Merge pull request #1884 from erdenezul/limit_behavior

Clone of Limit behavior pr #1614

Author: erdenezul

docs/changelog.rst

@@ -2,6 +2,11 @@
 Changelog
 =========
 
+Development
+===========
+- QuerySet limit function behaviour: Passing 0 as parameter will return all the documents in the cursor #1611
+- (Fill this out as you fix issues and develop your features).
+=======
 Changes in 0.15.4
 =================
 - Added `DateField` #513

mongoengine/queryset/base.py

@@ -396,7 +396,7 @@ def count(self, with_limit_and_skip=False):
             :meth:`skip` that has been applied to this cursor into account when
             getting the count
         """
-        if self._limit == 0 and with_limit_and_skip or self._none:
+        if self._limit == 0 and with_limit_and_skip is False or self._none:
             return 0
         return self._cursor.count(with_limit_and_skip=with_limit_and_skip)
 
@@ -775,10 +775,11 @@ def limit(self, n):
         """Limit the number of returned documents to `n`. This may also be
         achieved using array-slicing syntax (e.g. ``User.objects[:5]``).
 
-        :param n: the maximum number of objects to return
+        :param n: the maximum number of objects to return if n is greater than 0.
+        When 0 is passed, returns all the documents in the cursor
         """
         queryset = self.clone()
-        queryset._limit = n if n != 0 else 1
+        queryset._limit = n
 
         # If a cursor object has already been created, apply the limit to it.
         if queryset._cursor_obj:

tests/queryset/queryset.py

@@ -125,6 +125,11 @@ def test_limit(self):
         self.assertEqual(len(people2), 1)
         self.assertEqual(people2[0], user_a)
 
+        # Test limit with 0 as parameter
+        people = self.Person.objects.limit(0)
+        self.assertEqual(people.count(with_limit_and_skip=True), 2)
+        self.assertEqual(len(people), 2)
+
         # Test chaining of only after limit
         person = self.Person.objects().limit(1).only('name').first()
         self.assertEqual(person, user_a)
@@ -5272,6 +5277,16 @@ class BlogPost(Document):
         # in a way we'd expect) should raise a TypeError, too
         self.assertRaises(TypeError, BlogPost.objects(authors__in=author).count)
 
+    def test_create_count(self):
+        self.Person.drop_collection()
+        self.Person.objects.create(name="Foo")
+        self.Person.objects.create(name="Bar")
+        self.Person.objects.create(name="Baz")
+        self.assertEqual(self.Person.objects.count(with_limit_and_skip=True), 3)
+
+        newPerson = self.Person.objects.create(name="Foo_1")
+        self.assertEqual(self.Person.objects.count(with_limit_and_skip=True), 4)
+
 
 if __name__ == '__main__':
     unittest.main()