Method test_dataclasses_pickleable

Lib/test/test_dataclasses/__init__.py:2186–2213

(self)

        self.assertEqual(Child.__mro__, (Child, Parent, Generic, object))

    def test_dataclasses_pickleable(self):
        global P, Q, R
        @dataclass
        class P:
            x: int
            y: int = 0
        @dataclass
        class Q:
            x: int
            y: int = field(default=0, init=False)
        @dataclass
        class R:
            x: int
            y: List[int] = field(default_factory=list)
        q = Q(1)
        q.y = 2
        samples = [P(1), P(1, 2), Q(1), q, R(1), R(1, [2, 3, 4])]
        for sample in samples:
            for proto in range(pickle.HIGHEST_PROTOCOL + 1):
                with self.subTest(sample=sample, proto=proto):
                    new_sample = pickle.loads(pickle.dumps(sample, proto))
                    self.assertEqual(sample.x, new_sample.x)
                    self.assertEqual(sample.y, new_sample.y)
                    self.assertIsNot(sample, new_sample)
                    new_sample.x = 42
                    another_new_sample = pickle.loads(pickle.dumps(new_sample, proto))
                    self.assertEqual(new_sample.x, another_new_sample.x)
                    self.assertEqual(sample.y, another_new_sample.y)

    def test_dataclasses_qualnames(self):
        @dataclass(order=True, unsafe_hash=True, frozen=True)