Make code work for relations and arrays

app/mailers/producer_mailer.rb

@@ -60,11 +60,11 @@ class ProducerMailer < Spree::BaseMailer
   end
 
   def total_from_line_items(line_items)
-    Spree::Money.new line_items.sum(&:total)
+    Spree::Money.new line_items.to_a.sum(&:total)
   end
 
   def tax_total_from_line_items(line_items)
-    Spree::Money.new line_items.sum(&:included_tax)
+    Spree::Money.new line_items.to_a.sum(&:included_tax)
   end
 
   # This hack makes ActiveRecord skip the default_scope (deleted_at IS NULL)

app/views/spree/orders/_bought.html.haml

@@ -3,7 +3,7 @@
     %td.toggle-bought{ colspan: 2, ng: { click: 'showBought=!showBought' } }
       %h5.brick
         %i{ ng: { class: "{ 'ofn-i_007-caret-right': !showBought, 'ofn-i_005-caret-down': showBought}"} }
-        = t(:orders_bought_items_notice, count: @order.finalised_line_items.sum(&:quantity))
+        = t(:orders_bought_items_notice, count: @order.finalised_line_items.to_a.sum(&:quantity))
     %td.text-right{ colspan: 3 }
       %a.edit-finalised.button.radius.expand.small{ href: changeable_orders_link_path, ng: { class: "{secondary: !showBought, primary: showBought}" } }
         = t(:orders_bought_edit_button)

lib/open_food_network/xero_invoices_report.rb

@@ -180,11 +180,11 @@ module OpenFoodNetwork
     end
 
     def total_untaxable_products(order)
-      order.line_items.without_tax.sum(&:amount)
+      order.line_items.without_tax.to_a.sum(&:amount)
     end
 
     def total_taxable_products(order)
-      order.line_items.with_tax.sum(&:amount)
+      order.line_items.with_tax.to_a.sum(&:amount)
     end
 
     def total_untaxable_fees(order)