| # Copyright 2019 The ChromiumOS Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Test the attrs_freezer module.""" |
| |
| from chromite.lib import cros_test_lib |
| from chromite.utils import attrs_freezer |
| |
| |
| class FrozenAttributesTest(cros_test_lib.TestCase): |
| """Tests FrozenAttributesMixin functionality.""" |
| |
| class StubClass: |
| """Any class that does not override __setattr__.""" |
| |
| class SetattrClass: |
| """Class that does override __setattr__.""" |
| |
| SETATTR_OFFSET = 10 |
| |
| def __setattr__(self, attr, value): |
| """Adjust value here to later confirm that this code ran.""" |
| object.__setattr__(self, attr, self.SETATTR_OFFSET + value) |
| |
| def _TestBasics(self, cls): |
| # pylint: disable=attribute-defined-outside-init |
| def _Expected(val): |
| return getattr(cls, "SETATTR_OFFSET", 0) + val |
| |
| obj = cls() |
| obj.a = 1 |
| obj.b = 2 |
| self.assertEqual(_Expected(1), obj.a) |
| self.assertEqual(_Expected(2), obj.b) |
| |
| obj.Freeze() |
| self.assertRaises(attrs_freezer.Error, setattr, obj, "a", 3) |
| self.assertEqual(_Expected(1), obj.a) |
| |
| self.assertRaises(attrs_freezer.Error, setattr, obj, "c", 3) |
| self.assertFalse(hasattr(obj, "c")) |
| |
| def testFrozenByMetaclass(self): |
| """Test attribute freezing with FrozenAttributesClass.""" |
| |
| class StubByMeta(self.StubClass, metaclass=attrs_freezer.Class): |
| """Class that freezes StubClass using metaclass construct.""" |
| |
| self._TestBasics(StubByMeta) |
| |
| class SetattrByMeta(self.SetattrClass, metaclass=attrs_freezer.Class): |
| """Class that freezes SetattrClass using metaclass construct.""" |
| |
| self._TestBasics(SetattrByMeta) |
| |
| def testFrozenByMixinFirst(self): |
| """Test attribute freezing with Mixin first in hierarchy.""" |
| |
| class Stub(attrs_freezer.Mixin, self.StubClass): |
| """Class that freezes StubClass using mixin construct.""" |
| |
| self._TestBasics(Stub) |
| |
| class Setattr(attrs_freezer.Mixin, self.SetattrClass): |
| """Class that freezes SetattrClass using mixin construct.""" |
| |
| self._TestBasics(Setattr) |
| |
| def testFrozenByMixinLast(self): |
| """Test attribute freezing with Mixin last in hierarchy.""" |
| |
| class Stub(self.StubClass, attrs_freezer.Mixin): |
| """Class that freezes StubClass using mixin construct.""" |
| |
| self._TestBasics(Stub) |
| |
| class Setattr(self.SetattrClass, attrs_freezer.Mixin): |
| """Class that freezes SetattrClass using mixin construct.""" |
| |
| self._TestBasics(Setattr) |
