Method test_no_inheritance_from_nominal

Lib/test/test_typing.py:2944–2964

(self)

        self.assertIsInstance(f, HasCallProtocol)

    def test_no_inheritance_from_nominal(self):
        class C: pass

        class BP(Protocol): pass

        with self.assertRaises(TypeError):
            class P(C, Protocol):
                pass
        with self.assertRaises(TypeError):
            class Q(Protocol, C):
                pass
        with self.assertRaises(TypeError):
            class R(BP, C, Protocol):
                pass

        class D(BP, C): pass

        class E(C, BP): pass

        self.assertNotIsInstance(D(), E)
        self.assertNotIsInstance(E(), D)

    def test_inheritance_from_object(self):
        # Inheritance from object is specifically allowed, unlike other nominal classes