Check if args are passed to MatchedClient

fixes #176

ocs/matched_client.py

@@ -92,6 +92,9 @@ def __init__(self, instance_id, **kwargs):
         For additional kwargs see site_config.get_control_client.
 
         """
+        if kwargs.get('args') is None:
+            kwargs['args'] = []
+
         self._client = site_config.get_control_client(instance_id, **kwargs)
         self.instance_id = instance_id
 

tests/test_matched_client.py

@@ -0,0 +1,28 @@
+import os
+from unittest.mock import MagicMock, patch
+from ocs.matched_client import MatchedClient
+
+mocked_client = MagicMock()
+mock_from_yaml = MagicMock()
+
+
+@patch('ocs.client_http.ControlClient', mocked_client)
+@patch('ocs.site_config.SiteConfig.from_yaml', mock_from_yaml)
+@patch('sys.argv', ['example_client.py', 'test'])
+def test_extra_argv():
+    """If there are extra arguments in sys.argv and args=[] is not set when
+    instantiating a MatchedClient, then internally
+    site_config.get_control_client() will inspect sys.argv[1:], which causes
+    issues down the line when run through the site_config parser.
+
+    Here we patch in a mocked ControlClient to avoid needing to talk to a
+    crossbar server. We also patch in a mocked from_yaml() method, to avoid
+    needing to read a real site file. Lastly, and most importantly, we patch in
+    sys.argv with an actual additional argument. This will cause an
+    "unrecognized arguments" error when argparse inspects sys.argv within the
+    site_config parser.
+
+    """
+    # Set for get_config to pick up on
+    os.environ["OCS_CONFIG_DIR"] = '/tmp/'
+    MatchedClient("test")