fix: retry fullfillment

When retry fullfillment, the BasketTransactionIntegration was rasing mysql error.
fix #4

README.rst

@@ -31,7 +31,7 @@ edit the `ecommerce/settings/private.py` file add change to::
     NAU_FINANCIAL_MANAGER = {
         "edx": {
             "url": "http://financial-manager.local.nau.fccn.pt:8000/api/billing/transaction-complete/",
-            "token": "abcdABCD1234",
+            "token": "Bearer abcdABCD1234",
         }
     }
 

nau_extensions/models.py

@@ -123,12 +123,15 @@ class Meta:
     @staticmethod
     def create(basket):
         """
-        Create a new basket transaction integration for a basket.
+        Create a new basket basket transaction integration or reuse an existing one for a basket.
         """
         order = get_order(basket)
         if not order:
             raise ValueError(
                 f"The creation of BasketTransactionIntegration requires a basket with an order"
                 f", basket '{basket}'"
             )
-        return BasketTransactionIntegration(basket=basket)
+        bti = basket.basket_transaction_integration
+        if not bti:
+            bti = BasketTransactionIntegration(basket=basket)
+        return bti

nau_extensions/settings/test.py

@@ -2,3 +2,5 @@
 Test settings for the ecommerce nau extensions
 """
 from ecommerce.settings.test import *
+
+INSTALLED_APPS += ("nau_extensions",)

nau_extensions/tests/test_models.py

@@ -0,0 +1,27 @@
+from nau_extensions.models import BasketTransactionIntegration
+from oscar.test import factories
+
+from ecommerce.extensions.test.factories import create_basket, create_order
+from ecommerce.tests.factories import UserFactory
+from ecommerce.tests.testcases import TestCase
+
+
+class ModelsNAUExtensionsTests(TestCase):
+    """
+    This class aims to test the specifics of the nau extensions project related to django models.
+    """
+
+    def setUp(self):
+        super(ModelsNAUExtensionsTests, self).setUp()
+        self.order = create_order(user=UserFactory())
+        self.order.save()
+        self.order.basket.save()
+
+    def test_basket_integration_integration_create_second(self):
+        """
+        Test the creation of a second `BasketTransactionIntegration` for same basket/order.
+        """
+        BasketTransactionIntegration.create(self.order.basket)
+
+        # the 2nd call on create should fail
+        BasketTransactionIntegration.create(self.order.basket)