astral-sh/ruff

Split UP035 (deprecated-import) for aliases

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#7,436 opened on Sep 16, 2023

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 (3 comments) (0 reactions) (0 assignees)Rust (47,527 stars) (2,088 forks)batch import
help wantedrule

Description

I'd like to request the deprecated-import rule be split in two. Currently UP035 flags two different kinds of deprecations:

  • Names that have been moved, with a deprecated alias. Examples:
    • collections.* => collections.abc.*
    • {pipes => shlex}.quote
  • Types that are deprecated, considered equivalent by type checkers, but are different runtime values.
    • This is everything in the typing, typing_extensions and mypy_extensions modules.

For the former group, fixing them is significantly safer, since the only visible side-effects would be that a module wasn't imported (in the case of pipes), and a lack of a DeprecationWarning. It'd be rare for code to depend on those side-effects. The latter group can potentially be an unsafe change if something tries to observe the types directly at runtime though.

Ultimately I'd like to be able to autofix the moved names, whilst being able to separately flag (with a suggested fix) the typing changes that would be observable at runtime.

Contributor guide

Tech stack
rustpython
Domain
developer experiencetooling
Issue type
feature
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.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Rust programmingPython's typing moduleRuff's codebase structure
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Examine the UP035 rule implementation in the Ruff source code, likely in crates/ruff linter/src/rules/pycodestyle or similar. Understand how the rule currently detects both alias moves and typing deprecations. Review the three comments on the issue for any maintainer input. Propose a design to split the rule into two separate rules or add an option to differentiate safe and unsafe changes, ensuring autofix behavior aligns with the two categories.