make the test simpler by using a new doc class

mongoengine/connection.py

@@ -25,8 +25,7 @@ _dbs = {}
 
 def register_connection(alias, name=None, host=None, port=None,
                         read_preference=READ_PREFERENCE,
-                        username=None, password=None,
-                        authentication_source=None,
+                        username=None, password=None, authentication_source=None,
                         authentication_mechanism=None,
                         **kwargs):
     """Add a connection.
@@ -71,26 +70,20 @@ def register_connection(alias, name=None, host=None, port=None,
 
     resolved_hosts = []
     for entity in conn_host:
-
-        # Handle Mongomock
+        # Handle uri style connections
         if entity.startswith('mongomock://'):
             conn_settings['is_mock'] = True
             # `mongomock://` is not a valid url prefix and must be replaced by `mongodb://`
             resolved_hosts.append(entity.replace('mongomock://', 'mongodb://', 1))
-
-        # Handle URI style connections, only updating connection params which
-        # were explicitly specified in the URI.
         elif '://' in entity:
             uri_dict = uri_parser.parse_uri(entity)
             resolved_hosts.append(entity)
-
-            if uri_dict.get('database'):
-                conn_settings['name'] = uri_dict.get('database')
-
-            for param in ('read_preference', 'username', 'password'):
-                if uri_dict.get(param):
-                    conn_settings[param] = uri_dict[param]
-
+            conn_settings.update({
+                'name': uri_dict.get('database') or name,
+                'username': uri_dict.get('username'),
+                'password': uri_dict.get('password'),
+                'read_preference': read_preference,
+            })
             uri_options = uri_dict['options']
             if 'replicaset' in uri_options:
                 conn_settings['replicaSet'] = True

mongoengine/queryset/base.py

@@ -933,6 +933,14 @@ class BaseQuerySet(object):
         queryset._ordering = queryset._get_order_by(keys)
         return queryset
 
+    def comment(self, text):
+        """Add a comment to the query.
+
+        See https://docs.mongodb.com/manual/reference/method/cursor.comment/#cursor.comment
+        for details.
+        """
+        return self._chainable_method("comment", text)
+
     def explain(self, format=False):
         """Return an explain plan record for the
         :class:`~mongoengine.queryset.QuerySet`\ 's cursor.

tests/queryset/queryset.py

@@ -339,7 +339,6 @@ class QuerySetTest(unittest.TestCase):
 
     def test_update_write_concern(self):
         """Test that passing write_concern works"""
-
         self.Person.drop_collection()
 
         write_concern = {"fsync": True}
@@ -2199,6 +2198,21 @@ class QuerySetTest(unittest.TestCase):
             a.author.name for a in Author.objects.order_by('-author__age')]
         self.assertEqual(names, ['User A', 'User B', 'User C'])
 
+    def test_comment(self):
+        """Make sure adding a comment to the query works."""
+        class User(Document):
+            age = IntField()
+
+        with db_ops_tracker() as q:
+            adult = (User.objects.filter(age__gte=18)
+                .comment('looking for an adult')
+                .first())
+            ops = q.get_ops()
+            self.assertEqual(len(ops), 1)
+            op = ops[0]
+            self.assertEqual(op['query']['$query'], {'age': {'$gte': 18}})
+            self.assertEqual(op['query']['$comment'], 'looking for an adult')
+
     def test_map_reduce(self):
         """Ensure map/reduce is both mapping and reducing.
         """

tests/test_connection.py

@@ -174,9 +174,19 @@ class ConnectionTest(unittest.TestCase):
         c.mongoenginetest.system.users.remove({})
 
     def test_connect_uri_without_db(self):
-        """Ensure connect() method works properly if the URI doesn't
-        include a database name.
+        """Ensure connect() method works properly with uri's without database_name
         """
+        c = connect(db='mongoenginetest', alias='admin')
+        c.admin.system.users.remove({})
+        c.mongoenginetest.system.users.remove({})
+
+        c.admin.add_user("admin", "password")
+        c.admin.authenticate("admin", "password")
+        c.mongoenginetest.add_user("username", "password")
+
+        if not IS_PYMONGO_3:
+            self.assertRaises(ConnectionError, connect, "testdb_uri_bad", host='mongodb://test:password@localhost')
+
         connect("mongoenginetest", host='mongodb://localhost/')
 
         conn = get_connection()
@@ -186,31 +196,8 @@ class ConnectionTest(unittest.TestCase):
         self.assertTrue(isinstance(db, pymongo.database.Database))
         self.assertEqual(db.name, 'mongoenginetest')
 
-    def test_connect_uri_default_db(self):
-        """Ensure connect() defaults to the right database name if
-        the URI and the database_name don't explicitly specify it.
-        """
-        connect(host='mongodb://localhost/')
-
-        conn = get_connection()
-        self.assertTrue(isinstance(conn, pymongo.mongo_client.MongoClient))
-
-        db = get_db()
-        self.assertTrue(isinstance(db, pymongo.database.Database))
-        self.assertEqual(db.name, 'test')
-
-    def test_uri_without_credentials_doesnt_override_conn_settings(self):
-        """Ensure connect() uses the username & password params if the URI
-        doesn't explicitly specify them.
-        """
-        c = connect(host='mongodb://localhost/mongoenginetest',
-                    username='user',
-                    password='pass')
-
-        # OperationFailure means that mongoengine attempted authentication
-        # w/ the provided username/password and failed - that's the desired
-        # behavior. If the MongoDB URI would override the credentials
-        self.assertRaises(OperationFailure, get_db)
+        c.admin.system.users.remove({})
+        c.mongoenginetest.system.users.remove({})
 
     def test_connect_uri_with_authsource(self):
         """Ensure that the connect() method works well with