F821 false-positive for SQLAlchemy mappings with not yet declared classes

[aberres]

The described behavior happens since 0.3.3. It might be related to #10340

It is triggered throughout my SQLAlchemy models in cases where a model is not defined yet while used in a type annotation

Minimal repro:

from __future__ import annotations

from sqlalchemy.orm import DeclarativeBase, Mapped


class Base(DeclarativeBase):
    some_mapping: Mapped[list[Bar]] | None = None # F821 Undefined name `Bar`
    simplified: list[Bar] | None = None # F821 Undefined name `Bar`


class Bar:
    pass

I can only trigger the error when inheriting from DeclarativeBase. Without this inheritance or when inheriting from another class, things are fine.

[AlexWaygood]

Hi! I can't reproduce your error locally or in the Ruff playground: https://play.ruff.rs/1f9ab24b-394d-46c3-923a-ecf866705693

Can you paste a snippet that reproduces the error in the Ruff playground?

[aberres]

Does the playground have a real installation of SQLAlchemy?

I can only reproduce it locally with the actual sqlalchemy.orm.DeclarativeBase. Other classes as a base class are fine.

[AlexWaygood]

I don't think it should matter from Ruff's perspective whether sqlalchemy is installed into a Python environment or not, but let me check that :-)

[AlexWaygood]

I can't reproduce locally with SQLAlchemy installed either.

Does it still reproduce for you after running ruff clean?

[carl-baillargeon]

We are also hitting this issue in this project: https://github.com/arista-netdevops-community/anta

If you install the project locally with 0.3.3 you should see a bunch of F821 errors:

(.anta-dev) ~/git_projects/anta (main ✗) ruff check 
anta/models.py:273:27: F821 Undefined name `ResultOverwrite`
anta/models.py:274:18: F821 Undefined name `Filters`
anta/tests/bfd.py:40:25: F821 Undefined name `BFDPeer`
anta/tests/bfd.py:93:25: F821 Undefined name `BFDPeer`
anta/tests/connectivity.py:35:21: F821 Undefined name `Host`
anta/tests/connectivity.py:94:25: F821 Undefined name `Neighbor`
anta/tests/interfaces.py:176:26: F821 Undefined name `InterfaceState`
anta/tests/interfaces.py:535:26: F821 Undefined name `InterfaceDetail`
anta/tests/routing/bgp.py:175:32: F821 Undefined name `BgpAfi`
anta/tests/routing/bgp.py:285:32: F821 Undefined name `BgpAfi`
anta/tests/routing/bgp.py:397:32: F821 Undefined name `BgpAfi`
anta/tests/routing/bgp.py:509:25: F821 Undefined name `BgpNeighbor`
anta/tests/routing/bgp.py:581:25: F821 Undefined name `BgpPeer`
anta/tests/routing/bgp.py:653:25: F821 Undefined name `BgpPeer`
anta/tests/routing/bgp.py:719:25: F821 Undefined name `BgpPeer`
anta/tests/routing/bgp.py:785:25: F821 Undefined name `BgpPeer`
anta/tests/routing/bgp.py:846:31: F821 Undefined name `VxlanEndpoint`
anta/tests/routing/bgp.py:909:25: F821 Undefined name `BgpPeer`
anta/tests/routing/bgp.py:968:25: F821 Undefined name `BgpPeer`
anta/tests/security.py:303:28: F821 Undefined name `APISSLCertificate`
anta/tests/security.py:462:33: F821 Undefined name `IPv4ACL`
anta/tests/security.py:471:27: F821 Undefined name `IPv4ACLEntry`
anta/tests/services.py:106:27: F821 Undefined name `DnsServer`
anta/tests/services.py:159:23: F821 Undefined name `ErrDisableReason`
Found 24 errors.

Thanks

[charliermarsh]

I also can't reproduce this in the playground, but I can reproduce by running cargo run check anta/anta/models.py --select F821 -n locally.

[charliermarsh]

(I can't reproduce by running locally over the originating snippet.)

[charliermarsh]

This reproduces:

from __future__ import annotations

from pydantic import BaseModel

 
class Input(BaseModel):

    result_overwrite: ResultOverwrite | None = None
    filters: Filters | None = None

    class ResultOverwrite(BaseModel):
        ...

    class Filters(BaseModel):
        ...

[charliermarsh]

The original snippet doesn't reproduce because DeclarativeBase needs to be declared as runtime-required. Now it reproduces: https://play.ruff.rs/825f89f6-d49c-4688-bfe7-6866319fa764

[AlexWaygood]

Okay, so lint.flake8-type-checking.runtime-evaluated-base-classes needs to be set to ["sqlalchemy.orm.DeclarativeBase"] in order for it to reproduce

[carl-baillargeon]

This reproduces:

from __future__ import annotations

from pydantic import BaseModel

 
class Input(BaseModel):

    result_overwrite: ResultOverwrite | None = None
    filters: Filters | None = None

    class ResultOverwrite(BaseModel):
        ...

    class Filters(BaseModel):
        ...

Should I open a separate issue to track it?

[aberres]

@carl-baillargeon Should be the same issue due to pydantic.BaseModel being listed in lint.flake8-type-checking.runtime-evaluated-base-classes.

[AlexWaygood]

Confirmed that this (unsurprisingly) bisects to 704fefc. Sorry for the regression!

[insilications]

@carl-baillargeon Should be the same issue due to pydantic.BaseModel being listed in lint.flake8-type-checking.runtime-evaluated-base-classes.

Confirmed.