import unittest

import test.support

from ctypes import c_int, Union, Structure, sizeof

from ._support import StructCheckMixin

class AnonTest(unittest.TestCase, StructCheckMixin):

def test_anon(self):

class ANON(Union):

_fields_ = [("a", c_int),

("b", c_int)]

self.check_union(ANON)

class Y(Structure):

_fields_ = [("x", c_int),

("_", ANON),

("y", c_int)]

_anonymous_ = ["_"]

self.check_struct(Y)

self.assertEqual(Y.a.offset, sizeof(c_int))

self.assertEqual(Y.b.offset, sizeof(c_int))

self.assertEqual(ANON.a.offset, 0)

self.assertEqual(ANON.b.offset, 0)

def test_anon_nonseq(self):

# TypeError: _anonymous_ must be a sequence

self.assertRaises(TypeError,

lambda: type(Structure)("Name",

(Structure,),

{"_fields_": [], "_anonymous_": 42}))

def test_anon_nonmember(self):

# AttributeError: type object 'Name' has no attribute 'x'

self.assertRaises(AttributeError,

lambda: type(Structure)("Name",

(Structure,),

{"_fields_": [],

"_anonymous_": ["x"]}))

@test.support.cpython_only

def test_issue31490(self):

# There shouldn't be an assertion failure in case the class has an

# attribute whose name is specified in _anonymous_ but not in _fields_.

# AttributeError: 'x' is specified in _anonymous_ but not in _fields_

with self.assertRaises(AttributeError):

class Name(Structure):

_fields_ = []

_anonymous_ = ["x"]

x = 42

def test_nested(self):

class ANON_S(Structure):

_fields_ = [("a", c_int)]

self.check_struct(ANON_S)

class ANON_U(Union):

_fields_ = [("_", ANON_S),

("b", c_int)]

_anonymous_ = ["_"]

self.check_union(ANON_U)

class Y(Structure):

_fields_ = [("x", c_int),

("_", ANON_U),

("y", c_int)]

_anonymous_ = ["_"]

self.check_struct(Y)

self.assertEqual(Y.x.offset, 0)

self.assertEqual(Y.a.offset, sizeof(c_int))

self.assertEqual(Y.b.offset, sizeof(c_int))

self.assertEqual(Y._.offset, sizeof(c_int))

self.assertEqual(Y.y.offset, sizeof(c_int) * 2)

if __name__ == "__main__":

unittest.main()