Issue #10775: assertRaises, assertRaisesRegex, assertWarns, and assertWarnsRegex now accept a keyword argument 'msg' when used as context managers. Initial patch by Winston Ewert.
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index 881de6f..5b7c29d 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -104,9 +104,9 @@
class _AssertRaisesBaseContext(object):
def __init__(self, expected, test_case, callable_obj=None,
- expected_regex=None):
+ expected_regex=None):
self.expected = expected
- self.failureException = test_case.failureException
+ self.test_case = test_case
if callable_obj is not None:
try:
self.obj_name = callable_obj.__name__
@@ -117,6 +117,24 @@
if isinstance(expected_regex, (bytes, str)):
expected_regex = re.compile(expected_regex)
self.expected_regex = expected_regex
+ self.msg = None
+
+ def _raiseFailure(self, standardMsg):
+ msg = self.test_case._formatMessage(self.msg, standardMsg)
+ raise self.test_case.failureException(msg)
+
+ def handle(self, name, callable_obj, args, kwargs):
+ """
+ If callable_obj is None, assertRaises/Warns is being used as a
+ context manager, so check for a 'msg' kwarg and return self.
+ If callable_obj is not None, call it passing args and kwargs.
+ """
+ if callable_obj is None:
+ self.msg = kwargs.pop('msg', None)
+ return self
+ with self:
+ callable_obj(*args, **kwargs)
+
class _AssertRaisesContext(_AssertRaisesBaseContext):
@@ -132,11 +150,10 @@
except AttributeError:
exc_name = str(self.expected)
if self.obj_name:
- raise self.failureException("{0} not raised by {1}"
- .format(exc_name, self.obj_name))
+ self._raiseFailure("{} not raised by {}".format(exc_name,
+ self.obj_name))
else:
- raise self.failureException("{0} not raised"
- .format(exc_name))
+ self._raiseFailure("{} not raised".format(exc_name))
if not issubclass(exc_type, self.expected):
# let unexpected exceptions pass through
return False
@@ -147,8 +164,8 @@
expected_regex = self.expected_regex
if not expected_regex.search(str(exc_value)):
- raise self.failureException('"%s" does not match "%s"' %
- (expected_regex.pattern, str(exc_value)))
+ self._raiseFailure('"{}" does not match "{}"'.format(
+ expected_regex.pattern, str(exc_value)))
return True
@@ -192,14 +209,13 @@
return
# Now we simply try to choose a helpful failure message
if first_matching is not None:
- raise self.failureException('"%s" does not match "%s"' %
- (self.expected_regex.pattern, str(first_matching)))
+ self._raiseFailure('"{}" does not match "{}"'.format(
+ self.expected_regex.pattern, str(first_matching)))
if self.obj_name:
- raise self.failureException("{0} not triggered by {1}"
- .format(exc_name, self.obj_name))
+ self._raiseFailure("{} not triggered by {}".format(exc_name,
+ self.obj_name))
else:
- raise self.failureException("{0} not triggered"
- .format(exc_name))
+ self._raiseFailure("{} not triggered".format(exc_name))
class _TypeEqualityDict(object):
@@ -547,7 +563,6 @@
except UnicodeDecodeError:
return '%s : %s' % (safe_repr(standardMsg), safe_repr(msg))
-
def assertRaises(self, excClass, callableObj=None, *args, **kwargs):
"""Fail unless an exception of class excClass is thrown
by callableObj when invoked with arguments args and keyword
@@ -562,6 +577,9 @@
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::
@@ -572,25 +590,25 @@
self.assertEqual(the_exception.error_code, 3)
"""
context = _AssertRaisesContext(excClass, self, callableObj)
- if callableObj is None:
- return context
- with context:
- callableObj(*args, **kwargs)
+ return context.handle('assertRaises', callableObj, args, kwargs)
def assertWarns(self, expected_warning, callable_obj=None, *args, **kwargs):
"""Fail unless a warning of class warnClass is triggered
- by callableObj when invoked with arguments args and keyword
+ by callable_obj when invoked with arguments args and keyword
arguments kwargs. If a different type of warning is
triggered, it will not be handled: depending on the other
warning filtering rules in effect, it might be silenced, printed
out, or raised as an exception.
- If called with callableObj omitted or None, will return a
+ If called with callable_obj omitted or None, will return a
context object used like this::
with self.assertWarns(SomeWarning):
do_something()
+ An optional keyword argument 'msg' can be provided when assertWarns
+ is used as a context object.
+
The context manager keeps a reference to the first matching
warning as the 'warning' attribute; similarly, the 'filename'
and 'lineno' attributes give you information about the line
@@ -603,10 +621,7 @@
self.assertEqual(the_warning.some_attribute, 147)
"""
context = _AssertWarnsContext(expected_warning, self, callable_obj)
- if callable_obj is None:
- return context
- with context:
- callable_obj(*args, **kwargs)
+ return context.handle('assertWarns', callable_obj, args, kwargs)
def _getAssertEqualityFunc(self, first, second):
"""Get a detailed comparison function for the types of the two args.
@@ -1083,15 +1098,15 @@
expected_regex: Regex (re pattern object or string) expected
to be found in error message.
callable_obj: Function to be called.
+ msg: Optional message used in case of failure. Can only be used
+ when assertRaisesRegex is used as a context manager.
args: Extra args.
kwargs: Extra kwargs.
"""
context = _AssertRaisesContext(expected_exception, self, callable_obj,
expected_regex)
- if callable_obj is None:
- return context
- with context:
- callable_obj(*args, **kwargs)
+
+ return context.handle('assertRaisesRegex', callable_obj, args, kwargs)
def assertWarnsRegex(self, expected_warning, expected_regex,
callable_obj=None, *args, **kwargs):
@@ -1105,15 +1120,14 @@
expected_regex: Regex (re pattern object or string) expected
to be found in error message.
callable_obj: Function to be called.
+ msg: Optional message used in case of failure. Can only be used
+ when assertWarnsRegex is used as a context manager.
args: Extra args.
kwargs: Extra kwargs.
"""
context = _AssertWarnsContext(expected_warning, self, callable_obj,
expected_regex)
- if callable_obj is None:
- return context
- with context:
- callable_obj(*args, **kwargs)
+ return context.handle('assertWarnsRegex', callable_obj, args, kwargs)
def assertRegex(self, text, expected_regex, msg=None):
"""Fail the test unless the text matches the regular expression."""