fix: ensure updates to product attributes are persisted during updates

ecommerce/entitlements/tests/test_utils.py

@@ -23,20 +23,22 @@ def test_course_entitlement_creation(self):
 
     def test_course_entitlement_update(self):
         """ Test course entitlement product update """
+        original_variant_id = '00000000-0000-0000-0000-000000000000'
         product = create_or_update_course_entitlement(
-            'verified', 100, self.partner, 'foo-bar', 'Foo Bar Entitlement')
+            'verified', 100, self.partner, 'foo-bar', 'Foo Bar Entitlement', variant_id=original_variant_id)
+        assert product.attr.variant_id == original_variant_id
         stock_record = StockRecord.objects.get(product=product, partner=self.partner)
 
         self.assertEqual(stock_record.price_excl_tax, 100)
         self.assertEqual(product.title, 'Course Foo Bar Entitlement')
 
-        variant_id = '00000000-0000-0000-0000-000000000000'
+        new_variant_id = '11111111-1111-1111-1111-11111111'
         product = create_or_update_course_entitlement(
-            'verified', 200, self.partner, 'foo-bar', 'Foo Bar Entitlement', variant_id=variant_id)
+            'verified', 200, self.partner, 'foo-bar', 'Foo Bar Entitlement', variant_id=new_variant_id)
 
         stock_record = StockRecord.objects.get(product=product, partner=self.partner)
         self.assertEqual(stock_record.price_excl_tax, 200)
         self.assertEqual(stock_record.price_excl_tax, 200)
 
         product.refresh_from_db()
-        assert product.attr.variant_id == '00000000-0000-0000-0000-000000000000'
+        assert product.attr.variant_id == new_variant_id

ecommerce/entitlements/utils.py

@@ -62,10 +62,12 @@ def create_or_update_course_entitlement(
     """ Create or Update Course Entitlement Products """
     certificate_type = certificate_type.lower()
     UUID = str(UUID)
+    has_existing_course_entitlement = False
 
     try:
         parent_entitlement, __ = create_parent_course_entitlement(title, UUID)
         course_entitlement = get_entitlement(UUID, certificate_type)
+        has_existing_course_entitlement = True
     except Product.DoesNotExist:
         course_entitlement = Product()
 
@@ -79,6 +81,11 @@ def create_or_update_course_entitlement(
     course_entitlement.parent = parent_entitlement
     if variant_id:
         course_entitlement.attr.variant_id = variant_id
+    if has_existing_course_entitlement:
+        # Calling `save` on the attributes is necessary for any updates to persist. This is not necessary
+        # for new attributes, only for existing attributes. This `save` method must be called before saving
+        # the associated course entitlement below.
+        course_entitlement.attr.save()
     course_entitlement.save()
 
     __, created = StockRecord.objects.update_or_create(