Add continue_on_error optional kwarg to QuerySet.insert

.travis.yml

@@ -1,6 +1,3 @@
-# Use a container-based environment
-sudo: false
-
 language: python
 
 python:
@@ -11,41 +8,26 @@ python:
 - pypy
 - pypy3
 
-# Test on PyMongo v2.7.x, v2.8.x, and v3.x
 env:
 - PYMONGO=2.7
 - PYMONGO=2.8
 - PYMONGO=3.0
+- PYMONGO=dev
 
 matrix:
   fast_finish: true
 
-services:
-- mongodb
-
-addons:
-  apt:
-    sources:
-    - mongodb-upstart
-    packages:
-    - mongodb-org-server=2.6.9
-
-    # Optional dependencies for the ImageField and others
-    - python-dev
-    - python3-dev
-    - libopenjpeg-dev
-    - zlib1g-dev
-    - libjpeg-turbo8-dev
-    - libtiff4-dev
-    - libjpeg8-dev
-    - libfreetype6-dev
-    - liblcms2-dev
-    - libwebp-dev
-    - tcl8.5-dev
-    - tk8.5-dev
-    - python-tk
+before_install:
+- travis_retry sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
+- echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' |
+  sudo tee /etc/apt/sources.list.d/mongodb.list
+- travis_retry sudo apt-get update
+- travis_retry sudo apt-get install mongodb-org-server
 
 install:
+- sudo apt-get install python-dev python3-dev libopenjpeg-dev zlib1g-dev libjpeg-turbo8-dev
+  libtiff4-dev libjpeg8-dev libfreetype6-dev liblcms2-dev libwebp-dev tcl8.5-dev tk8.5-dev
+  python-tk
 - travis_retry pip install --upgrade pip
 - travis_retry pip install coveralls
 - travis_retry pip install flake8
@@ -53,9 +35,6 @@ install:
 - travis_retry pip install "virtualenv<14.0.0"  # virtualenv>=14.0.0 has dropped Python 3.2 support (and pypy3 is based on py32)
 - travis_retry tox -e $(echo py$TRAVIS_PYTHON_VERSION-mg$PYMONGO | tr -d . | sed -e 's/pypypy/pypy/') -- -e test
 
-# Cache dependencies installed via pip
-cache: pip
-
 # Run flake8 for py27
 before_script:
 - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then tox -e flake8; fi
@@ -66,7 +45,7 @@ script:
 # For now only submit coveralls for Python v2.7. Python v3.x currently shows
 # 0% coverage. That's caused by 'use_2to3', which builds the py3-compatible
 # code in a separate dir and runs tests on that.
-after_success:
+after_script:
 - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then coveralls --verbose; fi
 
 notifications:
@@ -77,22 +56,11 @@ branches:
   - master
   - /^v.*$/
 
-# Whenever a new release is created via GitHub, publish it on PyPI.
 deploy:
   provider: pypi
   user: the_drow
   password:
     secure: QMyatmWBnC6ZN3XLW2+fTBDU4LQcp1m/LjR2/0uamyeUzWKdlOoh/Wx5elOgLwt/8N9ppdPeG83ose1jOz69l5G0MUMjv8n/RIcMFSpCT59tGYqn3kh55b0cIZXFT9ar+5cxlif6a5rS72IHm5li7QQyxexJIII6Uxp0kpvUmek=
-
-  # create a source distribution and a pure python wheel for faster installs
-  distributions: "sdist bdist_wheel"
-
-  # only deploy on tagged commits (aka GitHub releases) and only for the
-  # parent repo's builds running Python 2.7 along with dev PyMongo (we run
-  # Travis against many different Python and PyMongo versions and we don't
-  # want the deploy to occur multiple times).
   on:
     tags: true
     repo: MongoEngine/mongoengine
-    condition: "$PYMONGO = 3.0"
-    python: 2.7

README.rst

@@ -35,22 +35,16 @@ setup.py install``.
 
 Dependencies
 ============
-All of the dependencies can easily be installed via `pip <https://pip.pypa.io/>`_. At the very least, you'll need these two packages to use MongoEngine:
-
 - pymongo>=2.7.1
-- six>=1.10.0
-
-If you utilize a ``DateTimeField``, you might also use a more flexible date parser:
+- sphinx (optional - for documentation generation)
 
+Optional Dependencies
+---------------------
+- **Image Fields**: Pillow>=2.0.0
 - dateutil>=2.1.0
 
-If you need to use an ``ImageField`` or ``ImageGridFsProxy``:
-
-- Pillow>=2.0.0
-
-If you want to generate the documentation (e.g. to contribute to it):
-
-- sphinx
+.. note
+   MongoEngine always runs it's test suite against the latest patch version of each dependecy. e.g.: PyMongo 3.0.1
 
 Examples
 ========

docs/changelog.rst

@@ -5,8 +5,6 @@ Changelog
 Development
 ===========
 - (Fill this out as you fix issues and develop you features).
-- POTENTIAL BREAKING CHANGE: Fixed limit/skip/hint/batch_size chaining #1476
-- POTENTIAL BREAKING CHANGE: Changed a public `QuerySet.clone_into` method to a private `QuerySet._clone_into` #1476
 - Fixed connecting to a replica set with PyMongo 2.x #1436
 - Fixed an obscure error message when filtering by `field__in=non_iterable`. #1237
 

docs/guide/defining-documents.rst

@@ -361,6 +361,11 @@ Its value can take any of the following constants:
    In Django, be sure to put all apps that have such delete rule declarations in
    their :file:`models.py` in the :const:`INSTALLED_APPS` tuple.
 
+
+.. warning::
+   Signals are not triggered when doing cascading updates / deletes - if this
+   is required you must manually handle the update / delete.
+
 Generic reference fields
 ''''''''''''''''''''''''
 A second kind of reference field also exists,

docs/guide/signals.rst

@@ -142,4 +142,11 @@ cleaner looking while still allowing manual execution of the callback::
         modified = DateTimeField()
 
 
+ReferenceFields and Signals
+---------------------------
+
+Currently `reverse_delete_rule` does not trigger signals on the other part of
+the relationship.  If this is required you must manually handle the
+reverse deletion.
+
 .. _blinker: http://pypi.python.org/pypi/blinker

docs/upgrade.rst

@@ -2,20 +2,6 @@
 Upgrading
 #########
 
-Development
-***********
-(Fill this out whenever you introduce breaking changes to MongoEngine)
-
-This release includes various fixes for the `BaseQuerySet` methods and how they
-are chained together. Since version 0.10.1 applying limit/skip/hint/batch_size
-to an already-existing queryset wouldn't modify the underlying PyMongo cursor.
-This has been fixed now, so you'll need to make sure that your code didn't rely
-on the broken implementation.
-
-Additionally, a public `BaseQuerySet.clone_into` has been renamed to a private
-`_clone_into`. If you directly used that method in your code, you'll need to
-rename its occurrences.
-
 0.11.0
 ******
 This release includes a major rehaul of MongoEngine's code quality and

mongoengine/fields.py

@@ -888,6 +888,10 @@ class ReferenceField(BaseField):
 
         Foo.register_delete_rule(Bar, 'foo', NULLIFY)
 
+    .. note ::
+        `reverse_delete_rule` does not trigger pre / post delete signals to be
+        triggered.
+
     .. versionchanged:: 0.5 added `reverse_delete_rule`
     """
 

mongoengine/queryset/base.py

@@ -86,7 +86,6 @@ class BaseQuerySet(object):
         self._batch_size = None
         self.only_fields = []
         self._max_time_ms = None
-        self._comment = None
 
     def __call__(self, q_obj=None, class_check=True, read_preference=None,
                  **query):
@@ -297,22 +296,25 @@ class BaseQuerySet(object):
             result = None
         return result
 
-    def insert(self, doc_or_docs, load_bulk=True,
-               write_concern=None, signal_kwargs=None):
+    def insert(self, doc_or_docs, load_bulk=True, write_concern=None,
+               signal_kwargs=None, continue_on_error=None):
         """bulk insert documents
 
         :param doc_or_docs: a document or list of documents to be inserted
         :param load_bulk (optional): If True returns the list of document
             instances
-        :param write_concern: Extra keyword arguments are passed down to
-                :meth:`~pymongo.collection.Collection.insert`
-                which will be used as options for the resultant
-                ``getLastError`` command.  For example,
-                ``insert(..., {w: 2, fsync: True})`` will wait until at least
-                two servers have recorded the write and will force an fsync on
-                each server being written to.
+        :param write_concern: Optional keyword argument passed down to
+                :meth:`~pymongo.collection.Collection.insert`, representing
+                the write concern. For example,
+                ``insert(..., write_concert={w: 2, fsync: True})`` will
+                wait until at least two servers have recorded the write
+                and will force an fsync on each server being written to.
         :parm signal_kwargs: (optional) kwargs dictionary to be passed to
             the signal calls.
+        :param continue_on_error: Optional keyword argument passed down to
+                :meth:`~pymongo.collection.Collection.insert`. Defines what
+                to do when a document cannot be inserted (e.g. due to
+                duplicate IDs). Read PyMongo's docs for more info.
 
         By default returns document instances, set ``load_bulk`` to False to
         return just ``ObjectIds``
@@ -323,12 +325,10 @@ class BaseQuerySet(object):
         """
         Document = _import_class('Document')
 
-        if write_concern is None:
-            write_concern = {}
-
+        # Determine if we're inserting one doc or more
         docs = doc_or_docs
         return_one = False
-        if isinstance(docs, Document) or issubclass(docs.__class__, Document):
+        if isinstance(docs, Document):
             return_one = True
             docs = [docs]
 
@@ -345,9 +345,16 @@ class BaseQuerySet(object):
         signals.pre_bulk_insert.send(self._document,
                                      documents=docs, **signal_kwargs)
 
+        # Resolve optional insert kwargs
+        insert_kwargs = {}
+        if write_concern is not None:
+            insert_kwargs.update(write_concern)
+        if continue_on_error is not None:
+            insert_kwargs['continue_on_error'] = continue_on_error
+
         raw = [doc.to_mongo() for doc in docs]
         try:
-            ids = self._collection.insert(raw, **write_concern)
+            ids = self._collection.insert(raw, **insert_kwargs)
         except pymongo.errors.DuplicateKeyError as err:
             message = 'Could not save document (%s)'
             raise NotUniqueError(message % six.text_type(err))
@@ -707,36 +714,39 @@ class BaseQuerySet(object):
         with switch_db(self._document, alias) as cls:
             collection = cls._get_collection()
 
-        return self._clone_into(self.__class__(self._document, collection))
+        return self.clone_into(self.__class__(self._document, collection))
 
     def clone(self):
-        """Create a copy of the current queryset."""
-        return self._clone_into(self.__class__(self._document, self._collection_obj))
+        """Creates a copy of the current
+          :class:`~mongoengine.queryset.QuerySet`
 
-    def _clone_into(self, new_qs):
-        """Copy all of the relevant properties of this queryset to
-        a new queryset (which has to be an instance of
-        :class:`~mongoengine.queryset.base.BaseQuerySet`).
+        .. versionadded:: 0.5
         """
-        if not isinstance(new_qs, BaseQuerySet):
+        return self.clone_into(self.__class__(self._document, self._collection_obj))
+
+    def clone_into(self, cls):
+        """Creates a copy of the current
+          :class:`~mongoengine.queryset.base.BaseQuerySet` into another child class
+        """
+        if not isinstance(cls, BaseQuerySet):
             raise OperationError(
-                '%s is not a subclass of BaseQuerySet' % new_qs.__name__)
+                '%s is not a subclass of BaseQuerySet' % cls.__name__)
 
         copy_props = ('_mongo_query', '_initial_query', '_none', '_query_obj',
                       '_where_clause', '_loaded_fields', '_ordering', '_snapshot',
                       '_timeout', '_class_check', '_slave_okay', '_read_preference',
                       '_iter', '_scalar', '_as_pymongo', '_as_pymongo_coerce',
                       '_limit', '_skip', '_hint', '_auto_dereference',
-                      '_search_text', 'only_fields', '_max_time_ms', '_comment')
+                      '_search_text', 'only_fields', '_max_time_ms')
 
         for prop in copy_props:
             val = getattr(self, prop)
-            setattr(new_qs, prop, copy.copy(val))
+            setattr(cls, prop, copy.copy(val))
 
         if self._cursor_obj:
-            new_qs._cursor_obj = self._cursor_obj.clone()
+            cls._cursor_obj = self._cursor_obj.clone()
 
-        return new_qs
+        return cls
 
     def select_related(self, max_depth=1):
         """Handles dereferencing of :class:`~bson.dbref.DBRef` objects or
@@ -758,11 +768,7 @@ class BaseQuerySet(object):
         """
         queryset = self.clone()
         queryset._limit = n if n != 0 else 1
-
-        # If a cursor object has already been created, apply the limit to it.
-        if queryset._cursor_obj:
-            queryset._cursor_obj.limit(queryset._limit)
-
+        # Return self to allow chaining
         return queryset
 
     def skip(self, n):
@@ -773,11 +779,6 @@ class BaseQuerySet(object):
         """
         queryset = self.clone()
         queryset._skip = n
-
-        # If a cursor object has already been created, apply the skip to it.
-        if queryset._cursor_obj:
-            queryset._cursor_obj.skip(queryset._skip)
-
         return queryset
 
     def hint(self, index=None):
@@ -795,11 +796,6 @@ class BaseQuerySet(object):
         """
         queryset = self.clone()
         queryset._hint = index
-
-        # If a cursor object has already been created, apply the hint to it.
-        if queryset._cursor_obj:
-            queryset._cursor_obj.hint(queryset._hint)
-
         return queryset
 
     def batch_size(self, size):
@@ -813,11 +809,6 @@ class BaseQuerySet(object):
         """
         queryset = self.clone()
         queryset._batch_size = size
-
-        # If a cursor object has already been created, apply the batch size to it.
-        if queryset._cursor_obj:
-            queryset._cursor_obj.batch_size(queryset._batch_size)
-
         return queryset
 
     def distinct(self, field):
@@ -989,31 +980,13 @@ class BaseQuerySet(object):
     def order_by(self, *keys):
         """Order the :class:`~mongoengine.queryset.QuerySet` by the keys. The
         order may be specified by prepending each of the keys by a + or a -.
-        Ascending order is assumed. If no keys are passed, existing ordering
-        is cleared instead.
+        Ascending order is assumed.
 
         :param keys: fields to order the query results by; keys may be
             prefixed with **+** or **-** to determine the ordering direction
         """
         queryset = self.clone()
-
-        old_ordering = queryset._ordering
-        new_ordering = queryset._get_order_by(keys)
-
-        if queryset._cursor_obj:
-
-            # If a cursor object has already been created, apply the sort to it
-            if new_ordering:
-                queryset._cursor_obj.sort(new_ordering)
-
-            # If we're trying to clear a previous explicit ordering, we need
-            # to clear the cursor entirely (because PyMongo doesn't allow
-            # clearing an existing sort on a cursor).
-            elif old_ordering:
-                queryset._cursor_obj = None
-
-        queryset._ordering = new_ordering
-
+        queryset._ordering = queryset._get_order_by(keys)
         return queryset
 
     def comment(self, text):
@@ -1459,13 +1432,10 @@ class BaseQuerySet(object):
             raise StopIteration
 
         raw_doc = self._cursor.next()
-
         if self._as_pymongo:
             return self._get_as_pymongo(raw_doc)
-
-        doc = self._document._from_son(
-            raw_doc, _auto_dereference=self._auto_dereference,
-            only_fields=self.only_fields)
+        doc = self._document._from_son(raw_doc,
+                                       _auto_dereference=self._auto_dereference, only_fields=self.only_fields)
 
         if self._scalar:
             return self._get_scalar(doc)
@@ -1475,6 +1445,7 @@ class BaseQuerySet(object):
     def rewind(self):
         """Rewind the cursor to its unevaluated state.
 
+
         .. versionadded:: 0.3
         """
         self._iter = False
@@ -1524,54 +1495,43 @@ class BaseQuerySet(object):
 
     @property
     def _cursor(self):
-        """Return a PyMongo cursor object corresponding to this queryset."""
+        if self._cursor_obj is None:
 
-        # If _cursor_obj already exists, return it immediately.
-        if self._cursor_obj is not None:
-            return self._cursor_obj
+            # In PyMongo 3+, we define the read preference on a collection
+            # level, not a cursor level. Thus, we need to get a cloned
+            # collection object using `with_options` first.
+            if IS_PYMONGO_3 and self._read_preference is not None:
+                self._cursor_obj = self._collection\
+                    .with_options(read_preference=self._read_preference)\
+                    .find(self._query, **self._cursor_args)
+            else:
+                self._cursor_obj = self._collection.find(self._query,
+                                                         **self._cursor_args)
+            # Apply where clauses to cursor
+            if self._where_clause:
+                where_clause = self._sub_js_fields(self._where_clause)
+                self._cursor_obj.where(where_clause)
 
-        # Create a new PyMongo cursor.
-        # XXX In PyMongo 3+, we define the read preference on a collection
-        # level, not a cursor level. Thus, we need to get a cloned collection
-        # object using `with_options` first.
-        if IS_PYMONGO_3 and self._read_preference is not None:
-            self._cursor_obj = self._collection\
-                .with_options(read_preference=self._read_preference)\
-                .find(self._query, **self._cursor_args)
-        else:
-            self._cursor_obj = self._collection.find(self._query,
-                                                     **self._cursor_args)
-        # Apply "where" clauses to cursor
-        if self._where_clause:
-            where_clause = self._sub_js_fields(self._where_clause)
-            self._cursor_obj.where(where_clause)
+            if self._ordering:
+                # Apply query ordering
+                self._cursor_obj.sort(self._ordering)
+            elif self._ordering is None and self._document._meta['ordering']:
+                # Otherwise, apply the ordering from the document model, unless
+                # it's been explicitly cleared via order_by with no arguments
+                order = self._get_order_by(self._document._meta['ordering'])
+                self._cursor_obj.sort(order)
 
-        # Apply ordering to the cursor.
-        # XXX self._ordering can be equal to:
-        # * None if we didn't explicitly call order_by on this queryset.
-        # * A list of PyMongo-style sorting tuples.
-        # * An empty list if we explicitly called order_by() without any
-        #   arguments. This indicates that we want to clear the default
-        #   ordering.
-        if self._ordering:
-            # explicit ordering
-            self._cursor_obj.sort(self._ordering)
-        elif self._ordering is None and self._document._meta['ordering']:
-            # default ordering
-            order = self._get_order_by(self._document._meta['ordering'])
-            self._cursor_obj.sort(order)
+            if self._limit is not None:
+                self._cursor_obj.limit(self._limit)
 
-        if self._limit is not None:
-            self._cursor_obj.limit(self._limit)
+            if self._skip is not None:
+                self._cursor_obj.skip(self._skip)
 
-        if self._skip is not None:
-            self._cursor_obj.skip(self._skip)
+            if self._hint != -1:
+                self._cursor_obj.hint(self._hint)
 
-        if self._hint != -1:
-            self._cursor_obj.hint(self._hint)
-
-        if self._batch_size is not None:
-            self._cursor_obj.batch_size(self._batch_size)
+            if self._batch_size is not None:
+                self._cursor_obj.batch_size(self._batch_size)
 
         return self._cursor_obj
 
@@ -1746,13 +1706,7 @@ class BaseQuerySet(object):
         return ret
 
     def _get_order_by(self, keys):
-        """Given a list of MongoEngine-style sort keys, return a list
-        of sorting tuples that can be applied to a PyMongo cursor. For
-        example:
-
-        >>> qs._get_order_by(['-last_name', 'first_name'])
-        [('last_name', -1), ('first_name', 1)]
-        """
+        """Creates a list of order by fields"""
         key_list = []
         for key in keys:
             if not key:
@@ -1765,19 +1719,17 @@ class BaseQuerySet(object):
             direction = pymongo.ASCENDING
             if key[0] == '-':
                 direction = pymongo.DESCENDING
-
             if key[0] in ('-', '+'):
                 key = key[1:]
-
             key = key.replace('__', '.')
             try:
                 key = self._document._translate_field_name(key)
             except Exception:
-                # TODO this exception should be more specific
                 pass
-
             key_list.append((key, direction))
 
+        if self._cursor_obj and key_list:
+            self._cursor_obj.sort(key_list)
         return key_list
 
     def _get_scalar(self, doc):
@@ -1875,21 +1827,10 @@ class BaseQuerySet(object):
         return code
 
     def _chainable_method(self, method_name, val):
-        """Call a particular method on the PyMongo cursor call a particular chainable method
-        with the provided value.
-        """
         queryset = self.clone()
-
-        # Get an existing cursor object or create a new one
-        cursor = queryset._cursor
-
-        # Find the requested method on the cursor and call it with the
-        # provided value
-        getattr(cursor, method_name)(val)
-
-        # Cache the value on the queryset._{method_name}
+        method = getattr(queryset._cursor, method_name)
+        method(val)
         setattr(queryset, '_' + method_name, val)
-
         return queryset
 
     # Deprecated

mongoengine/queryset/queryset.py

@@ -136,15 +136,13 @@ class QuerySet(BaseQuerySet):
         return self._len
 
     def no_cache(self):
-        """Convert to a non-caching queryset
+        """Convert to a non_caching queryset
 
         .. versionadded:: 0.8.3 Convert to non caching queryset
         """
         if self._result_cache is not None:
             raise OperationError('QuerySet already cached')
-
-        return self._clone_into(QuerySetNoCache(self._document,
-                                                self._collection))
+        return self.clone_into(QuerySetNoCache(self._document, self._collection))
 
 
 class QuerySetNoCache(BaseQuerySet):
@@ -155,7 +153,7 @@ class QuerySetNoCache(BaseQuerySet):
 
         .. versionadded:: 0.8.3 Convert to caching queryset
         """
-        return self._clone_into(QuerySet(self._document, self._collection))
+        return self.clone_into(QuerySet(self._document, self._collection))
 
     def __repr__(self):
         """Provides the string representation of the QuerySet

tests/queryset/queryset.py

@@ -106,111 +106,58 @@ class QuerySetTest(unittest.TestCase):
             list(BlogPost.objects(author2__name="test"))
 
     def test_find(self):
-        """Ensure that a query returns a valid set of results."""
-        user_a = self.Person.objects.create(name='User A', age=20)
-        user_b = self.Person.objects.create(name='User B', age=30)
+        """Ensure that a query returns a valid set of results.
+        """
+        self.Person(name="User A", age=20).save()
+        self.Person(name="User B", age=30).save()
 
         # Find all people in the collection
         people = self.Person.objects
         self.assertEqual(people.count(), 2)
         results = list(people)
-
         self.assertTrue(isinstance(results[0], self.Person))
         self.assertTrue(isinstance(results[0].id, (ObjectId, str, unicode)))
-
-        self.assertEqual(results[0], user_a)
-        self.assertEqual(results[0].name, 'User A')
+        self.assertEqual(results[0].name, "User A")
         self.assertEqual(results[0].age, 20)
-
-        self.assertEqual(results[1], user_b)
-        self.assertEqual(results[1].name, 'User B')
+        self.assertEqual(results[1].name, "User B")
         self.assertEqual(results[1].age, 30)
 
-        # Filter people by age
+        # Use a query to filter the people found to just person1
         people = self.Person.objects(age=20)
         self.assertEqual(people.count(), 1)
         person = people.next()
-        self.assertEqual(person, user_a)
         self.assertEqual(person.name, "User A")
         self.assertEqual(person.age, 20)
 
-    def test_limit(self):
-        """Ensure that QuerySet.limit works as expected."""
-        user_a = self.Person.objects.create(name='User A', age=20)
-        user_b = self.Person.objects.create(name='User B', age=30)
-
-        # Test limit on a new queryset
+        # Test limit
         people = list(self.Person.objects.limit(1))
         self.assertEqual(len(people), 1)
-        self.assertEqual(people[0], user_a)
+        self.assertEqual(people[0].name, 'User A')
 
-        # Test limit on an existing queryset
-        people = self.Person.objects
-        self.assertEqual(len(people), 2)
-        people2 = people.limit(1)
-        self.assertEqual(len(people), 2)
-        self.assertEqual(len(people2), 1)
-        self.assertEqual(people2[0], user_a)
-
-        # Test chaining of only after limit
-        person = self.Person.objects().limit(1).only('name').first()
-        self.assertEqual(person, user_a)
-        self.assertEqual(person.name, 'User A')
-        self.assertEqual(person.age, None)
-
-    def test_skip(self):
-        """Ensure that QuerySet.skip works as expected."""
-        user_a = self.Person.objects.create(name='User A', age=20)
-        user_b = self.Person.objects.create(name='User B', age=30)
-
-        # Test skip on a new queryset
+        # Test skip
         people = list(self.Person.objects.skip(1))
         self.assertEqual(len(people), 1)
-        self.assertEqual(people[0], user_b)
+        self.assertEqual(people[0].name, 'User B')
 
-        # Test skip on an existing queryset
-        people = self.Person.objects
-        self.assertEqual(len(people), 2)
-        people2 = people.skip(1)
-        self.assertEqual(len(people), 2)
-        self.assertEqual(len(people2), 1)
-        self.assertEqual(people2[0], user_b)
-
-        # Test chaining of only after skip
-        person = self.Person.objects().skip(1).only('name').first()
-        self.assertEqual(person, user_b)
-        self.assertEqual(person.name, 'User B')
-        self.assertEqual(person.age, None)
-
-    def test_slice(self):
-        """Ensure slicing a queryset works as expected."""
-        user_a = self.Person.objects.create(name='User A', age=20)
-        user_b = self.Person.objects.create(name='User B', age=30)
-        user_c = self.Person.objects.create(name="User C", age=40)
+        person3 = self.Person(name="User C", age=40)
+        person3.save()
 
         # Test slice limit
         people = list(self.Person.objects[:2])
         self.assertEqual(len(people), 2)
-        self.assertEqual(people[0], user_a)
-        self.assertEqual(people[1], user_b)
+        self.assertEqual(people[0].name, 'User A')
+        self.assertEqual(people[1].name, 'User B')
 
         # Test slice skip
         people = list(self.Person.objects[1:])
         self.assertEqual(len(people), 2)
-        self.assertEqual(people[0], user_b)
-        self.assertEqual(people[1], user_c)
+        self.assertEqual(people[0].name, 'User B')
+        self.assertEqual(people[1].name, 'User C')
 
         # Test slice limit and skip
         people = list(self.Person.objects[1:2])
         self.assertEqual(len(people), 1)
-        self.assertEqual(people[0], user_b)
-
-        # Test slice limit and skip on an existing queryset
-        people = self.Person.objects
-        self.assertEqual(len(people), 3)
-        people2 = people[1:2]
-        self.assertEqual(len(people2), 1)
-        self.assertEqual(people2[0], user_b)
+        self.assertEqual(people[0].name, 'User B')
 
         # Test slice limit and skip cursor reset
         qs = self.Person.objects[1:2]
@@ -221,7 +168,6 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(len(people), 1)
         self.assertEqual(people[0].name, 'User B')
 
-        # Test empty slice
         people = list(self.Person.objects[1:1])
         self.assertEqual(len(people), 0)
 
@@ -241,6 +187,12 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual("[<Person: Person object>, <Person: Person object>]",
                          "%s" % self.Person.objects[51:53])
 
+        # Test only after limit
+        self.assertEqual(self.Person.objects().limit(2).only('name')[0].age, None)
+
+        # Test only after skip
+        self.assertEqual(self.Person.objects().skip(2).only('name')[0].age, None)
+
     def test_find_one(self):
         """Ensure that a query using find_one returns a valid result.
         """
@@ -814,8 +766,7 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(record.embed.field, 2)
 
     def test_bulk_insert(self):
-        """Ensure that bulk insert works
-        """
+        """Ensure that bulk insert works."""
 
         class Comment(EmbeddedDocument):
             name = StringField()
@@ -933,9 +884,37 @@ class QuerySetTest(unittest.TestCase):
 
         self.assertEqual(Blog.objects.count(), 2)
 
-        Blog.objects.insert([blog2, blog3],
-                            write_concern={"w": 0, 'continue_on_error': True})
-        self.assertEqual(Blog.objects.count(), 3)
+    def test_bulk_insert_continue_on_error(self):
+        """Ensure that bulk insert works with the continue_on_error option."""
+
+        class Person(Document):
+            email = EmailField(unique=True)
+
+        Person.drop_collection()
+
+        Person.objects.insert([
+            Person(email='alice@example.com'),
+            Person(email='bob@example.com')
+        ])
+        self.assertEqual(Person.objects.count(), 2)
+
+        new_docs = [
+            Person(email='alice@example.com'),  # dupe
+            Person(email='bob@example.com'),  # dupe
+            Person(email='steve@example.com')  # new one
+        ]
+
+        # By default inserting dupe docs should fail and no new docs should
+        # be inserted.
+        with self.assertRaises(NotUniqueError):
+            Person.objects.insert(new_docs)
+        self.assertEqual(Person.objects.count(), 2)
+
+        # With continue_on_error, new doc should be inserted, even though we
+        # still get a NotUniqueError caused by the other 2 dupes.
+        with self.assertRaises(NotUniqueError):
+            Person.objects.insert(new_docs, continue_on_error=True)
+        self.assertEqual(Person.objects.count(), 3)
 
     def test_get_changed_fields_query_count(self):
 
@@ -1274,7 +1253,6 @@ class QuerySetTest(unittest.TestCase):
 
         BlogPost.drop_collection()
 
-        # default ordering should be used by default
         with db_ops_tracker() as q:
             BlogPost.objects.filter(title='whatever').first()
             self.assertEqual(len(q.get_ops()), 1)
@@ -1283,28 +1261,11 @@ class QuerySetTest(unittest.TestCase):
                 {'published_date': -1}
             )
 
-        # calling order_by() should clear the default ordering
         with db_ops_tracker() as q:
             BlogPost.objects.filter(title='whatever').order_by().first()
             self.assertEqual(len(q.get_ops()), 1)
             self.assertFalse('$orderby' in q.get_ops()[0]['query'])
 
-        # calling an explicit order_by should use a specified sort
-        with db_ops_tracker() as q:
-            BlogPost.objects.filter(title='whatever').order_by('published_date').first()
-            self.assertEqual(len(q.get_ops()), 1)
-            self.assertEqual(
-                q.get_ops()[0]['query']['$orderby'],
-                {'published_date': 1}
-            )
-
-        # calling order_by() after an explicit sort should clear it
-        with db_ops_tracker() as q:
-            qs = BlogPost.objects.filter(title='whatever').order_by('published_date')
-            qs.order_by().first()
-            self.assertEqual(len(q.get_ops()), 1)
-            self.assertFalse('$orderby' in q.get_ops()[0]['query'])
-
     def test_no_ordering_for_get(self):
         """ Ensure that Doc.objects.get doesn't use any ordering.
         """

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = {py27,py33,py34,py35,pypy,pypy3}-{mg27,mg28,mg30},flake8
+envlist = {py26,py27,py33,py34,py35,pypy,pypy3}-{mg27,mg28},flake8
 
 [testenv]
 commands =
@@ -7,10 +7,12 @@ commands =
 deps =
     nose
     mg27: PyMongo<2.8
-    mg28: PyMongo>=2.8,<2.9
+    mg28: PyMongo>=2.8,<3.0
     mg30: PyMongo>=3.0
+    mgdev: https://github.com/mongodb/mongo-python-driver/tarball/master
 setenv =
     PYTHON_EGG_CACHE = {envdir}/python-eggs
+passenv = windir
 
 [testenv:flake8]
 deps =