Update abc module to CPython 3.10.0

Author: moreal

Lib/abc.py

@@ -28,7 +28,14 @@ def my_abstract_method(self, ...):
 class abstractclassmethod(classmethod):
     """A decorator indicating abstract classmethods.
 
-    Deprecated, use 'classmethod' with 'abstractmethod' instead.
+    Deprecated, use 'classmethod' with 'abstractmethod' instead:
+
+        class C(ABC):
+            @classmethod
+            @abstractmethod
+            def my_abstract_classmethod(cls, ...):
+                ...
+
     """
 
     __isabstractmethod__ = True
@@ -41,7 +48,14 @@ def __init__(self, callable):
 class abstractstaticmethod(staticmethod):
     """A decorator indicating abstract staticmethods.
 
-    Deprecated, use 'staticmethod' with 'abstractmethod' instead.
+    Deprecated, use 'staticmethod' with 'abstractmethod' instead:
+
+        class C(ABC):
+            @staticmethod
+            @abstractmethod
+            def my_abstract_staticmethod(...):
+                ...
+
     """
 
     __isabstractmethod__ = True
@@ -54,7 +68,14 @@ def __init__(self, callable):
 class abstractproperty(property):
     """A decorator indicating abstract properties.
 
-    Deprecated, use 'property' with 'abstractmethod' instead.
+    Deprecated, use 'property' with 'abstractmethod' instead:
+
+        class C(ABC):
+            @property
+            @abstractmethod
+            def my_abstract_property(self):
+                ...
+
     """
 
     __isabstractmethod__ = True
@@ -64,6 +85,10 @@ class abstractproperty(property):
     from _abc import (get_cache_token, _abc_init, _abc_register,
                       _abc_instancecheck, _abc_subclasscheck, _get_dump,
                       _reset_registry, _reset_caches)
+# TODO: RUSTPYTHON missing _abc module implementation.
+except ModuleNotFoundError:
+    from _py_abc import ABCMeta, get_cache_token
+    ABCMeta.__module__ = 'abc'
 except ImportError:
     from _py_abc import ABCMeta, get_cache_token
     ABCMeta.__module__ = 'abc'
@@ -122,6 +147,44 @@ def _abc_caches_clear(cls):
             _reset_caches(cls)
 
 
+def update_abstractmethods(cls):
+    """Recalculate the set of abstract methods of an abstract class.
+
+    If a class has had one of its abstract methods implemented after the
+    class was created, the method will not be considered implemented until
+    this function is called. Alternatively, if a new abstract method has been
+    added to the class, it will only be considered an abstract method of the
+    class after this function is called.
+
+    This function should be called before any use is made of the class,
+    usually in class decorators that add methods to the subject class.
+
+    Returns cls, to allow usage as a class decorator.
+
+    If cls is not an instance of ABCMeta, does nothing.
+    """
+    if not hasattr(cls, '__abstractmethods__'):
+        # We check for __abstractmethods__ here because cls might by a C
+        # implementation or a python implementation (especially during
+        # testing), and we want to handle both cases.
+        return cls
+
+    abstracts = set()
+    # Check the existing abstract methods of the parents, keep only the ones
+    # that are not implemented.
+    for scls in cls.__bases__:
+        for name in getattr(scls, '__abstractmethods__', ()):
+            value = getattr(cls, name, None)
+            if getattr(value, "__isabstractmethod__", False):
+                abstracts.add(name)
+    # Also add any other newly added abstract methods.
+    for name, value in cls.__dict__.items():
+        if getattr(value, "__isabstractmethod__", False):
+            abstracts.add(name)
+    cls.__abstractmethods__ = frozenset(abstracts)
+    return cls
+
+
 class ABC(metaclass=ABCMeta):
     """Helper class that provides a standard way to create an ABC using
     inheritance.

Lib/test/test_abc.py

@@ -157,8 +157,25 @@ def foo(): return 4
             self.assertEqual(D.foo(), 4)
             self.assertEqual(D().foo(), 4)
 
-        # TODO: RUSTPYTHON
-        @unittest.expectedFailure
+        def test_object_new_with_one_abstractmethod(self):
+            class C(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def method_one(self):
+                    pass
+            msg = r"class C with abstract method method_one"
+            self.assertRaisesRegex(TypeError, msg, C)
+
+        def test_object_new_with_many_abstractmethods(self):
+            class C(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def method_one(self):
+                    pass
+                @abc.abstractmethod
+                def method_two(self):
+                    pass
+            msg = r"class C with abstract methods method_one, method_two"
+            self.assertRaisesRegex(TypeError, msg, C)
+
         def test_abstractmethod_integration(self):
             for abstractthing in [abc.abstractmethod, abc.abstractproperty,
                                   abc.abstractclassmethod,
@@ -219,6 +236,7 @@ def bar(self):
                     bar.__isabstractmethod__ = NotBool()
                     foo = property(bar)
 
+
         def test_customdescriptors_with_abstractmethod(self):
             class Descriptor:
                 def __init__(self, fget, fset=None):
@@ -318,7 +336,7 @@ class B:
             token_old = abc_get_cache_token()
             A.register(B)
             token_new = abc_get_cache_token()
-            self.assertNotEqual(token_old, token_new)
+            self.assertGreater(token_new, token_old)
             self.assertTrue(isinstance(b, A))
             self.assertTrue(isinstance(b, (A,)))
 
@@ -451,6 +469,24 @@ class S(metaclass=abc_ABCMeta):
             with self.assertRaisesRegex(Exception, exc_msg):
                 issubclass(int, S)
 
+        def test_subclasshook(self):
+            class A(metaclass=abc.ABCMeta):
+                @classmethod
+                def __subclasshook__(cls, C):
+                    if cls is A:
+                        return 'foo' in C.__dict__
+                    return NotImplemented
+            self.assertFalse(issubclass(A, A))
+            self.assertFalse(issubclass(A, (A,)))
+            class B:
+                foo = 42
+            self.assertTrue(issubclass(B, A))
+            self.assertTrue(issubclass(B, (A,)))
+            class C:
+                spam = 42
+            self.assertFalse(issubclass(C, A))
+            self.assertFalse(issubclass(C, (A,)))
+
         def test_all_new_methods_are_called(self):
             class A(metaclass=abc_ABCMeta):
                 pass
@@ -480,6 +516,155 @@ class C(with_metaclass(abc_ABCMeta, A, B)):
                 pass
             self.assertEqual(C.__class__, abc_ABCMeta)
 
+        def test_update_del(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            del A.foo
+            self.assertEqual(A.__abstractmethods__, {'foo'})
+            self.assertFalse(hasattr(A, 'foo'))
+
+            abc.update_abstractmethods(A)
+
+            self.assertEqual(A.__abstractmethods__, set())
+            A()
+
+
+        def test_update_new_abstractmethods(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def bar(self):
+                    pass
+
+            @abc.abstractmethod
+            def updated_foo(self):
+                pass
+
+            A.foo = updated_foo
+            abc.update_abstractmethods(A)
+            self.assertEqual(A.__abstractmethods__, {'foo', 'bar'})
+            msg = "class A with abstract methods bar, foo"
+            self.assertRaisesRegex(TypeError, msg, A)
+
+        def test_update_implementation(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            class B(A):
+                pass
+
+            msg = "class B with abstract method foo"
+            self.assertRaisesRegex(TypeError, msg, B)
+            self.assertEqual(B.__abstractmethods__, {'foo'})
+
+            B.foo = lambda self: None
+
+            abc.update_abstractmethods(B)
+
+            B()
+            self.assertEqual(B.__abstractmethods__, set())
+
+        def test_update_as_decorator(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            def class_decorator(cls):
+                cls.foo = lambda self: None
+                return cls
+
+            @abc.update_abstractmethods
+            @class_decorator
+            class B(A):
+                pass
+
+            B()
+            self.assertEqual(B.__abstractmethods__, set())
+
+        def test_update_non_abc(self):
+            class A:
+                pass
+
+            @abc.abstractmethod
+            def updated_foo(self):
+                pass
+
+            A.foo = updated_foo
+            abc.update_abstractmethods(A)
+            A()
+            self.assertFalse(hasattr(A, '__abstractmethods__'))
+
+        def test_update_del_implementation(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            class B(A):
+                def foo(self):
+                    pass
+
+            B()
+
+            del B.foo
+
+            abc.update_abstractmethods(B)
+
+            msg = "class B with abstract method foo"
+            self.assertRaisesRegex(TypeError, msg, B)
+
+        def test_update_layered_implementation(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            class B(A):
+                pass
+
+            class C(B):
+                def foo(self):
+                    pass
+
+            C()
+
+            del C.foo
+
+            abc.update_abstractmethods(C)
+
+            msg = "class C with abstract method foo"
+            self.assertRaisesRegex(TypeError, msg, C)
+
+        def test_update_multi_inheritance(self):
+            class A(metaclass=abc_ABCMeta):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            class B(metaclass=abc_ABCMeta):
+                def foo(self):
+                    pass
+
+            class C(B, A):
+                @abc.abstractmethod
+                def foo(self):
+                    pass
+
+            self.assertEqual(C.__abstractmethods__, {'foo'})
+
+            del C.foo
+
+            abc.update_abstractmethods(C)
+
+            self.assertEqual(C.__abstractmethods__, set())
+
+            C()
+
 
     class TestABCWithInitSubclass(unittest.TestCase):
         def test_works_with_init_subclass(self):