Function _from_string_test

tests/test_traitlets.py:2902–2918

Run a test of trait.from_string

(traittype, s, expected)

def _from_string_test(traittype, s, expected):
    """Run a test of trait.from_string"""
    if isinstance(traittype, TraitType):
        trait = traittype
    else:
        trait = traittype(allow_none=True)
    if isinstance(s, list):
        cast = trait.from_string_list  # type:ignore
    else:
        cast = trait.from_string
    if type(expected) is type and issubclass(expected, Exception):
        with pytest.raises(expected):  # noqa: PT012
            value = cast(s)
            trait.validate(CrossValidationStub(), value)  # type:ignore
    else:
        value = cast(s)
        assert value == expected


@pytest.mark.parametrize(