Ruff

Ruff's language server is now in Beta

`v0.4.5` marks the official Beta release of `ruff server`, an integrated language server built into Ruff.
`ruff server` supports the same feature set as `ruff-lsp`, powering linting, formatting, and
code fixes in Ruff's editor integrations -- but with superior performance and
no installation required. We'd love your feedback!

You can enable `ruff server` in the [VS Code extension](https://github.com/astral-sh/ruff-vscode?tab=readme-ov-file#enabling-the-rust-based-language-server) today.

To read more about this exciting milestone, check out our [blog post](https://astral.sh/blog/ruff-v0.4.5)!

Rule changes

- \[`flake8-future-annotations`\] Reword `future-rewritable-type-annotation` (`FA100`) message ([11381](https://github.com/astral-sh/ruff/pull/11381))
- \[`isort`\] Expanded the set of standard-library modules to include `_string`, etc. ([11374](https://github.com/astral-sh/ruff/pull/11374))
- \[`pycodestyle`\] Consider soft keywords for `E27` rules ([11446](https://github.com/astral-sh/ruff/pull/11446))
- \[`pyflakes`\] Recommend adding unused import bindings to `__all__` ([11314](https://github.com/astral-sh/ruff/pull/11314))
- \[`pyflakes`\] Update documentation and deprecate `ignore_init_module_imports` ([11436](https://github.com/astral-sh/ruff/pull/11436))
- \[`pyupgrade`\] Mark quotes as unnecessary for non-evaluated annotations ([11485](https://github.com/astral-sh/ruff/pull/11485))

Formatter

- Avoid multiline quotes warning with `quote-style = preserve` ([11490](https://github.com/astral-sh/ruff/pull/11490))

Server

- Support Jupyter Notebook files ([11206](https://github.com/astral-sh/ruff/pull/11206))
- Support `noqa` comment code actions ([11276](https://github.com/astral-sh/ruff/pull/11276))
- Fix automatic configuration reloading ([11492](https://github.com/astral-sh/ruff/pull/11492))
- Fix several issues with configuration in Neovim and Helix ([11497](https://github.com/astral-sh/ruff/pull/11497))

CLI

- Add `--output-format` as a CLI option for `ruff config` ([11438](https://github.com/astral-sh/ruff/pull/11438))

Bug fixes

- Avoid `PLE0237` for property with setter ([11377](https://github.com/astral-sh/ruff/pull/11377))
- Avoid `TCH005` for `if` stmt with `elif`/`else` block ([11376](https://github.com/astral-sh/ruff/pull/11376))
- Avoid flagging `__future__` annotations as required for non-evaluated type annotations ([11414](https://github.com/astral-sh/ruff/pull/11414))
- Check for ruff executable in 'bin' directory as installed by 'pip install --target'. ([11450](https://github.com/astral-sh/ruff/pull/11450))
- Sort edits prior to deduplicating in quotation fix ([11452](https://github.com/astral-sh/ruff/pull/11452))
- Treat escaped newline as valid sequence ([11465](https://github.com/astral-sh/ruff/pull/11465))
- \[`flake8-pie`\] Preserve parentheses in `unnecessary-dict-kwargs` ([11372](https://github.com/astral-sh/ruff/pull/11372))
- \[`pylint`\] Ignore `__slots__` with dynamic values ([11488](https://github.com/astral-sh/ruff/pull/11488))
- \[`pylint`\] Remove `try` body from branch counting ([11487](https://github.com/astral-sh/ruff/pull/11487))
- \[`refurb`\] Respect operator precedence in `FURB110` ([11464](https://github.com/astral-sh/ruff/pull/11464))

Documentation

- Add `--preview` to the README ([11395](https://github.com/astral-sh/ruff/pull/11395))
- Add Python 3.13 to list of allowed Python versions ([11411](https://github.com/astral-sh/ruff/pull/11411))
- Simplify Neovim setup documentation ([11489](https://github.com/astral-sh/ruff/pull/11489))
- Update CONTRIBUTING.md to reflect the new parser ([11434](https://github.com/astral-sh/ruff/pull/11434))
- Update server documentation with new migration guide ([11499](https://github.com/astral-sh/ruff/pull/11499))
- \[`pycodestyle`\] Clarify motivation for `E713` and `E714` ([11483](https://github.com/astral-sh/ruff/pull/11483))
- \[`pyflakes`\] Update docs to describe WAI behavior (F541) ([11362](https://github.com/astral-sh/ruff/pull/11362))
- \[`pylint`\] Clearly indicate what is counted as a branch ([11423](https://github.com/astral-sh/ruff/pull/11423))

Preview features

- \[`pycodestyle`\] Ignore end-of-line comments when determining blank line rules ([11342](https://github.com/astral-sh/ruff/pull/11342))
- \[`pylint`\] Detect `pathlib.Path.open` calls in `unspecified-encoding` (`PLW1514`) ([11288](https://github.com/astral-sh/ruff/pull/11288))
- \[`flake8-pyi`\] Implement `PYI059` (`generic-not-last-base-class`) ([11233](https://github.com/astral-sh/ruff/pull/11233))
- \[`flake8-pyi`\] Implement `PYI062` (`duplicate-literal-member`) ([11269](https://github.com/astral-sh/ruff/pull/11269))

Rule changes

- \[`flake8-boolean-trap`\] Allow passing booleans as positional-only arguments in code such as `set(True)` ([11287](https://github.com/astral-sh/ruff/pull/11287))
- \[`flake8-bugbear`\] Ignore enum classes in `cached-instance-method` (`B019`) ([11312](https://github.com/astral-sh/ruff/pull/11312))

Server

- Expand tildes when resolving Ruff server configuration file ([11283](https://github.com/astral-sh/ruff/pull/11283))
- Fix `ruff server` hanging after Neovim closes ([11291](https://github.com/astral-sh/ruff/pull/11291))
- Editor settings are used by default if no file-based configuration exists ([11266](https://github.com/astral-sh/ruff/pull/11266))

Bug fixes

- \[`pylint`\] Consider `with` statements for `too-many-branches` (`PLR0912`) ([11321](https://github.com/astral-sh/ruff/pull/11321))
- \[`flake8-blind-except`, `tryceratops`\] Respect logged and re-raised expressions in nested statements (`BLE001`, `TRY201`) ([11301](https://github.com/astral-sh/ruff/pull/11301))
- Recognise assignments such as `__all__ = builtins.list(["foo", "bar"])` as valid `__all__` definitions ([11335](https://github.com/astral-sh/ruff/pull/11335))

Enhancements

- Add support for PEP 696 syntax ([11120](https://github.com/astral-sh/ruff/pull/11120))

Preview features

- \[`refurb`\] Use function range for `reimplemented-operator` diagnostics ([11271](https://github.com/astral-sh/ruff/pull/11271))
- \[`refurb`\] Ignore methods in `reimplemented-operator` (`FURB118`) ([11270](https://github.com/astral-sh/ruff/pull/11270))
- \[`refurb`\] Implement `fstring-number-format` (`FURB116`) ([10921](https://github.com/astral-sh/ruff/pull/10921))
- \[`ruff`\] Implement `redirected-noqa` (`RUF101`) ([11052](https://github.com/astral-sh/ruff/pull/11052))
- \[`pyflakes`\] Distinguish between first-party and third-party imports for fix suggestions ([11168](https://github.com/astral-sh/ruff/pull/11168))

Rule changes

- \[`flake8-bugbear`\] Ignore non-abstract class attributes when enforcing `B024` ([11210](https://github.com/astral-sh/ruff/pull/11210))
- \[`flake8-logging`\] Include inline instantiations when detecting loggers ([11154](https://github.com/astral-sh/ruff/pull/11154))
- \[`pylint`\] Also emit `PLR0206` for properties with variadic parameters ([11200](https://github.com/astral-sh/ruff/pull/11200))
- \[`ruff`\] Detect duplicate codes as part of `unused-noqa` (`RUF100`) ([10850](https://github.com/astral-sh/ruff/pull/10850))

Formatter

- Avoid multiline expression if format specifier is present ([11123](https://github.com/astral-sh/ruff/pull/11123))

LSP

- Write `ruff server` setup guide for Helix ([11183](https://github.com/astral-sh/ruff/pull/11183))
- `ruff server` no longer hangs after shutdown ([11222](https://github.com/astral-sh/ruff/pull/11222))
- `ruff server` reads from a configuration TOML file in the user configuration directory if no local configuration exists ([11225](https://github.com/astral-sh/ruff/pull/11225))
- `ruff server` respects `per-file-ignores` configuration ([11224](https://github.com/astral-sh/ruff/pull/11224))
- `ruff server`: Support a custom TOML configuration file ([11140](https://github.com/astral-sh/ruff/pull/11140))
- `ruff server`: Support setting to prioritize project configuration over editor configuration ([11086](https://github.com/astral-sh/ruff/pull/11086))

Bug fixes

- Avoid debug assertion around NFKC renames ([11249](https://github.com/astral-sh/ruff/pull/11249))
- \[`pyflakes`\] Prioritize `redefined-while-unused` over `unused-import` ([11173](https://github.com/astral-sh/ruff/pull/11173))
- \[`ruff`\] Respect `async` expressions in comprehension bodies ([11219](https://github.com/astral-sh/ruff/pull/11219))
- \[`pygrep_hooks`\] Fix `blanket-noqa` panic when last line has noqa with no newline (`PGH004`) ([11108](https://github.com/astral-sh/ruff/pull/11108))
- \[`perflint`\] Ignore list-copy recommendations for async `for` loops ([11250](https://github.com/astral-sh/ruff/pull/11250))
- \[`pyflakes`\] Improve `invalid-print-syntax` documentation ([11171](https://github.com/astral-sh/ruff/pull/11171))

Performance

- Avoid allocations for isort module names ([11251](https://github.com/astral-sh/ruff/pull/11251))
- Build a separate ARM wheel for macOS ([11149](https://github.com/astral-sh/ruff/pull/11149))

Windows

- Increase the minimum requirement to Windows 10.

Rule changes

- \[`flake8-pyi`\] Allow for overloaded `__exit__` and `__aexit__` definitions (`PYI036`) ([11057](https://github.com/astral-sh/ruff/pull/11057))
- \[`pyupgrade`\] Catch usages of `"%s" % var` and provide an unsafe fix (`UP031`) ([11019](https://github.com/astral-sh/ruff/pull/11019))
- \[`refurb`\] Implement new rule that suggests min/max over `sorted()` (`FURB192`) ([10868](https://github.com/astral-sh/ruff/pull/10868))

Server

- Fix an issue with missing diagnostics for Neovim and Helix ([11092](https://github.com/astral-sh/ruff/pull/11092))
- Implement hover documentation for `noqa` codes ([11096](https://github.com/astral-sh/ruff/pull/11096))
- Introduce common Ruff configuration options with new server settings ([11062](https://github.com/astral-sh/ruff/pull/11062))

Bug fixes

- Use `macos-12` for building release wheels to enable macOS 11 compatibility ([11146](https://github.com/astral-sh/ruff/pull/11146))
- \[`flake8-blind-expect`\] Allow raise from in `BLE001` ([11131](https://github.com/astral-sh/ruff/pull/11131))
- \[`flake8-pyi`\] Allow simple assignments to `None` in enum class scopes (`PYI026`) ([11128](https://github.com/astral-sh/ruff/pull/11128))
- \[`flake8-simplify`\] Avoid raising `SIM911` for non-`zip` attribute calls ([11126](https://github.com/astral-sh/ruff/pull/11126))
- \[`refurb`\] Avoid `operator.itemgetter` suggestion for single-item tuple ([11095](https://github.com/astral-sh/ruff/pull/11095))
- \[`ruff`\] Respect per-file-ignores for `RUF100` with no other diagnostics ([11058](https://github.com/astral-sh/ruff/pull/11058))
- \[`ruff`\] Fix async comprehension false positive (`RUF029`) ([11070](https://github.com/astral-sh/ruff/pull/11070))

Documentation

- \[`flake8-bugbear`\] Document explicitly disabling strict zip (`B905`) ([11040](https://github.com/astral-sh/ruff/pull/11040))
- \[`flake8-type-checking`\] Mention `lint.typing-modules` in `TCH001`, `TCH002`, and `TCH003` ([11144](https://github.com/astral-sh/ruff/pull/11144))
- \[`isort`\] Improve documentation around custom `isort` sections ([11050](https://github.com/astral-sh/ruff/pull/11050))
- \[`pylint`\] Fix documentation oversight for `invalid-X-returns` ([11094](https://github.com/astral-sh/ruff/pull/11094))

Performance

- Use `matchit` to resolve per-file settings ([11111](https://github.com/astral-sh/ruff/pull/11111))

Preview features

- \[`pylint`\] Implement `invalid-hash-returned` (`PLE0309`) ([10961](https://github.com/astral-sh/ruff/pull/10961))
- \[`pylint`\] Implement `invalid-index-returned` (`PLE0305`) ([10962](https://github.com/astral-sh/ruff/pull/10962))

Bug fixes

- \[`pylint`\] Allow `NoReturn`-like functions for `__str__`, `__len__`, etc. (`PLE0307`) ([11017](https://github.com/astral-sh/ruff/pull/11017))
- Parser: Use empty range when there's "gap" in token source ([11032](https://github.com/astral-sh/ruff/pull/11032))
- \[`ruff`\] Ignore stub functions in `unused-async` (`RUF029`) ([11026](https://github.com/astral-sh/ruff/pull/11026))
- Parser: Expect indented case block instead of match stmt ([11033](https://github.com/astral-sh/ruff/pull/11033))

A new, hand-written parser

Ruff's new parser is **>2x faster**, which translates to a **20-40% speedup** for all linting and formatting invocations.
There's a lot to say about this exciting change, so check out the [blog post](https://astral.sh/blog/ruff-v0.4.0) for more details!

See [10036](https://github.com/astral-sh/ruff/pull/10036) for implementation details.

A new language server in Rust

With this release, we also want to highlight our new language server. `ruff server` is a Rust-powered language
server that comes built-in with Ruff. It can be used with any editor that supports the [Language Server Protocol](https://microsoft.github.io/language-server-protocol/) (LSP).
It uses a multi-threaded, lock-free architecture inspired by `rust-analyzer` and it will open the door for a lot
of exciting features. It’s also faster than our previous [Python-based language server](https://github.com/astral-sh/ruff-lsp)
-- but you probably guessed that already.

`ruff server` is only in alpha, but it has a lot of features that you can try out today:

- Lints Python files automatically and shows quick-fixes when available
- Formats Python files, with support for range formatting
- Comes with commands for quickly performing actions: `ruff.applyAutofix`, `ruff.applyFormat`, and `ruff.applyOrganizeImports`
- Supports `source.fixAll` and `source.organizeImports` source actions
- Automatically reloads your project configuration when you change it

To setup `ruff server` with your editor, refer to the [README.md](https://github.com/astral-sh/ruff/blob/main/crates/ruff_server/README.md).

Preview features

- \[`pycodestyle`\] Do not trigger `E3` rules on `def`s following a function/method with a dummy body ([10704](https://github.com/astral-sh/ruff/pull/10704))
- \[`pylint`\] Implement `invalid-bytes-returned` (`E0308`) ([10959](https://github.com/astral-sh/ruff/pull/10959))
- \[`pylint`\] Implement `invalid-length-returned` (`E0303`) ([10963](https://github.com/astral-sh/ruff/pull/10963))
- \[`pylint`\] Implement `self-cls-assignment` (`W0642`) ([9267](https://github.com/astral-sh/ruff/pull/9267))
- \[`pylint`\] Omit stubs from `invalid-bool` and `invalid-str-return-type` ([11008](https://github.com/astral-sh/ruff/pull/11008))
- \[`ruff`\] New rule `unused-async` (`RUF029`) to detect unneeded `async` keywords on functions ([9966](https://github.com/astral-sh/ruff/pull/9966))

Rule changes

- \[`flake8-bandit`\] Allow `urllib.request.urlopen` calls with static `Request` argument (`S310`) ([10964](https://github.com/astral-sh/ruff/pull/10964))
- \[`flake8-bugbear`\] Treat `raise NotImplemented`-only bodies as stub functions (`B006`) ([10990](https://github.com/astral-sh/ruff/pull/10990))
- \[`flake8-slots`\] Respect same-file `Enum` subclasses (`SLOT000`) ([11006](https://github.com/astral-sh/ruff/pull/11006))
- \[`pylint`\] Support inverted comparisons (`PLR1730`) ([10920](https://github.com/astral-sh/ruff/pull/10920))

Linter

- Improve handling of builtin symbols in linter rules ([10919](https://github.com/astral-sh/ruff/pull/10919))
- Improve display of rules in `--show-settings` ([11003](https://github.com/astral-sh/ruff/pull/11003))
- Improve inference capabilities of the `BuiltinTypeChecker` ([10976](https://github.com/astral-sh/ruff/pull/10976))
- Resolve classes and functions relative to script name ([10965](https://github.com/astral-sh/ruff/pull/10965))
- Improve performance of `RuleTable::any_enabled` ([10971](https://github.com/astral-sh/ruff/pull/10971))

Server

*This section is devoted to updates for our new language server, written in Rust.*

- Enable ruff-specific source actions ([10916](https://github.com/astral-sh/ruff/pull/10916))
- Refreshes diagnostics for open files when file configuration is changed ([10988](https://github.com/astral-sh/ruff/pull/10988))
- Important errors are now shown as popups ([10951](https://github.com/astral-sh/ruff/pull/10951))
- Introduce settings for directly configuring the linter and formatter ([10984](https://github.com/astral-sh/ruff/pull/10984))
- Resolve configuration for each document individually ([10950](https://github.com/astral-sh/ruff/pull/10950))
- Write a setup guide for Neovim ([10987](https://github.com/astral-sh/ruff/pull/10987))

Configuration

- Add `RUFF_OUTPUT_FILE` environment variable support ([10992](https://github.com/astral-sh/ruff/pull/10992))

Bug fixes

- Avoid `non-augmented-assignment` for reversed, non-commutative operators (`PLR6104`) ([10909](https://github.com/astral-sh/ruff/pull/10909))
- Limit commutative non-augmented-assignments to primitive data types (`PLR6104`) ([10912](https://github.com/astral-sh/ruff/pull/10912))
- Respect `per-file-ignores` for `RUF100` on blanket ` noqa` ([10908](https://github.com/astral-sh/ruff/pull/10908))
- Consider `if` expression for parenthesized with items parsing ([11010](https://github.com/astral-sh/ruff/pull/11010))
- Consider binary expr for parenthesized with items parsing ([11012](https://github.com/astral-sh/ruff/pull/11012))
- Reset `FOR_TARGET` context for all kinds of parentheses ([11009](https://github.com/astral-sh/ruff/pull/11009))