bpo-34536: raise error for invalid _missing_ results (GH-9147)
* raise exception if _missing_ returns None or invalid type
This commit is contained in:
parent
a5d1eb8d8b
commit
019f0a0cb8
20
Lib/enum.py
20
Lib/enum.py
|
@ -585,7 +585,25 @@ class Enum(metaclass=EnumMeta):
|
|||
if member._value_ == value:
|
||||
return member
|
||||
# still not found -- try _missing_ hook
|
||||
return cls._missing_(value)
|
||||
try:
|
||||
exc = None
|
||||
result = cls._missing_(value)
|
||||
except Exception as e:
|
||||
exc = e
|
||||
result = None
|
||||
if isinstance(result, cls):
|
||||
return result
|
||||
else:
|
||||
ve_exc = ValueError("%r is not a valid %s" % (value, cls.__name__))
|
||||
if result is None and exc is None:
|
||||
raise ve_exc
|
||||
elif exc is None:
|
||||
exc = TypeError(
|
||||
'error in %s._missing_: returned %r instead of None or a valid member'
|
||||
% (cls.__name__, result)
|
||||
)
|
||||
exc.__context__ = ve_exc
|
||||
raise exc
|
||||
|
||||
def _generate_next_value_(name, start, count, last_values):
|
||||
for last_value in reversed(last_values):
|
||||
|
|
|
@ -3,6 +3,7 @@ import inspect
|
|||
import pydoc
|
||||
import sys
|
||||
import unittest
|
||||
import sys
|
||||
import threading
|
||||
from collections import OrderedDict
|
||||
from enum import Enum, IntEnum, EnumMeta, Flag, IntFlag, unique, auto
|
||||
|
@ -1697,6 +1698,38 @@ class TestEnum(unittest.TestCase):
|
|||
third = auto()
|
||||
self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes))
|
||||
|
||||
def test_missing(self):
|
||||
class Color(Enum):
|
||||
red = 1
|
||||
green = 2
|
||||
blue = 3
|
||||
@classmethod
|
||||
def _missing_(cls, item):
|
||||
if item == 'three':
|
||||
return cls.blue
|
||||
elif item == 'bad return':
|
||||
# trigger internal error
|
||||
return 5
|
||||
elif item == 'error out':
|
||||
raise ZeroDivisionError
|
||||
else:
|
||||
# trigger not found
|
||||
return None
|
||||
self.assertIs(Color('three'), Color.blue)
|
||||
self.assertRaises(ValueError, Color, 7)
|
||||
try:
|
||||
Color('bad return')
|
||||
except TypeError as exc:
|
||||
self.assertTrue(isinstance(exc.__context__, ValueError))
|
||||
else:
|
||||
raise Exception('Exception not raised.')
|
||||
try:
|
||||
Color('error out')
|
||||
except ZeroDivisionError as exc:
|
||||
self.assertTrue(isinstance(exc.__context__, ValueError))
|
||||
else:
|
||||
raise Exception('Exception not raised.')
|
||||
|
||||
|
||||
class TestOrder(unittest.TestCase):
|
||||
|
||||
|
|
|
@ -0,0 +1,2 @@
|
|||
`Enum._missing_`: raise `ValueError` if None returned and `TypeError` if
|
||||
non-member is returned.
|
Loading…
Reference in New Issue