Merge branch 'bug/168' into 'master'

Add OptionManager#parse_known_args

*Description of changes*

Add `parse_known_args` to our `OptionManager` interface so plugin flags can be specified. This provides similar behaviour to argparse's `parse_known_args` method on its `ArgumentParser`. When we transition to argparse, we'll be able to take direct advantage of that.

*Related to:*  #168

See merge request !74

1 files changed, 9 insertions, 0 deletions

diff --git a/tests/unit/test_option_manager.py b/tests/unit/test_option_manager.py
index 6f6cb17..661b445 100644
--- a/tests/unit/test_option_manager.py
+++ b/tests/unit/test_option_manager.py
@@ -2,6 +2,7 @@
 import optparse
 import os
 
+import mock
 import pytest
 
 from flake8 import utils
@@ -194,3 +195,11 @@ def test_extend_default_ignore(optmanager):
     assert optmanager.extended_default_ignore == set(['T100',
                                                       'T101',
                                                       'T102'])
+
+
+def test_parse_known_args(optmanager):
+    """Verify we ignore unknown options."""
+    with mock.patch('sys.exit') as sysexit:
+        optmanager.parse_known_args(['--max-complexity', '5'])
+
+    assert sysexit.called is False