renane method and use new display only if newly calculated data present

app/models/charge.rb

@@ -53,7 +53,7 @@ class Charge < ApplicationRecord
 
   scope :pay_in_advance, -> { where(pay_in_advance: true) }
 
-  def simple_percentage?
+  def basic_rate_percentage?
     return false unless percentage?
 
     properties.keys == ['rate']

app/views/templates/invoices/v4/charge.slim

@@ -455,8 +455,8 @@ html
             td.body-2 = I18n.t('invoice.amount')
           - fees.order(:succeeded_at, :created_at).each do |fee|
             tr
-              - if fee.charge.percentage?
-                - if fee.charge.simple_percentage?
+              - if fee.charge.percentage? && fee.amount_details.present?
+                - if fee.charge.basic_rate_percentage?
                   tr
                     td.body-1
                       = fee.invoice_name + FeeDisplayHelper.grouped_by_display(fee)

spec/models/charge_spec.rb

@@ -525,17 +525,17 @@
     end
   end
 
-  describe '#simple_percentage?' do
+  describe '#basic_rate_percentage?' do
     it 'returns false if charge model is not percentage' do
-      expect(build(:standard_charge)).not_to be_simple_percentage
+      expect(build(:standard_charge)).not_to basic_rate_percentage
     end
 
     it 'returns false if charge model is percentage but has other properties except rate' do
-      expect(build(:charge, charge_model: 'percentage', properties: {fixed_amount: '20'})).not_to be_simple_percentage
+      expect(build(:charge, charge_model: 'percentage', properties: {fixed_amount: '20'})).not_to basic_rate_percentage
     end
 
     it 'returns true only if properties of percentage charge contain only rate' do
-      expect(build(:charge, charge_model: 'percentage', properties: {rate: '0.20'})).to be_simple_percentage
+      expect(build(:charge, charge_model: 'percentage', properties: {rate: '0.20'})).to basic_rate_percentage
     end
   end
 end