_prepare_for_put was not being called at entity level (#138)

src/google/cloud/ndb/model.py

@@ -4855,12 +4855,18 @@ def put(self):
 
             return self._key
 
+        self._prepare_for_put()
         future = put(self)
         future.add_done_callback(self._post_put_hook)
         return future
 
     put_async = _put_async
 
+    def _prepare_for_put(self):
+        if self._properties:
+            for prop in self._properties.values():
+                prop._prepare_for_put(self)
+
     @classmethod
     def _query(
         cls,

tests/system/test_crud.py

@@ -15,6 +15,7 @@
 """
 System tests for Create, Update, Delete. (CRUD)
 """
+import datetime
 import functools
 import operator
 import threading
@@ -581,3 +582,21 @@ class Cat(Feline):
     assert isinstance(retrieved, Cat)
 
     dispose_of(key._key)
+
+
+@pytest.mark.usefixtures("client_context")
+def test_insert_autonow_property(dispose_of):
+    class SomeKind(ndb.Model):
+        foo = ndb.StringProperty()
+        created_at = ndb.DateTimeProperty(indexed=True, auto_now_add=True)
+        updated_at = ndb.DateTimeProperty(indexed=True, auto_now=True)
+
+    entity = SomeKind(foo="bar")
+    key = entity.put()
+
+    retrieved = key.get()
+
+    assert isinstance(retrieved.created_at, datetime.datetime)
+    assert isinstance(retrieved.updated_at, datetime.datetime)
+
+    dispose_of(key._key)

tests/unit/test_model.py

@@ -3684,6 +3684,19 @@ def test__put_async(_datastore_api):
             entity_pb, _options.Options()
         )
 
+    @staticmethod
+    @pytest.mark.usefixtures("in_context")
+    def test__prepare_for_put():
+        class Simple(model.Model):
+            foo = model.DateTimeProperty()
+
+        entity = Simple(foo=datetime.datetime.now())
+        with unittest.mock.patch.object(
+            entity._properties["foo"], "_prepare_for_put"
+        ) as patched:
+            entity._prepare_for_put()
+            patched.assert_called_once()
+
     @staticmethod
     @pytest.mark.usefixtures("in_context")
     @unittest.mock.patch("google.cloud.ndb.model._datastore_api")