Formatter undocumented deviation: extra unnecessary wrapping of arguments and extra parenthesis for long return types

[Avasam]

• List of keywords you searched for before creating this issue. Write them down here so that others can find this issue more easily and help provide feedback. undocumented deviation black return

This is similar to https://github.com/astral-sh/ruff/issues/11791, but for return type annotations rather than variable annotations.

• A minimal code snippet that reproduces the bug.

With preview = True:

Black:

class Polygon:
    def cut_section(self, line) -> tuple[
        RegularPolygon | Polygon | Triangle | Point | Point2D | Point3D | Segment2D | Segment3D | Segment | None,
        RegularPolygon | Polygon | Triangle | Point | Point2D | Point3D | Segment2D | Segment3D | Segment | None,
    ]: ...

Ruff:

class Polygon:
    def cut_section(
        self, line
    ) -> tuple[
        RegularPolygon | Polygon | Triangle | Point | Point2D | Point3D | Segment2D | Segment3D | Segment | None,
        RegularPolygon | Polygon | Triangle | Point | Point2D | Point3D | Segment2D | Segment3D | Segment | None,
    ]: ...

See https://github.com/microsoft/python-type-stubs/commit/9eb6bb50ec2d16eccde13e8d51fc03f11a7c0807 for a lot more examples

As an added note, with preview = False, I also get the following deviation:

Black:

def get_basis_vectors() -> tuple[
    tuple[Literal[1], Literal[0], Literal[0]],
    tuple[Literal[0], Literal[1], Literal[0]],
    tuple[Literal[0], Literal[0], Literal[1]],
]: ...

Ruff:

def get_basis_vectors() -> (
    tuple[
        tuple[Literal[1], Literal[0], Literal[0]],
        tuple[Literal[0], Literal[1], Literal[0]],
        tuple[Literal[0], Literal[0], Literal[1]],
    ]
): ...

• The command you invoked (e.g., ruff /path/to/file.py --fix), ideally including the --isolated flag. ruff format

• The current Ruff settings (any relevant sections from your pyproject.toml).

[tool.ruff]
line-length = 130
# Target oldest supported Python version
target-version = "py39"
preview = true

• The current Ruff version (ruff --version). ruff 0.7.2

[MichaReiser]

Thanks. We're aware of the deviation with preview=False but the way this gets formatted with preview=True is rather bad

class Polygon:
    def cut_section(
        self, line
    ) -> tuple[
        RegularPolygon
        | Polygon
        | Triangle
        | Point
        | Point2D
        | Point3D
        | Segment2D
        | Segment3D
        | Segment
        | None,
        RegularPolygon
        | Polygon
        | Triangle
        | Point
        | Point2D
        | Point3D
        | Segment2D
        | Segment3D
        | Segment
        | None,
    ]: ...

[MichaReiser]

Interestingly, prettier does the exact same playground