Request: autofix for EM102 with msg

[jamesbraza]

some_string = "ruff"
raise ValueError(f"Hello {some_string}.")

Running with ruff==0.0.263:

> ruff --fixable=EM102 --fix --select=EM102 a.py
a.py:2:18: EM102 Exception must not use an f-string literal, assign to variable first
Found 1 error.

It would be nice if EM102 supported autofix with msg like the rule explanation so:

some_string = "ruff"
msg = f"Hello {some_string}."
raise ValueError(msg)

[charliermarsh]

👍 I think we should be able to support this.

[dhruvmanila]

What if the msg variable is already defined in same or outer scope? Should we try different variable names or maybe a config option for the user to specify the variable name? In any case, this would be a AutofixKind::Sometimes.

[charliermarsh]

I'd suggest just skipping the fix if msg is defined in the same scope or any parent scope (but not making the name configurable).

[dhruvmanila]

I would like to work on this, will get my hands dirty with the autofix API :)

[charliermarsh]

Rock on, thanks @dhruvmanila! (Know I owe you some responses in other PRs too.)