mypyc/test-data/run-weakref.test

# Test cases for weakrefs (compile and run)

[case testWeakrefRef]
# mypy: disable-error-code="union-attr"
from weakref import proxy, ref
from mypy_extensions import mypyc_attr
from testutil import assertRaises
from typing import Optional

@mypyc_attr(native_class=False)
class Object:
    """some random weakreffable object"""
    def some_meth(self) -> int:
        return 1

_callback_called_cache = {"ref": False, "proxy": False}

def test_weakref_ref() -> None:
    obj: Optional[Object] = Object()
    r = ref(obj)
    assert r() is obj
    obj = None
    assert r() is None, r()

def test_weakref_ref_with_callback() -> None:
    obj: Optional[Object] = Object()
    r = ref(obj, lambda x: _callback_called_cache.__setitem__("ref", True))
    assert r() is obj
    obj = None
    assert r() is None, r()
    assert _callback_called_cache["ref"] is True

def test_weakref_proxy() -> None:
    obj: Optional[Object] = Object()
    p = proxy(obj)
    assert obj.some_meth() == 1
    assert p.some_meth() == 1
    obj.some_meth()
    obj = None
    with assertRaises(ReferenceError):
        p.some_meth()

def test_weakref_proxy_with_callback() -> None:
    obj: Optional[Object] = Object()
    p = proxy(obj, lambda x: _callback_called_cache.__setitem__("proxy", True))
    assert obj.some_meth() == 1
    assert p.some_meth() == 1
    obj.some_meth()
    obj = None
    with assertRaises(ReferenceError):
        p.some_meth()
    assert _callback_called_cache["proxy"] is True