error message is misleading when executing await on non-async func

[sandeep-gh]

Bug report

Bug description:

 def wrapper(afunc):
    async def hook(arg):
        arg = arg + 1
        return await afunc(arg)
    return hook


# bug missing async keyword
def afunc(arg):
    print(f"afunc called with arg = {arg}")
    pass

callback_func = wrapper(afunc)

import asyncio
asyncio.run(callback_func(5))

The error message is:
TypeError: object NoneType can't be used in 'await' expression

The object is of type function , just not async function.

CPython versions tested on:

3.11

Operating systems tested on:

Other

[YvesDup]

Hi @sandeep-gh, your code could be reduce to:

async def main():
    await afunc(5)

asyncio.run(main())

Where afunc is a function (not a coroutine), which return None. And await None raise a TypeError exception.
So there is no bug here, just an exception raised.

[picnixz]

I agree (though AFAICT it should be afunc(6) but that's besides the point). I'm closing it as a non-CPython issue. More precisely, if you were to unroll the construction, callback_func would be equivalent to:

async def callback_func(x):
	x = x + 1
	z = afunc(x)  # your 'afunc' returns None
	t = await z   # await None raises normally
	return t