Close issue20653: allow Enum subclasses to override __reduce_ex__

Lib/test/test_enum.py

@@ -956,6 +956,7 @@ class TestEnum(unittest.TestCase):
         test_pickle_dump_load(self.assertEqual, NI5, 5)
         self.assertEqual(NEI.y.value, 2)
         test_pickle_dump_load(self.assertIs, NEI.y)
+        test_pickle_dump_load(self.assertIs, NEI)
 
     def test_subclasses_with_getnewargs_ex(self):
         class NamedInt(int):
@@ -1012,6 +1013,7 @@ class TestEnum(unittest.TestCase):
         test_pickle_dump_load(self.assertEqual, NI5, 5, protocol=(4, 4))
         self.assertEqual(NEI.y.value, 2)
         test_pickle_dump_load(self.assertIs, NEI.y, protocol=(4, 4))
+        test_pickle_dump_load(self.assertIs, NEI)
 
     def test_subclasses_with_reduce(self):
         class NamedInt(int):
@@ -1068,6 +1070,7 @@ class TestEnum(unittest.TestCase):
         test_pickle_dump_load(self.assertEqual, NI5, 5)
         self.assertEqual(NEI.y.value, 2)
         test_pickle_dump_load(self.assertIs, NEI.y)
+        test_pickle_dump_load(self.assertIs, NEI)
 
     def test_subclasses_with_reduce_ex(self):
         class NamedInt(int):
@@ -1124,8 +1127,9 @@ class TestEnum(unittest.TestCase):
         test_pickle_dump_load(self.assertEqual, NI5, 5)
         self.assertEqual(NEI.y.value, 2)
         test_pickle_dump_load(self.assertIs, NEI.y)
+        test_pickle_dump_load(self.assertIs, NEI)
 
-    def test_subclasses_without_getnewargs(self):
+    def test_subclasses_without_direct_pickle_support(self):
         class NamedInt(int):
             __qualname__ = 'NamedInt'
             def __new__(cls, *args):
@@ -1178,6 +1182,61 @@ class TestEnum(unittest.TestCase):
         test_pickle_exception(self.assertRaises, TypeError, NEI.x)
         test_pickle_exception(self.assertRaises, PicklingError, NEI)
 
+    def test_subclasses_without_direct_pickle_support_using_name(self):
+        class NamedInt(int):
+            __qualname__ = 'NamedInt'
+            def __new__(cls, *args):
+                _args = args
+                name, *args = args
+                if len(args) == 0:
+                    raise TypeError("name and value must be specified")
+                self = int.__new__(cls, *args)
+                self._intname = name
+                self._args = _args
+                return self
+            @property
+            def __name__(self):
+                return self._intname
+            def __repr__(self):
+                # repr() is updated to include the name and type info
+                return "{}({!r}, {})".format(type(self).__name__,
+                                             self.__name__,
+                                             int.__repr__(self))
+            def __str__(self):
+                # str() is unchanged, even if it relies on the repr() fallback
+                base = int
+                base_str = base.__str__
+                if base_str.__objclass__ is object:
+                    return base.__repr__(self)
+                return base_str(self)
+            # for simplicity, we only define one operator that
+            # propagates expressions
+            def __add__(self, other):
+                temp = int(self) + int( other)
+                if isinstance(self, NamedInt) and isinstance(other, NamedInt):
+                    return NamedInt(
+                        '({0} + {1})'.format(self.__name__, other.__name__),
+                        temp )
+                else:
+                    return temp
+
+        class NEI(NamedInt, Enum):
+            __qualname__ = 'NEI'
+            x = ('the-x', 1)
+            y = ('the-y', 2)
+            def __reduce_ex__(self, proto):
+                return getattr, (self.__class__, self._name_)
+
+        self.assertIs(NEI.__new__, Enum.__new__)
+        self.assertEqual(repr(NEI.x + NEI.y), "NamedInt('(the-x + the-y)', 3)")
+        globals()['NamedInt'] = NamedInt
+        globals()['NEI'] = NEI
+        NI5 = NamedInt('test', 5)
+        self.assertEqual(NI5, 5)
+        self.assertEqual(NEI.y.value, 2)
+        test_pickle_dump_load(self.assertIs, NEI.y)
+        test_pickle_dump_load(self.assertIs, NEI)
+
     def test_tuple_subclass(self):
         class SomeTuple(tuple, Enum):
             __qualname__ = 'SomeTuple'      # needed for pickle protocol 4