import pytest

from duckql.properties import Null


@pytest.fixture(scope="module")
def valid_instance() -> Null:
    return Null()


def test_string(valid_instance: Null):
    assert str(valid_instance) == 'NULL'


def test_obj(valid_instance: Null):
    assert valid_instance.obj == 'properties.Null'


def test_json_parse(valid_instance: Null):
    assert valid_instance.json() == '{"obj": "properties.Null"}'

[((6, 1, 6, 31), 'pytest.fixture', 'pytest.fixture', (), '', False, 'import pytest\n'), ((8, 11, 8, 17), 'duckql.properties.Null', 'Null', ({}, {}), '()', False, 'from duckql.properties import Null\n')]