import pytest

from yarl._url import cached_property


def test_reify():
    class A:
        def __init__(self):
            self._cache = {}

        @cached_property
        def prop(self):
            return 1

    a = A()
    assert 1 == a.prop


def test_reify_class():
    class A:
        def __init__(self):
            self._cache = {}

        @cached_property
        def prop(self):
            """Docstring."""
            return 1

    assert isinstance(A.prop, cached_property)
    assert "Docstring." == A.prop.__doc__


def test_reify_assignment():
    class A:
        def __init__(self):
            self._cache = {}

        @cached_property
        def prop(self):
            return 1

    a = A()

    with pytest.raises(AttributeError):
        a.prop = 123