test_roundtrips.py 文件源码

def test_union_field_roundtrip(converter, cl_and_vals_a, cl_and_vals_b, strat):
    """
    Classes with union fields can be unstructured and structured.
    """
    converter.unstruct_strat = strat
    cl_a, vals_a = cl_and_vals_a
    cl_b, vals_b = cl_and_vals_b
    a_field_names = {a.name for a in fields(cl_a)}
    b_field_names = {a.name for a in fields(cl_b)}
    assume(a_field_names)
    assume(b_field_names)

    common_names = a_field_names & b_field_names
    assume(len(a_field_names) > len(common_names))

    @attr.s
    class C(object):
        a = attr.ib(type=Union[cl_a, cl_b])

    inst = C(a=cl_a(*vals_a))

    if strat is UnstructureStrategy.AS_DICT:
        assert inst == converter.structure(converter.unstructure(inst), C)
    else:
        # Our disambiguation functions only support dictionaries for now.
        with pytest.raises(ValueError):
            converter.structure(converter.unstructure(inst), C)

        def handler(obj, _):
            return converter.structure(obj, cl_a)

        converter._union_registry[Union[cl_a, cl_b]] = handler
        assert inst == converter.structure(converter.unstructure(inst), C)
        del converter._union_registry[Union[cl_a, cl_b]]