1 files changed, 15 insertions, 0 deletions
diff --git a/Lib/unittest/test/testmock/testmagicmethods.py b/Lib/unittest/test/testmock/testmagicmethods.py
index 3c53ec4f0e1..bb9b956bb2e 100644
--- a/Lib/unittest/test/testmock/testmagicmethods.py
+++ b/Lib/unittest/test/testmock/testmagicmethods.py
@@ -450,5 +450,20 @@ class TestMockingMagicMethods(unittest.TestCase):
         bar_direct = m.__rdivmod__(2)
         self.assertIsInstance(bar_direct, MagicMock)
 
+    # http://bugs.python.org/issue23310
+    # Check if you can change behaviour of magic methds in MagicMock init
+    def test_magic_in_initialization(self):
+        m = MagicMock(**{'__str__.return_value': "12"})
+        self.assertEqual(str(m), "12")
+
+    def test_changing_magic_set_in_initialization(self):
+        m = MagicMock(**{'__str__.return_value': "12"})
+        m.__str__.return_value = "13"
+        self.assertEqual(str(m), "13")
+        m = MagicMock(**{'__str__.return_value': "12"})
+        m.configure_mock(**{'__str__.return_value': "14"})
+        self.assertEqual(str(m), "14")
+
+
 if __name__ == '__main__':
     unittest.main()