add TypeGuard to coroutines.iscoroutine (#6105)

make CoroutineType extend Coroutine

stdlib/asyncio/coroutines.pyi

@@ -1,7 +1,16 @@
-from typing import Any, Callable, TypeVar
+import sys
+import types
+from collections.abc import Callable, Coroutine
+from typing import Any, TypeVar
+from typing_extensions import TypeGuard
 
 _F = TypeVar("_F", bound=Callable[..., Any])
 
 def coroutine(func: _F) -> _F: ...
 def iscoroutinefunction(func: object) -> bool: ...
-def iscoroutine(obj: object) -> bool: ...
+
+if sys.version_info < (3, 8):
+    def iscoroutine(obj: object) -> TypeGuard[types.GeneratorType[Any, Any, Any] | Coroutine[Any, Any, Any]]: ...
+
+else:
+    def iscoroutine(obj: object) -> TypeGuard[Coroutine[Any, Any, Any]]: ...

stdlib/inspect.pyi

@@ -62,7 +62,7 @@ else:
     def iscoroutinefunction(object: object) -> bool: ...
 
 def isgenerator(object: object) -> TypeGuard[GeneratorType[Any, Any, Any]]: ...
-def iscoroutine(object: object) -> TypeGuard[CoroutineType]: ...
+def iscoroutine(object: object) -> TypeGuard[CoroutineType[Any, Any, Any]]: ...
 def isawaitable(object: object) -> TypeGuard[Awaitable[Any]]: ...
 
 if sys.version_info >= (3, 8):

stdlib/types.pyi

@@ -6,6 +6,7 @@ from typing import (
     AsyncGenerator,
     Awaitable,
     Callable,
+    Coroutine,
     Generator,
     Generic,
     ItemsView,
@@ -211,7 +212,7 @@ class AsyncGeneratorType(AsyncGenerator[_T_co, _T_contra]):
     def aclose(self) -> Awaitable[None]: ...
 
 @final
-class CoroutineType:
+class CoroutineType(Coroutine[_T_co, _T_contra, _V_co]):
     __name__: str
     __qualname__: str
     cr_await: Any | None
@@ -219,12 +220,14 @@ class CoroutineType:
     cr_frame: FrameType
     cr_running: bool
     def close(self) -> None: ...
-    def __await__(self) -> Generator[Any, None, Any]: ...
-    def send(self, __arg: Any) -> Any: ...
+    def __await__(self) -> Generator[Any, None, _V_co]: ...
+    def send(self, __arg: _T_contra) -> _T_co: ...
     @overload
-    def throw(self, __typ: Type[BaseException], __val: BaseException | object = ..., __tb: TracebackType | None = ...) -> Any: ...
+    def throw(
+        self, __typ: Type[BaseException], __val: BaseException | object = ..., __tb: TracebackType | None = ...
+    ) -> _T_co: ...
     @overload
-    def throw(self, __typ: BaseException, __val: None = ..., __tb: TracebackType | None = ...) -> Any: ...
+    def throw(self, __typ: BaseException, __val: None = ..., __tb: TracebackType | None = ...) -> _T_co: ...
 
 class _StaticFunctionType:
     """Fictional type to correct the type of MethodType.__func__.
@@ -365,7 +368,7 @@ def prepare_class(
 # Actually a different type, but `property` is special and we want that too.
 DynamicClassAttribute = property
 
-def coroutine(func: Callable[..., Any]) -> CoroutineType: ...
+def coroutine(func: Callable[..., Any]) -> CoroutineType[Any, Any, Any]: ...
 
 if sys.version_info >= (3, 8):
     CellType = _Cell