531 lines
19 KiB
Python
531 lines
19 KiB
Python
# Copyright 2007 Google, Inc. All Rights Reserved.
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# Licensed to PSF under a Contributor Agreement.
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# Note: each test is run with Python and C versions of ABCMeta. Except for
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# test_ABC_helper(), which assures that abc.ABC is an instance of abc.ABCMeta.
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"""Unit tests for abc.py."""
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import unittest
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import abc
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import _py_abc
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from inspect import isabstract
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def test_factory(abc_ABCMeta, abc_get_cache_token):
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class TestLegacyAPI(unittest.TestCase):
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def test_abstractproperty_basics(self):
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@abc.abstractproperty
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def foo(self): pass
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self.assertTrue(foo.__isabstractmethod__)
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def bar(self): pass
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self.assertFalse(hasattr(bar, "__isabstractmethod__"))
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class C(metaclass=abc_ABCMeta):
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@abc.abstractproperty
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def foo(self): return 3
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self.assertRaises(TypeError, C)
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class D(C):
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@property
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def foo(self): return super().foo
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self.assertEqual(D().foo, 3)
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self.assertFalse(getattr(D.foo, "__isabstractmethod__", False))
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def test_abstractclassmethod_basics(self):
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@abc.abstractclassmethod
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def foo(cls): pass
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self.assertTrue(foo.__isabstractmethod__)
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@classmethod
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def bar(cls): pass
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self.assertFalse(getattr(bar, "__isabstractmethod__", False))
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class C(metaclass=abc_ABCMeta):
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@abc.abstractclassmethod
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def foo(cls): return cls.__name__
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self.assertRaises(TypeError, C)
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class D(C):
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@classmethod
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def foo(cls): return super().foo()
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self.assertEqual(D.foo(), 'D')
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self.assertEqual(D().foo(), 'D')
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def test_abstractstaticmethod_basics(self):
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@abc.abstractstaticmethod
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def foo(): pass
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self.assertTrue(foo.__isabstractmethod__)
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@staticmethod
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def bar(): pass
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self.assertFalse(getattr(bar, "__isabstractmethod__", False))
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class C(metaclass=abc_ABCMeta):
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@abc.abstractstaticmethod
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def foo(): return 3
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self.assertRaises(TypeError, C)
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class D(C):
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@staticmethod
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def foo(): return 4
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self.assertEqual(D.foo(), 4)
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self.assertEqual(D().foo(), 4)
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class TestABC(unittest.TestCase):
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def test_ABC_helper(self):
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# create an ABC using the helper class and perform basic checks
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class C(abc.ABC):
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@classmethod
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@abc.abstractmethod
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def foo(cls): return cls.__name__
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self.assertEqual(type(C), abc.ABCMeta)
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self.assertRaises(TypeError, C)
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class D(C):
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@classmethod
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def foo(cls): return super().foo()
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self.assertEqual(D.foo(), 'D')
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def test_abstractmethod_basics(self):
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@abc.abstractmethod
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def foo(self): pass
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self.assertTrue(foo.__isabstractmethod__)
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def bar(self): pass
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self.assertFalse(hasattr(bar, "__isabstractmethod__"))
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def test_abstractproperty_basics(self):
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@property
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@abc.abstractmethod
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def foo(self): pass
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self.assertTrue(foo.__isabstractmethod__)
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def bar(self): pass
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self.assertFalse(getattr(bar, "__isabstractmethod__", False))
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class C(metaclass=abc_ABCMeta):
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@property
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@abc.abstractmethod
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def foo(self): return 3
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self.assertRaises(TypeError, C)
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class D(C):
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@C.foo.getter
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def foo(self): return super().foo
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self.assertEqual(D().foo, 3)
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def test_abstractclassmethod_basics(self):
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@classmethod
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@abc.abstractmethod
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def foo(cls): pass
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self.assertTrue(foo.__isabstractmethod__)
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@classmethod
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def bar(cls): pass
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self.assertFalse(getattr(bar, "__isabstractmethod__", False))
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class C(metaclass=abc_ABCMeta):
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@classmethod
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@abc.abstractmethod
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def foo(cls): return cls.__name__
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self.assertRaises(TypeError, C)
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class D(C):
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@classmethod
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def foo(cls): return super().foo()
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self.assertEqual(D.foo(), 'D')
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self.assertEqual(D().foo(), 'D')
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def test_abstractstaticmethod_basics(self):
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@staticmethod
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@abc.abstractmethod
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def foo(): pass
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self.assertTrue(foo.__isabstractmethod__)
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@staticmethod
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def bar(): pass
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self.assertFalse(getattr(bar, "__isabstractmethod__", False))
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class C(metaclass=abc_ABCMeta):
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@staticmethod
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@abc.abstractmethod
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def foo(): return 3
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self.assertRaises(TypeError, C)
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class D(C):
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@staticmethod
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def foo(): return 4
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self.assertEqual(D.foo(), 4)
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self.assertEqual(D().foo(), 4)
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def test_object_new_with_one_abstractmethod(self):
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class C(metaclass=abc_ABCMeta):
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@abc.abstractmethod
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def method_one(self):
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pass
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msg = r"class C with abstract method method_one"
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self.assertRaisesRegex(TypeError, msg, C)
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def test_object_new_with_many_abstractmethods(self):
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class C(metaclass=abc_ABCMeta):
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@abc.abstractmethod
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def method_one(self):
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pass
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@abc.abstractmethod
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def method_two(self):
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pass
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msg = r"class C with abstract methods method_one, method_two"
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self.assertRaisesRegex(TypeError, msg, C)
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def test_abstractmethod_integration(self):
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for abstractthing in [abc.abstractmethod, abc.abstractproperty,
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abc.abstractclassmethod,
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abc.abstractstaticmethod]:
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class C(metaclass=abc_ABCMeta):
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@abstractthing
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def foo(self): pass # abstract
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def bar(self): pass # concrete
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self.assertEqual(C.__abstractmethods__, {"foo"})
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self.assertRaises(TypeError, C) # because foo is abstract
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self.assertTrue(isabstract(C))
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class D(C):
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def bar(self): pass # concrete override of concrete
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self.assertEqual(D.__abstractmethods__, {"foo"})
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self.assertRaises(TypeError, D) # because foo is still abstract
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self.assertTrue(isabstract(D))
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class E(D):
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def foo(self): pass
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self.assertEqual(E.__abstractmethods__, set())
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E() # now foo is concrete, too
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self.assertFalse(isabstract(E))
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class F(E):
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@abstractthing
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def bar(self): pass # abstract override of concrete
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self.assertEqual(F.__abstractmethods__, {"bar"})
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self.assertRaises(TypeError, F) # because bar is abstract now
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self.assertTrue(isabstract(F))
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def test_descriptors_with_abstractmethod(self):
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class C(metaclass=abc_ABCMeta):
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@property
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@abc.abstractmethod
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def foo(self): return 3
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@foo.setter
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@abc.abstractmethod
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def foo(self, val): pass
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self.assertRaises(TypeError, C)
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class D(C):
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@C.foo.getter
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def foo(self): return super().foo
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self.assertRaises(TypeError, D)
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class E(D):
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@D.foo.setter
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def foo(self, val): pass
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self.assertEqual(E().foo, 3)
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# check that the property's __isabstractmethod__ descriptor does the
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# right thing when presented with a value that fails truth testing:
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class NotBool(object):
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def __bool__(self):
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raise ValueError()
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__len__ = __bool__
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with self.assertRaises(ValueError):
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class F(C):
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def bar(self):
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pass
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bar.__isabstractmethod__ = NotBool()
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foo = property(bar)
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def test_customdescriptors_with_abstractmethod(self):
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class Descriptor:
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def __init__(self, fget, fset=None):
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self._fget = fget
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self._fset = fset
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def getter(self, callable):
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return Descriptor(callable, self._fget)
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def setter(self, callable):
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return Descriptor(self._fget, callable)
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@property
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def __isabstractmethod__(self):
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return (getattr(self._fget, '__isabstractmethod__', False)
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or getattr(self._fset, '__isabstractmethod__', False))
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class C(metaclass=abc_ABCMeta):
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@Descriptor
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@abc.abstractmethod
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def foo(self): return 3
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@foo.setter
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@abc.abstractmethod
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def foo(self, val): pass
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self.assertRaises(TypeError, C)
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class D(C):
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@C.foo.getter
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def foo(self): return super().foo
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self.assertRaises(TypeError, D)
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class E(D):
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@D.foo.setter
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def foo(self, val): pass
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self.assertFalse(E.foo.__isabstractmethod__)
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def test_metaclass_abc(self):
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# Metaclasses can be ABCs, too.
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class A(metaclass=abc_ABCMeta):
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@abc.abstractmethod
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def x(self):
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pass
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self.assertEqual(A.__abstractmethods__, {"x"})
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class meta(type, A):
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def x(self):
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return 1
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class C(metaclass=meta):
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pass
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def test_registration_basics(self):
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class A(metaclass=abc_ABCMeta):
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pass
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class B(object):
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pass
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b = B()
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self.assertFalse(issubclass(B, A))
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self.assertFalse(issubclass(B, (A,)))
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self.assertNotIsInstance(b, A)
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self.assertNotIsInstance(b, (A,))
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B1 = A.register(B)
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self.assertTrue(issubclass(B, A))
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self.assertTrue(issubclass(B, (A,)))
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self.assertIsInstance(b, A)
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self.assertIsInstance(b, (A,))
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self.assertIs(B1, B)
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class C(B):
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pass
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c = C()
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self.assertTrue(issubclass(C, A))
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self.assertTrue(issubclass(C, (A,)))
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self.assertIsInstance(c, A)
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self.assertIsInstance(c, (A,))
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def test_register_as_class_deco(self):
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class A(metaclass=abc_ABCMeta):
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pass
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@A.register
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class B(object):
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pass
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b = B()
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self.assertTrue(issubclass(B, A))
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self.assertTrue(issubclass(B, (A,)))
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self.assertIsInstance(b, A)
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self.assertIsInstance(b, (A,))
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@A.register
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class C(B):
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pass
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c = C()
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self.assertTrue(issubclass(C, A))
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self.assertTrue(issubclass(C, (A,)))
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self.assertIsInstance(c, A)
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self.assertIsInstance(c, (A,))
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self.assertIs(C, A.register(C))
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def test_isinstance_invalidation(self):
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class A(metaclass=abc_ABCMeta):
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pass
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class B:
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pass
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b = B()
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self.assertFalse(isinstance(b, A))
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self.assertFalse(isinstance(b, (A,)))
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token_old = abc_get_cache_token()
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A.register(B)
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token_new = abc_get_cache_token()
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self.assertGreater(token_new, token_old)
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self.assertTrue(isinstance(b, A))
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self.assertTrue(isinstance(b, (A,)))
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def test_registration_builtins(self):
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class A(metaclass=abc_ABCMeta):
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pass
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A.register(int)
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self.assertIsInstance(42, A)
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self.assertIsInstance(42, (A,))
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self.assertTrue(issubclass(int, A))
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self.assertTrue(issubclass(int, (A,)))
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class B(A):
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pass
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B.register(str)
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class C(str): pass
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self.assertIsInstance("", A)
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self.assertIsInstance("", (A,))
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self.assertTrue(issubclass(str, A))
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self.assertTrue(issubclass(str, (A,)))
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self.assertTrue(issubclass(C, A))
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self.assertTrue(issubclass(C, (A,)))
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def test_registration_edge_cases(self):
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class A(metaclass=abc_ABCMeta):
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pass
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A.register(A) # should pass silently
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class A1(A):
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pass
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self.assertRaises(RuntimeError, A1.register, A) # cycles not allowed
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class B(object):
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pass
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A1.register(B) # ok
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A1.register(B) # should pass silently
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class C(A):
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pass
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A.register(C) # should pass silently
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self.assertRaises(RuntimeError, C.register, A) # cycles not allowed
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C.register(B) # ok
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def test_register_non_class(self):
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class A(metaclass=abc_ABCMeta):
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pass
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self.assertRaisesRegex(TypeError, "Can only register classes",
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A.register, 4)
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def test_registration_transitiveness(self):
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class A(metaclass=abc_ABCMeta):
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pass
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self.assertTrue(issubclass(A, A))
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self.assertTrue(issubclass(A, (A,)))
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class B(metaclass=abc_ABCMeta):
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pass
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self.assertFalse(issubclass(A, B))
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self.assertFalse(issubclass(A, (B,)))
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self.assertFalse(issubclass(B, A))
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self.assertFalse(issubclass(B, (A,)))
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class C(metaclass=abc_ABCMeta):
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pass
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A.register(B)
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class B1(B):
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pass
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self.assertTrue(issubclass(B1, A))
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self.assertTrue(issubclass(B1, (A,)))
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class C1(C):
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pass
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B1.register(C1)
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self.assertFalse(issubclass(C, B))
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self.assertFalse(issubclass(C, (B,)))
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self.assertFalse(issubclass(C, B1))
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self.assertFalse(issubclass(C, (B1,)))
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self.assertTrue(issubclass(C1, A))
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self.assertTrue(issubclass(C1, (A,)))
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self.assertTrue(issubclass(C1, B))
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self.assertTrue(issubclass(C1, (B,)))
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self.assertTrue(issubclass(C1, B1))
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self.assertTrue(issubclass(C1, (B1,)))
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C1.register(int)
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class MyInt(int):
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pass
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self.assertTrue(issubclass(MyInt, A))
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self.assertTrue(issubclass(MyInt, (A,)))
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self.assertIsInstance(42, A)
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self.assertIsInstance(42, (A,))
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def test_issubclass_bad_arguments(self):
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class A(metaclass=abc_ABCMeta):
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pass
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with self.assertRaises(TypeError):
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issubclass({}, A) # unhashable
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with self.assertRaises(TypeError):
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issubclass(42, A) # No __mro__
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# Python version supports any iterable as __mro__.
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# But it's implementation detail and don't emulate it in C version.
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class C:
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__mro__ = 42 # __mro__ is not tuple
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with self.assertRaises(TypeError):
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issubclass(C(), A)
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# bpo-34441: Check that issubclass() doesn't crash on bogus
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# classes.
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bogus_subclasses = [
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None,
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lambda x: [],
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lambda: 42,
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lambda: [42],
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]
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for i, func in enumerate(bogus_subclasses):
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class S(metaclass=abc_ABCMeta):
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__subclasses__ = func
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with self.subTest(i=i):
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with self.assertRaises(TypeError):
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issubclass(int, S)
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# Also check that issubclass() propagates exceptions raised by
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# __subclasses__.
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exc_msg = "exception from __subclasses__"
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def raise_exc():
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raise Exception(exc_msg)
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class S(metaclass=abc_ABCMeta):
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__subclasses__ = raise_exc
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with self.assertRaisesRegex(Exception, exc_msg):
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issubclass(int, S)
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def test_subclasshook(self):
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class A(metaclass=abc.ABCMeta):
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@classmethod
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def __subclasshook__(cls, C):
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if cls is A:
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return 'foo' in C.__dict__
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return NotImplemented
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self.assertFalse(issubclass(A, A))
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self.assertFalse(issubclass(A, (A,)))
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class B:
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foo = 42
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self.assertTrue(issubclass(B, A))
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self.assertTrue(issubclass(B, (A,)))
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class C:
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spam = 42
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self.assertFalse(issubclass(C, A))
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self.assertFalse(issubclass(C, (A,)))
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def test_all_new_methods_are_called(self):
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class A(metaclass=abc_ABCMeta):
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pass
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class B(object):
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counter = 0
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def __new__(cls):
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B.counter += 1
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return super().__new__(cls)
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class C(A, B):
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pass
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self.assertEqual(B.counter, 0)
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C()
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self.assertEqual(B.counter, 1)
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def test_ABC_has___slots__(self):
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self.assertTrue(hasattr(abc.ABC, '__slots__'))
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def test_tricky_new_works(self):
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def with_metaclass(meta, *bases):
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class metaclass(type):
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def __new__(cls, name, this_bases, d):
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return meta(name, bases, d)
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return type.__new__(metaclass, 'temporary_class', (), {})
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class A: ...
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class B: ...
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class C(with_metaclass(abc_ABCMeta, A, B)):
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pass
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self.assertEqual(C.__class__, abc_ABCMeta)
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class TestABCWithInitSubclass(unittest.TestCase):
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|
def test_works_with_init_subclass(self):
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class abc_ABC(metaclass=abc_ABCMeta):
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__slots__ = ()
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saved_kwargs = {}
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|
class ReceivesClassKwargs:
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|
def __init_subclass__(cls, **kwargs):
|
|
super().__init_subclass__()
|
|
saved_kwargs.update(kwargs)
|
|
class Receiver(ReceivesClassKwargs, abc_ABC, x=1, y=2, z=3):
|
|
pass
|
|
self.assertEqual(saved_kwargs, dict(x=1, y=2, z=3))
|
|
return TestLegacyAPI, TestABC, TestABCWithInitSubclass
|
|
|
|
TestLegacyAPI_Py, TestABC_Py, TestABCWithInitSubclass_Py = test_factory(abc.ABCMeta,
|
|
abc.get_cache_token)
|
|
TestLegacyAPI_C, TestABC_C, TestABCWithInitSubclass_C = test_factory(_py_abc.ABCMeta,
|
|
_py_abc.get_cache_token)
|
|
|
|
if __name__ == "__main__":
|
|
unittest.main()
|