[ty] Use ThinVec in various places

## Summary

This came up on
[Discord](https://discord.com/channels/1039017663004942429/1343692072921731082/1395447082520678440)
and also in #19387, but on macOS the tmp directory is a symlink to
`/private/tmp`, which breaks this filter. I'm still not quite sure why
only these tests are affected when we use the `tempdir_filter`
elsewhere, but hopefully this fixes the immediate issue. Just
`tempdir.path().canonicalize()` also worked, but I used `dunce` since
that's what I saw in other tests (I guess it's not _just_ these tests).

Some related links from uv:
-
1b2f212e8b/crates/uv/tests/it/common/mod.rs (L1161-L1178)
-
1b2f212e8b/crates/uv/tests/it/common/mod.rs (L424-L438)
- https://github.com/astral-sh/uv/pull/14290

Thanks to @zanieb for those!

## Test Plan

I tested the `main` branch on my MacBook and reproduced the test
failure, then confirmed that the tests pass after the change. Now to
make sure it passes on Windows, which caused most of the trouble in the
first PR!

CHANGELOG.md

@@ -1,5 +1,36 @@
 # Changelog
 
+## 0.12.4
+
+### Preview features
+
+- \[`flake8-type-checking`, `pyupgrade`, `ruff`\] Add `from __future__ import annotations` when it would allow new fixes (`TC001`, `TC002`, `TC003`, `UP037`, `RUF013`) ([#19100](https://github.com/astral-sh/ruff/pull/19100))
+- \[`flake8-use-pathlib`\] Add autofix for `PTH109` ([#19245](https://github.com/astral-sh/ruff/pull/19245))
+- \[`pylint`\] Detect indirect `pathlib.Path` usages for `unspecified-encoding` (`PLW1514`) ([#19304](https://github.com/astral-sh/ruff/pull/19304))
+
+### Bug fixes
+
+- \[`flake8-bugbear`\] Fix `B017` false negatives for keyword exception arguments ([#19217](https://github.com/astral-sh/ruff/pull/19217))
+- \[`flake8-use-pathlib`\] Fix false negative on direct `Path()` instantiation (`PTH210`) ([#19388](https://github.com/astral-sh/ruff/pull/19388))
+- \[`flake8-django`\] Fix `DJ008` false positive for abstract models with type-annotated `abstract` field ([#19221](https://github.com/astral-sh/ruff/pull/19221))
+- \[`isort`\] Fix `I002` import insertion after docstring with multiple string statements ([#19222](https://github.com/astral-sh/ruff/pull/19222))
+- \[`isort`\] Treat form feed as valid whitespace before a semicolon ([#19343](https://github.com/astral-sh/ruff/pull/19343))
+- \[`pydoclint`\] Fix `SyntaxError` from fixes with line continuations (`D201`, `D202`) ([#19246](https://github.com/astral-sh/ruff/pull/19246))
+- \[`refurb`\] `FURB164` fix should validate arguments and should usually be marked unsafe ([#19136](https://github.com/astral-sh/ruff/pull/19136))
+
+### Rule changes
+
+- \[`flake8-use-pathlib`\] Skip single dots for `invalid-pathlib-with-suffix` (`PTH210`) on versions >= 3.14 ([#19331](https://github.com/astral-sh/ruff/pull/19331))
+- \[`pep8_naming`\] Avoid false positives on standard library functions with uppercase names (`N802`) ([#18907](https://github.com/astral-sh/ruff/pull/18907))
+- \[`pycodestyle`\] Handle brace escapes for t-strings in logical lines ([#19358](https://github.com/astral-sh/ruff/pull/19358))
+- \[`pylint`\] Extend invalid string character rules to include t-strings ([#19355](https://github.com/astral-sh/ruff/pull/19355))
+- \[`ruff`\] Allow `strict` kwarg when checking for `starmap-zip` (`RUF058`) in Python 3.14+ ([#19333](https://github.com/astral-sh/ruff/pull/19333))
+
+### Documentation
+
+- \[`flake8-type-checking`\] Make `TC010` docs example more realistic ([#19356](https://github.com/astral-sh/ruff/pull/19356))
+- Make more documentation examples error out-of-the-box ([#19288](https://github.com/astral-sh/ruff/pull/19288),[#19272](https://github.com/astral-sh/ruff/pull/19272),[#19291](https://github.com/astral-sh/ruff/pull/19291),[#19296](https://github.com/astral-sh/ruff/pull/19296),[#19292](https://github.com/astral-sh/ruff/pull/19292),[#19295](https://github.com/astral-sh/ruff/pull/19295),[#19297](https://github.com/astral-sh/ruff/pull/19297),[#19309](https://github.com/astral-sh/ruff/pull/19309))
+
 ## 0.12.3
 
 ### Preview features

Cargo.lock

@@ -2711,7 +2711,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.4"
 dependencies = [
  "anyhow",
  "argfile",
@@ -2962,7 +2962,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.4"
 dependencies = [
  "aho-corasick",
  "anyhow",
@@ -3295,7 +3295,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.12.3"
+version = "0.12.4"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -4287,6 +4287,7 @@ dependencies = [
  "strum_macros",
  "tempfile",
  "test-case",
+ "thin-vec",
  "thiserror 2.0.12",
  "tracing",
  "ty_python_semantic",
@@ -4300,6 +4301,7 @@ name = "ty_server"
 version = "0.0.0"
 dependencies = [
  "anyhow",
+ "bitflags 2.9.1",
  "crossbeam",
  "jod-thread",
  "libc",

Cargo.toml

@@ -163,6 +163,7 @@ strum_macros = { version = "0.27.0" }
 syn = { version = "2.0.55" }
 tempfile = { version = "3.9.0" }
 test-case = { version = "3.3.1" }
+thin-vec = { version = "0.2.14" }
 thiserror = { version = "2.0.0" }
 tikv-jemallocator = { version = "0.6.0" }
 toml = { version = "0.9.0" }

README.md

@@ -148,8 +148,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.12.3/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.12.3/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.12.4/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.12.4/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -182,7 +182,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.4
   hooks:
     # Run the linter.
     - id: ruff-check

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.4"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff/tests/lint.rs

@@ -5718,8 +5718,11 @@ match 42:  # invalid-syntax
 
     let snapshot = format!("output_format_{output_format}");
 
+    let project_dir = dunce::canonicalize(tempdir.path())?;
+
     insta::with_settings!({
         filters => vec![
+            (tempdir_filter(&project_dir).as_str(), "[TMP]/"),
             (tempdir_filter(&tempdir).as_str(), "[TMP]/"),
             (r#""[^"]+\\?/?input.py"#, r#""[TMP]/input.py"#),
             (ruff_linter::VERSION, "[VERSION]"),

crates/ruff_linter/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.4"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/full_name.py

@@ -104,3 +104,6 @@ os.chmod(x)
 os.replace("src", "dst", src_dir_fd=1, dst_dir_fd=2)
 os.replace("src", "dst", src_dir_fd=1)
 os.replace("src", "dst", dst_dir_fd=2)
+
+os.getcwd()
+os.getcwdb()

crates/ruff_linter/src/checkers/ast/analyze/expression.rs

@@ -1044,7 +1044,6 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                 Rule::OsMakedirs,
                 Rule::OsRename,
                 Rule::OsReplace,
-                Rule::OsGetcwd,
                 Rule::OsStat,
                 Rule::OsPathJoin,
                 Rule::OsPathSamefile,
@@ -1110,6 +1109,9 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                 if checker.is_rule_enabled(Rule::OsReadlink) {
                     flake8_use_pathlib::rules::os_readlink(checker, call, segments);
                 }
+                if checker.is_rule_enabled(Rule::OsGetcwd) {
+                    flake8_use_pathlib::rules::os_getcwd(checker, call, segments);
+                }
                 if checker.is_rule_enabled(Rule::PathConstructorCurrentDirectory) {
                     flake8_use_pathlib::rules::path_constructor_current_directory(
                         checker, call, segments,

crates/ruff_linter/src/codes.rs

@@ -928,7 +928,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Flake8UsePathlib, "106") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRmdir),
         (Flake8UsePathlib, "107") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRemove),
         (Flake8UsePathlib, "108") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsUnlink),
-        (Flake8UsePathlib, "109") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsGetcwd),
+        (Flake8UsePathlib, "109") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsGetcwd),
         (Flake8UsePathlib, "110") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathExists),
         (Flake8UsePathlib, "111") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathExpanduser),
         (Flake8UsePathlib, "112") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathIsdir),

crates/ruff_linter/src/preview.rs

@@ -134,6 +134,11 @@ pub(crate) const fn is_fix_os_path_dirname_enabled(settings: &LinterSettings) ->
     settings.preview.is_enabled()
 }
 
+// https://github.com/astral-sh/ruff/pull/19245
+pub(crate) const fn is_fix_os_getcwd_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
 // https://github.com/astral-sh/ruff/pull/11436
 // https://github.com/astral-sh/ruff/pull/11168
 pub(crate) const fn is_dunder_init_fix_unused_import_enabled(settings: &LinterSettings) -> bool {

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/mod.rs

@@ -1,5 +1,6 @@
 pub(crate) use glob_rule::*;
 pub(crate) use invalid_pathlib_with_suffix::*;
+pub(crate) use os_getcwd::*;
 pub(crate) use os_path_abspath::*;
 pub(crate) use os_path_basename::*;
 pub(crate) use os_path_dirname::*;
@@ -23,6 +24,7 @@ pub(crate) use replaceable_by_pathlib::*;
 
 mod glob_rule;
 mod invalid_pathlib_with_suffix;
+mod os_getcwd;
 mod os_path_abspath;
 mod os_path_basename;
 mod os_path_dirname;

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_getcwd.rs

@@ -0,0 +1,100 @@
+use crate::checkers::ast::Checker;
+use crate::importer::ImportRequest;
+use crate::preview::is_fix_os_getcwd_enabled;
+use crate::{FixAvailability, Violation};
+use ruff_diagnostics::{Applicability, Edit, Fix};
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+use ruff_text_size::Ranged;
+
+/// ## What it does
+/// Checks for uses of `os.getcwd` and `os.getcwdb`.
+///
+/// ## Why is this bad?
+/// `pathlib` offers a high-level API for path manipulation, as compared to
+/// the lower-level API offered by `os`. When possible, using `Path` object
+/// methods such as `Path.cwd()` can improve readability over the `os`
+/// module's counterparts (e.g., `os.getcwd()`).
+///
+/// ## Examples
+/// ```python
+/// import os
+///
+/// cwd = os.getcwd()
+/// ```
+///
+/// Use instead:
+/// ```python
+/// from pathlib import Path
+///
+/// cwd = Path.cwd()
+/// ```
+///
+/// ## Known issues
+/// While using `pathlib` can improve the readability and type safety of your code,
+/// it can be less performant than the lower-level alternatives that work directly with strings,
+/// especially on older versions of Python.
+///
+/// ## Fix Safety
+/// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+///
+/// ## References
+/// - [Python documentation: `Path.cwd`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.cwd)
+/// - [Python documentation: `os.getcwd`](https://docs.python.org/3/library/os.html#os.getcwd)
+/// - [Python documentation: `os.getcwdb`](https://docs.python.org/3/library/os.html#os.getcwdb)
+/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
+/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
+/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
+/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
+#[derive(ViolationMetadata)]
+pub(crate) struct OsGetcwd;
+
+impl Violation for OsGetcwd {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::Sometimes;
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "`os.getcwd()` should be replaced by `Path.cwd()`".to_string()
+    }
+
+    fn fix_title(&self) -> Option<String> {
+        Some("Replace with `Path.cwd()`".to_string())
+    }
+}
+
+/// PTH109
+pub(crate) fn os_getcwd(checker: &Checker, call: &ExprCall, segments: &[&str]) {
+    if !matches!(segments, ["os", "getcwd" | "getcwdb"]) {
+        return;
+    }
+
+    let range = call.range();
+    let mut diagnostic = checker.report_diagnostic(OsGetcwd, call.func.range());
+
+    if !call.arguments.is_empty() {
+        return;
+    }
+
+    if is_fix_os_getcwd_enabled(checker.settings()) {
+        diagnostic.try_set_fix(|| {
+            let (import_edit, binding) = checker.importer().get_or_import_symbol(
+                &ImportRequest::import("pathlib", "Path"),
+                call.start(),
+                checker.semantic(),
+            )?;
+
+            let applicability = if checker.comment_ranges().intersects(range) {
+                Applicability::Unsafe
+            } else {
+                Applicability::Safe
+            };
+
+            let replacement = format!("{binding}.cwd()");
+
+            Ok(Fix::applicable_edits(
+                Edit::range_replacement(replacement, range),
+                [import_edit],
+                applicability,
+            ))
+        });
+    }
+}

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/replaceable_by_pathlib.rs

@@ -7,8 +7,8 @@ use crate::checkers::ast::Checker;
 use crate::rules::flake8_use_pathlib::helpers::is_keyword_only_argument_non_default;
 use crate::rules::flake8_use_pathlib::rules::Glob;
 use crate::rules::flake8_use_pathlib::violations::{
-    BuiltinOpen, Joiner, OsChmod, OsGetcwd, OsListdir, OsMakedirs, OsMkdir, OsPathJoin,
-    OsPathSamefile, OsPathSplitext, OsRename, OsReplace, OsStat, OsSymlink, PyPath,
+    BuiltinOpen, Joiner, OsChmod, OsListdir, OsMakedirs, OsMkdir, OsPathJoin, OsPathSamefile,
+    OsPathSplitext, OsRename, OsReplace, OsStat, OsSymlink, PyPath,
 };
 
 pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
@@ -83,10 +83,6 @@ pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
             }
             checker.report_diagnostic_if_enabled(OsReplace, range)
         }
-        // PTH109
-        ["os", "getcwd"] => checker.report_diagnostic_if_enabled(OsGetcwd, range),
-        ["os", "getcwdb"] => checker.report_diagnostic_if_enabled(OsGetcwd, range),
-
         // PTH116
         ["os", "stat"] => {
             // `dir_fd` is not supported by pathlib, so check if it's set to non-default values.

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__full_name.py.snap

@@ -103,6 +103,7 @@ full_name.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = os.path.exists(p)
 18 | bb = os.path.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:17:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -292,6 +293,7 @@ full_name.py:35:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 36 | os.path.join(p, *q)
 37 | os.sep.join(p, *q)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:36:1: PTH118 `os.path.join()` should be replaced by `Path.joinpath()`
    |
@@ -360,3 +362,21 @@ full_name.py:71:1: PTH123 `open()` should be replaced by `Path.open()`
 72 |
 73 | # https://github.com/astral-sh/ruff/issues/17693
    |
+
+full_name.py:108:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+106 | os.replace("src", "dst", dst_dir_fd=2)
+107 |
+108 | os.getcwd()
+    | ^^^^^^^^^ PTH109
+109 | os.getcwdb()
+    |
+    = help: Replace with `Path.cwd()`
+
+full_name.py:109:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+108 | os.getcwd()
+109 | os.getcwdb()
+    | ^^^^^^^^^^ PTH109
+    |
+    = help: Replace with `Path.cwd()`

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__import_as.py.snap

@@ -103,6 +103,7 @@ import_as.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = foo_p.exists(p)
 18 | bb = foo_p.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_as.py:17:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__import_from.py.snap

@@ -103,6 +103,7 @@ import_from.py:18:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 19 | b = exists(p)
 20 | bb = expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from.py:19:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__import_from_as.py.snap

@@ -103,6 +103,7 @@ import_from_as.py:23:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 24 | b = xexists(p)
 25 | bb = xexpanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from_as.py:24:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_full_name.py.snap

@@ -168,6 +168,7 @@ full_name.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = os.path.exists(p)
 18 | bb = os.path.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:17:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -510,6 +511,7 @@ full_name.py:35:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 36 | os.path.join(p, *q)
 37 | os.sep.join(p, *q)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:36:1: PTH118 `os.path.join()` should be replaced by `Path.joinpath()`
    |
@@ -578,3 +580,50 @@ full_name.py:71:1: PTH123 `open()` should be replaced by `Path.open()`
 72 |
 73 | # https://github.com/astral-sh/ruff/issues/17693
    |
+
+full_name.py:108:1: PTH109 [*] `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+106 | os.replace("src", "dst", dst_dir_fd=2)
+107 |
+108 | os.getcwd()
+    | ^^^^^^^^^ PTH109
+109 | os.getcwdb()
+    |
+    = help: Replace with `Path.cwd()`
+
+ℹ Safe fix
+1   1   | import os
+2   2   | import os.path
+    3   |+import pathlib
+3   4   | 
+4   5   | p = "/foo"
+5   6   | q = "bar"
+--------------------------------------------------------------------------------
+105 106 | os.replace("src", "dst", src_dir_fd=1)
+106 107 | os.replace("src", "dst", dst_dir_fd=2)
+107 108 | 
+108     |-os.getcwd()
+    109 |+pathlib.Path.cwd()
+109 110 | os.getcwdb()
+
+full_name.py:109:1: PTH109 [*] `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+108 | os.getcwd()
+109 | os.getcwdb()
+    | ^^^^^^^^^^ PTH109
+    |
+    = help: Replace with `Path.cwd()`
+
+ℹ Safe fix
+1   1   | import os
+2   2   | import os.path
+    3   |+import pathlib
+3   4   | 
+4   5   | p = "/foo"
+5   6   | q = "bar"
+--------------------------------------------------------------------------------
+106 107 | os.replace("src", "dst", dst_dir_fd=2)
+107 108 | 
+108 109 | os.getcwd()
+109     |-os.getcwdb()
+    110 |+pathlib.Path.cwd()

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_import_as.py.snap

@@ -168,6 +168,7 @@ import_as.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = foo_p.exists(p)
 18 | bb = foo_p.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_as.py:17:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_import_from.py.snap

@@ -172,6 +172,7 @@ import_from.py:18:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 19 | b = exists(p)
 20 | bb = expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from.py:19:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_import_from_as.py.snap

@@ -172,6 +172,7 @@ import_from_as.py:23:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 24 | b = xexists(p)
 25 | bb = xexpanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from_as.py:24:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/violations.rs

@@ -230,52 +230,6 @@ impl Violation for OsReplace {
     }
 }
 
-/// ## What it does
-/// Checks for uses of `os.getcwd` and `os.getcwdb`.
-///
-/// ## Why is this bad?
-/// `pathlib` offers a high-level API for path manipulation, as compared to
-/// the lower-level API offered by `os`. When possible, using `Path` object
-/// methods such as `Path.cwd()` can improve readability over the `os`
-/// module's counterparts (e.g., `os.getcwd()`).
-///
-/// ## Examples
-/// ```python
-/// import os
-///
-/// cwd = os.getcwd()
-/// ```
-///
-/// Use instead:
-/// ```python
-/// from pathlib import Path
-///
-/// cwd = Path.cwd()
-/// ```
-///
-/// ## Known issues
-/// While using `pathlib` can improve the readability and type safety of your code,
-/// it can be less performant than the lower-level alternatives that work directly with strings,
-/// especially on older versions of Python.
-///
-/// ## References
-/// - [Python documentation: `Path.cwd`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.cwd)
-/// - [Python documentation: `os.getcwd`](https://docs.python.org/3/library/os.html#os.getcwd)
-/// - [Python documentation: `os.getcwdb`](https://docs.python.org/3/library/os.html#os.getcwdb)
-/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
-/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
-/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
-/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
-#[derive(ViolationMetadata)]
-pub(crate) struct OsGetcwd;
-
-impl Violation for OsGetcwd {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        "`os.getcwd()` should be replaced by `Path.cwd()`".to_string()
-    }
-}
-
 /// ## What it does
 /// Checks for uses of `os.stat`.
 ///

crates/ruff_wasm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_wasm"
-version = "0.12.3"
+version = "0.12.4"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }

crates/ty_project/src/lib.rs

@@ -469,6 +469,14 @@ impl Project {
             self.set_file_set(db).to(IndexedFiles::lazy());
         }
     }
+
+    /// Check if the project's settings have any issues
+    pub fn check_settings(&self, db: &dyn Db) -> Vec<Diagnostic> {
+        self.settings_diagnostics(db)
+            .iter()
+            .map(OptionDiagnostic::to_diagnostic)
+            .collect()
+    }
 }
 
 #[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]

crates/ty_python_semantic/Cargo.toml

@@ -35,6 +35,7 @@ indexmap = { workspace = true }
 itertools = { workspace = true }
 ordermap = { workspace = true }
 salsa = { workspace = true, features = ["compact_str"] }
+thin-vec = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 rustc-hash = { workspace = true }

crates/ty_python_semantic/src/semantic_index.rs

@@ -26,6 +26,7 @@ use crate::semantic_index::place::{
 };
 use crate::semantic_index::use_def::{EagerSnapshotKey, ScopedEagerSnapshotId, UseDefMap};
 use crate::semantic_model::HasTrackedScope;
+use crate::util::get_size::ThinVecSized;
 use crate::util::get_size::untracked_arc_size;
 
 pub mod ast_ids;
@@ -238,7 +239,7 @@ pub(crate) struct SemanticIndex<'db> {
     eager_snapshots: FxHashMap<EagerSnapshotKey, ScopedEagerSnapshotId>,
 
     /// List of all semantic syntax errors in this file.
-    semantic_syntax_errors: Vec<SemanticSyntaxError>,
+    semantic_syntax_errors: ThinVecSized<SemanticSyntaxError>,
 
     /// Set of all generator functions in this file.
     generator_functions: FxHashSet<FileScopeId>,

crates/ty_python_semantic/src/semantic_index/builder.rs

@@ -115,7 +115,7 @@ pub(super) struct SemanticIndexBuilder<'db, 'ast> {
     generator_functions: FxHashSet<FileScopeId>,
     eager_snapshots: FxHashMap<EagerSnapshotKey, ScopedEagerSnapshotId>,
     /// Errors collected by the `semantic_checker`.
-    semantic_syntax_errors: RefCell<Vec<SemanticSyntaxError>>,
+    semantic_syntax_errors: RefCell<thin_vec::ThinVec<SemanticSyntaxError>>,
 }
 
 impl<'db, 'ast> SemanticIndexBuilder<'db, 'ast> {
@@ -1063,7 +1063,7 @@ impl<'db, 'ast> SemanticIndexBuilder<'db, 'ast> {
             imported_modules: Arc::new(self.imported_modules),
             has_future_annotations: self.has_future_annotations,
             eager_snapshots: self.eager_snapshots,
-            semantic_syntax_errors: self.semantic_syntax_errors.into_inner(),
+            semantic_syntax_errors: self.semantic_syntax_errors.into_inner().into(),
             generator_functions: self.generator_functions,
         }
     }

crates/ty_python_semantic/src/semantic_index/place.rs

@@ -10,13 +10,13 @@ use ruff_index::{IndexVec, newtype_index};
 use ruff_python_ast as ast;
 use ruff_python_ast::name::Name;
 use rustc_hash::FxHasher;
-use smallvec::{SmallVec, smallvec};
 
 use crate::Db;
 use crate::ast_node_ref::AstNodeRef;
 use crate::node_key::NodeKey;
 use crate::semantic_index::reachability_constraints::ScopedReachabilityConstraintId;
 use crate::semantic_index::{PlaceSet, SemanticIndex, semantic_index};
+use crate::util::get_size::ThinVecSized;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 pub(crate) enum PlaceExprSubSegment {
@@ -41,7 +41,7 @@ impl PlaceExprSubSegment {
 #[derive(Eq, PartialEq, Debug, get_size2::GetSize)]
 pub struct PlaceExpr {
     root_name: Name,
-    sub_segments: SmallVec<[PlaceExprSubSegment; 1]>,
+    sub_segments: ThinVecSized<PlaceExprSubSegment>,
 }
 
 impl std::fmt::Display for PlaceExpr {
@@ -165,7 +165,7 @@ impl PlaceExpr {
     pub(crate) fn name(name: Name) -> Self {
         Self {
             root_name: name,
-            sub_segments: smallvec![],
+            sub_segments: ThinVecSized::new(),
         }
     }
 
@@ -230,7 +230,9 @@ impl std::fmt::Display for PlaceExprWithFlags {
 }
 
 impl PlaceExprWithFlags {
-    pub(crate) fn new(expr: PlaceExpr) -> Self {
+    pub(crate) fn new(mut expr: PlaceExpr) -> Self {
+        expr.sub_segments.shrink_to_fit();
+
         PlaceExprWithFlags {
             expr,
             flags: PlaceFlags::empty(),

crates/ty_python_semantic/src/semantic_index/use_def/place_state.rs

@@ -71,16 +71,12 @@ impl ScopedDefinitionId {
     }
 }
 
-/// Can keep inline this many live bindings or declarations per place at a given time; more will
-/// go to heap.
-const INLINE_DEFINITIONS_PER_PLACE: usize = 4;
-
 /// Live declarations for a single place at some point in control flow, with their
 /// corresponding reachability constraints.
 #[derive(Clone, Debug, Default, PartialEq, Eq, salsa::Update, get_size2::GetSize)]
 pub(super) struct Declarations {
     /// A list of live declarations for this place, sorted by their `ScopedDefinitionId`
-    live_declarations: SmallVec<[LiveDeclaration; INLINE_DEFINITIONS_PER_PLACE]>,
+    live_declarations: SmallVec<[LiveDeclaration; 2]>,
 }
 
 /// One of the live declarations for a single place at some point in control flow.
@@ -199,7 +195,7 @@ pub(super) struct Bindings {
     /// "unbound" binding.
     unbound_narrowing_constraint: Option<ScopedNarrowingConstraint>,
     /// A list of live bindings for this place, sorted by their `ScopedDefinitionId`
-    live_bindings: SmallVec<[LiveBinding; INLINE_DEFINITIONS_PER_PLACE]>,
+    live_bindings: SmallVec<[LiveBinding; 2]>,
 }
 
 impl Bindings {

crates/ty_python_semantic/src/types.rs

@@ -93,7 +93,7 @@ mod definition;
 #[cfg(test)]
 mod property_tests;
 
-pub fn check_types(db: &dyn Db, file: File) -> Vec<Diagnostic> {
+pub fn check_types(db: &dyn Db, file: File) -> thin_vec::ThinVec<Diagnostic> {
     let _span = tracing::trace_span!("check_types", ?file).entered();
 
     tracing::debug!("Checking file '{path}'", path = file.path(db));

crates/ty_python_semantic/src/types/diagnostic.rs

@@ -18,6 +18,7 @@ use crate::types::string_annotation::{
 use crate::types::tuple::TupleType;
 use crate::types::{SpecialFormType, Type, protocol_class::ProtocolClassLiteral};
 use crate::util::diagnostics::format_enumeration;
+use crate::util::get_size::ThinVecSized;
 use crate::{Db, FxIndexMap, Module, ModuleName, Program, declare_lint};
 use itertools::Itertools;
 use ruff_db::diagnostic::{Annotation, Diagnostic, Severity, SubDiagnostic};
@@ -1614,7 +1615,7 @@ declare_lint! {
 /// A collection of type check diagnostics.
 #[derive(Default, Eq, PartialEq, get_size2::GetSize)]
 pub struct TypeCheckDiagnostics {
-    diagnostics: Vec<Diagnostic>,
+    diagnostics: ThinVecSized<Diagnostic>,
     used_suppressions: FxHashSet<FileSuppressionId>,
 }
 
@@ -1649,8 +1650,8 @@ impl TypeCheckDiagnostics {
         self.diagnostics.shrink_to_fit();
     }
 
-    pub(crate) fn into_vec(self) -> Vec<Diagnostic> {
-        self.diagnostics
+    pub(crate) fn into_vec(self) -> thin_vec::ThinVec<Diagnostic> {
+        self.diagnostics.into_inner()
     }
 
     pub fn iter(&self) -> std::slice::Iter<'_, Diagnostic> {
@@ -1666,7 +1667,7 @@ impl std::fmt::Debug for TypeCheckDiagnostics {
 
 impl IntoIterator for TypeCheckDiagnostics {
     type Item = Diagnostic;
-    type IntoIter = std::vec::IntoIter<Diagnostic>;
+    type IntoIter = thin_vec::IntoIter<Diagnostic>;
 
     fn into_iter(self) -> Self::IntoIter {
         self.diagnostics.into_iter()

crates/ty_python_semantic/src/util/get_size.rs

@@ -1,3 +1,4 @@
+use std::ops::{Deref, DerefMut};
 use std::sync::Arc;
 
 use get_size2::GetSize;
@@ -13,3 +14,105 @@ where
 {
     T::get_heap_size(&**arc)
 }
+
+#[derive(Clone, Hash, PartialEq, Eq)]
+pub(crate) struct ThinVecSized<T>(thin_vec::ThinVec<T>);
+
+impl<T> ThinVecSized<T> {
+    pub(crate) fn into_inner(self) -> thin_vec::ThinVec<T> {
+        self.0
+    }
+
+    pub(crate) fn new() -> Self {
+        Self(thin_vec::ThinVec::new())
+    }
+}
+
+impl<T> Default for ThinVecSized<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[allow(unsafe_code)]
+unsafe impl<T> salsa::Update for ThinVecSized<T>
+where
+    T: salsa::Update,
+{
+    unsafe fn maybe_update(old_pointer: *mut Self, new_value: Self) -> bool {
+        let old: &mut Self = unsafe { &mut *old_pointer };
+
+        unsafe { salsa::Update::maybe_update(&raw mut old.0, new_value.0) }
+    }
+}
+
+impl<T> std::fmt::Debug for ThinVecSized<T>
+where
+    T: std::fmt::Debug,
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl<T> From<thin_vec::ThinVec<T>> for ThinVecSized<T> {
+    fn from(vec: thin_vec::ThinVec<T>) -> Self {
+        Self(vec)
+    }
+}
+
+impl<T> Deref for ThinVecSized<T> {
+    type Target = thin_vec::ThinVec<T>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T> DerefMut for ThinVecSized<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl<T> GetSize for ThinVecSized<T>
+where
+    T: GetSize,
+{
+    fn get_heap_size(&self) -> usize {
+        let mut total = 0;
+        for v in self {
+            total += GetSize::get_size(v);
+        }
+        let additional: usize = self.capacity() - self.len();
+        total += additional * T::get_stack_size();
+        total
+    }
+}
+
+impl<'a, T> IntoIterator for &'a ThinVecSized<T> {
+    type Item = &'a T;
+    type IntoIter = std::slice::Iter<'a, T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.iter()
+    }
+}
+
+impl<'a, T> IntoIterator for &'a mut ThinVecSized<T> {
+    type Item = &'a mut T;
+    type IntoIter = std::slice::IterMut<'a, T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.iter_mut()
+    }
+}
+
+impl<T> IntoIterator for ThinVecSized<T> {
+    type Item = T;
+    type IntoIter = thin_vec::IntoIter<T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
+    }
+}

crates/ty_server/Cargo.toml

@@ -23,6 +23,7 @@ ty_python_semantic = { workspace = true }
 ty_vendored = { workspace = true }
 
 anyhow = { workspace = true }
+bitflags = { workspace = true }
 crossbeam = { workspace = true }
 jod-thread = { workspace = true }
 lsp-server = { workspace = true }

crates/ty_server/src/server.rs

@@ -21,8 +21,8 @@ mod schedule;
 
 use crate::session::client::Client;
 pub(crate) use api::Error;
+pub(crate) use api::publish_settings_diagnostics;
 pub(crate) use main_loop::{Action, ConnectionSender, Event, MainLoopReceiver, MainLoopSender};
-
 pub(crate) type Result<T> = std::result::Result<T, api::Error>;
 
 pub(crate) struct Server {

crates/ty_server/src/server/api.rs

@@ -17,6 +17,7 @@ mod traits;
 use self::traits::{NotificationHandler, RequestHandler};
 use super::{Result, schedule::BackgroundSchedule};
 use crate::session::client::Client;
+pub(crate) use diagnostics::publish_settings_diagnostics;
 use ruff_db::panic::PanicError;
 
 /// Processes a request from the client to the server.

crates/ty_server/src/server/api/diagnostics.rs

@@ -8,11 +8,13 @@ use rustc_hash::FxHashMap;
 use ruff_db::diagnostic::{Annotation, Severity, SubDiagnostic};
 use ruff_db::files::FileRange;
 use ruff_db::source::{line_index, source_text};
+use ruff_db::system::SystemPathBuf;
 use ty_project::{Db, ProjectDatabase};
 
 use crate::document::{DocumentKey, FileRangeExt, ToRangeExt};
 use crate::session::DocumentSnapshot;
 use crate::session::client::Client;
+use crate::system::{AnySystemPath, file_to_url};
 use crate::{PositionEncoding, Session};
 
 /// Represents the diagnostics for a text document or a notebook document.
@@ -64,7 +66,7 @@ pub(super) fn clear_diagnostics(key: &DocumentKey, client: &Client) {
 ///
 /// [publish diagnostics notification]: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_publishDiagnostics
 pub(super) fn publish_diagnostics(session: &Session, key: &DocumentKey, client: &Client) {
-    if session.client_capabilities().pull_diagnostics {
+    if session.client_capabilities().supports_pull_diagnostics() {
         return;
     }
 
@@ -109,6 +111,82 @@ pub(super) fn publish_diagnostics(session: &Session, key: &DocumentKey, client:
     }
 }
 
+/// Publishes settings diagnostics for all the project at the given path
+/// using the [publish diagnostics notification].
+///
+/// [publish diagnostics notification]: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_publishDiagnostics
+pub(crate) fn publish_settings_diagnostics(
+    session: &mut Session,
+    client: &Client,
+    path: SystemPathBuf,
+) {
+    // Don't publish settings diagnostics for workspace that are already doing full diagnostics.
+    //
+    // Note we DO NOT respect the fact that clients support pulls because these are
+    // files they *specifically* won't pull diagnostics from us for, because we don't
+    // claim to be an LSP for them.
+    let has_workspace_diagnostics = session
+        .workspaces()
+        .for_path(&path)
+        .map(|workspace| workspace.settings().diagnostic_mode().is_workspace())
+        .unwrap_or(false);
+    if has_workspace_diagnostics {
+        return;
+    }
+
+    let session_encoding = session.position_encoding();
+    let state = session.project_state_mut(&AnySystemPath::System(path));
+    let db = &state.db;
+    let project = db.project();
+    let settings_diagnostics = project.check_settings(db);
+
+    // We need to send diagnostics if we have non-empty ones, or we have ones to clear.
+    // These will both almost always be empty so this function will almost always be a no-op.
+    if settings_diagnostics.is_empty() && state.untracked_files_with_pushed_diagnostics.is_empty() {
+        return;
+    }
+
+    // Group diagnostics by URL
+    let mut diagnostics_by_url: FxHashMap<Url, Vec<_>> = FxHashMap::default();
+    for diagnostic in settings_diagnostics {
+        if let Some(span) = diagnostic.primary_span() {
+            let file = span.expect_ty_file();
+            let Some(url) = file_to_url(db, file) else {
+                tracing::debug!("Failed to convert file to URL at {}", file.path(db));
+                continue;
+            };
+            diagnostics_by_url.entry(url).or_default().push(diagnostic);
+        }
+    }
+
+    // Record the URLs we're sending non-empty diagnostics for, so we know to clear them
+    // the next time we publish settings diagnostics!
+    let old_untracked = std::mem::replace(
+        &mut state.untracked_files_with_pushed_diagnostics,
+        diagnostics_by_url.keys().cloned().collect(),
+    );
+
+    // Add empty diagnostics for any files that had diagnostics before but don't now.
+    // This will clear them (either the file is no longer relevant to us or fixed!)
+    for url in old_untracked {
+        diagnostics_by_url.entry(url).or_default();
+    }
+    // Send the settings diagnostics!
+    for (url, file_diagnostics) in diagnostics_by_url {
+        // Convert diagnostics to LSP format
+        let lsp_diagnostics = file_diagnostics
+            .into_iter()
+            .map(|diagnostic| to_lsp_diagnostic(db, &diagnostic, session_encoding))
+            .collect::<Vec<_>>();
+
+        client.send_notification::<PublishDiagnostics>(PublishDiagnosticsParams {
+            uri: url,
+            diagnostics: lsp_diagnostics,
+            version: None,
+        });
+    }
+}
+
 pub(super) fn compute_diagnostics(
     db: &ProjectDatabase,
     snapshot: &DocumentSnapshot,

crates/ty_server/src/server/api/notifications/did_change_watched_files.rs

@@ -1,5 +1,5 @@
 use crate::server::Result;
-use crate::server::api::diagnostics::publish_diagnostics;
+use crate::server::api::diagnostics::{publish_diagnostics, publish_settings_diagnostics};
 use crate::server::api::traits::{NotificationHandler, SyncNotificationHandler};
 use crate::session::Session;
 use crate::session::client::Client;
@@ -88,7 +88,8 @@ impl SyncNotificationHandler for DidChangeWatchedFiles {
         for (root, changes) in events_by_db {
             tracing::debug!("Applying changes to `{root}`");
 
-            let result = session.apply_changes(&AnySystemPath::System(root), changes);
+            let result = session.apply_changes(&AnySystemPath::System(root.clone()), changes);
+            publish_settings_diagnostics(session, client, root);
 
             project_changed |= result.project_changed();
         }
@@ -96,7 +97,7 @@ impl SyncNotificationHandler for DidChangeWatchedFiles {
         let client_capabilities = session.client_capabilities();
 
         if project_changed {
-            if client_capabilities.diagnostics_refresh {
+            if client_capabilities.supports_workspace_diagnostic_refresh() {
                 client.send_request::<types::request::WorkspaceDiagnosticRefresh>(
                     session,
                     (),
@@ -107,11 +108,10 @@ impl SyncNotificationHandler for DidChangeWatchedFiles {
                     publish_diagnostics(session, &key, client);
                 }
             }
-
             // TODO: always publish diagnostics for notebook files (since they don't use pull diagnostics)
         }
 
-        if client_capabilities.inlay_refresh {
+        if client_capabilities.supports_inlay_hint_refresh() {
             client.send_request::<types::request::InlayHintRefreshRequest>(session, (), |_, ()| {});
         }
 

crates/ty_server/src/server/api/requests/goto_declaration.rs

@@ -52,7 +52,7 @@ impl BackgroundDocumentRequestHandler for GotoDeclarationRequestHandler {
 
         if snapshot
             .resolved_client_capabilities()
-            .type_definition_link_support
+            .supports_declaration_link()
         {
             let src = Some(ranged.range);
             let links: Vec<_> = ranged

crates/ty_server/src/server/api/requests/goto_definition.rs

@@ -52,7 +52,7 @@ impl BackgroundDocumentRequestHandler for GotoDefinitionRequestHandler {
 
         if snapshot
             .resolved_client_capabilities()
-            .type_definition_link_support
+            .supports_definition_link()
         {
             let src = Some(ranged.range);
             let links: Vec<_> = ranged

crates/ty_server/src/server/api/requests/goto_type_definition.rs

@@ -52,7 +52,7 @@ impl BackgroundDocumentRequestHandler for GotoTypeDefinitionRequestHandler {
 
         if snapshot
             .resolved_client_capabilities()
-            .type_definition_link_support
+            .supports_type_definition_link()
         {
             let src = Some(ranged.range);
             let links: Vec<_> = ranged

crates/ty_server/src/server/api/requests/hover.rs

@@ -52,7 +52,7 @@ impl BackgroundDocumentRequestHandler for HoverRequestHandler {
 
         let (markup_kind, lsp_markup_kind) = if snapshot
             .resolved_client_capabilities()
-            .hover_prefer_markdown
+            .prefers_markdown_in_hover()
         {
             (MarkupKind::Markdown, lsp_types::MarkupKind::Markdown)
         } else {

crates/ty_server/src/server/api/requests/semantic_tokens.rs

@@ -41,7 +41,7 @@ impl BackgroundDocumentRequestHandler for SemanticTokensRequestHandler {
             snapshot.encoding(),
             snapshot
                 .resolved_client_capabilities()
-                .semantic_tokens_multiline_support,
+                .supports_multiline_semantic_tokens(),
         );
 
         Ok(Some(SemanticTokensResult::Tokens(SemanticTokens {

crates/ty_server/src/server/api/requests/semantic_tokens_range.rs

@@ -51,7 +51,7 @@ impl BackgroundDocumentRequestHandler for SemanticTokensRangeRequestHandler {
             snapshot.encoding(),
             snapshot
                 .resolved_client_capabilities()
-                .semantic_tokens_multiline_support,
+                .supports_multiline_semantic_tokens(),
         );
 
         Ok(Some(SemanticTokensRangeResult::Tokens(SemanticTokens {

crates/ty_server/src/server/api/requests/signature_help.rs

@@ -71,7 +71,7 @@ impl BackgroundDocumentRequestHandler for SignatureHelpRequestHandler {
                     .parameters
                     .into_iter()
                     .map(|param| {
-                        let label = if resolved_capabilities.signature_label_offset_support {
+                        let label = if resolved_capabilities.supports_signature_label_offset() {
                             // Find the parameter's offset in the signature label
                             if let Some(start) = sig.label.find(&param.label) {
                                 let encoding = snapshot.encoding();
@@ -114,11 +114,12 @@ impl BackgroundDocumentRequestHandler for SignatureHelpRequestHandler {
                     })
                     .collect();
 
-                let active_parameter = if resolved_capabilities.signature_active_parameter_support {
-                    sig.active_parameter.and_then(|p| u32::try_from(p).ok())
-                } else {
-                    None
-                };
+                let active_parameter =
+                    if resolved_capabilities.supports_signature_active_parameter() {
+                        sig.active_parameter.and_then(|p| u32::try_from(p).ok())
+                    } else {
+                        None
+                    };
 
                 SignatureInformation {
                     label: sig.label,

crates/ty_server/src/session.rs

@@ -21,6 +21,7 @@ pub(crate) use self::index::DocumentQuery;
 pub(crate) use self::options::{AllOptions, ClientOptions, DiagnosticMode};
 pub(crate) use self::settings::ClientSettings;
 use crate::document::{DocumentKey, DocumentVersion, NotebookDocument};
+use crate::server::publish_settings_diagnostics;
 use crate::session::client::Client;
 use crate::session::request_queue::RequestQueue;
 use crate::system::{AnySystemPath, LSPSystem};
@@ -49,7 +50,7 @@ pub(crate) struct Session {
     workspaces: Workspaces,
 
     /// The projects across all workspaces.
-    projects: BTreeMap<SystemPathBuf, ProjectDatabase>,
+    projects: BTreeMap<SystemPathBuf, ProjectState>,
 
     /// The project to use for files outside any workspace. For example, if the user
     /// opens the project `<home>/my_project` in VS code but they then opens a Python file from their Desktop.
@@ -62,7 +63,7 @@ pub(crate) struct Session {
     position_encoding: PositionEncoding,
 
     /// Tracks what LSP features the client supports and doesn't support.
-    resolved_client_capabilities: Arc<ResolvedClientCapabilities>,
+    resolved_client_capabilities: ResolvedClientCapabilities,
 
     /// Tracks the pending requests between client and server.
     request_queue: RequestQueue,
@@ -73,6 +74,25 @@ pub(crate) struct Session {
     deferred_messages: VecDeque<Message>,
 }
 
+/// LSP State for a Project
+pub(crate) struct ProjectState {
+    pub(crate) db: ProjectDatabase,
+    /// Files that we have outstanding otherwise-untracked pushed diagnostics for.
+    ///
+    /// In `CheckMode::OpenFiles` we still read some files that the client hasn't
+    /// told us to open. Notably settings files like `pyproject.toml`. In this
+    /// mode the client will never pull diagnostics for that file, and because
+    /// the file isn't formally "open" we also don't have a reliable signal to
+    /// refresh diagnostics for it either.
+    ///
+    /// However diagnostics for those files include things like "you typo'd your
+    /// configuration for the LSP itself", so it's really important that we tell
+    /// the user about them! So we remember which ones we have emitted diagnostics
+    /// for so that we can clear the diagnostics for all of them before we go
+    /// to update any of them.
+    pub(crate) untracked_files_with_pushed_diagnostics: Vec<Url>,
+}
+
 impl Session {
     pub(crate) fn new(
         client_capabilities: &ClientCapabilities,
@@ -94,9 +114,7 @@ impl Session {
             index: Some(index),
             default_project: DefaultProject::new(),
             projects: BTreeMap::new(),
-            resolved_client_capabilities: Arc::new(ResolvedClientCapabilities::new(
-                client_capabilities,
-            )),
+            resolved_client_capabilities: ResolvedClientCapabilities::new(client_capabilities),
             request_queue: RequestQueue::new(),
             shutdown_requested: false,
         })
@@ -170,17 +188,7 @@ impl Session {
     ///
     /// If the path is a virtual path, it will return the first project database in the session.
     pub(crate) fn project_db(&self, path: &AnySystemPath) -> &ProjectDatabase {
-        match path {
-            AnySystemPath::System(system_path) => self
-                .project_db_for_path(system_path)
-                .unwrap_or_else(|| self.default_project.get(self.index.as_ref())),
-            AnySystemPath::SystemVirtual(_virtual_path) => {
-                // TODO: Currently, ty only supports single workspace but we need to figure out
-                // which project should this virtual path belong to when there are multiple
-                // projects: https://github.com/astral-sh/ty/issues/794
-                self.projects.iter().next().map(|(_, db)| db).unwrap()
-            }
-        }
+        &self.project_state(path).db
     }
 
     /// Returns a mutable reference to the project's [`ProjectDatabase`] in which the given `path`
@@ -190,20 +198,7 @@ impl Session {
     ///
     /// [`project_db`]: Session::project_db
     pub(crate) fn project_db_mut(&mut self, path: &AnySystemPath) -> &mut ProjectDatabase {
-        match path {
-            AnySystemPath::System(system_path) => self
-                .projects
-                .range_mut(..=system_path.to_path_buf())
-                .next_back()
-                .map(|(_, db)| db)
-                .unwrap_or_else(|| self.default_project.get_mut(self.index.as_ref())),
-            AnySystemPath::SystemVirtual(_virtual_path) => {
-                // TODO: Currently, ty only supports single workspace but we need to figure out
-                // which project should this virtual path belong to when there are multiple
-                // projects: https://github.com/astral-sh/ty/issues/794
-                self.projects.iter_mut().next().map(|(_, db)| db).unwrap()
-            }
-        }
+        &mut self.project_state_mut(path).db
     }
 
     /// Returns a reference to the project's [`ProjectDatabase`] corresponding to the given path, if
@@ -212,10 +207,70 @@ impl Session {
         &self,
         path: impl AsRef<SystemPath>,
     ) -> Option<&ProjectDatabase> {
+        self.project_state_for_path(path).map(|state| &state.db)
+    }
+
+    /// Returns a reference to the project's [`ProjectState`] in which the given `path` belongs.
+    ///
+    /// If the path is a system path, it will return the project database that is closest to the
+    /// given path, or the default project if no project is found for the path.
+    ///
+    /// If the path is a virtual path, it will return the first project database in the session.
+    pub(crate) fn project_state(&self, path: &AnySystemPath) -> &ProjectState {
+        match path {
+            AnySystemPath::System(system_path) => self
+                .project_state_for_path(system_path)
+                .unwrap_or_else(|| self.default_project.get(self.index.as_ref())),
+            AnySystemPath::SystemVirtual(_virtual_path) => {
+                // TODO: Currently, ty only supports single workspace but we need to figure out
+                // which project should this virtual path belong to when there are multiple
+                // projects: https://github.com/astral-sh/ty/issues/794
+                self.projects
+                    .iter()
+                    .next()
+                    .map(|(_, project)| project)
+                    .unwrap()
+            }
+        }
+    }
+
+    /// Returns a mutable reference to the project's [`ProjectState`] in which the given `path`
+    /// belongs.
+    ///
+    /// Refer to [`project_db`] for more details on how the project is selected.
+    ///
+    /// [`project_db`]: Session::project_db
+    pub(crate) fn project_state_mut(&mut self, path: &AnySystemPath) -> &mut ProjectState {
+        match path {
+            AnySystemPath::System(system_path) => self
+                .projects
+                .range_mut(..=system_path.to_path_buf())
+                .next_back()
+                .map(|(_, project)| project)
+                .unwrap_or_else(|| self.default_project.get_mut(self.index.as_ref())),
+            AnySystemPath::SystemVirtual(_virtual_path) => {
+                // TODO: Currently, ty only supports single workspace but we need to figure out
+                // which project should this virtual path belong to when there are multiple
+                // projects: https://github.com/astral-sh/ty/issues/794
+                self.projects
+                    .iter_mut()
+                    .next()
+                    .map(|(_, project)| project)
+                    .unwrap()
+            }
+        }
+    }
+
+    /// Returns a reference to the project's [`ProjectState`] corresponding to the given path, if
+    /// any.
+    pub(crate) fn project_state_for_path(
+        &self,
+        path: impl AsRef<SystemPath>,
+    ) -> Option<&ProjectState> {
         self.projects
             .range(..=path.as_ref().to_path_buf())
             .next_back()
-            .map(|(_, db)| db)
+            .map(|(_, project)| project)
     }
 
     pub(crate) fn apply_changes(
@@ -239,6 +294,13 @@ impl Session {
     ///
     /// This iterator will only yield the default project database if it has been used.
     fn projects_mut(&mut self) -> impl Iterator<Item = &'_ mut ProjectDatabase> + '_ {
+        self.project_states_mut().map(|project| &mut project.db)
+    }
+
+    /// Returns a mutable iterator over all projects that have been initialized to this point.
+    ///
+    /// This iterator will only yield the default project if it has been used.
+    pub(crate) fn project_states_mut(&mut self) -> impl Iterator<Item = &'_ mut ProjectState> + '_ {
         let default_project = self.default_project.try_get_mut();
         self.projects.values_mut().chain(default_project)
     }
@@ -284,10 +346,8 @@ impl Session {
                     ProjectDatabase::new(metadata, system.clone())
                 });
 
-            match project {
-                Ok(project) => {
-                    self.projects.insert(root, project);
-                }
+            let (root, db) = match project {
+                Ok(db) => (root, db),
                 Err(err) => {
                     tracing::error!(
                         "Failed to create project for `{root}`: {err:#}. Falling back to default settings"
@@ -302,16 +362,29 @@ impl Session {
                             .context("Failed to convert default options to metadata")
                             .and_then(|metadata| ProjectDatabase::new(metadata, system))
                             .expect("Default configuration to be valid");
+                    let default_root = db_with_default_settings
+                        .project()
+                        .root(&db_with_default_settings)
+                        .to_path_buf();
 
-                    self.projects.insert(
-                        db_with_default_settings
-                            .project()
-                            .root(&db_with_default_settings)
-                            .to_path_buf(),
-                        db_with_default_settings,
-                    );
+                    (default_root, db_with_default_settings)
                 }
-            }
+            };
+
+            // Carry forward diagnostic state if any exists
+            let previous = self.projects.remove(&root);
+            let untracked = previous
+                .map(|state| state.untracked_files_with_pushed_diagnostics)
+                .unwrap_or_default();
+            self.projects.insert(
+                root.clone(),
+                ProjectState {
+                    db,
+                    untracked_files_with_pushed_diagnostics: untracked,
+                },
+            );
+
+            publish_settings_diagnostics(self, client, root);
         }
 
         assert!(
@@ -332,7 +405,7 @@ impl Session {
     pub(crate) fn take_document_snapshot(&self, url: Url) -> DocumentSnapshot {
         let index = self.index();
         DocumentSnapshot {
-            resolved_client_capabilities: self.resolved_client_capabilities.clone(),
+            resolved_client_capabilities: self.resolved_client_capabilities,
             client_settings: index.global_settings(),
             position_encoding: self.position_encoding,
             document_query_result: self
@@ -345,7 +418,12 @@ impl Session {
     /// Creates a snapshot of the current state of the [`Session`].
     pub(crate) fn take_session_snapshot(&self) -> SessionSnapshot {
         SessionSnapshot {
-            projects: self.projects.values().cloned().collect(),
+            projects: self
+                .projects
+                .values()
+                .map(|project| &project.db)
+                .cloned()
+                .collect(),
             index: self.index.clone().unwrap(),
             position_encoding: self.position_encoding,
         }
@@ -432,13 +510,17 @@ impl Session {
         }
     }
 
-    pub(crate) fn client_capabilities(&self) -> &ResolvedClientCapabilities {
-        &self.resolved_client_capabilities
+    pub(crate) fn client_capabilities(&self) -> ResolvedClientCapabilities {
+        self.resolved_client_capabilities
     }
 
     pub(crate) fn global_settings(&self) -> Arc<ClientSettings> {
         self.index().global_settings()
     }
+
+    pub(crate) fn position_encoding(&self) -> PositionEncoding {
+        self.position_encoding
+    }
 }
 
 /// A guard that holds the only reference to the index and allows modifying it.
@@ -483,7 +565,7 @@ impl Drop for MutIndexGuard<'_> {
 /// An immutable snapshot of [`Session`] that references a specific document.
 #[derive(Debug)]
 pub(crate) struct DocumentSnapshot {
-    resolved_client_capabilities: Arc<ResolvedClientCapabilities>,
+    resolved_client_capabilities: ResolvedClientCapabilities,
     client_settings: Arc<ClientSettings>,
     position_encoding: PositionEncoding,
     document_query_result: Result<DocumentQuery, DocumentQueryError>,
@@ -491,8 +573,8 @@ pub(crate) struct DocumentSnapshot {
 
 impl DocumentSnapshot {
     /// Returns the resolved client capabilities that were captured during initialization.
-    pub(crate) fn resolved_client_capabilities(&self) -> &ResolvedClientCapabilities {
-        &self.resolved_client_capabilities
+    pub(crate) fn resolved_client_capabilities(&self) -> ResolvedClientCapabilities {
+        self.resolved_client_capabilities
     }
 
     /// Returns the position encoding that was negotiated during initialization.
@@ -656,14 +738,14 @@ impl Workspace {
 ///    We really want that to be the actual project database and not our fallback database.
 /// 2. The logs when the server starts can be confusing if it once shows it uses Python X (for the default db)
 ///    but then has another log that it uses Python Y (for the actual project db).
-struct DefaultProject(std::sync::OnceLock<ProjectDatabase>);
+struct DefaultProject(std::sync::OnceLock<ProjectState>);
 
 impl DefaultProject {
     pub(crate) fn new() -> Self {
         DefaultProject(std::sync::OnceLock::new())
     }
 
-    pub(crate) fn get(&self, index: Option<&Arc<Index>>) -> &ProjectDatabase {
+    pub(crate) fn get(&self, index: Option<&Arc<Index>>) -> &ProjectState {
         self.0.get_or_init(|| {
             tracing::info!("Initialize default project");
 
@@ -674,11 +756,14 @@ impl DefaultProject {
                 None,
             )
             .unwrap();
-            ProjectDatabase::new(metadata, system).unwrap()
+            ProjectState {
+                db: ProjectDatabase::new(metadata, system).unwrap(),
+                untracked_files_with_pushed_diagnostics: Vec::new(),
+            }
         })
     }
 
-    pub(crate) fn get_mut(&mut self, index: Option<&Arc<Index>>) -> &mut ProjectDatabase {
+    pub(crate) fn get_mut(&mut self, index: Option<&Arc<Index>>) -> &mut ProjectState {
         let _ = self.get(index);
 
         // SAFETY: The `OnceLock` is guaranteed to be initialized at this point because
@@ -686,7 +771,7 @@ impl DefaultProject {
         self.0.get_mut().unwrap()
     }
 
-    pub(crate) fn try_get_mut(&mut self) -> Option<&mut ProjectDatabase> {
+    pub(crate) fn try_get_mut(&mut self) -> Option<&mut ProjectState> {
         self.0.get_mut()
     }
 }

crates/ty_server/src/session/capabilities.rs

@@ -1,87 +1,121 @@
 use lsp_types::{ClientCapabilities, MarkupKind};
 
-#[derive(Debug, Clone, PartialEq, Eq, Default)]
-#[expect(clippy::struct_excessive_bools)]
-pub(crate) struct ResolvedClientCapabilities {
-    pub(crate) code_action_deferred_edit_resolution: bool,
-    pub(crate) apply_edit: bool,
-    pub(crate) document_changes: bool,
-    pub(crate) diagnostics_refresh: bool,
-    pub(crate) inlay_refresh: bool,
-
-    /// Whether [pull diagnostics] is supported.
+bitflags::bitflags! {
+    /// Represents the resolved client capabilities for the language server.
     ///
-    /// [pull diagnostics]: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_pullDiagnostics
-    pub(crate) pull_diagnostics: bool,
-
-    /// Whether `textDocument.typeDefinition.linkSupport` is `true`
-    pub(crate) type_definition_link_support: bool,
-
-    /// `true`, if the first markup kind in `textDocument.hover.contentFormat` is `Markdown`
-    pub(crate) hover_prefer_markdown: bool,
-
-    /// Whether the client supports multiline semantic tokens
-    pub(crate) semantic_tokens_multiline_support: bool,
-
-    /// Whether the client supports signature label offsets in signature help
-    pub(crate) signature_label_offset_support: bool,
-
-    /// Whether the client supports per-signature active parameter in signature help
-    pub(crate) signature_active_parameter_support: bool,
+    /// This tracks various capabilities that the client supports.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+    pub(crate) struct ResolvedClientCapabilities: u32 {
+        const WORKSPACE_DIAGNOSTIC_REFRESH = 1 << 0;
+        const INLAY_HINT_REFRESH = 1 << 1;
+        const PULL_DIAGNOSTICS = 1 << 2;
+        const TYPE_DEFINITION_LINK_SUPPORT = 1 << 3;
+        const DEFINITION_LINK_SUPPORT = 1 << 4;
+        const DECLARATION_LINK_SUPPORT = 1 << 5;
+        const PREFER_MARKDOWN_IN_HOVER = 1 << 6;
+        const MULTILINE_SEMANTIC_TOKENS = 1 << 7;
+        const SIGNATURE_LABEL_OFFSET_SUPPORT = 1 << 8;
+        const SIGNATURE_ACTIVE_PARAMETER_SUPPORT = 1 << 9;
+    }
 }
 
 impl ResolvedClientCapabilities {
+    /// Returns `true` if the client supports workspace diagnostic refresh.
+    pub(crate) const fn supports_workspace_diagnostic_refresh(self) -> bool {
+        self.contains(Self::WORKSPACE_DIAGNOSTIC_REFRESH)
+    }
+
+    /// Returns `true` if the client supports inlay hint refresh.
+    pub(crate) const fn supports_inlay_hint_refresh(self) -> bool {
+        self.contains(Self::INLAY_HINT_REFRESH)
+    }
+
+    /// Returns `true` if the client supports pull diagnostics.
+    pub(crate) const fn supports_pull_diagnostics(self) -> bool {
+        self.contains(Self::PULL_DIAGNOSTICS)
+    }
+
+    /// Returns `true` if the client supports definition links in goto type definition.
+    pub(crate) const fn supports_type_definition_link(self) -> bool {
+        self.contains(Self::TYPE_DEFINITION_LINK_SUPPORT)
+    }
+
+    /// Returns `true` if the client supports definition links in goto definition.
+    pub(crate) const fn supports_definition_link(self) -> bool {
+        self.contains(Self::DEFINITION_LINK_SUPPORT)
+    }
+
+    /// Returns `true` if the client supports definition links in goto declaration.
+    pub(crate) const fn supports_declaration_link(self) -> bool {
+        self.contains(Self::DECLARATION_LINK_SUPPORT)
+    }
+
+    /// Returns `true` if the client prefers markdown in hover responses.
+    pub(crate) const fn prefers_markdown_in_hover(self) -> bool {
+        self.contains(Self::PREFER_MARKDOWN_IN_HOVER)
+    }
+
+    /// Returns `true` if the client supports multiline semantic tokens.
+    pub(crate) const fn supports_multiline_semantic_tokens(self) -> bool {
+        self.contains(Self::MULTILINE_SEMANTIC_TOKENS)
+    }
+
+    /// Returns `true` if the client supports signature label offsets in signature help.
+    pub(crate) const fn supports_signature_label_offset(self) -> bool {
+        self.contains(Self::SIGNATURE_LABEL_OFFSET_SUPPORT)
+    }
+
+    /// Returns `true` if the client supports per-signature active parameter in signature help.
+    pub(crate) const fn supports_signature_active_parameter(self) -> bool {
+        self.contains(Self::SIGNATURE_ACTIVE_PARAMETER_SUPPORT)
+    }
+
     pub(super) fn new(client_capabilities: &ClientCapabilities) -> Self {
-        let code_action_settings = client_capabilities
-            .text_document
-            .as_ref()
-            .and_then(|doc_settings| doc_settings.code_action.as_ref());
-        let code_action_data_support = code_action_settings
-            .and_then(|code_action_settings| code_action_settings.data_support)
-            .unwrap_or_default();
-        let code_action_edit_resolution = code_action_settings
-            .and_then(|code_action_settings| code_action_settings.resolve_support.as_ref())
-            .is_some_and(|resolve_support| resolve_support.properties.contains(&"edit".into()));
+        let mut flags = Self::empty();
 
-        let apply_edit = client_capabilities
-            .workspace
-            .as_ref()
-            .and_then(|workspace| workspace.apply_edit)
-            .unwrap_or_default();
+        let workspace = client_capabilities.workspace.as_ref();
+        let text_document = client_capabilities.text_document.as_ref();
 
-        let document_changes = client_capabilities
-            .workspace
-            .as_ref()
-            .and_then(|workspace| workspace.workspace_edit.as_ref()?.document_changes)
-            .unwrap_or_default();
-
-        let declaration_link_support = client_capabilities
-            .text_document
-            .as_ref()
-            .and_then(|document| document.type_definition?.link_support)
-            .unwrap_or_default();
-
-        let diagnostics_refresh = client_capabilities
-            .workspace
-            .as_ref()
+        if workspace
             .and_then(|workspace| workspace.diagnostics.as_ref()?.refresh_support)
-            .unwrap_or_default();
+            .unwrap_or_default()
+        {
+            flags |= Self::WORKSPACE_DIAGNOSTIC_REFRESH;
+        }
 
-        let inlay_refresh = client_capabilities
-            .workspace
-            .as_ref()
+        if workspace
             .and_then(|workspace| workspace.inlay_hint.as_ref()?.refresh_support)
-            .unwrap_or_default();
+            .unwrap_or_default()
+        {
+            flags |= Self::INLAY_HINT_REFRESH;
+        }
 
-        let pull_diagnostics = client_capabilities
-            .text_document
-            .as_ref()
-            .and_then(|text_document| text_document.diagnostic.as_ref())
-            .is_some();
+        if text_document.is_some_and(|text_document| text_document.diagnostic.is_some()) {
+            flags |= Self::PULL_DIAGNOSTICS;
+        }
 
-        let hover_prefer_markdown = client_capabilities
-            .text_document
-            .as_ref()
+        if text_document
+            .and_then(|text_document| text_document.type_definition?.link_support)
+            .unwrap_or_default()
+        {
+            flags |= Self::TYPE_DEFINITION_LINK_SUPPORT;
+        }
+
+        if text_document
+            .and_then(|text_document| text_document.definition?.link_support)
+            .unwrap_or_default()
+        {
+            flags |= Self::DEFINITION_LINK_SUPPORT;
+        }
+
+        if text_document
+            .and_then(|text_document| text_document.declaration?.link_support)
+            .unwrap_or_default()
+        {
+            flags |= Self::DECLARATION_LINK_SUPPORT;
+        }
+
+        if text_document
             .and_then(|text_document| {
                 Some(
                     text_document
@@ -92,18 +126,24 @@ impl ResolvedClientCapabilities {
                         .contains(&MarkupKind::Markdown),
                 )
             })
-            .unwrap_or_default();
+            .unwrap_or_default()
+        {
+            flags |= Self::PREFER_MARKDOWN_IN_HOVER;
+        }
 
-        let semantic_tokens_multiline_support = client_capabilities
-            .text_document
-            .as_ref()
-            .and_then(|doc| doc.semantic_tokens.as_ref())
-            .and_then(|semantic_tokens| semantic_tokens.multiline_token_support)
-            .unwrap_or(false);
+        if text_document
+            .and_then(|text_document| {
+                text_document
+                    .semantic_tokens
+                    .as_ref()?
+                    .multiline_token_support
+            })
+            .unwrap_or_default()
+        {
+            flags |= Self::MULTILINE_SEMANTIC_TOKENS;
+        }
 
-        let signature_label_offset_support = client_capabilities
-            .text_document
-            .as_ref()
+        if text_document
             .and_then(|text_document| {
                 text_document
                     .signature_help
@@ -114,11 +154,12 @@ impl ResolvedClientCapabilities {
                     .as_ref()?
                     .label_offset_support
             })
-            .unwrap_or_default();
+            .unwrap_or_default()
+        {
+            flags |= Self::SIGNATURE_LABEL_OFFSET_SUPPORT;
+        }
 
-        let signature_active_parameter_support = client_capabilities
-            .text_document
-            .as_ref()
+        if text_document
             .and_then(|text_document| {
                 text_document
                     .signature_help
@@ -127,21 +168,11 @@ impl ResolvedClientCapabilities {
                     .as_ref()?
                     .active_parameter_support
             })
-            .unwrap_or_default();
-
-        Self {
-            code_action_deferred_edit_resolution: code_action_data_support
-                && code_action_edit_resolution,
-            apply_edit,
-            document_changes,
-            diagnostics_refresh,
-            inlay_refresh,
-            pull_diagnostics,
-            type_definition_link_support: declaration_link_support,
-            hover_prefer_markdown,
-            semantic_tokens_multiline_support,
-            signature_label_offset_support,
-            signature_active_parameter_support,
+            .unwrap_or_default()
+        {
+            flags |= Self::SIGNATURE_ACTIVE_PARAMETER_SUPPORT;
         }
+
+        flags
     }
 }

docs/integrations.md

@@ -80,7 +80,7 @@ You can add the following configuration to `.gitlab-ci.yml` to run a `ruff forma
   stage: build
   interruptible: true
   image:
-    name: ghcr.io/astral-sh/ruff:0.12.3-alpine
+    name: ghcr.io/astral-sh/ruff:0.12.4-alpine
   before_script:
     - cd $CI_PROJECT_DIR
     - ruff --version
@@ -106,7 +106,7 @@ Ruff can be used as a [pre-commit](https://pre-commit.com) hook via [`ruff-pre-c
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.4
   hooks:
     # Run the linter.
     - id: ruff
@@ -119,7 +119,7 @@ To enable lint fixes, add the `--fix` argument to the lint hook:
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.4
   hooks:
     # Run the linter.
     - id: ruff
@@ -133,7 +133,7 @@ To avoid running on Jupyter Notebooks, remove `jupyter` from the list of allowed
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.4
   hooks:
     # Run the linter.
     - id: ruff

docs/tutorial.md

@@ -369,7 +369,7 @@ This tutorial has focused on Ruff's command-line interface, but Ruff can also be
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.4
   hooks:
     # Run the linter.
     - id: ruff

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.4"
 description = "An extremely fast Python linter and code formatter, written in Rust."
 authors = [{ name = "Astral Software Inc.", email = "hey@astral.sh" }]
 readme = "README.md"

scripts/benchmarks/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "scripts"
-version = "0.12.3"
+version = "0.12.4"
 description = ""
 authors = ["Charles Marsh <charlie.r.marsh@gmail.com>"]