Fix documentation of Queryset.update regarding full_result #1995

docs/changelog.rst

@@ -7,6 +7,7 @@ Development
 - (Fill this out as you fix issues and develop your features).
 - Fix .only() working improperly after using .count() of the same instance of QuerySet
 - POTENTIAL BREAKING CHANGE: All result fields are now passed, including internal fields (_cls, _id) when using `QuerySet.as_pymongo` #1976
+- Document a BREAKING CHANGE introduced in 0.15.3 and not reported at that time (#1995)
 
 =================
 Changes in 0.16.3
@@ -64,6 +65,7 @@ Changes in 0.16.0
 
 Changes in 0.15.3
 =================
+-  BREAKING CHANGES: `Queryset.update/update_one` methods now returns an UpdateResult when `full_result=True` is provided and no longer a dict (relates to #1491)
 -  Subfield resolve error in generic_emdedded_document query #1651 #1652
 -  use each modifier only with $position #1673 #1675
 -  Improve LazyReferenceField and GenericLazyReferenceField with nested fields #1704

mongoengine/queryset/base.py

@@ -498,11 +498,12 @@ class BaseQuerySet(object):
             ``save(..., write_concern={w: 2, fsync: True}, ...)`` will
             wait until at least two servers have recorded the write and
             will force an fsync on the primary server.
-        :param full_result: Return the full result dictionary rather than just the number
+        :param full_result: Return the associated ``pymongo.UpdateResult`` rather than just the number
-            updated, e.g. return
+            updated items
-            ``{'n': 2, 'nModified': 2, 'ok': 1.0, 'updatedExisting': True}``.
         :param update: Django-style update keyword arguments
 
+        :returns the number of updated documents (unless ``full_result`` is True)
+
         .. versionadded:: 0.2
         """
         if not update and not upsert:
@@ -566,7 +567,7 @@ class BaseQuerySet(object):
             document = self._document.objects.with_id(atomic_update.upserted_id)
         return document
 
-    def update_one(self, upsert=False, write_concern=None, **update):
+    def update_one(self, upsert=False, write_concern=None, full_result=False, **update):
         """Perform an atomic update on the fields of the first document
         matched by the query.
 
@@ -577,12 +578,19 @@ class BaseQuerySet(object):
             ``save(..., write_concern={w: 2, fsync: True}, ...)`` will
             wait until at least two servers have recorded the write and
             will force an fsync on the primary server.
+        :param full_result: Return the associated ``pymongo.UpdateResult`` rather than just the number
+            updated items
         :param update: Django-style update keyword arguments
-
+            full_result
+        :returns the number of updated documents (unless ``full_result`` is True)
         .. versionadded:: 0.2
         """
         return self.update(
-            upsert=upsert, multi=False, write_concern=write_concern, **update)
+            upsert=upsert,
+            multi=False,
+            write_concern=write_concern,
+            full_result=full_result,
+            **update)
 
     def modify(self, upsert=False, full_response=False, remove=False, new=False, **update):
         """Update and return the updated document.

tests/queryset/queryset.py

@@ -2233,6 +2233,19 @@ class QuerySetTest(unittest.TestCase):
         bar.reload()
         self.assertEqual(len(bar.foos), 0)
 
+    def test_update_one_check_return_with_full_result(self):
+        class BlogTag(Document):
+            name = StringField(required=True)
+
+        BlogTag.drop_collection()
+
+        BlogTag(name='garbage').save()
+        default_update = BlogTag.objects.update_one(name='new')
+        self.assertEqual(default_update, 1)
+
+        full_result_update = BlogTag.objects.update_one(name='new', full_result=True)
+        self.assertIsInstance(full_result_update, UpdateResult)
+
     def test_update_one_pop_generic_reference(self):
 
         class BlogTag(Document):