Add spec for db queries

spec/lib/reports/orders_and_distributors_report_spec.rb

@@ -132,6 +132,28 @@ RSpec.describe Reporting::Reports::OrdersAndDistributors::Base do
           end
         end
       end
+
+      it "minimises database queries" do
+        subject # build context first
+
+        # surely we can do better than that for each row
+        expect { subject.table_rows }.to query_database [
+          "Spree::Role Exists?",
+          "Spree::Role Exists?",
+          "SQL",
+          "Spree::LineItem Load",
+          "Spree::Order Load",
+          "Spree::Address Load",
+          "Spree::Payment Load",
+          "Spree::PaymentMethod Load",
+          "Spree::Calculator Load",
+          "Enterprise Load",
+          "Spree::Address Load",
+          "Spree::Shipment Load",
+          "Spree::ShippingRate Load",
+          "Spree::ShippingMethod Load",
+        ]
+      end
     end
   end
 end