run_coroutine_threadsafe type fix

Author: mikeshardmind

stdlib/asyncio/tasks.pyi

@@ -9,6 +9,7 @@ from _asyncio import (
 )
 from collections.abc import AsyncIterator, Awaitable, Coroutine, Generator, Iterable, Iterator
 from typing import Any, Literal, Protocol, TypeVar, overload
+from types import CoroutineType
 from typing_extensions import TypeAlias
 
 from . import _CoroutineLike
@@ -79,7 +80,10 @@ if sys.version_info >= (3, 12):
     _FutureLike: TypeAlias = Future[_T] | Awaitable[_T]
 else:
     _FutureLike: TypeAlias = Future[_T] | Generator[Any, None, _T] | Awaitable[_T]
+
 _TaskYieldType: TypeAlias = Future[object] | None
+_ThreadsafeCouroutineType: TypeAlias = Coroutine[Any, Any, _T] | CoroutineType[Any, Any, _T]
+
 
 FIRST_COMPLETED = concurrent.futures.FIRST_COMPLETED
 FIRST_EXCEPTION = concurrent.futures.FIRST_EXCEPTION
@@ -347,7 +351,8 @@ else:
         *coros_or_futures: _FutureLike[_T], loop: AbstractEventLoop | None = None, return_exceptions: bool
     ) -> Future[list[_T | BaseException]]: ...
 
-def run_coroutine_threadsafe(coro: _FutureLike[_T], loop: AbstractEventLoop) -> concurrent.futures.Future[_T]: ...
+# unlike some asyncio apis, This does strict runtime checking of actually being a coroutine, not of any future-like
+def run_coroutine_threadsafe(coro: _ThreadsafeCouroutineType[_T], loop: AbstractEventLoop) -> concurrent.futures.Future[_T]: ...
 
 if sys.version_info >= (3, 10):
     def shield(arg: _FutureLike[_T]) -> Future[_T]: ...