import typing
import unittest


class TestTypingNamedTuple(unittest.TestCase):
    def setUp(self):
        class A(typing.NamedTuple):
            value:bool = True

        class B(A):
            value:bool = False

        class C(A, typing.NamedTuple):
            """ The same if definition will be 
            class C(A, metaclass=typing.NamedTupleMeta)
            """
            
            value:bool = False
            
        self.__dict__.update(locals())

    def test_ok(self):
        # used default values
        self.assertTrue(self.A().value)
        self.assertFalse(self.B().value)
        self.assertFalse(self.C().value)

        self.assertFalse(self.A(value=False).value)

    def test_b_fail(self):
        self.assertFalse(self.B(value=False).value)
        self.assertTrue(self.B(value=True).value)  # fail here
    
    def test_c_ok(self):
        self.assertFalse(self.C(value=False).value)
        self.assertTrue(self.C(value=True).value)

    def test_eq_b_fail(self):
        for _class in (self.A, self.B, self.C):
            instance = _class()
            assert instance[0] == instance.value, _class  # fail here with B


if __name__ == '__main__':
    unittest.main()