[`pyupgrade`] Rename private type parameters in PEP 695 generics (`UP049`) #15862

ntBre · 2025-01-31T22:04:48Z

Summary

This is a new rule to implement the renaming of PEP 695 type parameters with leading underscores after they have (presumably) been converted from standalone type variables by either UP046 or UP047. Part of #15642.

I'm not 100% sure the fix is always safe, but I haven't come up with any counterexamples yet. Renamer seems pretty precise, so I don't think the usual issues with comments apply.

I initially tried writing this as a rule that receives a Stmt rather than a Binding, but in that case the checker.semantic().current_scope() was the global scope, rather than the scope of the type parameters as I needed. Most of the other rules using Renamer also used Bindings, but it does have the downside of offering separate diagnostics for each parameter to rename.

Test Plan

New snapshot tests for UP049 alone and the combination of UP046, UP049, and PYI018.

this is a correct UP046 fix, but UP051 isn't triggering afterward, and thus PYI018 isn't triggering either. my desired total fix is ```python _T = TypeVar("_T") class OldStyle[T]: var: T ```` with a diagnostic on the unused `_T`

github-actions · 2025-01-31T22:11:17Z

`ruff-ecosystem` results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

crates/ruff_linter/src/rules/pyupgrade/rules/pep695/private_type_parameter.rs

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP051.py

...f_linter/src/rules/pyupgrade/snapshots/ruff_linter__rules__pyupgrade__tests__UP051_1.py.snap

crates/ruff_linter/src/rules/pyupgrade/rules/pep695/private_type_parameter.rs

AlexWaygood

Overall this looks great!

crates/ruff_linter/src/rules/pyupgrade/rules/pep695/private_type_parameter.rs

Co-authored-by: Alex Waygood <[email protected]>

this is in line with S606, which renders correctly

Co-authored-by: Alex Waygood <[email protected]>

AlexWaygood

Great work!!

crates/ruff_linter/src/rules/ruff/rules/used_dummy_variable.rs

crates/ruff_linter/src/rules/pyupgrade/rules/pep695/private_type_parameter.rs

ntBre · 2025-02-04T17:11:41Z

Awesome, thanks for all of your help! Is UP051 an acceptable code to use? I just searched issues and PRs again, and the highest number I see now is UP048 (#15625). I think #15841 was previously UP050, which is probably where I got UP051. I'm happy to switch to UP049 to avoid leaving a gap, if you want.

AlexWaygood · 2025-02-04T17:15:15Z

It's nice to avoid leaving a gap where possible with the rule codes, but I don't think it matters too much in cases like this where there's no corresponding "upstream" rule! It is quite important to make sure we don't use the same code as a rule that we used to have but has since been deprecated or removed, however.

AlexWaygood · 2025-02-04T18:35:31Z

Oh shoot, I forgot to say. Can we add a mention of this rule to the ## See also sections in the docs for UP046, UP047 and UP040? The autofixes for those rules will work really well if this one is enabled as well

ntBre · 2025-02-04T18:37:02Z

Ahhh, good catch. I meant to do that the whole time but forgot. I'll open a follow-up!

* main: (66 commits) [red-knot] Use ternary decision diagrams (TDDs) for visibility constraints (#15861) [`pyupgrade`] Rename private type parameters in PEP 695 generics (`UP049`) (#15862) Simplify the `StringFlags` trait (#15944) [`flake8-pyi`] Make `PYI019` autofixable for `.py` files in preview mode as well as stubs (#15889) Docs (`linter.md`): clarify that Python files are always searched for in subdirectories (#15882) [`flake8-pyi`] Make PEP-695 functions with multiple type parameters fixable by PYI019 again (#15938) [red-knot] Use unambiguous invalid-syntax-construct for suppression comment test (#15933) Make `Binding::range()` point to the range of a type parameter's name, not the full type parameter (#15935) Update black deviations (#15928) [red-knot] MDTest: Fix line numbers in error messages (#15932) Preserve triple quotes and prefixes for strings (#15818) [red-knot] Hand-written MDTest parser (#15926) [`pylint`] Fix missing parens in unsafe fix for `unnecessary-dunder-call` (`PLC2801`) (#15762) nit: docs for ignore & select (#15883) [airflow] `BashOperator` has been moved to `airflow.providers.standard.operators.bash.BashOperator` (AIR302) (#15922) [`flake8-logging`] `.exception()` and `exc_info=` outside exception handlers (`LOG004`, `LOG014`) (#15799) [red-knot] Enforce specifying paths for mdtest code blocks in a separate preceding line (#15890) [red-knot] Internal refactoring of visibility constraints API (#15913) [red-knot] Implicit instance attributes (#15811) [`flake8-comprehensions`] Handle extraneous parentheses around list comprehension (`C403`) (#15877) ...

…P040 (#15956) ## Summary Minor docs follow-up to #15862 to mention UP049 in the UP046 and UP047 `See also` sections. I wanted to mention it in UP040 too but realized it didn't have a `See also` section, so I also added that, adapted from the other two rules. ## Test Plan cargo test

ntBre added 10 commits January 31, 2025 12:29

add module with docs and outline of violation struct

59b5b46

add basic tests and fix

2bf35cb

test multiple generics and comments

3154596

I think it's safe

8be2867

fix is always available when a diagnostic is

41ae987

add test for combining UP046, UP051, and PYI018

2034b3b

accept the wrong (overall) fix for now

92dbb32

this is a correct UP046 fix, but UP051 isn't triggering afterward, and thus PYI018 isn't triggering either. my desired total fix is ```python _T = TypeVar("_T") class OldStyle[T]: var: T ```` with a diagnostic on the unused `_T`

remove known problems section

c9c6811

clippy

b36de11

update schema

f11a0cf

ntBre added rule Implementing or modifying a lint rule preview Related to preview mode features labels Jan 31, 2025

ntBre mentioned this pull request Jan 31, 2025

Extend PEP 695 generic class and function rules #15642

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7 tasks

fix example formatting

76bff57

InSyncWithFoo reviewed Jan 31, 2025

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This was referenced Feb 2, 2025

[flake8-pyi] Fix more complex cases (PYI019) #15821

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Convert .md links in rule documentation to full URLs #15904

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AlexWaygood reviewed Feb 3, 2025

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...f_linter/src/rules/pyupgrade/snapshots/ruff_linter__rules__pyupgrade__tests__UP051_1.py.snap Outdated Show resolved Hide resolved

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ntBre and others added 7 commits February 3, 2025 15:18

add quoted tests

17d42cd

update links

8985267

add derive

7513991

Co-authored-by: Alex Waygood <[email protected]>

add separate test for bounds and tuples and such

f487a78

looping over type_params

5ffc6e1

update range

eac0205

Merge branch 'main' into brent/rename-typevars

767d6b0

ntBre and others added 13 commits February 4, 2025 11:54

add f401 and inline snapshot

c74f951

remove underscore trimming from try_shadowed_kind and update ruf052

977edca

pass new_name to try_shadowed_kind

01723f4

update docs

aed85b7

move try_shadowed_kind to ShadowedKind::new

dc7290e

improve docs

dea5d9c

Co-authored-by: Alex Waygood <[email protected]>

separate cases

1abba33

Co-authored-by: Alex Waygood <[email protected]>

explicitly document sunder and dunder name handling

0724f6d

remove quotes from links

f6fc544

this is in line with S606, which renders correctly

factor out ParamKind::as_str

af2e06d

Co-authored-by: Alex Waygood <[email protected]>

make shadows_any const

f550eb0

Co-authored-by: Alex Waygood <[email protected]>

use an actual type for ScopeConflict

40e4ad8

Co-authored-by: Alex Waygood <[email protected]>

add sunder, dunder, and all under test cases

3662181

Co-authored-by: Alex Waygood <[email protected]>

ntBre marked this pull request as ready for review February 4, 2025 17:04

AlexWaygood approved these changes Feb 4, 2025

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crates/ruff_linter/src/rules/ruff/rules/used_dummy_variable.rs Outdated Show resolved Hide resolved

crates/ruff_linter/src/rules/pyupgrade/rules/pep695/private_type_parameter.rs Outdated Show resolved Hide resolved

ntBre added 3 commits February 4, 2025 12:19

get_possible_fix -> get_possible_new_name

2232321

move sunder/dunder caveat to Why is this bad

85b5e12

recode from UP051 to UP049

d1edf78

AlexWaygood approved these changes Feb 4, 2025

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ntBre changed the title ~~[pyupgrade] Rename private type parameters in PEP 695 generics (UP051)~~ [pyupgrade] Rename private type parameters in PEP 695 generics (UP049) Feb 4, 2025

ntBre merged commit 6bb3235 into main Feb 4, 2025
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ntBre deleted the brent/rename-typevars branch February 4, 2025 18:22

ntBre mentioned this pull request Feb 5, 2025

[minor] Mention UP049 in UP046 and UP047, add See also section to UP040 #15956

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BrewTestBot mentioned this pull request Feb 6, 2025

ruff 0.9.5 Homebrew/homebrew-core#206789

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[`pyupgrade`] Rename private type parameters in PEP 695 generics (`UP049`) #15862

[`pyupgrade`] Rename private type parameters in PEP 695 generics (`UP049`) #15862

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ntBre commented Feb 4, 2025

[pyupgrade] Rename private type parameters in PEP 695 generics (UP049) #15862

[pyupgrade] Rename private type parameters in PEP 695 generics (UP049) #15862

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ntBre commented Jan 31, 2025 • edited Loading

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ntBre commented Feb 4, 2025

[`pyupgrade`] Rename private type parameters in PEP 695 generics (`UP049`) #15862

[`pyupgrade`] Rename private type parameters in PEP 695 generics (`UP049`) #15862

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