Issue #10775: assertRaises, assertRaisesRegex, assertWarns, and assertWarnsRegex now accept a keyword argument 'msg' when used as context managers. Initial patch by Winston Ewert.

1 files changed, 33 insertions, 12 deletions

diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index a623f3c..191d5b9 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -860,10 +860,11 @@ Test cases
    | <TestCase.assertNotIsInstance>`         |                             |               |
    +-----------------------------------------+-----------------------------+---------------+
 
-   All the assert methods (except :meth:`assertRaises`,
-   :meth:`assertRaisesRegex`, :meth:`assertWarns`, :meth:`assertWarnsRegex`)
-   accept a *msg* argument that, if specified, is used as the error message on
-   failure (see also :data:`longMessage`).
+   All the assert methods accept a *msg* argument that, if specified, is used
+   as the error message on failure (see also :data:`longMessage`).
+   Note that the *msg* keyword argument can be passed to :meth:`assertRaises`,
+   :meth:`assertRaisesRegex`, :meth:`assertWarns`, :meth:`assertWarnsRegex`
+   only when they are used as a context manager.
 
    .. method:: assertEqual(first, second, msg=None)
 
@@ -957,7 +958,7 @@ Test cases
    +---------------------------------------------------------+--------------------------------------+------------+
 
    .. method:: assertRaises(exception, callable, *args, **kwds)
-               assertRaises(exception)
+               assertRaises(exception, msg=None)
 
       Test that an exception is raised when *callable* is called with any
       positional or keyword arguments that are also passed to
@@ -966,12 +967,16 @@ Test cases
       To catch any of a group of exceptions, a tuple containing the exception
       classes may be passed as *exception*.
 
-      If only the *exception* argument is given, returns a context manager so
-      that the code under test can be written inline rather than as a function::
+      If only the *exception* and possibly the *msg* arguments are given,
+      return a context manager so that the code under test can be written
+      inline rather than as a function::
 
          with self.assertRaises(SomeException):
              do_something()
 
+      When used as a context manager, :meth:`assertRaises` accepts the
+      additional keyword argument *msg*.
+
       The context manager will store the caught exception object in its
       :attr:`exception` attribute.  This can be useful if the intention
       is to perform additional checks on the exception raised::
@@ -988,9 +993,12 @@ Test cases
       .. versionchanged:: 3.2
          Added the :attr:`exception` attribute.
 
+      .. versionchanged:: 3.3
+         Added the *msg* keyword argument when used as a context manager.
+
 
    .. method:: assertRaisesRegex(exception, regex, callable, *args, **kwds)
-               assertRaisesRegex(exception, regex)
+               assertRaisesRegex(exception, regex, msg=None)
 
       Like :meth:`assertRaises` but also tests that *regex* matches
       on the string representation of the raised exception.  *regex* may be
@@ -1007,12 +1015,16 @@ Test cases
 
       .. versionadded:: 3.1
          under the name ``assertRaisesRegexp``.
+
       .. versionchanged:: 3.2
          Renamed to :meth:`assertRaisesRegex`.
 
+      .. versionchanged:: 3.3
+         Added the *msg* keyword argument when used as a context manager.
+
 
    .. method:: assertWarns(warning, callable, *args, **kwds)
-               assertWarns(warning)
+               assertWarns(warning, msg=None)
 
       Test that a warning is triggered when *callable* is called with any
       positional or keyword arguments that are also passed to
@@ -1021,12 +1033,16 @@ Test cases
       To catch any of a group of warnings, a tuple containing the warning
       classes may be passed as *warnings*.
 
-      If only the *warning* argument is given, returns a context manager so
-      that the code under test can be written inline rather than as a function::
+      If only the *warning* and possibly the *msg* arguments are given,
+      returns a context manager so that the code under test can be written
+      inline rather than as a function::
 
          with self.assertWarns(SomeWarning):
              do_something()
 
+      When used as a context manager, :meth:`assertRaises` accepts the
+      additional keyword argument *msg*.
+
       The context manager will store the caught warning object in its
       :attr:`warning` attribute, and the source line which triggered the
       warnings in the :attr:`filename` and :attr:`lineno` attributes.
@@ -1044,9 +1060,12 @@ Test cases
 
       .. versionadded:: 3.2
 
+      .. versionchanged:: 3.3
+         Added the *msg* keyword argument when used as a context manager.
+
 
    .. method:: assertWarnsRegex(warning, regex, callable, *args, **kwds)
-               assertWarnsRegex(warning, regex)
+               assertWarnsRegex(warning, regex, msg=None)
 
       Like :meth:`assertWarns` but also tests that *regex* matches on the
       message of the triggered warning.  *regex* may be a regular expression
@@ -1064,6 +1083,8 @@ Test cases
 
       .. versionadded:: 3.2
 
+      .. versionchanged:: 3.3
+         Added the *msg* keyword argument when used as a context manager.
 
 
    There are also other methods used to perform more specific checks, such as: