Issue #24254: Preserve class attribute definition order.
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 7741a79..486f445 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -16,8 +16,10 @@
import types
import unittest
import warnings
+from collections import OrderedDict
from operator import neg
-from test.support import TESTFN, unlink, run_unittest, check_warnings
+from test.support import (TESTFN, unlink, run_unittest, check_warnings,
+ cpython_only)
from test.support.script_helper import assert_python_ok
try:
import pty, signal
@@ -1778,6 +1780,194 @@
A.__doc__ = doc
self.assertEqual(A.__doc__, doc)
+ def test_type_definition_order_nonempty(self):
+ class Spam:
+ b = 1
+ c = 3
+ a = 2
+ d = 4
+ eggs = 2
+ e = 5
+ b = 42
+
+ self.assertEqual(Spam.__definition_order__,
+ ('__module__', '__qualname__',
+ 'b', 'c', 'a', 'd', 'eggs', 'e'))
+
+ def test_type_definition_order_empty(self):
+ class Empty:
+ pass
+
+ self.assertEqual(Empty.__definition_order__,
+ ('__module__', '__qualname__'))
+
+ def test_type_definition_order_on_instance(self):
+ class Spam:
+ a = 2
+ b = 1
+ c = 3
+ with self.assertRaises(AttributeError):
+ Spam().__definition_order__
+
+ def test_type_definition_order_set_to_None(self):
+ class Spam:
+ a = 2
+ b = 1
+ c = 3
+ Spam.__definition_order__ = None
+ self.assertEqual(Spam.__definition_order__, None)
+
+ def test_type_definition_order_set_to_tuple(self):
+ class Spam:
+ a = 2
+ b = 1
+ c = 3
+ Spam.__definition_order__ = ('x', 'y', 'z')
+ self.assertEqual(Spam.__definition_order__, ('x', 'y', 'z'))
+
+ def test_type_definition_order_deleted(self):
+ class Spam:
+ a = 2
+ b = 1
+ c = 3
+ del Spam.__definition_order__
+ self.assertEqual(Spam.__definition_order__, None)
+
+ def test_type_definition_order_set_to_bad_type(self):
+ class Spam:
+ a = 2
+ b = 1
+ c = 3
+ Spam.__definition_order__ = 42
+ self.assertEqual(Spam.__definition_order__, 42)
+
+ def test_type_definition_order_builtins(self):
+ self.assertEqual(object.__definition_order__, None)
+ self.assertEqual(type.__definition_order__, None)
+ self.assertEqual(dict.__definition_order__, None)
+ self.assertEqual(type(None).__definition_order__, None)
+
+ def test_type_definition_order_dunder_names_included(self):
+ class Dunder:
+ VAR = 3
+ def __init__(self):
+ pass
+
+ self.assertEqual(Dunder.__definition_order__,
+ ('__module__', '__qualname__',
+ 'VAR', '__init__'))
+
+ def test_type_definition_order_only_dunder_names(self):
+ class DunderOnly:
+ __xyz__ = None
+ def __init__(self):
+ pass
+
+ self.assertEqual(DunderOnly.__definition_order__,
+ ('__module__', '__qualname__',
+ '__xyz__', '__init__'))
+
+ def test_type_definition_order_underscore_names(self):
+ class HalfDunder:
+ __whether_to_be = True
+ or_not_to_be__ = False
+
+ self.assertEqual(HalfDunder.__definition_order__,
+ ('__module__', '__qualname__',
+ '_HalfDunder__whether_to_be', 'or_not_to_be__'))
+
+ def test_type_definition_order_with_slots(self):
+ class Slots:
+ __slots__ = ('x', 'y')
+ a = 1
+ b = 2
+
+ self.assertEqual(Slots.__definition_order__,
+ ('__module__', '__qualname__',
+ '__slots__', 'a', 'b'))
+
+ def test_type_definition_order_overwritten_None(self):
+ class OverwrittenNone:
+ __definition_order__ = None
+ a = 1
+ b = 2
+ c = 3
+
+ self.assertEqual(OverwrittenNone.__definition_order__, None)
+
+ def test_type_definition_order_overwritten_tuple(self):
+ class OverwrittenTuple:
+ __definition_order__ = ('x', 'y', 'z')
+ a = 1
+ b = 2
+ c = 3
+
+ self.assertEqual(OverwrittenTuple.__definition_order__,
+ ('x', 'y', 'z'))
+
+ def test_type_definition_order_overwritten_bad_item(self):
+ with self.assertRaises(TypeError):
+ class PoorlyOverwritten:
+ __definition_order__ = ('a', 2, 'c')
+ a = 1
+ b = 2
+ c = 3
+
+ def test_type_definition_order_overwritten_bad_type(self):
+ with self.assertRaises(TypeError):
+ class PoorlyOverwritten:
+ __definition_order__ = ['a', 2, 'c']
+ a = 1
+ b = 2
+ c = 3
+
+ def test_type_definition_order_metaclass(self):
+ class Meta(type):
+ SPAM = 42
+
+ def __init__(self, *args, **kwargs):
+ super().__init__(*args, **kwargs)
+
+ self.assertEqual(Meta.__definition_order__,
+ ('__module__', '__qualname__',
+ 'SPAM', '__init__'))
+
+ def test_type_definition_order_OrderedDict(self):
+ class Meta(type):
+ def __prepare__(self, *args, **kwargs):
+ return OrderedDict()
+
+ class WithODict(metaclass=Meta):
+ x='y'
+
+ self.assertEqual(WithODict.__definition_order__,
+ ('__module__', '__qualname__', 'x'))
+
+ class Meta(type):
+ def __prepare__(self, *args, **kwargs):
+ class ODictSub(OrderedDict):
+ pass
+ return ODictSub()
+
+ class WithODictSub(metaclass=Meta):
+ x='y'
+
+ self.assertEqual(WithODictSub.__definition_order__,
+ ('__module__', '__qualname__', 'x'))
+
+ @cpython_only
+ def test_type_definition_order_cpython(self):
+ # some implementations will have an ordered-by-default dict.
+
+ class Meta(type):
+ def __prepare__(self, *args, **kwargs):
+ return {}
+
+ class NotOrdered(metaclass=Meta):
+ x='y'
+
+ self.assertEqual(NotOrdered.__definition_order__, None)
+
def test_bad_args(self):
with self.assertRaises(TypeError):
type()