How to use _assert_raises_context_manager method in Testify

Best Python code snippet using Testify_python

assertions.py

Source:assertions.py

...105    ...     raise Exception106    >>> assert_raises(Exception, raise_exception, 1, kwarg=234)107    """108    if (len(args) == 1) and not kwargs:109        return _assert_raises_context_manager(args[0])110    else:111        return _assert_raises(*args, **kwargs)112def assert_raises_such_that(exception_class, exception_test=lambda e: e, callable_obj=None, *args, **kwargs):113    """114    Assert that an exception is raised such that expection_test(exception)115    passes, either in a with statement via a context manager or while calling116    a given callable on given arguments.117    Arguments:118        exception_class - class corresponding to the expected exception119        exception_test - a callable which takes an exception instance and120            asserts things about it121        callable_obj, *args, **kwargs - optional, a callable object and122            arguments to pass into it which when used are expected to raise the123            exception; if not provided, this function returns a context manager124            which will check that the assertion is raised within the context125            (the body of the with statement).126    As a context manager:127    >>> says_whatever = lambda e: assert_equal(str(e), "whatever")128    >>> with assert_raises_such_that(Exception, says_whatever):129    ...     raise Exception("whatever")130    Pass in a callable:131    >>> says_whatever = lambda e: assert_equal(str(e), "whatever")132    >>> def raise_exception(arg, kwarg=None):133    ...     raise Exception("whatever")134    >>> assert_raises_such_that(Exception, says_whatever, raise_exception, 1, kwarg=234)135    """136    if callable_obj is None:137        return _assert_raises_context_manager(exception_class, exception_test)138    else:139        with _assert_raises_context_manager(exception_class, exception_test):140            callable_obj(*args, **kwargs)141def assert_raises_exactly(exception_class, *args):142    """143    Assert that a particular exception_class is raised with particular arguments.144    Use this assertion when the exception message is important.145    """146    def test_exception(exception):147        # We want to know the exact exception type, not that it has some superclass.148        assert_is(type(exception), exception_class)149        assert_equal(exception.args, args)150    return assert_raises_such_that(exception_class, test_exception)151def assert_raises_and_contains(expected_exception_class, strings, callable_obj, *args, **kwargs):152    """Assert an exception is raised by passing in a callable and its153    arguments and that the string representation of the exception154    contains the case-insensitive list of passed in strings.155    Args156        strings -- can be a string or an iterable of strings157    """158    try:159        callable_obj(*args, **kwargs)160    except expected_exception_class as e:161        message = str(e).lower()162        try:163            is_string = isinstance(strings, basestring)164        except NameError:165            is_string = isinstance(strings, str)166        if is_string:167            strings = [strings]168        for string in strings:169            assert_in(string.lower(), message)170    else:171        assert_not_reached("No exception was raised (expected %s)" % expected_exception_class)172@contextlib.contextmanager173def _assert_raises_context_manager(exception_class, exception_test=lambda e: e):174    """Builds a context manager for testing that code raises an assertion.175    Args:176        exception_class - a subclass of Exception177        exception_test - optional, a function to apply to the exception (to178            test something about it)179    """180    try:181        yield182    except exception_class as e:183        exception_test(e)184    else:185        assert_not_reached("No exception was raised (expected %r)" %186                           exception_class)187def _assert_raises(exception_class, callable, *args, **kwargs):188    with _assert_raises_context_manager(exception_class):189        callable(*args, **kwargs)190def _diff_message(lhs, rhs):191    """If `lhs` and `rhs` are strings, return the a formatted message192    describing their differences. If they're not strings, describe the193    differences in their `repr()`s.194    NOTE: Only works well for strings not containing newlines.195    """196    lhs = _to_characters(lhs)197    rhs = _to_characters(rhs)198    message = u'Diff:\nl: %s\nr: %s' % stringdiffer.highlight(lhs, rhs)199    # Python2 exceptions require bytes.200    if six.PY2:201        return message.encode('UTF-8')202    else:...

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