bpo-41877 Check for asert, aseert, assrt in mocks

Lib/unittest/mock.py

@@ -631,9 +631,9 @@ def __getattr__(self, name):
         elif _is_magic(name):
             raise AttributeError(name)
         if not self._mock_unsafe:
-            if name.startswith(('assert', 'assret')):
+            if name.startswith(('assert', 'assret', 'asert', 'aseert', 'assrt')):
                 raise AttributeError("Attributes cannot start with 'assert' "
-                                     "or 'assret'")
+                                     "or its misspellings")
 
         result = self._mock_children.get(name)
         if result is _deleted:

Lib/unittest/test/testmock/testmock.py

@@ -1598,14 +1598,23 @@ def static_method(): pass
     #Issue21238
     def test_mock_unsafe(self):
         m = Mock()
-        msg = "Attributes cannot start with 'assert' or 'assret'"
+        msg = "Attributes cannot start with 'assert' or its misspellings"
         with self.assertRaisesRegex(AttributeError, msg):
             m.assert_foo_call()
         with self.assertRaisesRegex(AttributeError, msg):
             m.assret_foo_call()
+        with self.assertRaisesRegex(AttributeError, msg):
+            m.asert_foo_call()
+        with self.assertRaisesRegex(AttributeError, msg):
+            m.aseert_foo_call()
+        with self.assertRaisesRegex(AttributeError, msg):
+            m.assrt_foo_call()
         m = Mock(unsafe=True)
         m.assert_foo_call()
         m.assret_foo_call()
+        m.asert_foo_call()
+        m.aseert_foo_call()
+        m.assrt_foo_call()
 
     #Issue21262
     def test_assert_not_called(self):

Misc/NEWS.d/next/Library/2020-11-05-16-00-03.bpo-41877.FHbngM.rst

@@ -0,0 +1,2 @@
+Mock objects which are not unsafe will now raise an AttributeError if an attribute with the prefix asert, aseert,
+or assrt is accessed, in addition to this already happening for the prefixes assert or assret.