Add assertNotRegex. (#289)

Fixes #288.

Co-authored-by: Benjamin Peterson <benjamin@python.org>

documentation/index.rst

@@ -510,6 +510,11 @@ Note these functions are only available on Python 2.7 or later.
    Alias for :meth:`~py3:unittest.TestCase.assertRegex` on Python 3 and
    :meth:`~py2:unittest.TestCase.assertRegexpMatches` on Python 2.
 
+.. function:: assertNotRegex()
+
+   Alias for :meth:`~py3:unittest.TestCase.assertNotRegex` on Python 3 and
+   :meth:`~py2:unittest.TestCase.assertNotRegexpMatches` on Python 2.
+
 
 Renamed modules and attributes compatibility
 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

six.py

@@ -644,9 +644,11 @@ def u(s):
     if sys.version_info[1] <= 1:
         _assertRaisesRegex = "assertRaisesRegexp"
         _assertRegex = "assertRegexpMatches"
+        _assertNotRegex = "assertNotRegexpMatches"
     else:
         _assertRaisesRegex = "assertRaisesRegex"
         _assertRegex = "assertRegex"
+        _assertNotRegex = "assertNotRegex"
 else:
     def b(s):
         return s
@@ -668,6 +670,7 @@ def indexbytes(buf, i):
     _assertCountEqual = "assertItemsEqual"
     _assertRaisesRegex = "assertRaisesRegexp"
     _assertRegex = "assertRegexpMatches"
+    _assertNotRegex = "assertNotRegexpMatches"
 _add_doc(b, """Byte literal""")
 _add_doc(u, """Text literal""")
 
@@ -684,6 +687,10 @@ def assertRegex(self, *args, **kwargs):
     return getattr(self, _assertRegex)(*args, **kwargs)
 
 
+def assertNotRegex(self, *args, **kwargs):
+    return getattr(self, _assertNotRegex)(*args, **kwargs)
+
+
 if PY3:
     exec_ = getattr(moves.builtins, "exec")
 

test_six.py

@@ -938,6 +938,17 @@ def test(self):
     TestAssertRegex('test').test()
 
 
+def test_assertNotRegex():
+    class TestAssertNotRegex(unittest.TestCase):
+        def test(self):
+            with self.assertRaises(AssertionError):
+                six.assertNotRegex(self, 'test', r'^t')
+
+            six.assertNotRegex(self, 'test', r'^a')
+
+    TestAssertNotRegex('test').test()
+
+
 def test_assertRaisesRegex():
     class TestAssertRaisesRegex(unittest.TestCase):
         def test(self):