also apply rounding in line item

Author: langalex

lib/secretariat/line_item.rb

@@ -74,7 +74,7 @@ def valid?
       gross_price = BigDecimal(gross_amount)
       charge_price = BigDecimal(charge_amount)
       tax = BigDecimal(tax_amount)
-      unit_price = net_price * BigDecimal(billed_quantity.abs)
+      unit_price = (net_price * BigDecimal(billed_quantity.abs)).round(2)
 
       if charge_price != unit_price
         @errors << "charge price and gross price times quantity deviate: #{charge_price} / #{unit_price}"

test/invoice_test.rb

@@ -793,18 +793,27 @@ def test_invoice_object_extensions
     end
 
     def test_invoice_with_quantity_causing_sub_cent_amounts
+      errors = []
+
       invoice = make_de_invoice
       invoice.tax_calculation_method = :ITEM_BASED
       invoice.line_items.first.net_amount = BigDecimal('10.12')
+      invoice.line_items.first.gross_amount = BigDecimal('10.12')
+      invoice.line_items.first.discount_amount = BigDecimal('0')
       invoice.line_items.first.billed_quantity = BigDecimal('0.1')
       invoice.line_items.first.charge_amount = BigDecimal('1.01')
       invoice.line_items.first.tax_amount = BigDecimal('0.19')
       invoice.basis_amount = BigDecimal('1.01') # 1.012 rounded
       invoice.tax_amount = BigDecimal('0.19')
       invoice.grand_total_amount = BigDecimal('1.2')
 
-      invoice.valid?
-      assert_equal [], invoice.errors
+      begin
+        invoice.to_xml(version: 2)
+      rescue ValidationError => e
+        errors = e.errors
+        pp e.errors
+      end
+      assert_equal [], errors
     end
   end
 end