Issue #23661: unittest.mock side_effects can now be exceptions again.

This was a regression vs Python 3.4. Patch from Ignacio Rossi

Lib/unittest/mock.py

@@ -506,7 +506,8 @@ class NonCallableMock(Base):
         if delegated is None:
             return self._mock_side_effect
         sf = delegated.side_effect
-        if sf is not None and not callable(sf) and not isinstance(sf, _MockIter):
+        if (sf is not None and not callable(sf)
+                and not isinstance(sf, _MockIter) and not _is_exception(sf)):
             sf = _MockIter(sf)
             delegated.side_effect = sf
         return sf

Lib/unittest/test/testmock/testmock.py

@@ -173,6 +173,15 @@ class MockTest(unittest.TestCase):
         self.assertEqual([mock(), mock(), mock()], [3, 2, 1],
                           "callable side effect not used correctly")
 
+    def test_autospec_side_effect_exception(self):
+        # Test for issue 23661
+        def f():
+            pass
+
+        mock = create_autospec(f)
+        mock.side_effect = ValueError('Bazinga!')
+        self.assertRaisesRegex(ValueError, 'Bazinga!', mock)
+
     @unittest.skipUnless('java' in sys.platform,
                           'This test only applies to Jython')
     def test_java_exception_side_effect(self):

Misc/ACKS

@@ -1581,3 +1581,4 @@ Tarek Ziadé
 Gennadiy Zlobin
 Doug Zongker
 Peter Åstrand
+Ignacio Rossi

Misc/NEWS

@@ -17,6 +17,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #23661: unittest.mock side_effects can now be exceptions again. This
+  was a regression vs Python 3.4. Patch from Ignacio Rossi
+
 - Issue #24608: chunk.Chunk.read() now always returns bytes, not str.
 
 - Issue #18684: Fixed reading out of the buffer in the re module.