fix: discount

Fix the discount sent to SageX3
related to #257

apps/billing/models.py

@@ -103,7 +103,7 @@ def discount_rate(self):
         The discount rate
         """
         try:
-            round(self.discount_incl_tax / (self.unit_price_incl_vat + self.discount_incl_tax), 2)
+            return round(self.discount_incl_tax / (self.unit_price_incl_vat + self.discount_incl_tax), 2)
         except ZeroDivisionError:
             return 0
 

apps/billing/services/processor_service.py

@@ -71,7 +71,7 @@ def __generate_items_as_xml(self, items: list[TransactionItem]) -> str:
                 <FLD NAME="QTY">{item.quantity}</FLD>
                 <FLD NAME="STU">UN</FLD>
                 <FLD NAME="GROPRI">{item.unit_price_excl_vat}</FLD>
-                <FLD NAME="DISCRGVAL1">{item.discount_rate}</FLD>
+                <FLD NAME="DISCRGVAL1">{item.discount_rate * 100}</FLD>
                 <FLD NAME="VACITM1">{self.__vacitm1}</FLD>
             </LIN>
             """

apps/billing/tests/test_discount.py

@@ -0,0 +1,46 @@
+import decimal
+import logging
+
+from django.test import TestCase
+
+from apps.billing.factories import TransactionFactory, TransactionItemFactory
+
+log = logging.getLogger(__name__)
+
+
+class DiscountTest(TestCase):
+    """
+    Test the discount
+    """
+
+    def test_discount_transaction_no_all_zero(self):
+        """
+        Test the discount model with discount with zero.
+        """
+        transaction = TransactionFactory.build()
+        item = TransactionItemFactory.build(
+            transaction=transaction, discount_excl_tax=decimal.Decimal(0.00), discount_incl_tax=decimal.Decimal(0.00)
+        )
+        print(item.discount_incl_tax)
+        print(item.unit_price_incl_vat)
+        self.assertEqual(item.discount_rate, 0.00)
+
+    def test_discount_transaction_some_discount(self):
+        """
+        Test discount value with including vat fields.
+        """
+        transaction = TransactionFactory.build()
+        item = TransactionItemFactory.build(
+            transaction=transaction, unit_price_incl_vat=decimal.Decimal(9.00), discount_incl_tax=decimal.Decimal(1.00)
+        )
+        self.assertEqual(item.discount_rate, round(decimal.Decimal(0.10), 2))
+
+    def test_discount_transaction_some_discount_percentage(self):
+        """
+        Test discount value like a percentage.
+        """
+        transaction = TransactionFactory.build()
+        item = TransactionItemFactory.build(
+            transaction=transaction, unit_price_incl_vat=decimal.Decimal(4.00), discount_incl_tax=decimal.Decimal(1.00)
+        )
+        self.assertEqual(item.discount_rate * 100, 20)