Can't set the value of a DateTimeField with auto_now or auto_now_add #23

 (#451)


---------

Co-authored-by: Rust Saiargaliev <fly.amureki@gmail.com>

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased](https://github.com/model-bakers/model_bakery/tree/main)
 
 ### Added
+- Add support to `auto_now` and `auto_now_add` fields.
 
 ### Changed
 - Remove unnecessary casting to string methods random_gen.gen_slug and random_gen.gen_string

model_bakery/baker.py

@@ -498,17 +498,30 @@ def instance(
         self, attrs: Dict[str, Any], _commit, _save_kwargs, _from_manager
     ) -> M:
         one_to_many_keys = {}
+        auto_now_keys = {}
+
         for k in tuple(attrs.keys()):
             field = getattr(self.model, k, None)
+
+            if not field:
+                continue
+
             if isinstance(field, ForeignRelatedObjectsDescriptor):
                 one_to_many_keys[k] = attrs.pop(k)
 
+            if hasattr(field, "field") and (
+                getattr(field.field, "auto_now_add", False)
+                or getattr(field.field, "auto_now", False)
+            ):
+                auto_now_keys[k] = attrs[k]
+
         instance = self.model(**attrs)
         # m2m only works for persisted instances
         if _commit:
             instance.save(**_save_kwargs)
             self._handle_one_to_many(instance, one_to_many_keys)
             self._handle_m2m(instance)
+            self._handle_auto_now(instance, auto_now_keys)
 
             if _from_manager:
                 # Fetch the instance using the given Manager, e.g.
@@ -609,6 +622,12 @@ def _skip_field(self, field: Field) -> bool:
 
         return False
 
+    def _handle_auto_now(self, instance: Model, attrs: Dict[str, Any]):
+        if not attrs:
+            return
+
+        instance.__class__.objects.filter(pk=instance.pk).update(**attrs)
+
     def _handle_one_to_many(self, instance: Model, attrs: Dict[str, Any]):
         for key, values in attrs.items():
             manager = getattr(instance, key)

tests/generic/models.py

@@ -472,3 +472,9 @@ class Issue291Model3(models.Model):
         Issue291Model2, related_name="bazs", on_delete=models.CASCADE
     )
     name = models.CharField(max_length=32)
+
+
+class ModelWithAutoNowFields(models.Model):
+    sent_date = models.DateTimeField()
+    created = models.DateTimeField(auto_now_add=True)
+    updated = models.DateTimeField(auto_now=True)

tests/test_baker.py

@@ -1069,3 +1069,26 @@ def test_seed(self, reset_seed):
     @pytest.mark.django_db
     def test_unseeded(self):
         assert baker.Baker._global_seed is baker.Baker.SENTINEL
+
+
+class TestAutoNowFields:
+    @pytest.mark.django_db
+    @pytest.mark.parametrize("use_tz", [False, True])
+    def test_make_with_auto_now(self, use_tz, settings):
+        settings.USE_TZ = use_tz
+        tzinfo = datetime.timezone.utc if use_tz else None
+
+        now = datetime.datetime(2023, 10, 20, 15, 30).replace(tzinfo=tzinfo)
+
+        instance = baker.make(
+            models.ModelWithAutoNowFields,
+            created=now,
+            updated=now,
+            sent_date=now,
+        )
+
+        instance.refresh_from_db()
+
+        assert instance.created == now
+        assert instance.updated == now
+        assert instance.sent_date == now