fix inconsistencies in ._changed_fields computation

mongoengine/base/document.py

@@ -537,6 +537,9 @@ class BaseDocument:
         """Using _get_changed_fields iterate and remove any fields that
         are marked as changed.
         """
+        ReferenceField = _import_class("ReferenceField")
+        GenericReferenceField = _import_class("GenericReferenceField")
+
         for changed in self._get_changed_fields():
             parts = changed.split(".")
             data = self
@@ -549,7 +552,8 @@ class BaseDocument:
                 elif isinstance(data, dict):
                     data = data.get(part, None)
                 else:
-                    data = getattr(data, part, None)
+                    field_name = data._reverse_db_field_map.get(part, part)
+                    data = getattr(data, field_name, None)
 
                 if not isinstance(data, LazyReference) and hasattr(
                     data, "_changed_fields"
@@ -558,10 +562,40 @@ class BaseDocument:
                         continue
 
                     data._changed_fields = []
+                elif isinstance(data, (list, tuple, dict)):
+                    if hasattr(data, "field") and isinstance(
+                        data.field, (ReferenceField, GenericReferenceField)
+                    ):
+                        continue
+                    BaseDocument._nestable_types_clear_changed_fields(data)
 
         self._changed_fields = []
 
-    def _nestable_types_changed_fields(self, changed_fields, base_key, data):
+    @staticmethod
+    def _nestable_types_clear_changed_fields(data):
+        """Inspect nested data for changed fields
+
+        :param data: data to inspect for changes
+        """
+        Document = _import_class("Document")
+
+        # Loop list / dict fields as they contain documents
+        # Determine the iterator to use
+        if not hasattr(data, "items"):
+            iterator = enumerate(data)
+        else:
+            iterator = data.items()
+
+        for index_or_key, value in iterator:
+            if hasattr(value, "_get_changed_fields") and not isinstance(
+                value, Document
+            ):  # don't follow references
+                value._clear_changed_fields()
+            elif isinstance(value, (list, tuple, dict)):
+                BaseDocument._nestable_types_clear_changed_fields(value)
+
+    @staticmethod
+    def _nestable_types_changed_fields(changed_fields, base_key, data):
         """Inspect nested data for changed fields
 
         :param changed_fields: Previously collected changed fields
@@ -586,7 +620,9 @@ class BaseDocument:
                 changed = value._get_changed_fields()
                 changed_fields += ["{}{}".format(item_key, k) for k in changed if k]
             elif isinstance(value, (list, tuple, dict)):
-                self._nestable_types_changed_fields(changed_fields, item_key, value)
+                BaseDocument._nestable_types_changed_fields(
+                    changed_fields, item_key, value
+                )
 
     def _get_changed_fields(self):
         """Return a list of all fields that have explicitly been changed.

tests/document/test_delta.py

@@ -537,6 +537,7 @@ class TestDelta(MongoDBTestCase):
             {},
         )
         doc.save()
+        assert doc._get_changed_fields() == []
         doc = doc.reload(10)
 
         assert doc.embedded_field.list_field[0] == "1"
@@ -767,9 +768,7 @@ class TestDelta(MongoDBTestCase):
 
         MyDoc.drop_collection()
 
-        mydoc = MyDoc(
-            name="testcase1", subs={"a": {"b": EmbeddedDoc(name="foo")}}
-        ).save()
+        MyDoc(name="testcase1", subs={"a": {"b": EmbeddedDoc(name="foo")}}).save()
 
         mydoc = MyDoc.objects.first()
         subdoc = mydoc.subs["a"]["b"]
@@ -781,6 +780,35 @@ class TestDelta(MongoDBTestCase):
         mydoc._clear_changed_fields()
         assert [] == mydoc._get_changed_fields()
 
+    def test_nested_nested_fields_db_field_set__gets_mark_as_changed_and_cleaned(self):
+        class EmbeddedDoc(EmbeddedDocument):
+            name = StringField(db_field="db_name")
+
+        class MyDoc(Document):
+            embed = EmbeddedDocumentField(EmbeddedDoc, db_field="db_embed")
+            name = StringField(db_field="db_name")
+
+        MyDoc.drop_collection()
+
+        MyDoc(name="testcase1", embed=EmbeddedDoc(name="foo")).save()
+
+        mydoc = MyDoc.objects.first()
+        mydoc.embed.name = "foo1"
+
+        assert mydoc.embed._get_changed_fields() == ["db_name"]
+        assert mydoc._get_changed_fields() == ["db_embed.db_name"]
+
+        mydoc = MyDoc.objects.first()
+        embed = EmbeddedDoc(name="foo2")
+        embed.name = "bar"
+        mydoc.embed = embed
+
+        assert embed._get_changed_fields() == ["db_name"]
+        assert mydoc._get_changed_fields() == ["db_embed"]
+
+        mydoc._clear_changed_fields()
+        assert mydoc._get_changed_fields() == []
+
     def test_lower_level_mark_as_changed(self):
         class EmbeddedDoc(EmbeddedDocument):
             name = StringField()

tests/test_dereference.py

@@ -370,8 +370,7 @@ class FieldTest(unittest.TestCase):
         assert Post.objects.all()[0].user_lists == [[u1, u2], [u3]]
 
     def test_circular_reference(self):
-        """Ensure you can handle circular references
-        """
+        """Ensure you can handle circular references"""
 
         class Relation(EmbeddedDocument):
             name = StringField()
@@ -426,6 +425,7 @@ class FieldTest(unittest.TestCase):
 
         daughter.relations.append(mother)
         daughter.relations.append(daughter)
+        assert daughter._get_changed_fields() == ["relations"]
         daughter.save()
 
         assert "[<Person: Mother>, <Person: Daughter>]" == "%s" % Person.objects()