12777: add specs

spec/system/admin/invoice_print_spec.rb

@@ -300,6 +300,21 @@
             expect(page).to have_content "Total (Excl. tax): $1,458.67"
           end
         end
+
+        context "Line item with variant having variant_unit as 'items'" do
+          before do
+            line_item1.variant.update_columns(variant_unit: "items", display_as: "1 bucket")
+            login_as_admin
+            visit spree.print_admin_order_path(order1, params: url_params)
+            convert_pdf_to_page
+          end
+
+          it 'should have correct display as value' do
+            # first line item
+            expect(page).to have_content Spree::Product.first.name.to_s
+            expect(page).to have_content "(1 bucket)" # display as
+          end
+        end
       end
 
       context "added" do