New submission from Guillaume Chorn: In the unittest.mock library, when a Mock object stores the calls made on it in its `mock_calls` attribute, it appears to store references to the call arguments instead of the actual values of the call arguments. In cases where call args are mutable types, this results in the undesirable behavior below:
```python import mock arg = ['one'] test_function(arg) # passes test_function.assert_has_calls([mock.call(['one'])]) arg += ['two'] test_function(arg) # fails, even though we just verified the first call above! test_function.assert_has_calls([ mock.call(['one']), mock.call(['one','two']) ]) # passes, even though we didn't make the exact same call twice! test_function.assert_has_calls([ mock.call(['one', 'two']), mock.call(['one', 'two']) ]) ``` ---------- components: Tests messages: 277764 nosy: Guillaume Chorn priority: normal severity: normal status: open title: Python unittest.mock.mock_calls stores references to arguments instead of their values type: behavior versions: Python 3.4 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue28318> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com