register a possible async database

tests/async/test_connection.py

@@ -0,0 +1,36 @@
+from mongoengine import *
+import motor
+import mongoengine.connection
+from mongoengine.connection import get_db, get_connection, ConnectionError
+
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+
+class ConnectionTest(unittest.TestCase):
+
+    def setUp(self):
+        mongoengine.connection._connection_settings = {}
+        mongoengine.connection._connections = {}
+        mongoengine.connection._dbs = {}
+
+    def test_register_connection(self):
+        """
+        Ensure that the connect() method works properly.
+        """
+        register_connection('asyncdb', 'mongoengineasynctest', async=True)
+
+        self.assertEqual(
+            mongoengine.connection._connection_settings['asyncdb']['name'],
+            'mongoengineasynctest')
+
+        self.assertTrue(
+            mongoengine.connection._connection_settings['asyncdb']['async'])
+        conn = get_connection('asyncdb')
+        self.assertTrue(isinstance(conn, motor.MotorClient))
+
+        db = get_db('asyncdb')
+        self.assertTrue(isinstance(db, motor.MotorDatabase))
+        self.assertEqual(db.name, 'mongoengineasynctest')