Implement collation for queryset

tests/document/indexes.py

@@ -539,6 +539,35 @@ class IndexesTest(unittest.TestCase):
         with self.assertRaises(ValueError):
             BlogPost.objects.hint(("tags", 1)).count()
 
+    def test_collation(self):
+        base = {'locale': "en", 'strength': 2}
+
+        class BlogPost(Document):
+            name = StringField()
+            meta = {"indexes": [
+                {"fields": ["name"], "name": 'name_index',
+                 'collation': base}
+            ]}
+
+        BlogPost.drop_collection()
+
+        names = tuple("%sag %i" % ('t' if n % 2 == 0 else 'T', n) for n in range(10))
+        for name in names:
+            BlogPost(name=name).save()
+
+        query_result = BlogPost.objects.collation(base).order_by('name')
+        self.assertEqual([x.name for x in query_result],
+                         sorted(names, key=lambda x: x.lower()))
+        self.assertEqual(10, query_result.count())
+
+        incorrect_collation = {'arndom': 'wrdo'}
+        with self.assertRaises(OperationFailure):
+            BlogPost.objects.collation(incorrect_collation).count()
+
+        query_result = BlogPost.objects.collation({}).order_by('name')
+        self.assertEqual([x.name for x in query_result],
+                         sorted(names))
+
     def test_unique(self):
         """Ensure that uniqueness constraints are applied to fields.
         """