I tried to be a good boy scout and refactor some duplicated code in

pants.backend.python.target_types_rules

into a helper method, but then Pants gets upset

Exception: pants.backend.python.target_types_rules:134:generate_targets_from_python_tests() returned a result value that did not satisfy its constraints: <coroutine object _generate_targets_helper at 0x7f84820224c0>

Do you use `Get`s outside of the

async def

rule?

Oops, rookie mistake. I forgot to

await

my helper 😮

Why is the helper async?

I assumed only

async

functions could

await

things?

That’s true.. but from the limitation mentioned above, your helper will not have to await anything…

But it sounds like I can't use a helper because the rudimentary parser isn't smart enough to follow along and see the

Get

s int he helper?

Indeed, so helper methods are limited to work on what they get, without invoking other rules.

Bummer

Agree.

A coroutine could maybe work, but I'm not sure it'd result in the most readable code 🤔

what are you trying to break out?

I'm adding a 4th

generate_targets_from_*

function to

src/python/pants/backend/python/target_types_rules.py

. It has slightly different way of collecting sources, so I thought using a helper would not only clean up some duplication but allow me to highlight the difference (that way whoever adds the 5th one doesn't copy mine)

Ah 🙂

I'll probably flounder around trying to puzzle out how to do that with all the different types involved. I think I'll wait until my code works... duplicated, and then ask for some coaching

If your helper needs to

await Get

then it needs to be an async

@rule

and you need to

await Get

it, yes.