Detecting unneeded async keywords on functions

[Greesb]

Hello,

I refactored a bunch of code and thought about a rule that could be useful: detecting function defined with the async keywords not using any await inside it, example:

async def unneeded_async() -> None:  # should raise the error
    print("lol")

async def legit_async() -> None:  # should not raise the error
    await some_stuff()

There's probably some use cases where the async is needed, but, imo, most of the time those async can be removed.

What do you think ?

[zanieb]

We like this idea :) this is a duplicate of #9833 though

[Greesb]

Doesn't look like it is, the issue you mentioned is for detecting missing await keywords when calling async functions.

What i'm talking about is to detect functions that are defined with the async keyword but do not need it because there's no await inside them. @zanieb

[zanieb]

Yeah I see, it's a little mixed up over there as we're discussing both things.

We can track this separately.

@plredmond I'll move you over to this issue.

[plredmond]

In progress implementation: main...plredmond:ruff:issue9951-spurious_async