Mock dns lookups in test_conn (#1739)

Small change to avoid doing dns resolution when running local connection tests. This fixture always returns a broker on localhost:9092, so DNS lookups don't make sense here.

Author: dpkp

test/test_conn.py

@@ -16,6 +16,13 @@
 import kafka.errors as Errors
 
 
+@pytest.fixture
+def dns_lookup(mocker):
+    return mocker.patch('kafka.conn.dns_lookup',
+                        return_value=[(socket.AF_INET,
+                                       None, None, None,
+                                       ('localhost', 9092))])
+
 @pytest.fixture
 def _socket(mocker):
     socket = mocker.MagicMock()
@@ -25,7 +32,7 @@ def _socket(mocker):
 
 
 @pytest.fixture
-def conn(_socket):
+def conn(_socket, dns_lookup):
     conn = BrokerConnection('localhost', 9092, socket.AF_INET)
     return conn