Python unit test how to assert message format

Question

I have my Python unit test code that looks like the following

self.assertRaises(exc.UserError, module.function, args)

This basically asserts that a UserError was raised. I however cannot find how to check if the message in the exception matches my regular expression.

How can I do this? (I would prefer not to write any extra code and just leverage python unittest module features)

May this help? http://stackoverflow.com/questions/8215653/using-a-context-manager-with-python-assertraises Should there be an assertRaisesRegex? — User, Feb 19 '13 at 12:44

score 3 · Answer 1 · edited May 23 '17 at 12:28

3

class ExtendedTestCase(unittest.TestCase):

    def assertRaisesWithMessage(self, msg, func, *args, **kwargs):
        try:
            func(*args, **kwargs)
            self.assertFail()
        except Exception as inst:
            self.assertEqual(inst.message, msg)

The standard unittest module provides no such method. If you use this more often you can use the code above and inherit from the ExtendedTestCase.

PS: Stolen from How to show the error messages caught by assertRaises() in unittest in Python2.7? :)

edited May 23 '17 at 12:28

Community

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answered Feb 19 '13 at 13:45

floqqi

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"The standard unittest module provides no such method." False, see the answer of Calm Storm. However this solution works in python<2.7. – Bakuriu Nov 11 '13 at 12:55

score 2 · Accepted Answer · answered Nov 11 '13 at 12:30

2

Python seems to have the same method in 2.7.3, the method is named "assertRaisesRegexp" so we do not (and should not) write our own wrappers :)

http://docs.python.org/2/library/unittest.html#unittest.TestCase.assertRaisesRegexp

answered Nov 11 '13 at 12:30

Kannan Ekanath

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Python unit test how to assert message format

2 Answers2