""" This is a backport of assertRaises() and assertRaisesRegex from Python 3.5.4 The original copyright message is as follows Python unit testing framework, based on Erich Gamma's JUnit and Kent Beck's Smalltalk testing framework (used with permission). This module contains the core framework classes that form the basis of specific test cases and suites (TestCase, TestSuite etc.), and also a text-based utility class for running the tests and reporting the results (TextTestRunner). Simple usage: import unittest class IntegerArithmeticTestCase(unittest.TestCase): def testAdd(self): # test method names begin with 'test' self.assertEqual((1 + 2), 3) self.assertEqual(0 + 1, 1) def testMultiply(self): self.assertEqual((0 * 10), 0) self.assertEqual((5 * 8), 40) if __name__ == '__main__': unittest.main() Further information is available in the bundled documentation, and from https://docs.python.org/library/unittest.html Copyright (c) 1999-2003 Steve Purcell Copyright (c) 2003-2010 Python Software Foundation This module is free software, and you may redistribute it and/or modify it under the same terms as Python itself, so long as this copyright message and disclaimer are retained in their original form. IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. """ import re import warnings import unittest def _is_subtype(expected, basetype): if isinstance(expected, tuple): return all(_is_subtype(e, basetype) for e in expected) return isinstance(expected, type) and issubclass(expected, basetype) class _BaseTestCaseContext: def __init__(self, test_case): self.test_case = test_case def _raiseFailure(self, standardMsg): msg = self.test_case._formatMessage(self.msg, standardMsg) raise self.test_case.failureException(msg) class _AssertRaisesBaseContext(_BaseTestCaseContext): def __init__(self, expected, test_case, expected_regex=None): _BaseTestCaseContext.__init__(self, test_case) self.expected = expected self.test_case = test_case if expected_regex is not None: expected_regex = re.compile(expected_regex) self.expected_regex = expected_regex self.obj_name = None self.msg = None def handle(self, name, args, kwargs): """ If args is empty, assertRaises/Warns is being used as a context manager, so check for a 'msg' kwarg and return self. If args is not empty, call a callable passing positional and keyword arguments. """ try: if not _is_subtype(self.expected, self._base_type): raise TypeError('%s() arg 1 must be %s' % (name, self._base_type_str)) if args and args[0] is None: warnings.warn("callable is None", DeprecationWarning, 3) args = () if not args: self.msg = kwargs.pop('msg', None) if kwargs: warnings.warn('%r is an invalid keyword argument for ' 'this function' % next(iter(kwargs)), DeprecationWarning, 3) return self callable_obj, args = args[0], args[1:] try: self.obj_name = callable_obj.__name__ except AttributeError: self.obj_name = str(callable_obj) with self: callable_obj(*args, **kwargs) finally: # bpo-23890: manually break a reference cycle self = None class _AssertRaisesContext(_AssertRaisesBaseContext): """A context manager used to implement TestCase.assertRaises* methods.""" _base_type = BaseException _base_type_str = 'an exception type or tuple of exception types' def __enter__(self): return self def __exit__(self, exc_type, exc_value, tb): if exc_type is None: try: exc_name = self.expected.__name__ except AttributeError: exc_name = str(self.expected) if self.obj_name: self._raiseFailure("{} not raised by {}".format(exc_name, self.obj_name)) else: self._raiseFailure("{} not raised".format(exc_name)) if not issubclass(exc_type, self.expected): return False if self.expected_regex is None: return True expected_regex = self.expected_regex if not expected_regex.search(str(exc_value)): self._raiseFailure('"{}" does not match "{}"'.format( expected_regex.pattern, str(exc_value))) return True class TestCase(unittest.TestCase): longMessage = True failureException = AssertionError def _formatMessage(self, msg, standardMsg): """Honour the longMessage attribute when generating failure messages. If longMessage is False this means: * Use only an explicit message if it is provided * Otherwise use the standard message for the assert If longMessage is True: * Use the standard message * If an explicit message is provided, plus ' : ' and the explicit msg """ if not self.longMessage: return msg or standardMsg if msg is None: return standardMsg try: # don't switch to '{}' formatting in Python 2.X # it changes the way unicode input is handled return '%s : %s' % (standardMsg, msg) except UnicodeDecodeError: return '%s : %s' % (standardMsg, msg) def assertRaises(self, expected_exception, *args, **kwargs): """Fail unless an exception of class expected_exception is raised by the callable when invoked with specified positional and keyword arguments. If a different type of exception is raised, it will not be caught, and the test case will be deemed to have suffered an error, exactly as for an unexpected exception. If called with the callable and arguments omitted, will return a context object used like this:: with self.assertRaises(SomeException): do_something() An optional keyword argument 'msg' can be provided when assertRaises is used as a context object. The context manager keeps a reference to the exception as the 'exception' attribute. This allows you to inspect the exception after the assertion:: with self.assertRaises(SomeException) as cm: do_something() the_exception = cm.exception self.assertEqual(the_exception.error_code, 3) """ context = _AssertRaisesContext(expected_exception, self) try: return context.handle('assertRaises', args, kwargs) finally: # bpo-23890: manually break a reference cycle context = None def assertRaisesRegex(self, expected_exception, expected_regex, *args, **kwargs): """Asserts that the message in a raised exception matches a regex. Args: expected_exception: Exception class expected to be raised. expected_regex: Regex (re pattern object or string) expected to be found in error message. args: Function to be called and extra positional args. kwargs: Extra kwargs. msg: Optional message used in case of failure. Can only be used when assertRaisesRegex is used as a context manager. """ context = _AssertRaisesContext(expected_exception, self, expected_regex) return context.handle('assertRaisesRegex', args, kwargs)