gh-100739: Respect mock spec when checking for unsafe prefixes (GH-100740)

(cherry picked from commit 7f1eefc6f4843f0fca60308f557a71af11d18a53)

Co-authored-by: Christian Klein <167265+cklein@users.noreply.github.com>
Co-authored-by: Nikita Sobolev <mail@sobolevn.me>

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py
index fdba543..535f908 100644
--- a/Lib/unittest/test/testmock/testmock.py
+++ b/Lib/unittest/test/testmock/testmock.py
@@ -1644,6 +1644,22 @@ class MockTest(unittest.TestCase):
         m.aseert_foo_call()
         m.assrt_foo_call()
 
+    # gh-100739
+    def test_mock_safe_with_spec(self):
+        class Foo(object):
+            def assert_bar(self):
+                pass
+
+            def assertSome(self):
+                pass
+
+        m = Mock(spec=Foo)
+        m.assert_bar()
+        m.assertSome()
+
+        m.assert_bar.assert_called_once()
+        m.assertSome.assert_called_once()
+
     #Issue21262
     def test_assert_not_called(self):
         m = Mock()