Mocking a function to raise an Exception to test an except block
Your mock is raising the exception just fine, but the error.resp.status value is missing. Rather than use return_value, just tell Mock that status is an attribute:
barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')Additional keyword arguments to Mock() are set as attributes on the resulting object.
I put your foo and bar definitions in a my_tests module, added in the HttpError class so I could use it too, and your test then can be ran to success:
>>> from my_tests import foo, HttpError>>> import mock>>> with mock.patch('my_tests.bar') as barMock:... barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')... result = my_test.foo()... 404 - >>> result is NoneTrueYou can even see the print '404 - %s' % error.message line run, but I think you wanted to use error.content there instead; that's the attribute HttpError() sets from the second argument, at any rate.