Sales::FinancialValidations
     end
   end
 
+  def validate_newservicecharges(record)
+    return unless record.newservicecharges
+
+    if record.newservicecharges.negative?
+      record.errors.add :newservicecharges, I18n.t("validations.sales.financial.newservicecharges.negative")
+    elsif record.newservicecharges > 9999.99
+      record.errors.add :newservicecharges, I18n.t("validations.sales.financial.newservicecharges.over_max")
+    end
+  end
+
+  def validate_newservicecharges_different_from_mscharge(record)
+    return unless record.hasservicechargeschanged == 1 && record.newservicecharges && record.mscharge
+
+    if record.newservicecharges == record.mscharge
+      record.errors.add :newservicecharges, I18n.t("validations.sales.financial.newservicecharges.same_as_previous")
+    end
+  end
+
 private
 
   def is_relationship_child?(relationship)

config/locales/validations/sales/financial.en.yml

@@ -49,6 +49,11 @@ en:
           monthly_leasehold_charges:
             not_zero: "Monthly leasehold charges cannot be £0 if the property has monthly charges."
 
+        newservicecharges:
+          negative: "Service charge cannot be negative."
+          over_max: "Service charge cannot be higher than £9,999.99."
+          same_as_previous: "You said that the service charge will change and you entered the same amount as the previous question. If the service charge will not change, answer 'No'."
+
         resale:
           equity_over_max: "The maximum initial equity stake is %{max_equity}%."