Method test_inherit_from_protocol

Lib/test/test_dataclasses/__init__.py:2467–2485

(self)

        self.assertEqual(C(5).x, 10)

    def test_inherit_from_protocol(self):
        # Dataclasses inheriting from protocol should preserve their own `__init__`.
        # See bpo-45081.

        class P(Protocol):
            a: int

        @dataclass
        class C(P):
            a: int

        self.assertEqual(C(5).a, 5)

        @dataclass
        class D(P):
            def __init__(self, a):
                self.a = a * 2

        self.assertEqual(D(5).a, 10)


class TestInitAnnotate(unittest.TestCase):