Backport some new `Protocol` tests from CPython (#227)
diff --git a/src/test_typing_extensions.py b/src/test_typing_extensions.py
index 37d4c5d..4bec45f 100644
--- a/src/test_typing_extensions.py
+++ b/src/test_typing_extensions.py
@@ -2956,6 +2956,71 @@
# before any isinstance() checks against Sized
self.assertNotIsInstance(1, typing.Sized)
+ def test_empty_protocol_decorated_with_final(self):
+ @final
+ @runtime_checkable
+ class EmptyProtocol(Protocol): ...
+
+ self.assertIsSubclass(object, EmptyProtocol)
+ self.assertIsInstance(object(), EmptyProtocol)
+
+ def test_protocol_decorated_with_final_callable_members(self):
+ @final
+ @runtime_checkable
+ class ProtocolWithMethod(Protocol):
+ def startswith(self, string: str) -> bool: ...
+
+ self.assertIsSubclass(str, ProtocolWithMethod)
+ self.assertNotIsSubclass(int, ProtocolWithMethod)
+ self.assertIsInstance('foo', ProtocolWithMethod)
+ self.assertNotIsInstance(42, ProtocolWithMethod)
+
+ def test_protocol_decorated_with_final_noncallable_members(self):
+ @final
+ @runtime_checkable
+ class ProtocolWithNonCallableMember(Protocol):
+ x: int
+
+ class Foo:
+ x = 42
+
+ only_callable_members_please = (
+ r"Protocols with non-method members don't support issubclass()"
+ )
+
+ with self.assertRaisesRegex(TypeError, only_callable_members_please):
+ issubclass(Foo, ProtocolWithNonCallableMember)
+
+ with self.assertRaisesRegex(TypeError, only_callable_members_please):
+ issubclass(int, ProtocolWithNonCallableMember)
+
+ self.assertIsInstance(Foo(), ProtocolWithNonCallableMember)
+ self.assertNotIsInstance(42, ProtocolWithNonCallableMember)
+
+ def test_protocol_decorated_with_final_mixed_members(self):
+ @final
+ @runtime_checkable
+ class ProtocolWithMixedMembers(Protocol):
+ x: int
+ def method(self) -> None: ...
+
+ class Foo:
+ x = 42
+ def method(self) -> None: ...
+
+ only_callable_members_please = (
+ r"Protocols with non-method members don't support issubclass()"
+ )
+
+ with self.assertRaisesRegex(TypeError, only_callable_members_please):
+ issubclass(Foo, ProtocolWithMixedMembers)
+
+ with self.assertRaisesRegex(TypeError, only_callable_members_please):
+ issubclass(int, ProtocolWithMixedMembers)
+
+ self.assertIsInstance(Foo(), ProtocolWithMixedMembers)
+ self.assertNotIsInstance(42, ProtocolWithMixedMembers)
+
class Point2DGeneric(Generic[T], TypedDict):
a: T
