astral-sh/ruff

SIM114: Safe fix removes comments

Open

#19576 opened on Jul 27, 2025

View on GitHub
 (8 comments) (1 reaction) (0 assignees)Rust (47,527 stars) (2,088 forks)batch import
bugfixeshelp wanted

Description

Summary

Example:

ruff check src/s3ql/backends/b2/b2_backend.py 
src/s3ql/backends/b2/b2_backend.py:362:9: SIM114 [*] Combine `if` branches using logical `or` operator
    |
360 |               return True
361 |
362 | /         elif isinstance(exc, HTTPError) and (
363 | |             (500 <= exc.status <= 599)
364 | |             or exc.status == 408  # server errors
365 | |             or exc.status == 429  # request timeout
366 | |         ):  # too many requests
367 | |             return True
368 | |
369 | |         # Consider all SSL errors as temporary. There are a lot of bug
370 | |         # reports from people where various SSL errors cause a crash
371 | |         # but are actually just temporary. On the other hand, we have
372 | |         # no information if this ever revealed a problem where retrying
373 | |         # was not the right choice.
374 | |         elif isinstance(exc, ssl.SSLError):
375 | |             return True
    | |_______________________^ SIM114
376 |
377 |           return False
    |
    = help: Combine `if` branches
[...]
Found 7 errors.
[*] 1 fixable with the `--fix` option (2 hidden fixes can be enabled with the `--unsafe-fixes` option).

I noticed that there's at least one older report about a similar problem with another rule. Perhaps there's a need for some generic safeguard that prevents removal of comments for any rule?

Version

ruff 0.12.5

Contributor guide

Tech stack
rustpython
Domain
toolingdeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
knowledge of Rustunderstanding of ruff's linter internalsfamiliarity with SIM114 rule
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Examine the implementation of the SIM114 rule in the Ruff codebase, likely in crates/ruff linter/src/rules/flake8 simplify/ or similar. The safe fix currently removes comments when combining if branches. Investigate how other rules handle comment preservation during autofixes, and consider adding a generic safeguard to prevent comment removal across all rules. Review the linked thread for additional context on similar issues.