[3.9] bpo-42567: [Enum] call __init_subclass__ after members are added (GH-23714) (GH-23772)

When creating an Enum, `type.__new__` calls `__init_subclass__`, but at that point the members have not been added.

This patch suppresses the initial call, then manually calls the ancestor `__init_subclass__` before returning the new Enum class.
(cherry picked from commit 6bd94de168)
This commit is contained in:
Ethan Furman 2020-12-14 18:41:34 -08:00 committed by GitHub
parent aba12b67c1
commit 9d1fff1fcd
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 103 additions and 3 deletions

View file

@ -2049,7 +2049,6 @@ def test_empty_globals(self):
local_ls = {}
exec(code, global_ns, local_ls)
@unittest.skipUnless(
sys.version_info[:2] == (3, 9),
'private variables are now normal attributes',
@ -2066,6 +2065,42 @@ class Private(Enum):
except ValueError:
pass
def test_init_subclass(self):
class MyEnum(Enum):
def __init_subclass__(cls, **kwds):
super(MyEnum, cls).__init_subclass__(**kwds)
self.assertFalse(cls.__dict__.get('_test', False))
cls._test1 = 'MyEnum'
#
class TheirEnum(MyEnum):
def __init_subclass__(cls, **kwds):
super().__init_subclass__(**kwds)
cls._test2 = 'TheirEnum'
class WhoseEnum(TheirEnum):
def __init_subclass__(cls, **kwds):
pass
class NoEnum(WhoseEnum):
ONE = 1
self.assertEqual(TheirEnum.__dict__['_test1'], 'MyEnum')
self.assertEqual(WhoseEnum.__dict__['_test1'], 'MyEnum')
self.assertEqual(WhoseEnum.__dict__['_test2'], 'TheirEnum')
self.assertFalse(NoEnum.__dict__.get('_test1', False))
self.assertFalse(NoEnum.__dict__.get('_test2', False))
#
class OurEnum(MyEnum):
def __init_subclass__(cls, **kwds):
cls._test2 = 'OurEnum'
class WhereEnum(OurEnum):
def __init_subclass__(cls, **kwds):
pass
class NeverEnum(WhereEnum):
ONE = 'one'
self.assertEqual(OurEnum.__dict__['_test1'], 'MyEnum')
self.assertFalse(WhereEnum.__dict__.get('_test1', False))
self.assertEqual(WhereEnum.__dict__['_test2'], 'OurEnum')
self.assertFalse(NeverEnum.__dict__.get('_test1', False))
self.assertFalse(NeverEnum.__dict__.get('_test2', False))
class TestOrder(unittest.TestCase):
@ -2516,6 +2551,42 @@ def cycle_enum():
'at least one thread failed while creating composite members')
self.assertEqual(256, len(seen), 'too many composite members created')
def test_init_subclass(self):
class MyEnum(Flag):
def __init_subclass__(cls, **kwds):
super().__init_subclass__(**kwds)
self.assertFalse(cls.__dict__.get('_test', False))
cls._test1 = 'MyEnum'
#
class TheirEnum(MyEnum):
def __init_subclass__(cls, **kwds):
super(TheirEnum, cls).__init_subclass__(**kwds)
cls._test2 = 'TheirEnum'
class WhoseEnum(TheirEnum):
def __init_subclass__(cls, **kwds):
pass
class NoEnum(WhoseEnum):
ONE = 1
self.assertEqual(TheirEnum.__dict__['_test1'], 'MyEnum')
self.assertEqual(WhoseEnum.__dict__['_test1'], 'MyEnum')
self.assertEqual(WhoseEnum.__dict__['_test2'], 'TheirEnum')
self.assertFalse(NoEnum.__dict__.get('_test1', False))
self.assertFalse(NoEnum.__dict__.get('_test2', False))
#
class OurEnum(MyEnum):
def __init_subclass__(cls, **kwds):
cls._test2 = 'OurEnum'
class WhereEnum(OurEnum):
def __init_subclass__(cls, **kwds):
pass
class NeverEnum(WhereEnum):
ONE = 1
self.assertEqual(OurEnum.__dict__['_test1'], 'MyEnum')
self.assertFalse(WhereEnum.__dict__.get('_test1', False))
self.assertEqual(WhereEnum.__dict__['_test2'], 'OurEnum')
self.assertFalse(NeverEnum.__dict__.get('_test1', False))
self.assertFalse(NeverEnum.__dict__.get('_test2', False))
class TestIntFlag(unittest.TestCase):
"""Tests of the IntFlags."""