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|
import sys
import unittest
import types
import pytest
from pure_eval import CannotEval
from pure_eval.my_getattr_static import getattr_static, safe_descriptors_raw
class TestGetattrStatic(unittest.TestCase):
def assert_getattr(self, thing, attr):
self.assertEqual(
getattr_static(thing, attr),
getattr(thing, attr),
)
def assert_cannot_getattr(self, thing, attr):
with self.assertRaises(CannotEval):
getattr_static(thing, attr)
def test_basic(self):
class Thing(object):
x = object()
thing = Thing()
self.assert_getattr(thing, 'x')
self.assert_cannot_getattr(thing, 'y')
def test_inherited(self):
class Thing(object):
x = object()
class OtherThing(Thing):
pass
something = OtherThing()
self.assert_getattr(something, 'x')
def test_instance_attr(self):
class Thing(object):
x = 2
def __init__(self, x):
self.x = x
thing = Thing(3)
self.assert_getattr(thing, 'x')
self.assert_getattr(Thing, 'x')
del thing.x
self.assert_getattr(thing, 'x')
def test_property(self):
class Thing(object):
@property
def x(self):
raise AttributeError("I'm pretending not to exist")
thing = Thing()
self.assert_cannot_getattr(thing, 'x')
# TODO this should be doable as Thing.x is the property object
# It would require checking that type(klass_result) is property and then just returning that
self.assert_cannot_getattr(Thing, 'x')
def test_descriptor_raises_AttributeError(self):
class descriptor(object):
def __get__(*_):
raise AttributeError("I'm pretending not to exist")
desc = descriptor()
class Thing(object):
x = desc
thing = Thing()
self.assert_cannot_getattr(thing, 'x')
self.assert_cannot_getattr(Thing, 'x')
def test_classAttribute(self):
class Thing(object):
x = object()
self.assert_getattr(Thing, 'x')
def test_classVirtualAttribute(self):
class Thing(object):
@types.DynamicClassAttribute
def x(self):
return self._x
_x = object()
self.assert_cannot_getattr(Thing(), 'x')
self.assert_cannot_getattr(Thing, 'x')
def test_inherited_classattribute(self):
class Thing(object):
x = object()
class OtherThing(Thing):
pass
self.assert_getattr(OtherThing, 'x')
def test_slots(self):
class Thing(object):
y = 'bar'
__slots__ = ['x']
def __init__(self):
self.x = 'foo'
thing = Thing()
self.assert_getattr(thing, 'x')
self.assert_getattr(Thing, 'x')
self.assert_getattr(thing, 'y')
self.assert_getattr(Thing, 'y')
del thing.x
self.assert_cannot_getattr(thing, 'x')
def test_metaclass(self):
class meta(type):
attr = 'foo'
class Thing(object, metaclass=meta):
pass
self.assert_getattr(Thing, 'attr')
class SubThing(Thing):
pass
self.assert_getattr(SubThing, 'attr')
class sub(meta):
pass
class OtherThing(object, metaclass=sub):
x = 3
self.assert_getattr(OtherThing, 'attr')
class OtherOtherThing(OtherThing):
pass
self.assert_getattr(OtherOtherThing, 'x')
self.assert_getattr(OtherOtherThing, 'attr')
def test_no_dict_no_slots(self):
self.assert_cannot_getattr(1, 'foo')
self.assert_getattr('foo', 'lower')
def test_no_dict_no_slots_instance_member(self):
# returns descriptor
with open(__file__) as handle:
self.assert_cannot_getattr(handle, 'name')
def test_inherited_slots(self):
class Thing(object):
__slots__ = ['x']
def __init__(self):
self.x = 'foo'
class OtherThing(Thing):
pass
self.assert_getattr(OtherThing(), 'x')
def test_descriptor(self):
class descriptor(object):
def __get__(self, instance, owner):
return 3
class Foo(object):
d = descriptor()
foo = Foo()
# for a non data descriptor we return the instance attribute
foo.__dict__['d'] = 1
self.assert_getattr(foo, 'd')
# if the descriptor is a data-descriptor it would be invoked so we can't get it
descriptor.__set__ = lambda s, i, v: None
self.assert_cannot_getattr(foo, 'd')
del descriptor.__set__
descriptor.__delete__ = lambda s, i, o: None
self.assert_cannot_getattr(foo, 'd')
def test_metaclass_with_descriptor(self):
class descriptor(object):
def __get__(self, instance, owner):
return 3
class meta(type):
d = descriptor()
class Thing(object, metaclass=meta):
pass
self.assert_cannot_getattr(Thing, 'd')
def test_class_as_property(self):
class Base(object):
foo = 3
class Something(Base):
@property
def __class__(self):
return 1 / 0
instance = Something()
self.assert_getattr(instance, 'foo')
self.assert_getattr(Something, 'foo')
def test_mro_as_property(self):
class Meta(type):
@property
def __mro__(self):
return 1 / 0
class Base(object):
foo = 3
class Something(Base, metaclass=Meta):
pass
self.assert_getattr(Something(), 'foo')
self.assert_getattr(Something, 'foo')
def test_dict_as_property(self):
class Foo(dict):
a = 3
@property
def __dict__(self):
return 1 / 0
foo = Foo()
foo.a = 4
self.assert_cannot_getattr(foo, 'a')
self.assert_getattr(Foo, 'a')
def test_custom_object_dict(self):
class Custom(dict):
def get(self, key, default=None):
return 1 / 0
__getitem__ = get
class Foo(object):
a = 3
foo = Foo()
foo.__dict__ = Custom()
foo.x = 5
self.assert_getattr(foo, 'a')
self.assert_getattr(foo, 'x')
def test_metaclass_dict_as_property(self):
class Meta(type):
@property
def __dict__(self):
return 1 / 0
class Thing(metaclass=Meta):
bar = 4
def __init__(self):
self.spam = 42
instance = Thing()
self.assert_getattr(instance, "spam")
# TODO this fails with CannotEval, it doesn't like the __dict__ property,
# but it seems that shouldn't actually matter because it's not called
# self.assert_getattr(Thing, "bar")
def test_module(self):
self.assert_getattr(sys, "version")
def test_metaclass_with_metaclass_with_dict_as_property(self):
class MetaMeta(type):
@property
def __dict__(self):
self.executed = True
return dict(spam=42)
class Meta(type, metaclass=MetaMeta):
executed = False
class Thing(metaclass=Meta):
pass
self.assert_cannot_getattr(Thing, "spam")
self.assertFalse(Thing.executed)
def test_safe_descriptors_immutable():
for d in safe_descriptors_raw:
with pytest.raises((TypeError, AttributeError)):
type(d).__get__ = None
|
