attrs/tests/test_compat.py

66 lines
1.6 KiB
Python

# SPDX-License-Identifier: MIT
import types
from typing import Protocol
import pytest
import attr
@pytest.fixture(name="mp")
def _mp():
return types.MappingProxyType({"x": 42, "y": "foo"})
class TestMetadataProxy:
"""
Ensure properties of metadata proxy independently of hypothesis strategies.
"""
def test_repr(self, mp):
"""
repr makes sense and is consistent across Python versions.
"""
assert any(
[
"mappingproxy({'x': 42, 'y': 'foo'})" == repr(mp),
"mappingproxy({'y': 'foo', 'x': 42})" == repr(mp),
]
)
def test_immutable(self, mp):
"""
All mutating methods raise errors.
"""
with pytest.raises(TypeError, match="not support item assignment"):
mp["z"] = 23
with pytest.raises(TypeError, match="not support item deletion"):
del mp["x"]
with pytest.raises(AttributeError, match="no attribute 'update'"):
mp.update({})
with pytest.raises(AttributeError, match="no attribute 'clear'"):
mp.clear()
with pytest.raises(AttributeError, match="no attribute 'pop'"):
mp.pop("x")
with pytest.raises(AttributeError, match="no attribute 'popitem'"):
mp.popitem()
with pytest.raises(AttributeError, match="no attribute 'setdefault'"):
mp.setdefault("x")
def test_attrsinstance_subclass_protocol():
"""
It's possible to subclass AttrsInstance and Protocol at once.
"""
class Foo(attr.AttrsInstance, Protocol):
def attribute(self) -> int: ...