asyncgen.athrow() checks args on asyncgen.athrow().send() but should check them on asyncgen.athrow()

[graingert]

Bug report

Bug description:

async def agen():
    return
    yield


try:
    athrow = agen().athrow()
    athrow.close()
except TypeError:
    print("good")
else:
    print("bad")

output:

bad

CPython versions tested on:

3.8, 3.9, 3.10, 3.11, 3.12, 3.13, CPython main branch

Operating systems tested on:

Linux

[graingert]

to get the error you have to actually await the coroutine:

async def agen():
    return
    yield


athrow = agen().athrow()
athrow.send(None)

output:

Traceback (most recent call last):
  File "/home/graingert/projects/cpython/demo.py", line 7, in <module>
    athrow.send(None)
    ~~~~~~~~~~~^^^^^^
TypeError: athrow expected at least 1 argument, got 0