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