Fix update on save() for fields

docs/fields.md

@@ -180,9 +180,9 @@ class MyModel(saffier.Model):
 
 ##### Parameters
 
-* **auto_now** - A boolean indicating the `auto_now` enabled.
-* **auto_now_add** - A boolean indicating the `auto_now_add` enabled.
-
+* **auto_now** - A boolean indicating the `auto_now` enabled. Useful for auto updates.
+* **auto_now_add** - A boolean indicating the `auto_now_add` enabled. This will ensure that its
+only added once.
 
 #### DateTimeField
 
@@ -199,9 +199,9 @@ class MyModel(saffier.Model):
 
 ##### Parameters
 
-* **auto_now** - A boolean indicating the `auto_now` enabled.
-* **auto_now_add** - A boolean indicating the `auto_now_add` enabled.
-
+* **auto_now** - A boolean indicating the `auto_now` enabled. Useful for auto updates.
+* **auto_now_add** - A boolean indicating the `auto_now_add` enabled. This will ensure that its
+only added once.
 
 #### DecimalField
 

saffier/core/db/models/model.py

@@ -119,17 +119,8 @@ async def _save(self, **kwargs: typing.Any) -> "Model":
         saffier_setattr(self, self.pkname, awaitable)
         return self
 
-    async def _update(self, **kwargs: typing.Any) -> typing.Any:
-        """
-        Performs the save instruction.
-        """
-        pk_column = getattr(self.table.c, self.pkname)
-        expression = self.table.update().values(**kwargs).where(pk_column == self.pk)
-        awaitable = await self.database.execute(expression)
-        return awaitable
-
     async def save(
-        self: typing.Any,
+        self,
         force_save: bool = False,
         values: typing.Any = None,
         **kwargs: typing.Any,
@@ -162,7 +153,7 @@ async def save(
             await self._save(**kwargs)
         else:
             await self.signals.pre_update.send(sender=self.__class__, instance=self, kwargs=kwargs)
-            await self._update(**kwargs)
+            await self.update(**kwargs)
             await self.signals.post_update.send(sender=self.__class__, instance=self)
 
         # Refresh the results

tests/models/test_datetime.py

@@ -0,0 +1,66 @@
+import datetime
+import time
+
+import pytest
+
+import saffier
+from saffier.testclient import DatabaseTestClient as Database
+from tests.settings import DATABASE_URL
+
+database = Database(url=DATABASE_URL)
+models = saffier.Registry(database=database)
+
+pytestmark = pytest.mark.anyio
+
+
+class User(saffier.Model):
+    name: str = saffier.CharField(max_length=255, secret=True)
+    created_at: datetime.datetime = saffier.DateTimeField(auto_now_add=True)
+    updated_at: datetime.datetime = saffier.DateTimeField(auto_now=True)
+
+    class Meta:
+        registry = models
+
+
+@pytest.fixture(autouse=True, scope="module")
+async def create_test_database():
+    await models.create_all()
+    yield
+    await models.drop_all()
+
+
+@pytest.fixture(autouse=True)
+async def rollback_transactions():
+    with database.force_rollback():
+        async with database:
+            yield
+
+
+async def test_creates_and_updates_only_updated_at():
+    user = await User.query.create(name="Test")
+
+    last_created_datetime = user.created_at
+    last_updated_datetime = user.updated_at
+
+    time.sleep(2)
+
+    await user.update(name="Test 2")
+
+    assert user.created_at == last_created_datetime
+    assert user.updated_at != last_updated_datetime
+
+
+async def test_creates_and_updates_only_updated_at_on_save():
+    user = await User.query.create(name="Test")
+
+    last_created_datetime = user.created_at
+    last_updated_datetime = user.updated_at
+
+    time.sleep(2)
+
+    user.name = "Test 2"
+    await user.save()
+
+    assert user.name == "Test 2"
+    assert user.created_at == last_created_datetime
+    assert user.updated_at != last_updated_datetime