add tax_adjustment total to the invoice

app/models/invoice/data_presenter.rb

@@ -105,6 +105,10 @@ class Invoice
       I18n.l(invoice_date.to_date, format: :long)
     end
 
+    def display_tax_adjustment_total
+      Spree::Money.new(all_tax_adjustments.map(&:amount).sum, currency:)
+    end
+
     def tax_adjustment_totals
       all_tax_adjustments.each_with_object(Hash.new(0)) do |adjustment, totals|
         totals[adjustment.originator.id] += adjustment.amount

app/views/spree/admin/orders/_invoice_table4.html.haml

@@ -73,6 +73,12 @@
           = t(:tax_total, rate: tax[:percentage])
         %td{:align => "right", :colspan => "2"}
           = tax[:amount]
+    %tr
+      %td{:align => "right", :colspan => "5"}
+        = t(:total_all_tax)
+      %td{:align => "right", :colspan => "2"}
+        =  @order.display_tax_adjustment_total
+      
     %tr
       %td{:align => "right", :colspan => "5"}
         %strong= t(:total_incl_tax)

config/locales/en.yml

@@ -1888,6 +1888,7 @@ en:
   invoice_shipping_type: "Type:"
   total_excl_tax: "Total (Excl. tax):"
   total_incl_tax: "Total (Incl. tax):"
+  total_all_tax: "Total tax:"
   abn: "ABN:"
   acn: "ACN:"
   invoice_issued_on: "Invoice issued on:"