Last active
August 29, 2015 14:13
-
-
Save acdha/f1f506b47a38574f3a5f to your computer and use it in GitHub Desktop.
Quick mock example showing how to simulate errors
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
>>> from unittest import mock | |
>>> import json | |
>>> m_o = mock.mock_open() | |
>>> m_o.side_effect = OSError('Insufficient voltage') | |
>>> json.load(m_o('foo.json', 'rb')) | |
Traceback (most recent call last): | |
File "<stdin>", line 1, in <module> | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 896, in __call__ | |
return _mock_self._mock_call(*args, **kwargs) | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 952, in _mock_call | |
raise effect | |
OSError: Insufficient voltage | |
>>> with mock.patch('__main__.open', m_o, create=True): | |
... json.load(open('foo', 'rb')) | |
... | |
Traceback (most recent call last): | |
File "<stdin>", line 2, in <module> | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 896, in __call__ | |
return _mock_self._mock_call(*args, **kwargs) | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 952, in _mock_call | |
raise effect | |
File "<stdin>", line 1, in <module> | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 896, in __call__ | |
return _mock_self._mock_call(*args, **kwargs) | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 952, in _mock_call | |
raise effect | |
OSError: Insufficient voltage | |
>>> def read_the_json(filename): | |
... with open(filename, 'r') as f: | |
... return json.load(f) | |
... | |
>>> read_the_json('foo.json') | |
[0, 1, 2] | |
>>> with patch('__main__.open', m_o, create=True): | |
... read_the_json('foo.json') | |
... | |
Traceback (most recent call last): | |
File "<stdin>", line 2, in <module> | |
File "<stdin>", line 2, in read_the_json | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 896, in __call__ | |
return _mock_self._mock_call(*args, **kwargs) | |
File "/usr/local/Cellar/python3/3.4.2_1/Frameworks/Python.framework/Versions/3.4/lib/python3.4/unittest/mock.py", line 952, in _mock_call | |
raise effect | |
OSError: Insufficient voltage |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment