[Autofix error] RUF005 autofix fails inside f-string: f"{a() + ['b']}"

[konstin]

In ruff 99a755f, the following snippet causes the autofix RUF005 to introduce a syntax error:

f"{a() + ['b']}"

$ ./ruff --no-cache --select RUF005 --fix code.py

error: Autofix introduced a syntax error. Reverting all changes.

This indicates a bug in `ruff`. If you could open an issue at:

    https://github.com/charliermarsh/ruff/issues/new?title=%5BAutofix%20error%5D

...quoting the contents of `code.py`, the rule codes RUF005, along with the `pyproject.toml` settings and executed command, we'd be very appreciative!

code.py:1:4: RUF005 Consider `[*a(), "b"]` instead of concatenation
Found 1 error.

This was originally discovered in https://github.com/Mojino01/hugging_face/blob/3dae0d7b4fb8d7e9383b893e4e1799191bb2ab7b/src/transformers/pipelines/base.py#L1181

[charliermarsh]

I think we have a few options for addressing this class of issues:

1. Always skip autofix within f-strings (easiest).
2. Skip autofix within f-strings on a rule-by-rule basis. This is fine, but we're going to have to omit most rules. Even RUF005 only fails because we go through unparse_expr, which changes the quote style of the 'b' to "b".
3. Improve unparse_expr to enforce specific quote styles within f-strings. This would require tracking the quote style of the f-string, threading it down to unparse_expr, and respecting it throughout the unparse logic.

I'm honestly tempted to do (1).

[konstin]

One note to add here is that most of these will valid syntax with PEP 701 implemented, currently targeted for python 3.12, i.e. we could very ambitiously allow autofixes in f-strings for projects with minimum python version 3.12.