[ty] Implicit type aliases: Instantiation and attribute access

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Micha Reiser <micha@reiser.io>

.github/workflows/ci.yaml

@@ -284,6 +284,10 @@ jobs:
         run: cargo insta test --all-features --unreferenced reject --test-runner nextest
       - name: Dogfood ty on py-fuzzer
         run: uv run --project=./python/py-fuzzer cargo run -p ty check --project=./python/py-fuzzer
+      - name: Dogfood ty on the scripts directory
+        run: uv run --project=./scripts cargo run -p ty check --project=./scripts
+      - name: Dogfood ty on ty_benchmark
+        run: uv run --project=./scripts/ty_benchmark cargo run -p ty check --project=./scripts/ty_benchmark
       # Check for broken links in the documentation.
       - run: cargo doc --all --no-deps
         env:

.github/workflows/ty-ecosystem-analyzer.yaml

@@ -67,7 +67,7 @@ jobs:
 
           cd ..
 
-          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@e26ebfb78d372b8b091e1cb1d6fc522e135474c1"
+          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@55df3c868f3fa9ab34cff0498dd6106722aac205"
 
           ecosystem-analyzer \
             --repository ruff \

.github/workflows/ty-ecosystem-report.yaml

@@ -52,7 +52,7 @@ jobs:
 
           cd ..
 
-          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@e26ebfb78d372b8b091e1cb1d6fc522e135474c1"
+          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@55df3c868f3fa9ab34cff0498dd6106722aac205"
 
           ecosystem-analyzer \
             --verbose \

.vscode/settings.json

@@ -5,5 +5,6 @@
     "rust-analyzer.check.command": "clippy",
     "search.exclude": {
         "**/*.snap": true
-    }
+    },
+    "ty.diagnosticMode": "openFilesOnly"
 }

Cargo.lock

@@ -4474,6 +4474,7 @@ dependencies = [
  "quickcheck_macros",
  "ruff_annotate_snippets",
  "ruff_db",
+ "ruff_diagnostics",
  "ruff_index",
  "ruff_macros",
  "ruff_memory_usage",
@@ -4519,6 +4520,7 @@ dependencies = [
  "lsp-types",
  "regex",
  "ruff_db",
+ "ruff_diagnostics",
  "ruff_macros",
  "ruff_notebook",
  "ruff_python_ast",
@@ -4559,6 +4561,7 @@ dependencies = [
  "path-slash",
  "regex",
  "ruff_db",
+ "ruff_diagnostics",
  "ruff_index",
  "ruff_notebook",
  "ruff_python_ast",
@@ -4600,6 +4603,7 @@ dependencies = [
  "js-sys",
  "log",
  "ruff_db",
+ "ruff_diagnostics",
  "ruff_notebook",
  "ruff_python_formatter",
  "ruff_source_file",

crates/ruff/src/printer.rs

@@ -34,9 +34,21 @@ struct ExpandedStatistics<'a> {
     code: Option<&'a SecondaryCode>,
     name: &'static str,
     count: usize,
-    fixable: bool,
+    #[serde(rename = "fixable")]
+    all_fixable: bool,
+    fixable_count: usize,
 }
 
+impl ExpandedStatistics<'_> {
+    fn any_fixable(&self) -> bool {
+        self.fixable_count > 0
+    }
+}
+
+/// Accumulator type for grouping diagnostics by code.
+/// Format: (`code`, `representative_diagnostic`, `total_count`, `fixable_count`)
+type DiagnosticGroup<'a> = (Option<&'a SecondaryCode>, &'a Diagnostic, usize, usize);
+
 pub(crate) struct Printer {
     format: OutputFormat,
     log_level: LogLevel,
@@ -133,7 +145,7 @@ impl Printer {
                         if fixables.applicable > 0 {
                             writeln!(
                                 writer,
-                                "{fix_prefix} {} fixable with the --fix option.",
+                                "{fix_prefix} {} fixable with the `--fix` option.",
                                 fixables.applicable
                             )?;
                         }
@@ -256,35 +268,41 @@ impl Printer {
         diagnostics: &Diagnostics,
         writer: &mut dyn Write,
     ) -> Result<()> {
+        let required_applicability = self.unsafe_fixes.required_applicability();
         let statistics: Vec<ExpandedStatistics> = diagnostics
             .inner
             .iter()
-            .map(|message| (message.secondary_code(), message))
-            .sorted_by_key(|(code, message)| (*code, message.fixable()))
-            .fold(
-                vec![],
-                |mut acc: Vec<((Option<&SecondaryCode>, &Diagnostic), usize)>, (code, message)| {
-                    if let Some(((prev_code, _prev_message), count)) = acc.last_mut() {
-                        if *prev_code == code {
-                            *count += 1;
-                            return acc;
+            .sorted_by_key(|diagnostic| diagnostic.secondary_code())
+            .fold(vec![], |mut acc: Vec<DiagnosticGroup>, diagnostic| {
+                let is_fixable = diagnostic
+                    .fix()
+                    .is_some_and(|fix| fix.applies(required_applicability));
+                let code = diagnostic.secondary_code();
+
+                if let Some((prev_code, _prev_message, count, fixable_count)) = acc.last_mut() {
+                    if *prev_code == code {
+                        *count += 1;
+                        if is_fixable {
+                            *fixable_count += 1;
                         }
+                        return acc;
                     }
-                    acc.push(((code, message), 1));
-                    acc
+                }
+                acc.push((code, diagnostic, 1, usize::from(is_fixable)));
+                acc
+            })
+            .iter()
+            .map(
+                |&(code, message, count, fixable_count)| ExpandedStatistics {
+                    code,
+                    name: message.name(),
+                    count,
+                    // Backward compatibility: `fixable` is true only when all violations are fixable.
+                    // See: https://github.com/astral-sh/ruff/pull/21513
+                    all_fixable: fixable_count == count,
+                    fixable_count,
                 },
             )
-            .iter()
-            .map(|&((code, message), count)| ExpandedStatistics {
-                code,
-                name: message.name(),
-                count,
-                fixable: if let Some(fix) = message.fix() {
-                    fix.applies(self.unsafe_fixes.required_applicability())
-                } else {
-                    false
-                },
-            })
             .sorted_by_key(|statistic| Reverse(statistic.count))
             .collect();
 
@@ -308,13 +326,14 @@ impl Printer {
                     .map(|statistic| statistic.code.map_or(0, |s| s.len()))
                     .max()
                     .unwrap();
-                let any_fixable = statistics.iter().any(|statistic| statistic.fixable);
+                let any_fixable = statistics.iter().any(ExpandedStatistics::any_fixable);
 
-                let fixable = format!("[{}] ", "*".cyan());
+                let all_fixable = format!("[{}] ", "*".cyan());
+                let partially_fixable = format!("[{}] ", "-".cyan());
                 let unfixable = "[ ] ";
 
                 // By default, we mimic Flake8's `--statistics` format.
-                for statistic in statistics {
+                for statistic in &statistics {
                     writeln!(
                         writer,
                         "{:>count_width$}\t{:<code_width$}\t{}{}",
@@ -326,8 +345,10 @@ impl Printer {
                             .red()
                             .bold(),
                         if any_fixable {
-                            if statistic.fixable {
-                                &fixable
+                            if statistic.all_fixable {
+                                &all_fixable
+                            } else if statistic.any_fixable() {
+                                &partially_fixable
                             } else {
                                 unfixable
                             }

crates/ruff/tests/integration_test.rs

@@ -1043,7 +1043,7 @@ def mvce(keys, values):
     ----- stdout -----
     1	C416	[*] unnecessary-comprehension
     Found 1 error.
-    [*] 1 fixable with the --fix option.
+    [*] 1 fixable with the `--fix` option.
 
     ----- stderr -----
     ");
@@ -1073,7 +1073,8 @@ def mvce(keys, values):
         "code": "C416",
         "name": "unnecessary-comprehension",
         "count": 1,
-        "fixable": false
+        "fixable": false,
+        "fixable_count": 0
       }
     ]
 
@@ -1106,7 +1107,8 @@ def mvce(keys, values):
         "code": "C416",
         "name": "unnecessary-comprehension",
         "count": 1,
-        "fixable": true
+        "fixable": true,
+        "fixable_count": 1
       }
     ]
 
@@ -1114,6 +1116,54 @@ def mvce(keys, values):
     "#);
 }
 
+#[test]
+fn show_statistics_json_partial_fix() {
+    let mut cmd = RuffCheck::default()
+        .args([
+            "--select",
+            "UP035",
+            "--statistics",
+            "--output-format",
+            "json",
+        ])
+        .build();
+    assert_cmd_snapshot!(cmd
+        .pass_stdin("from typing import List, AsyncGenerator"), @r#"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    [
+      {
+        "code": "UP035",
+        "name": "deprecated-import",
+        "count": 2,
+        "fixable": false,
+        "fixable_count": 1
+      }
+    ]
+
+    ----- stderr -----
+    "#);
+}
+
+#[test]
+fn show_statistics_partial_fix() {
+    let mut cmd = RuffCheck::default()
+        .args(["--select", "UP035", "--statistics"])
+        .build();
+    assert_cmd_snapshot!(cmd
+        .pass_stdin("from typing import List, AsyncGenerator"), @r"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    2	UP035	[-] deprecated-import
+    Found 2 errors.
+    [*] 1 fixable with the `--fix` option.
+
+    ----- stderr -----
+    ");
+}
+
 #[test]
 fn show_statistics_syntax_errors() {
     let mut cmd = RuffCheck::default()
@@ -1810,7 +1860,7 @@ fn check_no_hint_for_hidden_unsafe_fixes_when_disabled() {
     --> -:1:1
 
     Found 2 errors.
-    [*] 1 fixable with the --fix option.
+    [*] 1 fixable with the `--fix` option.
 
     ----- stderr -----
     ");
@@ -1853,7 +1903,7 @@ fn check_shows_unsafe_fixes_with_opt_in() {
     --> -:1:1
 
     Found 2 errors.
-    [*] 2 fixable with the --fix option.
+    [*] 2 fixable with the `--fix` option.
 
     ----- stderr -----
     ");

crates/ruff_benchmark/benches/ty_walltime.rs

@@ -223,7 +223,7 @@ static STATIC_FRAME: Benchmark = Benchmark::new(
         max_dep_date: "2025-08-09",
         python_version: PythonVersion::PY311,
     },
-    900,
+    950,
 );
 
 #[track_caller]

crates/ruff_linter/resources/test/fixtures/flake8_bandit/S310.py

@@ -45,3 +45,22 @@ urllib.request.urlopen(urllib.request.Request(url))
 # https://github.com/astral-sh/ruff/issues/15522
 map(urllib.request.urlopen, [])
 foo = urllib.request.urlopen
+
+# https://github.com/astral-sh/ruff/issues/21462
+path = "https://example.com/data.csv"
+urllib.request.urlretrieve(path, "data.csv")
+url = "https://example.com/api"
+urllib.request.Request(url)
+
+# Test resolved f-strings and concatenated string literals
+fstring_url = f"https://example.com/data.csv"
+urllib.request.urlopen(fstring_url)
+urllib.request.Request(fstring_url)
+
+concatenated_url = "https://" + "example.com/data.csv"
+urllib.request.urlopen(concatenated_url)
+urllib.request.Request(concatenated_url)
+
+nested_concatenated = "http://" + "example.com" + "/data.csv"
+urllib.request.urlopen(nested_concatenated)
+urllib.request.Request(nested_concatenated)

crates/ruff_linter/resources/test/fixtures/ruff/RUF066.py

@@ -0,0 +1,70 @@
+import abc
+import typing
+
+
+class User:  # Test normal class properties
+    @property
+    def name(self):  # ERROR: No return
+        f"{self.first_name} {self.last_name}"
+
+    @property
+    def age(self):  # OK: Returning something
+        return 100
+
+    def method(self):  # OK: Not a property
+        x = 1
+
+    @property
+    def nested(self):  # ERROR: Property itself doesn't return
+        def inner():
+            return 0
+
+    @property
+    def stub(self): ...  # OK: A stub; doesn't return anything
+
+
+class UserMeta(metaclass=abc.ABCMeta):  # Test properies inside of an ABC class
+    @property
+    @abc.abstractmethod
+    def abstr_prop1(self): ...  # OK: Abstract methods doesn't need to return anything
+
+    @property
+    @abc.abstractmethod
+    def abstr_prop2(self):  # OK: Abstract methods doesn't need to return anything
+        """
+        A cool docstring
+        """
+
+    @property
+    def prop1(self):  # OK: Returning a value
+        return 1
+
+    @property
+    def prop2(self):  # ERROR: Not returning something (even when we are inside an ABC)
+        50
+
+    def method(self):  # OK: Not a property
+        x = 1
+
+
+def func():  # OK: Not a property
+    x = 1
+
+
+class Proto(typing.Protocol):  # Tests for a Protocol class
+    @property
+    def prop1(self) -> int: ...  # OK: A stub property
+
+
+class File:  # Extra tests for things like yield/yield from/raise
+    @property
+    def stream1(self):  # OK: Yields something
+        yield
+
+    @property
+    def stream2(self):  # OK: Yields from something
+        yield from self.stream1
+
+    @property
+    def children(self):  # OK: Raises
+        raise ValueError("File does not have children")

crates/ruff_linter/resources/test/project/README.md

@@ -17,7 +17,7 @@ crates/ruff_linter/resources/test/project/examples/docs/docs/file.py:8:5: F841 [
 crates/ruff_linter/resources/test/project/project/file.py:1:8: F401 [*] `os` imported but unused
 crates/ruff_linter/resources/test/project/project/import_file.py:1:1: I001 [*] Import block is un-sorted or un-formatted
 Found 7 errors.
-[*] 7 potentially fixable with the --fix option.
+[*] 7 potentially fixable with the `--fix` option.
 ```
 
 Running from the project directory itself should exhibit the same behavior:
@@ -32,7 +32,7 @@ examples/docs/docs/file.py:8:5: F841 [*] Local variable `x` is assigned to but n
 project/file.py:1:8: F401 [*] `os` imported but unused
 project/import_file.py:1:1: I001 [*] Import block is un-sorted or un-formatted
 Found 7 errors.
-[*] 7 potentially fixable with the --fix option.
+[*] 7 potentially fixable with the `--fix` option.
 ```
 
 Running from the sub-package directory should exhibit the same behavior, but omit the top-level
@@ -43,7 +43,7 @@ files:
 docs/file.py:1:1: I001 [*] Import block is un-sorted or un-formatted
 docs/file.py:8:5: F841 [*] Local variable `x` is assigned to but never used
 Found 2 errors.
-[*] 2 potentially fixable with the --fix option.
+[*] 2 potentially fixable with the `--fix` option.
 ```
 
 `--config` should force Ruff to use the specified `pyproject.toml` for all files, and resolve
@@ -61,7 +61,7 @@ crates/ruff_linter/resources/test/project/examples/docs/docs/file.py:4:27: F401
 crates/ruff_linter/resources/test/project/examples/excluded/script.py:1:8: F401 [*] `os` imported but unused
 crates/ruff_linter/resources/test/project/project/file.py:1:8: F401 [*] `os` imported but unused
 Found 9 errors.
-[*] 9 potentially fixable with the --fix option.
+[*] 9 potentially fixable with the `--fix` option.
 ```
 
 Running from a parent directory should "ignore" the `exclude` (hence, `concepts/file.py` gets
@@ -74,7 +74,7 @@ docs/docs/file.py:1:1: I001 [*] Import block is un-sorted or un-formatted
 docs/docs/file.py:8:5: F841 [*] Local variable `x` is assigned to but never used
 excluded/script.py:5:5: F841 [*] Local variable `x` is assigned to but never used
 Found 4 errors.
-[*] 4 potentially fixable with the --fix option.
+[*] 4 potentially fixable with the `--fix` option.
 ```
 
 Passing an excluded directory directly should report errors in the contained files:
@@ -83,7 +83,7 @@ Passing an excluded directory directly should report errors in the contained fil
 ∴ cargo run -p ruff -- check crates/ruff_linter/resources/test/project/examples/excluded/
 crates/ruff_linter/resources/test/project/examples/excluded/script.py:1:8: F401 [*] `os` imported but unused
 Found 1 error.
-[*] 1 potentially fixable with the --fix option.
+[*] 1 potentially fixable with the `--fix` option.
 ```
 
 Unless we `--force-exclude`:

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

@@ -347,6 +347,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             if checker.is_rule_enabled(Rule::InvalidArgumentName) {
                 pep8_naming::rules::invalid_argument_name_function(checker, function_def);
             }
+            if checker.is_rule_enabled(Rule::PropertyWithoutReturn) {
+                ruff::rules::property_without_return(checker, function_def);
+            }
         }
         Stmt::Return(_) => {
             if checker.is_rule_enabled(Rule::ReturnInInit) {

crates/ruff_linter/src/codes.rs

@@ -1058,6 +1058,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Ruff, "063") => rules::ruff::rules::AccessAnnotationsFromClassDict,
         (Ruff, "064") => rules::ruff::rules::NonOctalPermissions,
         (Ruff, "065") => rules::ruff::rules::LoggingEagerConversion,
+        (Ruff, "066") => rules::ruff::rules::PropertyWithoutReturn,
 
         (Ruff, "100") => rules::ruff::rules::UnusedNOQA,
         (Ruff, "101") => rules::ruff::rules::RedirectedNOQA,

crates/ruff_linter/src/preview.rs

@@ -279,3 +279,10 @@ pub(crate) const fn is_extended_snmp_api_path_detection_enabled(settings: &Linte
 pub(crate) const fn is_enumerate_for_loop_int_index_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()
 }
+
+// https://github.com/astral-sh/ruff/pull/21469
+pub(crate) const fn is_s310_resolve_string_literal_bindings_enabled(
+    settings: &LinterSettings,
+) -> bool {
+    settings.preview.is_enabled()
+}

crates/ruff_linter/src/rules/flake8_bandit/mod.rs

@@ -10,11 +10,11 @@ mod tests {
     use anyhow::Result;
     use test_case::test_case;
 
-    use crate::assert_diagnostics;
     use crate::registry::Rule;
     use crate::settings::LinterSettings;
     use crate::settings::types::PreviewMode;
     use crate::test::test_path;
+    use crate::{assert_diagnostics, assert_diagnostics_diff};
 
     #[test_case(Rule::Assert, Path::new("S101.py"))]
     #[test_case(Rule::BadFilePermissions, Path::new("S103.py"))]
@@ -112,14 +112,19 @@ mod tests {
             rule_code.noqa_code(),
             path.to_string_lossy()
         );
-        let diagnostics = test_path(
+
+        assert_diagnostics_diff!(
+            snapshot,
             Path::new("flake8_bandit").join(path).as_path(),
+            &LinterSettings {
+                preview: PreviewMode::Disabled,
+                ..LinterSettings::for_rule(rule_code)
+            },
             &LinterSettings {
                 preview: PreviewMode::Enabled,
                 ..LinterSettings::for_rule(rule_code)
-            },
-        )?;
-        assert_diagnostics!(snapshot, diagnostics);
+            }
+        );
         Ok(())
     }
 

crates/ruff_linter/src/rules/flake8_bandit/rules/suspicious_function_call.rs

@@ -4,11 +4,16 @@
 use itertools::Either;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::{self as ast, Arguments, Decorator, Expr, ExprCall, Operator};
+use ruff_python_semantic::SemanticModel;
+use ruff_python_semantic::analyze::typing::find_binding_value;
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::Violation;
 use crate::checkers::ast::Checker;
-use crate::preview::is_suspicious_function_reference_enabled;
+use crate::preview::{
+    is_s310_resolve_string_literal_bindings_enabled, is_suspicious_function_reference_enabled,
+};
+use crate::settings::LinterSettings;
 
 /// ## What it does
 /// Checks for calls to `pickle` functions or modules that wrap them.
@@ -1016,6 +1021,25 @@ fn suspicious_function(
             || has_prefix(chars.skip_while(|c| c.is_whitespace()), "https://")
     }
 
+    /// Resolves `expr` to its binding and checks if the resolved expression starts with an HTTP or HTTPS prefix.
+    fn expression_starts_with_http_prefix(
+        expr: &Expr,
+        semantic: &SemanticModel,
+        settings: &LinterSettings,
+    ) -> bool {
+        let resolved_expression = if is_s310_resolve_string_literal_bindings_enabled(settings)
+            && let Some(name_expr) = expr.as_name_expr()
+            && let Some(binding_id) = semantic.only_binding(name_expr)
+            && let Some(value) = find_binding_value(semantic.binding(binding_id), semantic)
+        {
+            value
+        } else {
+            expr
+        };
+
+        leading_chars(resolved_expression).is_some_and(has_http_prefix)
+    }
+
     /// Return the leading characters for an expression, if it's a string literal, f-string, or
     /// string concatenation.
     fn leading_chars(expr: &Expr) -> Option<impl Iterator<Item = char> + Clone + '_> {
@@ -1139,17 +1163,19 @@ fn suspicious_function(
         // URLOpen (`Request`)
         ["urllib", "request", "Request"] | ["six", "moves", "urllib", "request", "Request"] => {
             if let Some(arguments) = arguments {
-                // If the `url` argument is a string literal or an f-string, allow `http` and `https` schemes.
+                // If the `url` argument is a string literal (including resolved bindings), allow `http` and `https` schemes.
                 if arguments.args.iter().all(|arg| !arg.is_starred_expr())
                     && arguments
                         .keywords
                         .iter()
                         .all(|keyword| keyword.arg.is_some())
                 {
-                    if arguments
-                        .find_argument_value("url", 0)
-                        .and_then(leading_chars)
-                        .is_some_and(has_http_prefix)
+                    if let Some(url_expr) = arguments.find_argument_value("url", 0)
+                        && expression_starts_with_http_prefix(
+                            url_expr,
+                            checker.semantic(),
+                            checker.settings(),
+                        )
                     {
                         return;
                     }
@@ -1186,19 +1212,25 @@ fn suspicious_function(
                                     name.segments() == ["urllib", "request", "Request"]
                                 })
                             {
-                                if arguments
-                                    .find_argument_value("url", 0)
-                                    .and_then(leading_chars)
-                                    .is_some_and(has_http_prefix)
+                                if let Some(url_expr) = arguments.find_argument_value("url", 0)
+                                    && expression_starts_with_http_prefix(
+                                        url_expr,
+                                        checker.semantic(),
+                                        checker.settings(),
+                                    )
                                 {
                                     return;
                                 }
                             }
                         }
 
-                        // If the `url` argument is a string literal, allow `http` and `https` schemes.
+                        // If the `url` argument is a string literal (including resolved bindings), allow `http` and `https` schemes.
                         Some(expr) => {
-                            if leading_chars(expr).is_some_and(has_http_prefix) {
+                            if expression_starts_with_http_prefix(
+                                expr,
+                                checker.semantic(),
+                                checker.settings(),
+                            ) {
                                 return;
                             }
                         }

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__S310_S310.py.snap

@@ -254,3 +254,84 @@ S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom sch
 42 | urllib.request.urlopen(urllib.request.Request(url))
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:51:1
+   |
+49 | # https://github.com/astral-sh/ruff/issues/21462
+50 | path = "https://example.com/data.csv"
+51 | urllib.request.urlretrieve(path, "data.csv")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:53:1
+   |
+51 | urllib.request.urlretrieve(path, "data.csv")
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+54 |
+55 | # Test resolved f-strings and concatenated string literals
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:57:1
+   |
+55 | # Test resolved f-strings and concatenated string literals
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+58 | urllib.request.Request(fstring_url)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:58:1
+   |
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+58 | urllib.request.Request(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+59 |
+60 | concatenated_url = "https://" + "example.com/data.csv"
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:61:1
+   |
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+62 | urllib.request.Request(concatenated_url)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:62:1
+   |
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+62 | urllib.request.Request(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+63 |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:65:1
+   |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+66 | urllib.request.Request(nested_concatenated)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:66:1
+   |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+66 | urllib.request.Request(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S301_S301.py.snap

@@ -1,15 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S301 `pickle` and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue
- --> S301.py:3:1
-  |
-1 | import pickle
-2 |
-3 | pickle.loads()
-  | ^^^^^^^^^^^^^^
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
+--- Summary ---
+Removed: 0
+Added: 2
+
+--- Added ---
 S301 `pickle` and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue
  --> S301.py:7:5
   |
@@ -19,6 +19,7 @@ S301 `pickle` and modules that wrap it can be unsafe when used to deserialize un
 8 | foo = pickle.load
   |
 
+
 S301 `pickle` and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue
  --> S301.py:8:7
   |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S307_S307.py.snap

@@ -1,24 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S307 Use of possibly insecure function; consider using `ast.literal_eval`
- --> S307.py:3:7
-  |
-1 | import os
-2 |
-3 | print(eval("1+1"))  # S307
-  |       ^^^^^^^^^^^
-4 | print(eval("os.getcwd()"))  # S307
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S307 Use of possibly insecure function; consider using `ast.literal_eval`
- --> S307.py:4:7
-  |
-3 | print(eval("1+1"))  # S307
-4 | print(eval("os.getcwd()"))  # S307
-  |       ^^^^^^^^^^^^^^^^^^^
-  |
+--- Summary ---
+Removed: 0
+Added: 2
 
+--- Added ---
 S307 Use of possibly insecure function; consider using `ast.literal_eval`
   --> S307.py:16:5
    |
@@ -28,6 +19,7 @@ S307 Use of possibly insecure function; consider using `ast.literal_eval`
 17 | foo = eval
    |
 
+
 S307 Use of possibly insecure function; consider using `ast.literal_eval`
   --> S307.py:17:7
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S308_S308.py.snap

@@ -1,60 +1,37 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
- --> S308.py:6:5
-  |
-4 | def bad_func():
-5 |     inject = "harmful_input"
-6 |     mark_safe(inject)
-  |     ^^^^^^^^^^^^^^^^^
-7 |     mark_safe("I will add" + inject + "to my string")
-8 |     mark_safe("I will add %s to my string" % inject)
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
- --> S308.py:7:5
-  |
-5 |     inject = "harmful_input"
-6 |     mark_safe(inject)
-7 |     mark_safe("I will add" + inject + "to my string")
-  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-8 |     mark_safe("I will add %s to my string" % inject)
-9 |     mark_safe("I will add {} to my string".format(inject))
-  |
+--- Summary ---
+Removed: 2
+Added: 4
 
+--- Removed ---
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:8:5
+  --> S308.py:16:1
    |
- 6 |     mark_safe(inject)
- 7 |     mark_safe("I will add" + inject + "to my string")
- 8 |     mark_safe("I will add %s to my string" % inject)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- 9 |     mark_safe("I will add {} to my string".format(inject))
-10 |     mark_safe(f"I will add {inject} to my string")
+16 | @mark_safe
+   | ^^^^^^^^^^
+17 | def some_func():
+18 |     return '<script>alert("evil!")</script>'
    |
 
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:9:5
-   |
- 7 |     mark_safe("I will add" + inject + "to my string")
- 8 |     mark_safe("I will add %s to my string" % inject)
- 9 |     mark_safe("I will add {} to my string".format(inject))
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10 |     mark_safe(f"I will add {inject} to my string")
-   |
 
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:10:5
+  --> S308.py:36:1
    |
- 8 |     mark_safe("I will add %s to my string" % inject)
- 9 |     mark_safe("I will add {} to my string".format(inject))
-10 |     mark_safe(f"I will add {inject} to my string")
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-11 |
-12 | def good_func():
+36 | @mark_safe
+   | ^^^^^^^^^^
+37 | def some_func():
+38 |     return '<script>alert("evil!")</script>'
    |
 
+
+
+--- Added ---
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:16:2
    |
@@ -64,59 +41,6 @@ S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
 18 |     return '<script>alert("evil!")</script>'
    |
 
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:26:5
-   |
-24 | def bad_func():
-25 |     inject = "harmful_input"
-26 |     mark_safe(inject)
-   |     ^^^^^^^^^^^^^^^^^
-27 |     mark_safe("I will add" + inject + "to my string")
-28 |     mark_safe("I will add %s to my string" % inject)
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:27:5
-   |
-25 |     inject = "harmful_input"
-26 |     mark_safe(inject)
-27 |     mark_safe("I will add" + inject + "to my string")
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-28 |     mark_safe("I will add %s to my string" % inject)
-29 |     mark_safe("I will add {} to my string".format(inject))
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:28:5
-   |
-26 |     mark_safe(inject)
-27 |     mark_safe("I will add" + inject + "to my string")
-28 |     mark_safe("I will add %s to my string" % inject)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-29 |     mark_safe("I will add {} to my string".format(inject))
-30 |     mark_safe(f"I will add {inject} to my string")
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:29:5
-   |
-27 |     mark_safe("I will add" + inject + "to my string")
-28 |     mark_safe("I will add %s to my string" % inject)
-29 |     mark_safe("I will add {} to my string".format(inject))
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-30 |     mark_safe(f"I will add {inject} to my string")
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:30:5
-   |
-28 |     mark_safe("I will add %s to my string" % inject)
-29 |     mark_safe("I will add {} to my string".format(inject))
-30 |     mark_safe(f"I will add {inject} to my string")
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-31 |
-32 | def good_func():
-   |
 
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:36:2
@@ -127,6 +51,7 @@ S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
 38 |     return '<script>alert("evil!")</script>'
    |
 
+
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:42:5
    |
@@ -136,6 +61,7 @@ S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
 43 | foo = mark_safe
    |
 
+
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:43:7
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S310_S310.py.snap

@@ -1,260 +1,106 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
- --> S310.py:6:1
-  |
-4 | urllib.request.urlopen(url=f'http://www.google.com')
-5 | urllib.request.urlopen(url='http://' + 'www' + '.google.com')
-6 | urllib.request.urlopen(url='http://www.google.com', **kwargs)
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-7 | urllib.request.urlopen(url=f'http://www.google.com', **kwargs)
-8 | urllib.request.urlopen('http://www.google.com')
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
- --> S310.py:7:1
-  |
-5 | urllib.request.urlopen(url='http://' + 'www' + '.google.com')
-6 | urllib.request.urlopen(url='http://www.google.com', **kwargs)
-7 | urllib.request.urlopen(url=f'http://www.google.com', **kwargs)
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-8 | urllib.request.urlopen('http://www.google.com')
-9 | urllib.request.urlopen(f'http://www.google.com')
-  |
+--- Summary ---
+Removed: 8
+Added: 2
 
+--- Removed ---
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:10:1
+  --> S310.py:51:1
    |
- 8 | urllib.request.urlopen('http://www.google.com')
- 9 | urllib.request.urlopen(f'http://www.google.com')
-10 | urllib.request.urlopen('file:///foo/bar/baz')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-11 | urllib.request.urlopen(url)
+49 | # https://github.com/astral-sh/ruff/issues/21462
+50 | path = "https://example.com/data.csv"
+51 | urllib.request.urlretrieve(path, "data.csv")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:11:1
+  --> S310.py:53:1
    |
- 9 | urllib.request.urlopen(f'http://www.google.com')
-10 | urllib.request.urlopen('file:///foo/bar/baz')
-11 | urllib.request.urlopen(url)
+51 | urllib.request.urlretrieve(path, "data.csv")
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-12 |
-13 | urllib.request.Request(url='http://www.google.com')
+54 |
+55 | # Test resolved f-strings and concatenated string literals
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:16:1
+  --> S310.py:57:1
    |
-14 | urllib.request.Request(url=f'http://www.google.com')
-15 | urllib.request.Request(url='http://' + 'www' + '.google.com')
-16 | urllib.request.Request(url='http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-17 | urllib.request.Request(url=f'http://www.google.com', **kwargs)
-18 | urllib.request.Request('http://www.google.com')
+55 | # Test resolved f-strings and concatenated string literals
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+58 | urllib.request.Request(fstring_url)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:17:1
+  --> S310.py:58:1
    |
-15 | urllib.request.Request(url='http://' + 'www' + '.google.com')
-16 | urllib.request.Request(url='http://www.google.com', **kwargs)
-17 | urllib.request.Request(url=f'http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18 | urllib.request.Request('http://www.google.com')
-19 | urllib.request.Request(f'http://www.google.com')
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+58 | urllib.request.Request(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+59 |
+60 | concatenated_url = "https://" + "example.com/data.csv"
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:20:1
+  --> S310.py:61:1
    |
-18 | urllib.request.Request('http://www.google.com')
-19 | urllib.request.Request(f'http://www.google.com')
-20 | urllib.request.Request('file:///foo/bar/baz')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-21 | urllib.request.Request(url)
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+62 | urllib.request.Request(concatenated_url)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:21:1
+  --> S310.py:62:1
    |
-19 | urllib.request.Request(f'http://www.google.com')
-20 | urllib.request.Request('file:///foo/bar/baz')
-21 | urllib.request.Request(url)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-22 |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+62 | urllib.request.Request(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+63 |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:23:1
+  --> S310.py:65:1
    |
-21 | urllib.request.Request(url)
-22 |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+66 | urllib.request.Request(nested_concatenated)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:24:1
+  --> S310.py:66:1
    |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+66 | urllib.request.Request(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:25:1
-   |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-   |
 
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:26:1
-   |
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-28 | urllib.request.URLopener().open('http://www.google.com')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:27:1
-   |
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-28 | urllib.request.URLopener().open('http://www.google.com')
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:28:1
-   |
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-28 | urllib.request.URLopener().open('http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:29:1
-   |
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-28 | urllib.request.URLopener().open('http://www.google.com')
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:30:1
-   |
-28 | urllib.request.URLopener().open('http://www.google.com')
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-32 | urllib.request.URLopener().open(url)
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:31:1
-   |
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-32 | urllib.request.URLopener().open(url)
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:32:1
-   |
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-32 | urllib.request.URLopener().open(url)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-33 |
-34 | urllib.request.urlopen(url=urllib.request.Request('http://www.google.com'))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:37:1
-   |
-35 | urllib.request.urlopen(url=urllib.request.Request(f'http://www.google.com'))
-36 | urllib.request.urlopen(url=urllib.request.Request('http://' + 'www' + '.google.com'))
-37 | urllib.request.urlopen(url=urllib.request.Request('http://www.google.com'), **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-38 | urllib.request.urlopen(url=urllib.request.Request(f'http://www.google.com'), **kwargs)
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:38:1
-   |
-36 | urllib.request.urlopen(url=urllib.request.Request('http://' + 'www' + '.google.com'))
-37 | urllib.request.urlopen(url=urllib.request.Request('http://www.google.com'), **kwargs)
-38 | urllib.request.urlopen(url=urllib.request.Request(f'http://www.google.com'), **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:41:1
-   |
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:41:24
-   |
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:42:1
-   |
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:42:24
-   |
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
 
+--- Added ---
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
   --> S310.py:46:5
    |
@@ -264,6 +110,7 @@ S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom sch
 47 | foo = urllib.request.urlopen
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
   --> S310.py:47:7
    |
@@ -271,4 +118,6 @@ S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom sch
 46 | map(urllib.request.urlopen, [])
 47 | foo = urllib.request.urlopen
    |       ^^^^^^^^^^^^^^^^^^^^^^
+48 |
+49 | # https://github.com/astral-sh/ruff/issues/21462
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S311_S311.py.snap

@@ -1,103 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:10:1
-   |
- 9 | # Errors
-10 | random.Random()
-   | ^^^^^^^^^^^^^^^
-11 | random.random()
-12 | random.randrange()
-   |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:11:1
-   |
- 9 | # Errors
-10 | random.Random()
-11 | random.random()
-   | ^^^^^^^^^^^^^^^
-12 | random.randrange()
-13 | random.randint()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:12:1
-   |
-10 | random.Random()
-11 | random.random()
-12 | random.randrange()
-   | ^^^^^^^^^^^^^^^^^^
-13 | random.randint()
-14 | random.choice()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:13:1
-   |
-11 | random.random()
-12 | random.randrange()
-13 | random.randint()
-   | ^^^^^^^^^^^^^^^^
-14 | random.choice()
-15 | random.choices()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:14:1
-   |
-12 | random.randrange()
-13 | random.randint()
-14 | random.choice()
-   | ^^^^^^^^^^^^^^^
-15 | random.choices()
-16 | random.uniform()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:15:1
-   |
-13 | random.randint()
-14 | random.choice()
-15 | random.choices()
-   | ^^^^^^^^^^^^^^^^
-16 | random.uniform()
-17 | random.triangular()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:16:1
-   |
-14 | random.choice()
-15 | random.choices()
-16 | random.uniform()
-   | ^^^^^^^^^^^^^^^^
-17 | random.triangular()
-18 | random.randbytes()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:17:1
-   |
-15 | random.choices()
-16 | random.uniform()
-17 | random.triangular()
-   | ^^^^^^^^^^^^^^^^^^^
-18 | random.randbytes()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:18:1
-   |
-16 | random.uniform()
-17 | random.triangular()
-18 | random.randbytes()
-   | ^^^^^^^^^^^^^^^^^^
-19 |
-20 | # Unrelated
-   |
+--- Summary ---
+Removed: 0
+Added: 2
 
+--- Added ---
 S311 Standard pseudo-random generators are not suitable for cryptographic purposes
   --> S311.py:26:5
    |
@@ -107,6 +19,7 @@ S311 Standard pseudo-random generators are not suitable for cryptographic purpos
 27 | foo = random.randrange
    |
 
+
 S311 Standard pseudo-random generators are not suitable for cryptographic purposes
   --> S311.py:27:7
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S312_S312.py.snap

@@ -1,15 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
- --> S312.py:3:1
-  |
-1 | from telnetlib import Telnet
-2 |
-3 | Telnet("localhost", 23)
-  | ^^^^^^^^^^^^^^^^^^^^^^^
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
+--- Summary ---
+Removed: 0
+Added: 3
+
+--- Added ---
 S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
  --> S312.py:7:5
   |
@@ -19,6 +19,7 @@ S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
 8 | foo = Telnet
   |
 
+
 S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
   --> S312.py:8:7
    |
@@ -30,6 +31,7 @@ S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
 10 | import telnetlib
    |
 
+
 S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
   --> S312.py:11:5
    |
@@ -39,13 +41,3 @@ S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
 12 |
 13 | from typing import Annotated
    |
-
-S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
-  --> S312.py:14:24
-   |
-13 | from typing import Annotated
-14 | foo: Annotated[Telnet, telnetlib.Telnet()]
-   |                        ^^^^^^^^^^^^^^^^^^
-15 |
-16 | def _() -> Telnet: ...
-   |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S508_S508.py.snap

@@ -1,26 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
- --> S508.py:3:25
-  |
-1 | from pysnmp.hlapi import CommunityData
-2 |
-3 | CommunityData("public", mpModel=0)  # S508
-  |                         ^^^^^^^^^
-4 | CommunityData("public", mpModel=1)  # S508
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
- --> S508.py:4:25
-  |
-3 | CommunityData("public", mpModel=0)  # S508
-4 | CommunityData("public", mpModel=1)  # S508
-  |                         ^^^^^^^^^
-5 |
-6 | CommunityData("public", mpModel=2)  # OK
-  |
+--- Summary ---
+Removed: 0
+Added: 8
 
+--- Added ---
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:18:46
    |
@@ -32,6 +21,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 20 | pysnmp.hlapi.v1arch.asyncio.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:19:58
    |
@@ -42,6 +32,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 21 | pysnmp.hlapi.v1arch.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:20:53
    |
@@ -53,6 +44,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 22 | pysnmp.hlapi.v3arch.asyncio.auth.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:21:45
    |
@@ -64,6 +56,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 23 | pysnmp.hlapi.v3arch.asyncio.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:22:58
    |
@@ -75,6 +68,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 24 | pysnmp.hlapi.v3arch.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:23:53
    |
@@ -86,6 +80,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 25 | pysnmp.hlapi.auth.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:24:45
    |
@@ -96,6 +91,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 25 | pysnmp.hlapi.auth.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:25:43
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S509_S509.py.snap

@@ -1,24 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
- --> S509.py:4:12
-  |
-4 | insecure = UsmUserData("securityName")  # S509
-  |            ^^^^^^^^^^^
-5 | auth_no_priv = UsmUserData("securityName", "authName")  # S509
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
- --> S509.py:5:16
-  |
-4 | insecure = UsmUserData("securityName")  # S509
-5 | auth_no_priv = UsmUserData("securityName", "authName")  # S509
-  |                ^^^^^^^^^^^
-6 |
-7 | less_insecure = UsmUserData("securityName", "authName", "privName")  # OK
-  |
+--- Summary ---
+Removed: 0
+Added: 4
 
+--- Added ---
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:15:1
    |
@@ -30,6 +21,7 @@ S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv`
 17 | pysnmp.hlapi.v3arch.asyncio.auth.UsmUserData("user")  # S509
    |
 
+
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:16:1
    |
@@ -40,6 +32,7 @@ S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv`
 18 | pysnmp.hlapi.auth.UsmUserData("user")  # S509
    |
 
+
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:17:1
    |
@@ -50,6 +43,7 @@ S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv`
 18 | pysnmp.hlapi.auth.UsmUserData("user")  # S509
    |
 
+
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:18:1
    |

crates/ruff_linter/src/rules/flake8_boolean_trap/rules/boolean_default_value_positional_argument.rs

@@ -25,6 +25,11 @@ use crate::rules::flake8_boolean_trap::helpers::is_allowed_func_def;
 /// keyword-only argument, to force callers to be explicit when providing
 /// the argument.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override],
+/// since changing the signature of a subclass method that overrides a
+/// superclass method may cause type checkers to complain about a violation of
+/// the Liskov Substitution Principle.
+///
 /// ## Example
 /// ```python
 /// from math import ceil, floor
@@ -89,6 +94,8 @@ use crate::rules::flake8_boolean_trap::helpers::is_allowed_func_def;
 /// ## References
 /// - [Python documentation: Calls](https://docs.python.org/3/reference/expressions.html#calls)
 /// - [_How to Avoid “The Boolean Trap”_ by Adam Johnson](https://adamj.eu/tech/2021/07/10/python-type-hints-how-to-avoid-the-boolean-trap/)
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.127")]
 pub(crate) struct BooleanDefaultValuePositionalArgument;

crates/ruff_linter/src/rules/flake8_boolean_trap/rules/boolean_type_hint_positional_argument.rs

@@ -28,7 +28,7 @@ use crate::rules::flake8_boolean_trap::helpers::is_allowed_func_def;
 /// the argument.
 ///
 /// Dunder methods that define operators are exempt from this rule, as are
-/// setters and `@override` definitions.
+/// setters and [`@override`][override] definitions.
 ///
 /// ## Example
 ///
@@ -93,6 +93,8 @@ use crate::rules::flake8_boolean_trap::helpers::is_allowed_func_def;
 /// ## References
 /// - [Python documentation: Calls](https://docs.python.org/3/reference/expressions.html#calls)
 /// - [_How to Avoid “The Boolean Trap”_ by Adam Johnson](https://adamj.eu/tech/2021/07/10/python-type-hints-how-to-avoid-the-boolean-trap/)
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.127")]
 pub(crate) struct BooleanTypeHintPositionalArgument;

crates/ruff_linter/src/rules/flake8_builtins/rules/builtin_argument_shadowing.rs

@@ -17,6 +17,8 @@ use crate::rules::flake8_builtins::helpers::shadows_builtin;
 /// non-obvious errors, as readers may mistake the argument for the
 /// builtin and vice versa.
 ///
+/// Function definitions decorated with [`@override`][override] or
+/// [`@overload`][overload] are exempt from this rule by default.
 /// Builtins can be marked as exceptions to this rule via the
 /// [`lint.flake8-builtins.ignorelist`] configuration option.
 ///
@@ -48,6 +50,9 @@ use crate::rules::flake8_builtins::helpers::shadows_builtin;
 /// ## References
 /// - [_Is it bad practice to use a built-in function name as an attribute or method identifier?_](https://stackoverflow.com/questions/9109333/is-it-bad-practice-to-use-a-built-in-function-name-as-an-attribute-or-method-ide)
 /// - [_Why is it a bad idea to name a variable `id` in Python?_](https://stackoverflow.com/questions/77552/id-is-a-bad-variable-name-in-python)
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
+/// [overload]: https://docs.python.org/3/library/typing.html#typing.overload
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.48")]
 pub(crate) struct BuiltinArgumentShadowing {

crates/ruff_linter/src/rules/flake8_pie/rules/unnecessary_placeholder.rs

@@ -1,8 +1,6 @@
 use ruff_macros::{ViolationMetadata, derive_message_formats};
-use ruff_python_ast::helpers::map_subscript;
 use ruff_python_ast::whitespace::trailing_comment_start_offset;
 use ruff_python_ast::{Expr, ExprStringLiteral, Stmt, StmtExpr};
-use ruff_python_semantic::{ScopeKind, SemanticModel};
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
@@ -101,7 +99,7 @@ pub(crate) fn unnecessary_placeholder(checker: &Checker, body: &[Stmt]) {
                 // Ellipses are significant in protocol methods and abstract methods.
                 // Specifically, Pyright uses the presence of an ellipsis to indicate that
                 // a method is a stub, rather than a default implementation.
-                if in_protocol_or_abstract_method(checker.semantic()) {
+                if checker.semantic().in_protocol_or_abstract_method() {
                     return;
                 }
                 Placeholder::Ellipsis
@@ -163,21 +161,3 @@ impl std::fmt::Display for Placeholder {
         }
     }
 }
-
-/// Return `true` if the [`SemanticModel`] is in a `typing.Protocol` subclass or an abstract
-/// method.
-fn in_protocol_or_abstract_method(semantic: &SemanticModel) -> bool {
-    semantic.current_scopes().any(|scope| match scope.kind {
-        ScopeKind::Class(class_def) => class_def
-            .bases()
-            .iter()
-            .any(|base| semantic.match_typing_expr(map_subscript(base), "Protocol")),
-        ScopeKind::Function(function_def) => {
-            ruff_python_semantic::analyze::visibility::is_abstract(
-                &function_def.decorator_list,
-                semantic,
-            )
-        }
-        _ => false,
-    })
-}

crates/ruff_linter/src/rules/flake8_unused_arguments/rules/unused_arguments.rs

@@ -60,6 +60,16 @@ impl Violation for UnusedFunctionArgument {
 /// prefixed with an underscore, or some other value that adheres to the
 /// [`lint.dummy-variable-rgx`] pattern.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Removing a parameter from a subclass method (or changing a parameter's
+/// name) may cause type checkers to complain about a violation of the Liskov
+/// Substitution Principle if it means that the method now incompatibly
+/// overrides a method defined on a superclass. Explicitly decorating an
+/// overriding method with `@override` signals to Ruff that the method is
+/// intended to override a superclass method and that a type checker will
+/// enforce that it does so; Ruff therefore knows that it should not enforce
+/// rules about unused arguments on such methods.
+///
 /// ## Example
 /// ```python
 /// class Class:
@@ -76,6 +86,8 @@ impl Violation for UnusedFunctionArgument {
 ///
 /// ## Options
 /// - `lint.dummy-variable-rgx`
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.168")]
 pub(crate) struct UnusedMethodArgument {
@@ -101,6 +113,16 @@ impl Violation for UnusedMethodArgument {
 /// prefixed with an underscore, or some other value that adheres to the
 /// [`lint.dummy-variable-rgx`] pattern.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Removing a parameter from a subclass method (or changing a parameter's
+/// name) may cause type checkers to complain about a violation of the Liskov
+/// Substitution Principle if it means that the method now incompatibly
+/// overrides a method defined on a superclass. Explicitly decorating an
+/// overriding method with `@override` signals to Ruff that the method is
+/// intended to override a superclass method and that a type checker will
+/// enforce that it does so; Ruff therefore knows that it should not enforce
+/// rules about unused arguments on such methods.
+///
 /// ## Example
 /// ```python
 /// class Class:
@@ -119,6 +141,8 @@ impl Violation for UnusedMethodArgument {
 ///
 /// ## Options
 /// - `lint.dummy-variable-rgx`
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.168")]
 pub(crate) struct UnusedClassMethodArgument {
@@ -144,6 +168,16 @@ impl Violation for UnusedClassMethodArgument {
 /// prefixed with an underscore, or some other value that adheres to the
 /// [`lint.dummy-variable-rgx`] pattern.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Removing a parameter from a subclass method (or changing a parameter's
+/// name) may cause type checkers to complain about a violation of the Liskov
+/// Substitution Principle if it means that the method now incompatibly
+/// overrides a method defined on a superclass. Explicitly decorating an
+/// overriding method with `@override` signals to Ruff that the method is
+/// intended to override a superclass method, and that a type checker will
+/// enforce that it does so; Ruff therefore knows that it should not enforce
+/// rules about unused arguments on such methods.
+///
 /// ## Example
 /// ```python
 /// class Class:
@@ -162,6 +196,8 @@ impl Violation for UnusedClassMethodArgument {
 ///
 /// ## Options
 /// - `lint.dummy-variable-rgx`
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.168")]
 pub(crate) struct UnusedStaticMethodArgument {

crates/ruff_linter/src/rules/pep8_naming/rules/invalid_argument_name.rs

@@ -23,7 +23,7 @@ use crate::checkers::ast::Checker;
 /// > mixedCase is allowed only in contexts where that’s already the
 /// > prevailing style (e.g. threading.py), to retain backwards compatibility.
 ///
-/// Methods decorated with `@typing.override` are ignored.
+/// Methods decorated with [`@typing.override`][override] are ignored.
 ///
 /// ## Example
 /// ```python
@@ -43,6 +43,8 @@ use crate::checkers::ast::Checker;
 ///
 /// [PEP 8]: https://peps.python.org/pep-0008/#function-and-method-arguments
 /// [preview]: https://docs.astral.sh/ruff/preview/
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.77")]
 pub(crate) struct InvalidArgumentName {

crates/ruff_linter/src/rules/pep8_naming/rules/invalid_function_name.rs

@@ -24,6 +24,11 @@ use crate::rules::pep8_naming::settings::IgnoreNames;
 /// to ignore all functions starting with `test_` from this rule, set the
 /// [`lint.pep8-naming.extend-ignore-names`] option to `["test_*"]`.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Explicitly decorating a method with `@override` signals to Ruff that the method is intended
+/// to override a superclass method, and that a type checker will enforce that it does so. Ruff
+/// therefore knows that it should not enforce naming conventions on such methods.
+///
 /// ## Example
 /// ```python
 /// def myFunction():
@@ -41,6 +46,7 @@ use crate::rules::pep8_naming::settings::IgnoreNames;
 /// - `lint.pep8-naming.extend-ignore-names`
 ///
 /// [PEP 8]: https://peps.python.org/pep-0008/#function-and-variable-names
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.77")]
 pub(crate) struct InvalidFunctionName {

crates/ruff_linter/src/rules/pydocstyle/rules/not_missing.rs

@@ -169,7 +169,12 @@ impl Violation for UndocumentedPublicClass {
 /// If the codebase adheres to a standard format for method docstrings, follow
 /// that format for consistency.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override],
+/// since it is a common practice to document a method on a superclass but not
+/// on an overriding method in a subclass.
+///
 /// ## Example
+///
 /// ```python
 /// class Cat(Animal):
 ///     def greet(self, happy: bool = True):
@@ -180,6 +185,7 @@ impl Violation for UndocumentedPublicClass {
 /// ```
 ///
 /// Use instead (in the NumPy docstring format):
+///
 /// ```python
 /// class Cat(Animal):
 ///     def greet(self, happy: bool = True):
@@ -202,6 +208,7 @@ impl Violation for UndocumentedPublicClass {
 /// ```
 ///
 /// Or (in the Google docstring format):
+///
 /// ```python
 /// class Cat(Animal):
 ///     def greet(self, happy: bool = True):
@@ -227,6 +234,8 @@ impl Violation for UndocumentedPublicClass {
 /// - [PEP 287 – reStructuredText Docstring Format](https://peps.python.org/pep-0287/)
 /// - [NumPy Style Guide](https://numpydoc.readthedocs.io/en/latest/format.html)
 /// - [Google Python Style Guide - Docstrings](https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings)
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.70")]
 pub(crate) struct UndocumentedPublicMethod;

crates/ruff_linter/src/rules/pylint/rules/bad_dunder_method_name.rs

@@ -21,7 +21,7 @@ use crate::rules::pylint::helpers::is_known_dunder_method;
 ///
 /// This rule will detect all methods starting and ending with at least
 /// one underscore (e.g., `_str_`), but ignores known dunder methods (like
-/// `__init__`), as well as methods that are marked with `@override`.
+/// `__init__`), as well as methods that are marked with [`@override`][override].
 ///
 /// Additional dunder methods names can be allowed via the
 /// [`lint.pylint.allow-dunder-method-names`] setting.
@@ -42,6 +42,8 @@ use crate::rules::pylint::helpers::is_known_dunder_method;
 ///
 /// ## Options
 /// - `lint.pylint.allow-dunder-method-names`
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(preview_since = "v0.0.285")]
 pub(crate) struct BadDunderMethodName {

crates/ruff_linter/src/rules/pylint/rules/no_self_use.rs

@@ -17,6 +17,16 @@ use crate::rules::flake8_unused_arguments::rules::is_not_implemented_stub_with_v
 /// Unused `self` parameters are usually a sign of a method that could be
 /// replaced by a function, class method, or static method.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Converting an instance method into a static method or class method may
+/// cause type checkers to complain about a violation of the Liskov
+/// Substitution Principle if it means that the method now incompatibly
+/// overrides a method defined on a superclass. Explicitly decorating an
+/// overriding method with `@override` signals to Ruff that the method is
+/// intended to override a superclass method and that a type checker will
+/// enforce that it does so; Ruff therefore knows that it should not enforce
+/// rules about unused `self` parameters on such methods.
+///
 /// ## Example
 /// ```python
 /// class Person:
@@ -38,6 +48,8 @@ use crate::rules::flake8_unused_arguments::rules::is_not_implemented_stub_with_v
 ///     def greeting():
 ///         print("Greetings friend!")
 /// ```
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(preview_since = "v0.0.286")]
 pub(crate) struct NoSelfUse {

crates/ruff_linter/src/rules/pylint/rules/too_many_arguments.rs

@@ -12,6 +12,16 @@ use crate::checkers::ast::Checker;
 /// By default, this rule allows up to five arguments, as configured by the
 /// [`lint.pylint.max-args`] option.
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Changing the signature of a subclass method may cause type checkers to
+/// complain about a violation of the Liskov Substitution Principle if it
+/// means that the method now incompatibly overrides a method defined on a
+/// superclass. Explicitly decorating an overriding method with `@override`
+/// signals to Ruff that the method is intended to override a superclass
+/// method and that a type checker will enforce that it does so; Ruff
+/// therefore knows that it should not enforce rules about methods having
+/// too many arguments.
+///
 /// ## Why is this bad?
 /// Functions with many arguments are harder to understand, maintain, and call.
 /// Consider refactoring functions with many arguments into smaller functions
@@ -43,6 +53,8 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Options
 /// - `lint.pylint.max-args`
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(stable_since = "v0.0.238")]
 pub(crate) struct TooManyArguments {

crates/ruff_linter/src/rules/pylint/rules/too_many_positional_arguments.rs

@@ -21,6 +21,16 @@ use crate::checkers::ast::Checker;
 /// with fewer arguments, using objects to group related arguments, or migrating to
 /// [keyword-only arguments](https://docs.python.org/3/tutorial/controlflow.html#special-parameters).
 ///
+/// This rule exempts methods decorated with [`@typing.override`][override].
+/// Changing the signature of a subclass method may cause type checkers to
+/// complain about a violation of the Liskov Substitution Principle if it
+/// means that the method now incompatibly overrides a method defined on a
+/// superclass. Explicitly decorating an overriding method with `@override`
+/// signals to Ruff that the method is intended to override a superclass
+/// method and that a type checker will enforce that it does so; Ruff
+/// therefore knows that it should not enforce rules about methods having
+/// too many arguments.
+///
 /// ## Example
 ///
 /// ```python
@@ -41,6 +51,8 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Options
 /// - `lint.pylint.max-positional-args`
+///
+/// [override]: https://docs.python.org/3/library/typing.html#typing.override
 #[derive(ViolationMetadata)]
 #[violation_metadata(preview_since = "v0.1.7")]
 pub(crate) struct TooManyPositionalArguments {

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

@@ -115,6 +115,7 @@ mod tests {
     #[test_case(Rule::NonOctalPermissions, Path::new("RUF064.py"))]
     #[test_case(Rule::LoggingEagerConversion, Path::new("RUF065_0.py"))]
     #[test_case(Rule::LoggingEagerConversion, Path::new("RUF065_1.py"))]
+    #[test_case(Rule::PropertyWithoutReturn, Path::new("RUF066.py"))]
     #[test_case(Rule::RedirectedNOQA, Path::new("RUF101_0.py"))]
     #[test_case(Rule::RedirectedNOQA, Path::new("RUF101_1.py"))]
     #[test_case(Rule::InvalidRuleCode, Path::new("RUF102.py"))]

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

@@ -35,6 +35,7 @@ pub(crate) use non_octal_permissions::*;
 pub(crate) use none_not_at_end_of_union::*;
 pub(crate) use parenthesize_chained_operators::*;
 pub(crate) use post_init_default::*;
+pub(crate) use property_without_return::*;
 pub(crate) use pytest_raises_ambiguous_pattern::*;
 pub(crate) use quadratic_list_summation::*;
 pub(crate) use redirected_noqa::*;
@@ -99,6 +100,7 @@ mod non_octal_permissions;
 mod none_not_at_end_of_union;
 mod parenthesize_chained_operators;
 mod post_init_default;
+mod property_without_return;
 mod pytest_raises_ambiguous_pattern;
 mod quadratic_list_summation;
 mod redirected_noqa;

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

@@ -0,0 +1,119 @@
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::identifier::Identifier;
+use ruff_python_ast::visitor::{Visitor, walk_expr, walk_stmt};
+use ruff_python_ast::{Expr, Stmt, StmtFunctionDef};
+use ruff_python_semantic::analyze::{function_type, visibility};
+
+use crate::checkers::ast::Checker;
+use crate::{FixAvailability, Violation};
+
+/// ## What it does
+/// Detects class `@property` methods that does not have a `return` statement.
+///
+/// ## Why is this bad?
+/// Property methods are expected to return a computed value, a missing return in a property usually indicates an implementation mistake.
+///
+/// ## Example
+/// ```python
+/// class User:
+///     @property
+///     def full_name(self):
+///         f"{self.first_name} {self.last_name}"
+/// ```
+///
+/// Use instead:
+/// ```python
+/// class User:
+///     @property
+///     def full_name(self):
+///         return f"{self.first_name} {self.last_name}"
+/// ```
+///
+/// ## References
+/// - [Python documentation: The property class](https://docs.python.org/3/library/functions.html#property)
+#[derive(ViolationMetadata)]
+#[violation_metadata(preview_since = "0.14.7")]
+pub(crate) struct PropertyWithoutReturn {
+    name: String,
+}
+
+impl Violation for PropertyWithoutReturn {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::None;
+
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        let Self { name } = self;
+        format!("`{name}` is a property without a `return` statement")
+    }
+}
+
+/// RUF066
+pub(crate) fn property_without_return(checker: &Checker, function_def: &StmtFunctionDef) {
+    let semantic = checker.semantic();
+
+    if checker.source_type.is_stub() || semantic.in_protocol_or_abstract_method() {
+        return;
+    }
+
+    let StmtFunctionDef {
+        decorator_list,
+        body,
+        name,
+        ..
+    } = function_def;
+
+    if !visibility::is_property(decorator_list, [], semantic)
+        || visibility::is_overload(decorator_list, semantic)
+        || function_type::is_stub(function_def, semantic)
+    {
+        return;
+    }
+
+    let mut visitor = PropertyVisitor::default();
+    visitor.visit_body(body);
+    if visitor.found {
+        return;
+    }
+
+    checker.report_diagnostic(
+        PropertyWithoutReturn {
+            name: name.to_string(),
+        },
+        function_def.identifier(),
+    );
+}
+
+#[derive(Default)]
+struct PropertyVisitor {
+    found: bool,
+}
+
+// NOTE: We are actually searching for the presence of
+// `yield`/`yield from`/`raise`/`return` statement/expression,
+// as having one of those indicates that there's likely no implementation mistake
+impl Visitor<'_> for PropertyVisitor {
+    fn visit_expr(&mut self, expr: &Expr) {
+        if self.found {
+            return;
+        }
+
+        match expr {
+            Expr::Yield(_) | Expr::YieldFrom(_) => self.found = true,
+            _ => walk_expr(self, expr),
+        }
+    }
+
+    fn visit_stmt(&mut self, stmt: &Stmt) {
+        if self.found {
+            return;
+        }
+
+        match stmt {
+            Stmt::Return(_) | Stmt::Raise(_) => self.found = true,
+            Stmt::FunctionDef(_) => {
+                // Do not recurse into nested functions; they're evaluated separately.
+            }
+            _ => walk_stmt(self, stmt),
+        }
+    }
+}

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF066_RUF066.py.snap

@@ -0,0 +1,31 @@
+---
+source: crates/ruff_linter/src/rules/ruff/mod.rs
+---
+RUF066 `name` is a property without a `return` statement
+ --> RUF066.py:7:9
+  |
+5 | class User:  # Test normal class properties
+6 |     @property
+7 |     def name(self):  # ERROR: No return
+  |         ^^^^
+8 |         f"{self.first_name} {self.last_name}"
+  |
+
+RUF066 `nested` is a property without a `return` statement
+  --> RUF066.py:18:9
+   |
+17 |     @property
+18 |     def nested(self):  # ERROR: Property itself doesn't return
+   |         ^^^^^^
+19 |         def inner():
+20 |             return 0
+   |
+
+RUF066 `prop2` is a property without a `return` statement
+  --> RUF066.py:43:9
+   |
+42 |     @property
+43 |     def prop2(self):  # ERROR: Not returning something (even when we are inside an ABC)
+   |         ^^^^^
+44 |         50
+   |

crates/ruff_python_semantic/src/model.rs

@@ -3,12 +3,13 @@ use std::path::Path;
 use bitflags::bitflags;
 use rustc_hash::FxHashMap;
 
-use ruff_python_ast::helpers::from_relative_import;
+use ruff_python_ast::helpers::{from_relative_import, map_subscript};
 use ruff_python_ast::name::{QualifiedName, UnqualifiedName};
 use ruff_python_ast::{self as ast, Expr, ExprContext, PySourceType, Stmt};
 use ruff_text_size::{Ranged, TextRange, TextSize};
 
 use crate::Imported;
+use crate::analyze::visibility;
 use crate::binding::{
     Binding, BindingFlags, BindingId, BindingKind, Bindings, Exceptions, FromImport, Import,
     SubmoduleImport,
@@ -2153,6 +2154,21 @@ impl<'a> SemanticModel<'a> {
             function.range() == function_def.range()
         })
     }
+
+    /// Return `true` if the model is in a `typing.Protocol` subclass or an abstract
+    /// method.
+    pub fn in_protocol_or_abstract_method(&self) -> bool {
+        self.current_scopes().any(|scope| match scope.kind {
+            ScopeKind::Class(class_def) => class_def
+                .bases()
+                .iter()
+                .any(|base| self.match_typing_expr(map_subscript(base), "Protocol")),
+            ScopeKind::Function(function_def) => {
+                visibility::is_abstract(&function_def.decorator_list, self)
+            }
+            _ => false,
+        })
+    }
 }
 
 pub struct ShadowedBinding {

crates/ty/docs/rules.md

@@ -39,7 +39,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-non-callable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L126" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L133" target="_blank">View source</a>
 </small>
 
 
@@ -63,7 +63,7 @@ Calling a non-callable object will raise a `TypeError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-argument-forms" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L170" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L177" target="_blank">View source</a>
 </small>
 
 
@@ -95,7 +95,7 @@ f(int)  # error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-declarations" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L196" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L203" target="_blank">View source</a>
 </small>
 
 
@@ -126,7 +126,7 @@ a = 1
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L221" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L228" target="_blank">View source</a>
 </small>
 
 
@@ -158,7 +158,7 @@ class C(A, B): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-class-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L247" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L254" target="_blank">View source</a>
 </small>
 
 
@@ -184,13 +184,41 @@ class B(A): ...
 
 [method resolution order]: https://docs.python.org/3/glossary.html#term-method-resolution-order
 
+## `cyclic-type-alias-definition`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-type-alias-definition" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L280" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for type alias definitions that (directly or mutually) refer to themselves.
+
+**Why is it bad?**
+
+Although it is permitted to define a recursive type alias, it is not meaningful
+to have a type alias whose expansion can only result in itself, and is therefore not allowed.
+
+**Examples**
+
+```python
+type Itself = Itself
+
+type A = B
+type B = A
+```
+
 ## `duplicate-base`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L312" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L341" target="_blank">View source</a>
 </small>
 
 
@@ -217,7 +245,7 @@ class B(A, A): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-kw-only" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L333" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L362" target="_blank">View source</a>
 </small>
 
 
@@ -329,7 +357,7 @@ def test(): -> "Literal[5]":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20inconsistent-mro" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L537" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L566" target="_blank">View source</a>
 </small>
 
 
@@ -359,7 +387,7 @@ class C(A, B): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20index-out-of-bounds" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L561" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L590" target="_blank">View source</a>
 </small>
 
 
@@ -385,7 +413,7 @@ t[3]  # IndexError: tuple index out of range
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20instance-layout-conflict" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L365" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L394" target="_blank">View source</a>
 </small>
 
 
@@ -474,7 +502,7 @@ an atypical memory layout.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-argument-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L615" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L644" target="_blank">View source</a>
 </small>
 
 
@@ -501,7 +529,7 @@ func("foo")  # error: [invalid-argument-type]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-assignment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L655" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L684" target="_blank">View source</a>
 </small>
 
 
@@ -529,7 +557,7 @@ a: int = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-attribute-access" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1814" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1920" target="_blank">View source</a>
 </small>
 
 
@@ -563,7 +591,7 @@ C.instance_var = 3  # error: Cannot assign to instance variable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-await" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L677" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L706" target="_blank">View source</a>
 </small>
 
 
@@ -599,7 +627,7 @@ asyncio.run(main())
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L707" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L736" target="_blank">View source</a>
 </small>
 
 
@@ -623,7 +651,7 @@ class A(42): ...  # error: [invalid-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-context-manager" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L758" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L787" target="_blank">View source</a>
 </small>
 
 
@@ -650,7 +678,7 @@ with 1:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-declaration" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L779" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L808" target="_blank">View source</a>
 </small>
 
 
@@ -679,7 +707,7 @@ a: str
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L802" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L831" target="_blank">View source</a>
 </small>
 
 
@@ -717,13 +745,55 @@ except ZeroDivisionError:
 
  This rule corresponds to Ruff's [`except-with-non-exception-classes` (`B030`)](https://docs.astral.sh/ruff/rules/except-with-non-exception-classes)
 
+## `invalid-explicit-override`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.28">0.0.1-alpha.28</a> ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-explicit-override" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1617" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for methods that are decorated with `@override` but do not override any method in a superclass.
+
+**Why is this bad?**
+
+Decorating a method with `@override` declares to the type checker that the intention is that it should
+override a method from a superclass.
+
+**Example**
+
+
+```python
+from typing import override
+
+class A:
+    @override
+    def foo(self): ...  # Error raised here
+
+class B(A):
+    @override
+    def ffooo(self): ...  # Error raised here
+
+class C:
+    @override
+    def __repr__(self): ...  # fine: overrides `object.__repr__`
+
+class D(A):
+    @override
+    def foo(self): ...  # fine: overrides `A.foo`
+```
+
 ## `invalid-generic-class`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L838" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L867" target="_blank">View source</a>
 </small>
 
 
@@ -756,7 +826,7 @@ class C[U](Generic[T]): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.17">0.0.1-alpha.17</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L582" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L611" target="_blank">View source</a>
 </small>
 
 
@@ -795,7 +865,7 @@ carol = Person(name="Carol", age=25)  # typo!
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-legacy-type-variable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L864" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L893" target="_blank">View source</a>
 </small>
 
 
@@ -830,7 +900,7 @@ def f(t: TypeVar("U")): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L961" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L990" target="_blank">View source</a>
 </small>
 
 
@@ -864,7 +934,7 @@ class B(metaclass=f): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-method-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1942" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2048" target="_blank">View source</a>
 </small>
 
 
@@ -942,7 +1012,28 @@ classes in Python do indeed behave this way, the strongly held convention is tha
 be avoided wherever possible. As part of this check, therefore, ty enforces that `__eq__`
 and `__ne__` methods accept `object` as their second argument.
 
+**Why does ty disagree with Ruff about how to write my method?**
+
+
+Ruff has several rules that will encourage you to rename a parameter, or change its type
+signature, if it thinks you're falling into a certain anti-pattern. For example, Ruff's
+[ARG002](https://docs.astral.sh/ruff/rules/unused-method-argument/) rule recommends that an
+unused parameter should either be removed or renamed to start with `_`. Applying either of
+these suggestions can cause ty to start reporting an `invalid-method-override` error if
+the function in question is a method on a subclass that overrides a method on a superclass,
+and the change would cause the subclass method to no longer accept all argument combinations
+that the superclass method accepts.
+
+This can usually be resolved by adding [`@typing.override`][override] to your method
+definition. Ruff knows that a method decorated with `@typing.override` is intended to
+override a method by the same name on a superclass, and avoids reporting rules like ARG002
+for such methods; it knows that the changes recommended by ARG002 would violate the Liskov
+Substitution Principle.
+
+Correct use of `@override` is enforced by ty's `invalid-explicit-override` rule.
+
 [Liskov Substitution Principle]: https://en.wikipedia.org/wiki/Liskov_substitution_principle
+[override]: https://docs.python.org/3/library/typing.html#typing.override
 
 ## `invalid-named-tuple`
 
@@ -950,7 +1041,7 @@ and `__ne__` methods accept `object` as their second argument.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-named-tuple" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L511" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L540" target="_blank">View source</a>
 </small>
 
 
@@ -982,7 +1073,7 @@ TypeError: can only inherit from a NamedTuple type and Generic
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-newtype" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L937" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L966" target="_blank">View source</a>
 </small>
 
 
@@ -1012,7 +1103,7 @@ Baz = NewType("Baz", int | str)  # error: invalid base for `typing.NewType`
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L988" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1017" target="_blank">View source</a>
 </small>
 
 
@@ -1062,7 +1153,7 @@ def foo(x: int) -> int: ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-parameter-default" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1087" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1116" target="_blank">View source</a>
 </small>
 
 
@@ -1088,7 +1179,7 @@ def f(a: int = ''): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-paramspec" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L892" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L921" target="_blank">View source</a>
 </small>
 
 
@@ -1119,7 +1210,7 @@ P2 = ParamSpec("S2")  # error: ParamSpec name must match the variable it's assig
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-protocol" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L447" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L476" target="_blank">View source</a>
 </small>
 
 
@@ -1153,7 +1244,7 @@ TypeError: Protocols can only inherit from other protocols, got <class 'int'>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1107" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1136" target="_blank">View source</a>
 </small>
 
 
@@ -1202,7 +1293,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-return-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L636" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L665" target="_blank">View source</a>
 </small>
 
 
@@ -1227,7 +1318,7 @@ def func() -> int:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1150" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1179" target="_blank">View source</a>
 </small>
 
 
@@ -1285,7 +1376,7 @@ TODO #14889
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.6">0.0.1-alpha.6</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-alias-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L916" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L945" target="_blank">View source</a>
 </small>
 
 
@@ -1306,13 +1397,60 @@ IntOrStr = TypeAliasType("IntOrStr", int | str)  # okay
 NewAlias = TypeAliasType(get_name(), int)        # error: TypeAliasType name must be a string literal
 ```
 
+## `invalid-type-arguments`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.29">0.0.1-alpha.29</a> ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-arguments" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1411" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for invalid type arguments in explicit type specialization.
+
+**Why is this bad?**
+
+Providing the wrong number of type arguments or type arguments that don't
+satisfy the type variable's bounds or constraints will lead to incorrect
+type inference and may indicate a misunderstanding of the generic type's
+interface.
+
+**Examples**
+
+
+Using legacy type variables:
+```python
+from typing import Generic, TypeVar
+
+T1 = TypeVar('T1', int, str)
+T2 = TypeVar('T2', bound=int)
+
+class Foo1(Generic[T1]): ...
+class Foo2(Generic[T2]): ...
+
+Foo1[bytes]  # error: bytes does not satisfy T1's constraints
+Foo2[str]  # error: str does not satisfy T2's bound
+```
+
+Using PEP 695 type variables:
+```python
+class Foo[T]: ...
+class Bar[T, U]: ...
+
+Foo[int, str]  # error: too many arguments
+Bar[int]  # error: too few arguments
+```
+
 ## `invalid-type-checking-constant`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1189" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1218" target="_blank">View source</a>
 </small>
 
 
@@ -1342,7 +1480,7 @@ TYPE_CHECKING = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-form" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1213" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1242" target="_blank">View source</a>
 </small>
 
 
@@ -1372,7 +1510,7 @@ b: Annotated[int]  # `Annotated` expects at least two arguments
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1265" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1294" target="_blank">View source</a>
 </small>
 
 
@@ -1406,7 +1544,7 @@ f(10)  # Error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1237" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1266" target="_blank">View source</a>
 </small>
 
 
@@ -1440,7 +1578,7 @@ class C:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-variable-constraints" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1293" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1322" target="_blank">View source</a>
 </small>
 
 
@@ -1475,7 +1613,7 @@ T = TypeVar('T', bound=str)  # valid bound TypeVar
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1322" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1351" target="_blank">View source</a>
 </small>
 
 
@@ -1500,7 +1638,7 @@ func()  # TypeError: func() missing 1 required positional argument: 'x'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-typed-dict-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1915" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2021" target="_blank">View source</a>
 </small>
 
 
@@ -1533,7 +1671,7 @@ alice["age"]  # KeyError
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20no-matching-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1341" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1370" target="_blank">View source</a>
 </small>
 
 
@@ -1562,7 +1700,7 @@ func("string")  # error: [no-matching-overload]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20non-subscriptable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1364" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1393" target="_blank">View source</a>
 </small>
 
 
@@ -1586,7 +1724,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-iterable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1382" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1452" target="_blank">View source</a>
 </small>
 
 
@@ -1612,7 +1750,7 @@ for i in 34:  # TypeError: 'int' object is not iterable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20parameter-already-assigned" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1433" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1503" target="_blank">View source</a>
 </small>
 
 
@@ -1639,7 +1777,7 @@ f(1, x=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20positional-only-parameter-as-kwarg" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1668" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1774" target="_blank">View source</a>
 </small>
 
 
@@ -1697,7 +1835,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20static-assert-error" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1790" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1896" target="_blank">View source</a>
 </small>
 
 
@@ -1727,7 +1865,7 @@ static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known tr
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20subclass-of-final-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1524" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1594" target="_blank">View source</a>
 </small>
 
 
@@ -1756,7 +1894,7 @@ class B(A): ...  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20too-many-positional-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1569" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1675" target="_blank">View source</a>
 </small>
 
 
@@ -1783,7 +1921,7 @@ f("foo")  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20type-assertion-failure" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1547" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1653" target="_blank">View source</a>
 </small>
 
 
@@ -1811,7 +1949,7 @@ def _(x: int):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1590" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1696" target="_blank">View source</a>
 </small>
 
 
@@ -1857,7 +1995,7 @@ class A:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1647" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1753" target="_blank">View source</a>
 </small>
 
 
@@ -1884,7 +2022,7 @@ f(x=1, y=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1689" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1795" target="_blank">View source</a>
 </small>
 
 
@@ -1912,7 +2050,7 @@ A().foo  # AttributeError: 'A' object has no attribute 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1711" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1817" target="_blank">View source</a>
 </small>
 
 
@@ -1937,7 +2075,7 @@ import foo  # ModuleNotFoundError: No module named 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1730" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1836" target="_blank">View source</a>
 </small>
 
 
@@ -1962,7 +2100,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1402" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1472" target="_blank">View source</a>
 </small>
 
 
@@ -1999,7 +2137,7 @@ b1 < b2 < b1  # exception raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-operator" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1749" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1855" target="_blank">View source</a>
 </small>
 
 
@@ -2027,7 +2165,7 @@ A() + A()  # TypeError: unsupported operand type(s) for +: 'A' and 'A'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20zero-stepsize-in-slice" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1771" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1877" target="_blank">View source</a>
 </small>
 
 
@@ -2052,7 +2190,7 @@ l[1:10:0]  # ValueError: slice step cannot be zero
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ambiguous-protocol-member" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L476" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L505" target="_blank">View source</a>
 </small>
 
 
@@ -2093,7 +2231,7 @@ class SubProto(BaseProto, Protocol):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.16">0.0.1-alpha.16</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20deprecated" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L291" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L320" target="_blank">View source</a>
 </small>
 
 
@@ -2120,7 +2258,7 @@ old_func()  # emits [deprecated] diagnostic
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ignore-comment-unknown-rule" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L40" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L47" target="_blank">View source</a>
 </small>
 
 
@@ -2151,7 +2289,7 @@ a = 20 / 0  # ty: ignore[division-by-zero]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-ignore-comment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L65" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L72" target="_blank">View source</a>
 </small>
 
 
@@ -2181,7 +2319,7 @@ a = 20 / 0  # type: ignore
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1454" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1524" target="_blank">View source</a>
 </small>
 
 
@@ -2209,7 +2347,7 @@ A.c  # AttributeError: type object 'A' has no attribute 'c'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-implicit-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L144" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L151" target="_blank">View source</a>
 </small>
 
 
@@ -2241,7 +2379,7 @@ A()[0]  # TypeError: 'A' object is not subscriptable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1476" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1546" target="_blank">View source</a>
 </small>
 
 
@@ -2273,7 +2411,7 @@ from module import a  # ImportError: cannot import name 'a' from 'module'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1842" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1948" target="_blank">View source</a>
 </small>
 
 
@@ -2300,7 +2438,7 @@ cast(int, f())  # Redundant
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1629" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1735" target="_blank">View source</a>
 </small>
 
 
@@ -2324,7 +2462,7 @@ reveal_type(1)  # NameError: name 'reveal_type' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.15">0.0.1-alpha.15</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-global" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1863" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1969" target="_blank">View source</a>
 </small>
 
 
@@ -2382,7 +2520,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.7">0.0.1-alpha.7</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L725" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L754" target="_blank">View source</a>
 </small>
 
 
@@ -2421,7 +2559,7 @@ class D(C): ...  # error: [unsupported-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20useless-overload-body" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1031" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1060" target="_blank">View source</a>
 </small>
 
 
@@ -2484,7 +2622,7 @@ def foo(x: int | str) -> int | str:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20division-by-zero" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L273" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L302" target="_blank">View source</a>
 </small>
 
 
@@ -2508,7 +2646,7 @@ Dividing by zero raises a `ZeroDivisionError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1502" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1572" target="_blank">View source</a>
 </small>
 
 
@@ -2536,7 +2674,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unused-ignore-comment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L15" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L22" target="_blank">View source</a>
 </small>
 
 

crates/ty/src/lib.rs

@@ -313,7 +313,8 @@ impl MainLoop {
                     let terminal_settings = db.project().settings(db).terminal();
                     let display_config = DisplayDiagnosticConfig::default()
                         .format(terminal_settings.output_format.into())
-                        .color(colored::control::SHOULD_COLORIZE.should_colorize());
+                        .color(colored::control::SHOULD_COLORIZE.should_colorize())
+                        .show_fix_diff(true);
 
                     if check_revision == revision {
                         if db.project().files(db).is_empty() {

crates/ty_ide/src/all_symbols.rs

@@ -143,7 +143,7 @@ ABCDEFGHIJKLMNOP = 'https://api.example.com'
 
     impl CursorTest {
         fn all_symbols(&self, query: &str) -> String {
-            let symbols = all_symbols(&self.db, &QueryPattern::new(query));
+            let symbols = all_symbols(&self.db, &QueryPattern::fuzzy(query));
 
             if symbols.is_empty() {
                 return "No symbols found".to_string();

crates/ty_ide/src/code_action.rs

@@ -0,0 +1,43 @@
+use crate::{completion, find_node::covering_node};
+use ruff_db::{files::File, parsed::parsed_module};
+use ruff_diagnostics::Edit;
+use ruff_text_size::TextRange;
+use ty_project::Db;
+use ty_python_semantic::types::UNRESOLVED_REFERENCE;
+
+/// A `QuickFix` Code Action
+#[derive(Debug, Clone)]
+pub struct QuickFix {
+    pub title: String,
+    pub edits: Vec<Edit>,
+    pub preferred: bool,
+}
+
+pub fn code_actions(
+    db: &dyn Db,
+    file: File,
+    diagnostic_range: TextRange,
+    diagnostic_id: &str,
+) -> Option<Vec<QuickFix>> {
+    let registry = db.lint_registry();
+    let Ok(lint_id) = registry.get(diagnostic_id) else {
+        return None;
+    };
+    if lint_id.name() == UNRESOLVED_REFERENCE.name() {
+        let parsed = parsed_module(db, file).load(db);
+        let node = covering_node(parsed.syntax().into(), diagnostic_range).node();
+        let symbol = &node.expr_name()?.id;
+
+        let fixes = completion::missing_imports(db, file, &parsed, symbol, node)
+            .into_iter()
+            .map(|import| QuickFix {
+                title: import.label,
+                edits: vec![import.edit],
+                preferred: true,
+            })
+            .collect();
+        Some(fixes)
+    } else {
+        None
+    }
+}

crates/ty_ide/src/completion.rs

@@ -4,8 +4,8 @@ use ruff_db::files::File;
 use ruff_db::parsed::{ParsedModuleRef, parsed_module};
 use ruff_db::source::source_text;
 use ruff_diagnostics::Edit;
-use ruff_python_ast as ast;
 use ruff_python_ast::name::Name;
+use ruff_python_ast::{self as ast, AnyNodeRef};
 use ruff_python_codegen::Stylist;
 use ruff_python_parser::{Token, TokenAt, TokenKind, Tokens};
 use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};
@@ -37,9 +37,9 @@ impl<'db> Completions<'db> {
     /// the user has typed as part of the next symbol they are writing.
     /// This collection will treat it as a query when present, and only
     /// add completions that match it.
-    fn new(db: &'db dyn Db, typed: Option<&str>) -> Completions<'db> {
+    fn fuzzy(db: &'db dyn Db, typed: Option<&str>) -> Completions<'db> {
         let query = typed
-            .map(QueryPattern::new)
+            .map(QueryPattern::fuzzy)
             .unwrap_or_else(QueryPattern::matches_all_symbols);
         Completions {
             db,
@@ -48,6 +48,15 @@ impl<'db> Completions<'db> {
         }
     }
 
+    fn exactly(db: &'db dyn Db, symbol: &str) -> Completions<'db> {
+        let query = QueryPattern::exactly(symbol);
+        Completions {
+            db,
+            items: vec![],
+            query,
+        }
+    }
+
     /// Convert this collection into a simple
     /// sequence of completions.
     fn into_completions(mut self) -> Vec<Completion<'db>> {
@@ -57,6 +66,21 @@ impl<'db> Completions<'db> {
         self.items
     }
 
+    fn into_imports(mut self) -> Vec<ImportEdit> {
+        self.items.sort_by(compare_suggestions);
+        self.items
+            .dedup_by(|c1, c2| (&c1.name, c1.module_name) == (&c2.name, c2.module_name));
+        self.items
+            .into_iter()
+            .filter_map(|item| {
+                Some(ImportEdit {
+                    label: format!("import {}.{}", item.module_name?, item.name),
+                    edit: item.import?,
+                })
+            })
+            .collect()
+    }
+
     /// Attempts to adds the given completion to this collection.
     ///
     /// When added, `true` is returned.
@@ -369,7 +393,7 @@ pub fn completion<'db>(
         return vec![];
     }
 
-    let mut completions = Completions::new(db, typed.as_deref());
+    let mut completions = Completions::fuzzy(db, typed.as_deref());
 
     if let Some(import) = ImportStatement::detect(db, file, &parsed, tokens, typed.as_deref()) {
         import.add_completions(db, file, &mut completions);
@@ -417,6 +441,25 @@ pub fn completion<'db>(
     completions.into_completions()
 }
 
+pub(crate) struct ImportEdit {
+    pub label: String,
+    pub edit: Edit,
+}
+
+pub(crate) fn missing_imports(
+    db: &dyn Db,
+    file: File,
+    parsed: &ParsedModuleRef,
+    symbol: &str,
+    node: AnyNodeRef,
+) -> Vec<ImportEdit> {
+    let mut completions = Completions::exactly(db, symbol);
+    let scoped = ScopedTarget { node };
+    add_unimported_completions(db, file, parsed, scoped, &mut completions);
+
+    completions.into_imports()
+}
+
 /// Adds completions derived from keywords.
 ///
 /// This should generally only be used when offering "scoped" completions.
@@ -1315,7 +1358,8 @@ fn find_typed_text(
     if last.end() < offset || last.range().is_empty() {
         return None;
     }
-    Some(source[last.range()].to_string())
+    let range = TextRange::new(last.start(), offset);
+    Some(source[range].to_string())
 }
 
 /// Whether the last token is in a place where we should not provide completions.
@@ -1406,6 +1450,24 @@ fn is_in_variable_binding(parsed: &ParsedModuleRef, offset: TextSize, typed: Opt
             type_param.name.range.contains_range(range)
         }
         ast::AnyNodeRef::StmtFor(stmt_for) => stmt_for.target.range().contains_range(range),
+        // The AST does not produce `ast::AnyNodeRef::Parameter` nodes for keywords
+        // or otherwise invalid syntax. Rather they are captured in a
+        // `ast::AnyNodeRef::Parameters` node as "empty space". To ensure
+        // we still suppress suggestions even when the syntax is technically
+        // invalid we extract the token under the cursor and check if it makes
+        // up that "empty space" inside the Parameters Node. If it does, we know
+        // that we are still binding variables, just that the current state is
+        // syntatically invalid. Hence we suppress autocomplete suggestons
+        // also in those cases.
+        ast::AnyNodeRef::Parameters(params) => {
+            if !params.range.contains_range(range) {
+                return false;
+            }
+            params
+                .iter()
+                .map(|param| param.range())
+                .all(|r| !r.contains_range(range))
+        }
         _ => false,
     })
 }
@@ -1633,6 +1695,21 @@ mod tests {
         );
     }
 
+    #[test]
+    fn inside_token() {
+        let test = completion_test_builder(
+            "\
+foo_bar_baz = 1
+x = foo<CURSOR>bad
+",
+        );
+
+        assert_snapshot!(
+            test.skip_builtins().build().snapshot(),
+            @"foo_bar_baz",
+        );
+    }
+
     #[test]
     fn type_keyword_dedup() {
         let test = completion_test_builder(
@@ -5347,6 +5424,45 @@ def foo(p<CURSOR>
         );
     }
 
+    #[test]
+    fn no_completions_in_function_param_keyword() {
+        let builder = completion_test_builder(
+            "\
+def foo(in<CURSOR>
+",
+        );
+        assert_snapshot!(
+            builder.build().snapshot(),
+            @"<No completions found>",
+        );
+    }
+
+    #[test]
+    fn no_completions_in_function_param_multi_keyword() {
+        let builder = completion_test_builder(
+            "\
+def foo(param, in<CURSOR>
+",
+        );
+        assert_snapshot!(
+            builder.build().snapshot(),
+            @"<No completions found>",
+        );
+    }
+
+    #[test]
+    fn no_completions_in_function_param_multi_keyword_middle() {
+        let builder = completion_test_builder(
+            "\
+def foo(param, in<CURSOR>, param_two
+",
+        );
+        assert_snapshot!(
+            builder.build().snapshot(),
+            @"<No completions found>",
+        );
+    }
+
     #[test]
     fn no_completions_in_function_type_param() {
         let builder = completion_test_builder(

crates/ty_ide/src/doc_highlights.rs

@@ -3,6 +3,7 @@ use crate::references::{ReferencesMode, references};
 use crate::{Db, ReferenceTarget};
 use ruff_db::files::File;
 use ruff_text_size::TextSize;
+use ty_python_semantic::SemanticModel;
 
 /// Find all document highlights for a symbol at the given position.
 /// Document highlights are limited to the current file only.
@@ -13,9 +14,10 @@ pub fn document_highlights(
 ) -> Option<Vec<ReferenceTarget>> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the cursor position
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     // Use DocumentHighlights mode which limits search to current file only
     references(db, file, &goto_target, ReferencesMode::DocumentHighlights)

crates/ty_ide/src/goto.rs

@@ -190,6 +190,24 @@ pub(crate) enum GotoTarget<'a> {
         /// The call of the callable
         call: &'a ast::ExprCall,
     },
+
+    /// Go to on a sub-expression of a string annotation's sub-AST
+    ///
+    /// ```py
+    /// x: "int | None"
+    ///           ^^^^
+    /// ```
+    ///
+    /// This is equivalent to `GotoTarget::Expression` but the expression
+    /// isn't actually in the AST.
+    StringAnnotationSubexpr {
+        /// The string literal that is a string annotation.
+        string_expr: &'a ast::ExprStringLiteral,
+        /// The range to query in the sub-AST for the sub-expression.
+        subrange: TextRange,
+        /// If the expression is a Name of some kind this is the name (just a cached result).
+        name: Option<String>,
+    },
 }
 
 /// The resolved definitions for a `GotoTarget`
@@ -227,7 +245,7 @@ impl<'db> DefinitionsOrTargets<'db> {
     /// In this case it basically returns exactly what was found.
     pub(crate) fn declaration_targets(
         self,
-        db: &'db dyn crate::Db,
+        db: &'db dyn ty_python_semantic::Db,
     ) -> Option<crate::NavigationTargets> {
         match self {
             DefinitionsOrTargets::Definitions(definitions) => {
@@ -243,7 +261,7 @@ impl<'db> DefinitionsOrTargets<'db> {
     /// if the definition we have is found in a stub file.
     pub(crate) fn definition_targets(
         self,
-        db: &'db dyn crate::Db,
+        db: &'db dyn ty_python_semantic::Db,
     ) -> Option<crate::NavigationTargets> {
         match self {
             DefinitionsOrTargets::Definitions(definitions) => {
@@ -313,6 +331,32 @@ impl GotoTarget<'_> {
                 let module = import_name(module_name, *component_index);
                 model.resolve_module_type(Some(module), *level)?
             }
+            GotoTarget::StringAnnotationSubexpr {
+                string_expr,
+                subrange,
+                ..
+            } => {
+                let (subast, _submodel) = model.enter_string_annotation(string_expr)?;
+                let submod = subast.syntax();
+                let subnode = covering_node(submod.into(), *subrange).node();
+
+                // The type checker knows the type of the full annotation but nothing else
+                if AnyNodeRef::from(&*submod.body) == subnode {
+                    string_expr.inferred_type(model)
+                } else {
+                    // TODO: force the typechecker to tell us its secrets
+                    // (it computes but then immediately discards these types)
+                    return None;
+                }
+            }
+            GotoTarget::BinOp { expression, .. } => {
+                let (_, ty) = ty_python_semantic::definitions_for_bin_op(model, expression)?;
+                ty
+            }
+            GotoTarget::UnaryOp { expression, .. } => {
+                let (_, ty) = ty_python_semantic::definitions_for_unary_op(model, expression)?;
+                ty
+            }
             // TODO: Support identifier targets
             GotoTarget::PatternMatchRest(_)
             | GotoTarget::PatternKeywordArgument(_)
@@ -322,16 +366,6 @@ impl GotoTarget<'_> {
             | GotoTarget::TypeParamTypeVarTupleName(_)
             | GotoTarget::NonLocal { .. }
             | GotoTarget::Globals { .. } => return None,
-            GotoTarget::BinOp { expression, .. } => {
-                let (_, ty) =
-                    ty_python_semantic::definitions_for_bin_op(model.db(), model, expression)?;
-                ty
-            }
-            GotoTarget::UnaryOp { expression, .. } => {
-                let (_, ty) =
-                    ty_python_semantic::definitions_for_unary_op(model.db(), model, expression)?;
-                ty
-            }
         };
 
         Some(ty)
@@ -343,7 +377,7 @@ impl GotoTarget<'_> {
         model: &SemanticModel,
     ) -> Option<String> {
         if let GotoTarget::Call { call, .. } = self {
-            call_type_simplified_by_overloads(model.db(), model, call)
+            call_type_simplified_by_overloads(model, call)
         } else {
             None
         }
@@ -367,14 +401,9 @@ impl GotoTarget<'_> {
         alias_resolution: ImportAliasResolution,
     ) -> Option<DefinitionsOrTargets<'db>> {
         use crate::NavigationTarget;
-        let db = model.db();
-        let file = model.file();
-
         match self {
-            GotoTarget::Expression(expression) => {
-                definitions_for_expression(model, expression).map(DefinitionsOrTargets::Definitions)
-            }
-
+            GotoTarget::Expression(expression) => definitions_for_expression(model, *expression)
+                .map(DefinitionsOrTargets::Definitions),
             // For already-defined symbols, they are their own definitions
             GotoTarget::FunctionDef(function) => Some(DefinitionsOrTargets::Definitions(vec![
                 ResolvedDefinition::Definition(function.definition(model)),
@@ -395,8 +424,7 @@ impl GotoTarget<'_> {
                 let symbol_name = alias.name.as_str();
                 Some(DefinitionsOrTargets::Definitions(
                     definitions_for_imported_symbol(
-                        db,
-                        file,
+                        model,
                         import_from,
                         symbol_name,
                         alias_resolution,
@@ -423,7 +451,7 @@ impl GotoTarget<'_> {
                     let alias_range = alias.asname.as_ref().unwrap().range;
                     Some(DefinitionsOrTargets::Targets(
                         crate::NavigationTargets::single(NavigationTarget {
-                            file,
+                            file: model.file(),
                             focus_range: alias_range,
                             full_range: alias.range(),
                         }),
@@ -436,7 +464,7 @@ impl GotoTarget<'_> {
                 keyword,
                 call_expression,
             } => Some(DefinitionsOrTargets::Definitions(
-                definitions_for_keyword_argument(db, file, keyword, call_expression),
+                definitions_for_keyword_argument(model, keyword, call_expression),
             )),
 
             // For exception variables, they are their own definitions (like parameters)
@@ -451,7 +479,10 @@ impl GotoTarget<'_> {
                 if let Some(rest_name) = &pattern_mapping.rest {
                     let range = rest_name.range;
                     Some(DefinitionsOrTargets::Targets(
-                        crate::NavigationTargets::single(NavigationTarget::new(file, range)),
+                        crate::NavigationTargets::single(NavigationTarget::new(
+                            model.file(),
+                            range,
+                        )),
                     ))
                 } else {
                     None
@@ -463,7 +494,10 @@ impl GotoTarget<'_> {
                 if let Some(name) = &pattern_as.name {
                     let range = name.range;
                     Some(DefinitionsOrTargets::Targets(
-                        crate::NavigationTargets::single(NavigationTarget::new(file, range)),
+                        crate::NavigationTargets::single(NavigationTarget::new(
+                            model.file(),
+                            range,
+                        )),
                     ))
                 } else {
                     None
@@ -476,7 +510,7 @@ impl GotoTarget<'_> {
             GotoTarget::Call { callable, call } => {
                 let mut definitions = definitions_for_callable(model, call);
                 let expr_definitions =
-                    definitions_for_expression(model, callable).unwrap_or_default();
+                    definitions_for_expression(model, *callable).unwrap_or_default();
                 definitions.extend(expr_definitions);
 
                 if definitions.is_empty() {
@@ -488,19 +522,45 @@ impl GotoTarget<'_> {
 
             GotoTarget::BinOp { expression, .. } => {
                 let (definitions, _) =
-                    ty_python_semantic::definitions_for_bin_op(db, model, expression)?;
+                    ty_python_semantic::definitions_for_bin_op(model, expression)?;
 
                 Some(DefinitionsOrTargets::Definitions(definitions))
             }
 
             GotoTarget::UnaryOp { expression, .. } => {
                 let (definitions, _) =
-                    ty_python_semantic::definitions_for_unary_op(db, model, expression)?;
+                    ty_python_semantic::definitions_for_unary_op(model, expression)?;
 
                 Some(DefinitionsOrTargets::Definitions(definitions))
             }
 
-            _ => None,
+            // String annotations sub-expressions require us to recurse into the sub-AST
+            GotoTarget::StringAnnotationSubexpr {
+                string_expr,
+                subrange,
+                ..
+            } => {
+                let (subast, submodel) = model.enter_string_annotation(string_expr)?;
+                let subexpr = covering_node(subast.syntax().into(), *subrange)
+                    .node()
+                    .as_expr_ref()?;
+                definitions_for_expression(&submodel, subexpr)
+                    .map(DefinitionsOrTargets::Definitions)
+            }
+            GotoTarget::NonLocal { identifier } | GotoTarget::Globals { identifier } => {
+                Some(DefinitionsOrTargets::Definitions(definitions_for_name(
+                    model,
+                    identifier.as_str(),
+                    AnyNodeRef::Identifier(identifier),
+                )))
+            }
+
+            // TODO: implement these
+            GotoTarget::PatternKeywordArgument(..)
+            | GotoTarget::PatternMatchStarName(..)
+            | GotoTarget::TypeParamTypeVarName(..)
+            | GotoTarget::TypeParamParamSpecName(..)
+            | GotoTarget::TypeParamTypeVarTupleName(..) => None,
         }
     }
 
@@ -519,6 +579,7 @@ impl GotoTarget<'_> {
                 ast::ExprRef::Attribute(attr) => Some(Cow::Borrowed(attr.attr.as_str())),
                 _ => None,
             },
+            GotoTarget::StringAnnotationSubexpr { name, .. } => name.as_deref().map(Cow::Borrowed),
             GotoTarget::FunctionDef(function) => Some(Cow::Borrowed(function.name.as_str())),
             GotoTarget::ClassDef(class) => Some(Cow::Borrowed(class.name.as_str())),
             GotoTarget::Parameter(parameter) => Some(Cow::Borrowed(parameter.name.as_str())),
@@ -579,6 +640,7 @@ impl GotoTarget<'_> {
 
     /// Creates a `GotoTarget` from a `CoveringNode` and an offset within the node
     pub(crate) fn from_covering_node<'a>(
+        model: &SemanticModel,
         covering_node: &crate::find_node::CoveringNode<'a>,
         offset: TextSize,
         tokens: &Tokens,
@@ -778,6 +840,31 @@ impl GotoTarget<'_> {
                 Some(GotoTarget::Expression(unary.into()))
             }
 
+            node @ AnyNodeRef::ExprStringLiteral(string_expr) => {
+                // Check if we've clicked on a sub-GotoTarget inside a string annotation's sub-AST
+                if let Some((subast, submodel)) = model.enter_string_annotation(string_expr)
+                    && let Some(GotoTarget::Expression(subexpr)) = find_goto_target_impl(
+                        &submodel,
+                        subast.tokens(),
+                        subast.syntax().into(),
+                        offset,
+                    )
+                {
+                    let name = match subexpr {
+                        ast::ExprRef::Name(name) => Some(name.id.to_string()),
+                        ast::ExprRef::Attribute(attr) => Some(attr.attr.to_string()),
+                        _ => None,
+                    };
+                    Some(GotoTarget::StringAnnotationSubexpr {
+                        string_expr,
+                        subrange: subexpr.range(),
+                        name,
+                    })
+                } else {
+                    node.as_expr_ref().map(GotoTarget::Expression)
+                }
+            }
+
             node => {
                 // Check if this is seemingly a callable being invoked (the `x` in `x(...)`)
                 let parent = covering_node.parent();
@@ -813,6 +900,7 @@ impl Ranged for GotoTarget<'_> {
             GotoTarget::ImportModuleComponent {
                 component_range, ..
             } => *component_range,
+            GotoTarget::StringAnnotationSubexpr { subrange, .. } => *subrange,
             GotoTarget::ImportModuleAlias { alias } => alias.asname.as_ref().unwrap().range,
             GotoTarget::ExceptVariable(except) => except.name.as_ref().unwrap().range,
             GotoTarget::KeywordArgument { keyword, .. } => keyword.arg.as_ref().unwrap().range,
@@ -832,9 +920,9 @@ impl Ranged for GotoTarget<'_> {
 }
 
 /// Converts a collection of `ResolvedDefinition` items into `NavigationTarget` items.
-fn convert_resolved_definitions_to_targets(
-    db: &dyn crate::Db,
-    definitions: Vec<ty_python_semantic::ResolvedDefinition<'_>>,
+fn convert_resolved_definitions_to_targets<'db>(
+    db: &'db dyn ty_python_semantic::Db,
+    definitions: Vec<ty_python_semantic::ResolvedDefinition<'db>>,
 ) -> Vec<crate::NavigationTarget> {
     definitions
         .into_iter()
@@ -869,14 +957,16 @@ fn convert_resolved_definitions_to_targets(
 /// Shared helper to get definitions for an expr (that is presumably a name/attr)
 fn definitions_for_expression<'db>(
     model: &SemanticModel<'db>,
-    expression: &ruff_python_ast::ExprRef<'_>,
+    expression: ruff_python_ast::ExprRef<'_>,
 ) -> Option<Vec<ResolvedDefinition<'db>>> {
     match expression {
-        ast::ExprRef::Name(name) => Some(definitions_for_name(model.db(), model.file(), name)),
+        ast::ExprRef::Name(name) => Some(definitions_for_name(
+            model,
+            name.id.as_str(),
+            expression.into(),
+        )),
         ast::ExprRef::Attribute(attribute) => Some(ty_python_semantic::definitions_for_attribute(
-            model.db(),
-            model.file(),
-            attribute,
+            model, attribute,
         )),
         _ => None,
     }
@@ -887,7 +977,7 @@ fn definitions_for_callable<'db>(
     call: &ast::ExprCall,
 ) -> Vec<ResolvedDefinition<'db>> {
     // Attempt to refine to a specific call
-    let signature_info = call_signature_details(model.db(), model, call);
+    let signature_info = call_signature_details(model, call);
     signature_info
         .into_iter()
         .filter_map(|signature| signature.definition.map(ResolvedDefinition::Definition))
@@ -896,7 +986,7 @@ fn definitions_for_callable<'db>(
 
 /// Shared helper to map and convert resolved definitions into navigation targets.
 fn definitions_to_navigation_targets<'db>(
-    db: &dyn crate::Db,
+    db: &dyn ty_python_semantic::Db,
     stub_mapper: Option<&StubMapper<'db>>,
     mut definitions: Vec<ty_python_semantic::ResolvedDefinition<'db>>,
 ) -> Option<crate::NavigationTargets> {
@@ -911,12 +1001,21 @@ fn definitions_to_navigation_targets<'db>(
     }
 }
 
-pub(crate) fn find_goto_target(
-    parsed: &ParsedModuleRef,
+pub(crate) fn find_goto_target<'a>(
+    model: &'a SemanticModel,
+    parsed: &'a ParsedModuleRef,
     offset: TextSize,
-) -> Option<GotoTarget<'_>> {
-    let token = parsed
-        .tokens()
+) -> Option<GotoTarget<'a>> {
+    find_goto_target_impl(model, parsed.tokens(), parsed.syntax().into(), offset)
+}
+
+pub(crate) fn find_goto_target_impl<'a>(
+    model: &'a SemanticModel,
+    tokens: &'a Tokens,
+    syntax: AnyNodeRef<'a>,
+    offset: TextSize,
+) -> Option<GotoTarget<'a>> {
+    let token = tokens
         .at_offset(offset)
         .max_by_key(|token| match token.kind() {
             TokenKind::Name
@@ -937,18 +1036,18 @@ pub(crate) fn find_goto_target(
         return None;
     }
 
-    let covering_node = covering_node(parsed.syntax().into(), token.range())
+    let covering_node = covering_node(syntax, token.range())
         .find_first(|node| {
             node.is_identifier() || node.is_expression() || node.is_stmt_import_from()
         })
         .ok()?;
 
-    GotoTarget::from_covering_node(&covering_node, offset, parsed.tokens())
+    GotoTarget::from_covering_node(model, &covering_node, offset, tokens)
 }
 
 /// Helper function to resolve a module name and create a navigation target.
 fn definitions_for_module<'db>(
-    model: &SemanticModel,
+    model: &SemanticModel<'db>,
     module: Option<&str>,
     level: u32,
 ) -> Option<DefinitionsOrTargets<'db>> {

crates/ty_ide/src/goto_declaration.rs

@@ -16,9 +16,9 @@ pub fn goto_declaration(
     offset: TextSize,
 ) -> Option<RangedValue<NavigationTargets>> {
     let module = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&module, offset)?;
-
     let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &module, offset)?;
+
     let declaration_targets = goto_target
         .get_definition_targets(&model, ImportAliasResolution::ResolveAliases)?
         .declaration_targets(db)?;
@@ -889,6 +889,190 @@ def another_helper(path):
         ");
     }
 
+    #[test]
+    fn goto_declaration_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "MyClass | No" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
     #[test]
     fn goto_declaration_nested_instance_attribute() {
         let test = cursor_test(
@@ -1070,6 +1254,45 @@ def outer():
         "#);
     }
 
+    #[test]
+    fn goto_declaration_nonlocal_stmt() {
+        let test = cursor_test(
+            r#"
+def outer():
+    xy = "outer_value"
+    
+    def inner():
+        nonlocal x<CURSOR>y
+        xy = "modified"
+        return x  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:3:5
+          |
+        2 | def outer():
+        3 |     xy = "outer_value"
+          |     ^^
+        4 |
+        5 |     def inner():
+          |
+        info: Source
+         --> main.py:6:18
+          |
+        5 |     def inner():
+        6 |         nonlocal xy
+          |                  ^^
+        7 |         xy = "modified"
+        8 |         return x  # Should find the nonlocal x declaration in outer scope
+          |
+        "#);
+    }
+
     #[test]
     fn goto_declaration_global_binding() {
         let test = cursor_test(
@@ -1104,6 +1327,41 @@ def function():
         "#);
     }
 
+    #[test]
+    fn goto_declaration_global_stmt() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_<CURSOR>var
+    global_var = "modified"
+    return global_var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:2:1
+          |
+        2 | global_var = "global_value"
+          | ^^^^^^^^^^
+        3 |
+        4 | def function():
+          |
+        info: Source
+         --> main.py:5:12
+          |
+        4 | def function():
+        5 |     global global_var
+          |            ^^^^^^^^^^
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |
+        "#);
+    }
+
     #[test]
     fn goto_declaration_inherited_attribute() {
         let test = cursor_test(

crates/ty_ide/src/goto_definition.rs

@@ -17,8 +17,8 @@ pub fn goto_definition(
     offset: TextSize,
 ) -> Option<RangedValue<NavigationTargets>> {
     let module = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&module, offset)?;
     let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &module, offset)?;
     let definition_targets = goto_target
         .get_definition_targets(&model, ImportAliasResolution::ResolveAliases)?
         .definition_targets(db)?;

crates/ty_ide/src/goto_references.rs

@@ -3,6 +3,7 @@ use crate::references::{ReferencesMode, references};
 use crate::{Db, ReferenceTarget};
 use ruff_db::files::File;
 use ruff_text_size::TextSize;
+use ty_python_semantic::SemanticModel;
 
 /// Find all references to a symbol at the given position.
 /// Search for references across all files in the project.
@@ -14,9 +15,10 @@ pub fn goto_references(
 ) -> Option<Vec<ReferenceTarget>> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the cursor position
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     let mode = if include_declaration {
         ReferencesMode::References
@@ -147,7 +149,6 @@ result = calculate_sum(value=42)
     }
 
     #[test]
-    #[ignore] // TODO: Enable when nonlocal support is fully implemented in goto.rs
     fn test_nonlocal_variable_references() {
         let test = cursor_test(
             "
@@ -181,7 +182,7 @@ def outer_function():
         2 | def outer_function():
         3 |     counter = 0
           |     ^^^^^^^
-        4 |     
+        4 |
         5 |     def increment():
           |
 
@@ -212,7 +213,7 @@ def outer_function():
          7 |         counter += 1
          8 |         return counter
            |                ^^^^^^^
-         9 |     
+         9 |
         10 |     def decrement():
            |
 
@@ -243,7 +244,7 @@ def outer_function():
         12 |         counter -= 1
         13 |         return counter
            |                ^^^^^^^
-        14 |     
+        14 |
         15 |     # Use counter in outer scope
            |
 
@@ -264,14 +265,13 @@ def outer_function():
         18 |     decrement()
         19 |     final = counter
            |             ^^^^^^^
-        20 |     
+        20 |
         21 |     return increment, decrement
            |
         ");
     }
 
     #[test]
-    #[ignore] // TODO: Enable when global support is fully implemented in goto.rs
     fn test_global_variable_references() {
         let test = cursor_test(
             "
@@ -710,6 +710,194 @@ cls = MyClass
         ");
     }
 
+    #[test]
+    fn references_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
+    #[test]
+    fn references_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
+    #[test]
+    fn references_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
+    #[test]
+    fn references_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "MyClass | No" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
     #[test]
     fn test_multi_file_function_references() {
         let test = CursorTest::builder()

crates/ty_ide/src/goto_type_definition.rs

@@ -11,9 +11,9 @@ pub fn goto_type_definition(
     offset: TextSize,
 ) -> Option<RangedValue<NavigationTargets>> {
     let module = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&module, offset)?;
-
     let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &module, offset)?;
+
     let ty = goto_target.inferred_type(&model)?;
 
     tracing::debug!("Inferred type of covering node is {}", ty.display(db));
@@ -744,6 +744,226 @@ mod tests {
         assert_snapshot!(test.goto_type_definition(), @"No type definitions found");
     }
 
+    #[test]
+    fn goto_type_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+         --> main.py:4:7
+          |
+        2 | a: "MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[goto-type-definition]: Type definition
+           --> stdlib/types.pyi:950:11
+            |
+        948 | if sys.version_info >= (3, 10):
+        949 |     @final
+        950 |     class NoneType:
+            |           ^^^^^^^^
+        951 |         """The type of the None singleton."""
+            |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[goto-type-definition]: Type definition
+           --> stdlib/types.pyi:950:11
+            |
+        948 | if sys.version_info >= (3, 10):
+        949 |     @final
+        950 |     class NoneType:
+            |           ^^^^^^^^
+        951 |         """The type of the None singleton."""
+            |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "MyClass |" = 1
+          |    ^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
     #[test]
     fn goto_type_on_keyword_argument() {
         let test = cursor_test(
@@ -842,6 +1062,118 @@ f(**kwargs<CURSOR>)
         "#);
     }
 
+    #[test]
+    fn goto_type_nonlocal_binding() {
+        let test = cursor_test(
+            r#"
+def outer():
+    x = "outer_value"
+    
+    def inner():
+        nonlocal x
+        x = "modified"
+        return x<CURSOR>  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+          --> main.py:8:16
+           |
+         6 |         nonlocal x
+         7 |         x = "modified"
+         8 |         return x  # Should find the nonlocal x declaration in outer scope
+           |                ^
+         9 |
+        10 |     return inner
+           |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_nonlocal_stmt() {
+        let test = cursor_test(
+            r#"
+def outer():
+    xy = "outer_value"
+    
+    def inner():
+        nonlocal x<CURSOR>y
+        xy = "modified"
+        return x  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_global_binding() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_var
+    global_var = "modified"
+    return global_<CURSOR>var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+         --> main.py:7:12
+          |
+        5 |     global global_var
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |            ^^^^^^^^^^
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_global_stmt() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_<CURSOR>var
+    global_var = "modified"
+    return global_var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
     #[test]
     fn goto_type_of_expression_with_builtin() {
         let test = cursor_test(

crates/ty_ide/src/hover.rs

@@ -11,7 +11,8 @@ use ty_python_semantic::{DisplaySettings, SemanticModel};
 
 pub fn hover(db: &dyn Db, file: File, offset: TextSize) -> Option<RangedValue<Hover<'_>>> {
     let parsed = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&parsed, offset)?;
+    let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &parsed, offset)?;
 
     if let GotoTarget::Expression(expr) = goto_target {
         if expr.is_literal_expr() {
@@ -19,7 +20,6 @@ pub fn hover(db: &dyn Db, file: File, offset: TextSize) -> Option<RangedValue<Ho
         }
     }
 
-    let model = SemanticModel::new(db, file);
     let docs = goto_target
         .get_definition_targets(
             &model,
@@ -904,6 +904,191 @@ mod tests {
         ");
     }
 
+    #[test]
+    fn hover_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        MyClass
+        ---------------------------------------------
+        some docs
+
+        ---------------------------------------------
+        ```python
+        MyClass
+        ```
+        ---
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^-^
+          |     |    |
+          |     |    Cursor offset
+          |     source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        some docs
+
+        ---------------------------------------------
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^-^^
+          |            |   |
+          |            |   Cursor offset
+          |            source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        some docs
+
+        ---------------------------------------------
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^- Cursor offset
+          |            |
+          |            source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        some docs
+
+        ---------------------------------------------
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^-^^
+          |     |   |
+          |     |   Cursor offset
+          |     source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
     #[test]
     fn hover_overload_type_disambiguated1() {
         let test = CursorTest::builder()
@@ -1463,6 +1648,117 @@ def ab(a: int, *, c: int):
         ");
     }
 
+    #[test]
+    fn hover_nonlocal_binding() {
+        let test = cursor_test(
+            r#"
+def outer():
+    x = "outer_value"
+    
+    def inner():
+        nonlocal x
+        x = "modified"
+        return x<CURSOR>  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.hover(), @r#"
+        Literal["modified"]
+        ---------------------------------------------
+        ```python
+        Literal["modified"]
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+          --> main.py:8:16
+           |
+         6 |         nonlocal x
+         7 |         x = "modified"
+         8 |         return x  # Should find the nonlocal x declaration in outer scope
+           |                ^- Cursor offset
+           |                |
+           |                source
+         9 |
+        10 |     return inner
+           |
+        "#);
+    }
+
+    #[test]
+    fn hover_nonlocal_stmt() {
+        let test = cursor_test(
+            r#"
+def outer():
+    xy = "outer_value"
+    
+    def inner():
+        nonlocal x<CURSOR>y
+        xy = "modified"
+        return x  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_global_binding() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_var
+    global_var = "modified"
+    return global_<CURSOR>var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.hover(), @r#"
+        Literal["modified"]
+        ---------------------------------------------
+        ```python
+        Literal["modified"]
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:7:12
+          |
+        5 |     global global_var
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |            ^^^^^^^-^^
+          |            |      |
+          |            |      Cursor offset
+          |            source
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_global_stmt() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_<CURSOR>var
+    global_var = "modified"
+    return global_var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
     #[test]
     fn hover_module_import() {
         let mut test = cursor_test(

crates/ty_ide/src/inlay_hints.rs

@@ -6,8 +6,8 @@ use ruff_db::parsed::parsed_module;
 use ruff_python_ast::visitor::source_order::{self, SourceOrderVisitor, TraversalSignal};
 use ruff_python_ast::{AnyNodeRef, ArgOrKeyword, Expr, ExprUnaryOp, Stmt, UnaryOp};
 use ruff_text_size::{Ranged, TextRange, TextSize};
-use ty_python_semantic::types::Type;
 use ty_python_semantic::types::ide_support::inlay_hint_call_argument_details;
+use ty_python_semantic::types::{Type, TypeDetail};
 use ty_python_semantic::{HasType, SemanticModel};
 
 #[derive(Debug, Clone)]
@@ -15,10 +15,12 @@ pub struct InlayHint {
     pub position: TextSize,
     pub kind: InlayHintKind,
     pub label: InlayHintLabel,
+    pub text_edits: Vec<InlayHintTextEdit>,
 }
 
 impl InlayHint {
-    fn variable_type(position: TextSize, ty: Type, db: &dyn Db) -> Self {
+    fn variable_type(expr: &Expr, ty: Type, db: &dyn Db, allow_edits: bool) -> Self {
+        let position = expr.range().end();
         // Render the type to a string, and get subspans for all the types that make it up
         let details = ty.display(db).to_string_parts();
 
@@ -34,7 +36,7 @@ impl InlayHint {
         let mut label_parts = vec![": ".into()];
         for (target, detail) in details.targets.iter().zip(&details.details) {
             match detail {
-                ty_python_semantic::types::TypeDetail::Type(ty) => {
+                TypeDetail::Type(ty) => {
                     let start = target.start().to_usize();
                     let end = target.end().to_usize();
                     // If we skipped over some bytes, push them with no target
@@ -50,9 +52,9 @@ impl InlayHint {
                         offset = end;
                     }
                 }
-                ty_python_semantic::types::TypeDetail::SignatureStart
-                | ty_python_semantic::types::TypeDetail::SignatureEnd
-                | ty_python_semantic::types::TypeDetail::Parameter(_) => {
+                TypeDetail::SignatureStart
+                | TypeDetail::SignatureEnd
+                | TypeDetail::Parameter(_) => {
                     // Don't care about these
                 }
             }
@@ -62,10 +64,20 @@ impl InlayHint {
             label_parts.push(details.label[offset..details.label.len()].into());
         }
 
+        let text_edits = if details.is_valid_syntax && allow_edits {
+            vec![InlayHintTextEdit {
+                range: TextRange::new(position, position),
+                new_text: format!(": {}", details.label),
+            }]
+        } else {
+            vec![]
+        };
+
         Self {
             position,
             kind: InlayHintKind::Type,
             label: InlayHintLabel { parts: label_parts },
+            text_edits,
         }
     }
 
@@ -83,6 +95,7 @@ impl InlayHint {
             position,
             kind: InlayHintKind::CallArgumentName,
             label: InlayHintLabel { parts: label_parts },
+            text_edits: vec![],
         }
     }
 
@@ -175,6 +188,12 @@ impl From<&str> for InlayHintLabelPart {
     }
 }
 
+#[derive(Debug, Clone)]
+pub struct InlayHintTextEdit {
+    pub range: TextRange,
+    pub new_text: String,
+}
+
 pub fn inlay_hints(
     db: &dyn Db,
     file: File,
@@ -234,6 +253,7 @@ struct InlayHintVisitor<'a, 'db> {
     in_assignment: bool,
     range: TextRange,
     settings: &'a InlayHintSettings,
+    in_no_edits_allowed: bool,
 }
 
 impl<'a, 'db> InlayHintVisitor<'a, 'db> {
@@ -245,15 +265,16 @@ impl<'a, 'db> InlayHintVisitor<'a, 'db> {
             in_assignment: false,
             range,
             settings,
+            in_no_edits_allowed: false,
         }
     }
 
-    fn add_type_hint(&mut self, position: TextSize, ty: Type<'db>) {
+    fn add_type_hint(&mut self, expr: &Expr, ty: Type<'db>, allow_edits: bool) {
         if !self.settings.variable_types {
             return;
         }
 
-        let inlay_hint = InlayHint::variable_type(position, ty, self.db);
+        let inlay_hint = InlayHint::variable_type(expr, ty, self.db, allow_edits);
 
         self.hints.push(inlay_hint);
     }
@@ -297,9 +318,13 @@ impl SourceOrderVisitor<'_> for InlayHintVisitor<'_, '_> {
         match stmt {
             Stmt::Assign(assign) => {
                 self.in_assignment = !type_hint_is_excessive_for_expr(&assign.value);
+                if !annotations_are_valid_syntax(assign) {
+                    self.in_no_edits_allowed = true;
+                }
                 for target in &assign.targets {
                     self.visit_expr(target);
                 }
+                self.in_no_edits_allowed = false;
                 self.in_assignment = false;
 
                 self.visit_expr(&assign.value);
@@ -325,7 +350,7 @@ impl SourceOrderVisitor<'_> for InlayHintVisitor<'_, '_> {
                 if self.in_assignment {
                     if name.ctx.is_store() {
                         let ty = expr.inferred_type(&self.model);
-                        self.add_type_hint(expr.range().end(), ty);
+                        self.add_type_hint(expr, ty, !self.in_no_edits_allowed);
                     }
                 }
                 source_order::walk_expr(self, expr);
@@ -334,7 +359,7 @@ impl SourceOrderVisitor<'_> for InlayHintVisitor<'_, '_> {
                 if self.in_assignment {
                     if attribute.ctx.is_store() {
                         let ty = expr.inferred_type(&self.model);
-                        self.add_type_hint(expr.range().end(), ty);
+                        self.add_type_hint(expr, ty, !self.in_no_edits_allowed);
                     }
                 }
                 source_order::walk_expr(self, expr);
@@ -420,6 +445,22 @@ fn type_hint_is_excessive_for_expr(expr: &Expr) -> bool {
     }
 }
 
+fn annotations_are_valid_syntax(stmt_assign: &ruff_python_ast::StmtAssign) -> bool {
+    if stmt_assign.targets.len() > 1 {
+        return false;
+    }
+
+    if stmt_assign
+        .targets
+        .iter()
+        .any(|target| matches!(target, Expr::Tuple(_)))
+    {
+        return false;
+    }
+
+    true
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -427,6 +468,7 @@ mod tests {
     use crate::NavigationTarget;
     use crate::tests::IntoDiagnostic;
     use insta::{assert_snapshot, internals::SettingsBindDropGuard};
+    use itertools::Itertools;
     use ruff_db::{
         diagnostic::{
             Annotation, Diagnostic, DiagnosticFormat, DiagnosticId, DisplayDiagnosticConfig,
@@ -517,12 +559,15 @@ mod tests {
         fn inlay_hints_with_settings(&mut self, settings: &InlayHintSettings) -> String {
             let hints = inlay_hints(&self.db, self.file, self.range, settings);
 
-            let mut buf = source_text(&self.db, self.file).as_str().to_string();
+            let mut inlay_hint_buf = source_text(&self.db, self.file).as_str().to_string();
+            let mut text_edit_buf = inlay_hint_buf.clone();
 
             let mut tbd_diagnostics = Vec::new();
 
             let mut offset = 0;
 
+            let mut edit_offset = 0;
+
             for hint in hints {
                 let end_position = hint.position.to_usize() + offset;
                 let mut hint_str = "[".to_string();
@@ -538,36 +583,65 @@ mod tests {
                     hint_str.push_str(part.text());
                 }
 
+                for edit in hint.text_edits {
+                    let start = edit.range.start().to_usize() + edit_offset;
+                    let end = edit.range.end().to_usize() + edit_offset;
+
+                    text_edit_buf.replace_range(start..end, &edit.new_text);
+
+                    if start == end {
+                        edit_offset += edit.new_text.len();
+                    } else {
+                        edit_offset += edit.new_text.len() - edit.range.len().to_usize();
+                    }
+                }
+
                 hint_str.push(']');
                 offset += hint_str.len();
 
-                buf.insert_str(end_position, &hint_str);
+                inlay_hint_buf.insert_str(end_position, &hint_str);
             }
 
-            self.db.write_file("main2.py", &buf).unwrap();
+            self.db.write_file("main2.py", &inlay_hint_buf).unwrap();
             let inlayed_file =
                 system_path_to_file(&self.db, "main2.py").expect("newly written file to existing");
 
-            let diagnostics = tbd_diagnostics.into_iter().map(|(label_range, target)| {
+            let location_diagnostics = tbd_diagnostics.into_iter().map(|(label_range, target)| {
                 InlayHintLocationDiagnostic::new(FileRange::new(inlayed_file, label_range), &target)
             });
 
-            let mut rendered_diagnostics = self.render_diagnostics(diagnostics);
+            let mut rendered_diagnostics = location_diagnostics
+                .map(|diagnostic| self.render_diagnostic(diagnostic))
+                .join("");
 
             if !rendered_diagnostics.is_empty() {
                 rendered_diagnostics = format!(
                     "{}{}",
                     crate::MarkupKind::PlainText.horizontal_line(),
                     rendered_diagnostics
+                        .strip_suffix("\n")
+                        .unwrap_or(&rendered_diagnostics)
                 );
             }
 
-            format!("{buf}{rendered_diagnostics}",)
+            let rendered_edit_diagnostic = if edit_offset != 0 {
+                let edit_diagnostic = InlayHintEditDiagnostic::new(text_edit_buf);
+                let text_edit_buf = self.render_diagnostic(edit_diagnostic);
+
+                format!(
+                    "{}{}",
+                    crate::MarkupKind::PlainText.horizontal_line(),
+                    text_edit_buf
+                )
+            } else {
+                String::new()
+            };
+
+            format!("{inlay_hint_buf}{rendered_diagnostics}{rendered_edit_diagnostic}",)
         }
 
-        fn render_diagnostics<I, D>(&self, diagnostics: I) -> String
+        fn render_diagnostic<D>(&self, diagnostic: D) -> String
         where
-            I: IntoIterator<Item = D>,
             D: IntoDiagnostic,
         {
             use std::fmt::Write;
@@ -578,10 +652,8 @@ mod tests {
                 .color(false)
                 .format(DiagnosticFormat::Full);
 
-            for diagnostic in diagnostics {
-                let diag = diagnostic.into_diagnostic();
-                write!(buf, "{}", diag.display(&self.db, &config)).unwrap();
-            }
+            let diag = diagnostic.into_diagnostic();
+            write!(buf, "{}", diag.display(&self.db, &config)).unwrap();
 
             buf
         }
@@ -728,6 +800,20 @@ mod tests {
         10 | bb[: Literal[b"foo"]] = aa
            |              ^^^^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+
+        x = 1
+        y: Literal[1] = x
+        z: int = i(1)
+        w: int = z
+        aa = b'foo'
+        bb: Literal[b"foo"] = aa
         "#);
     }
 
@@ -1321,6 +1407,20 @@ mod tests {
         10 | w[: tuple[int, str]] = z
            |                ^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+        def s(x: str, /) -> str:
+            return x
+
+        x = (1, 'abc')
+        y: tuple[Literal[1], Literal["abc"]] = x
+        z: tuple[int, str] = (i(1), s('abc'))
+        w: tuple[int, str] = z
         "#);
     }
 
@@ -1654,6 +1754,18 @@ mod tests {
         8 | w[: int] = z
           |     ^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+
+        x: int = 1
+        y: Literal[1] = x
+        z: int = i(1)
+        w: int = z
         "#);
     }
 
@@ -1691,6 +1803,15 @@ mod tests {
           |     ^^^
         5 | z = x
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+        x: int = i(1)
+        z = x
         "#);
     }
 
@@ -1810,6 +1931,18 @@ mod tests {
         8 | a.y[: int] = int(3)
           |       ^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class A:
+            def __init__(self, y):
+                self.x: int = int(1)
+                self.y: Unknown = y
+
+        a: A = A(2)
+        a.y: int = int(3)
         "#);
     }
 
@@ -2640,6 +2773,22 @@ mod tests {
         12 | k[: list[Unknown | int | float]] = [-1, -2.0]
            |                          ^^^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        a: list[Unknown | int] = [1, 2]
+        b: list[Unknown | float] = [1.0, 2.0]
+        c: list[Unknown | bool] = [True, False]
+        d: list[Unknown | None] = [None, None]
+        e: list[Unknown | str] = ["hel", "lo"]
+        f: list[Unknown | str] = ['the', 're']
+        g: list[Unknown | str] = [f"{ft}", f"{ft}"]
+        h: list[Unknown | Template] = [t"wow %d", t"wow %d"]
+        i: list[Unknown | bytes] = [b'/x01', b'/x02']
+        j: list[Unknown | int | float] = [+1, +2.0]
+        k: list[Unknown | int | float] = [-1, -2.0]
         "#);
     }
 
@@ -2811,6 +2960,19 @@ mod tests {
         9 | c[: MyClass], d[: MyClass] = (MyClass(), MyClass())
           |                   ^^^^^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class MyClass:
+            def __init__(self):
+                self.x: int = 1
+
+        x: MyClass = MyClass()
+        y: tuple[MyClass, MyClass] = (MyClass(), MyClass())
+        a, b = MyClass(), MyClass()
+        c, d = (MyClass(), MyClass())
         "#);
     }
 
@@ -3681,6 +3843,20 @@ mod tests {
         10 | c[: MyClass[Unknown | int, str]], d[: MyClass[Unknown | int, str]] = (MyClass([x=][42], [y=]("a", "b")), MyClass([x=][42], [y=]("a", "…
            |                                                                                                                             ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class MyClass[T, U]:
+            def __init__(self, x: list[T], y: tuple[U, U]):
+                self.x = x
+                self.y = y
+
+        x: MyClass[Unknown | int, str] = MyClass([42], ("a", "b"))
+        y: tuple[MyClass[Unknown | int, str], MyClass[Unknown | int, str]] = (MyClass([42], ("a", "b")), MyClass([42], ("a", "b")))
+        a, b = MyClass([42], ("a", "b")), MyClass([42], ("a", "b"))
+        c, d = (MyClass([42], ("a", "b")), MyClass([42], ("a", "b")))
         "#);
     }
 
@@ -3836,6 +4012,20 @@ mod tests {
         10 | foo([x=]val.y)
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+                self.x: int = 1
+                self.y: int = 2
+        val: MyClass = MyClass()
+
+        foo(val.x)
+        foo(val.y)
         ");
     }
 
@@ -3901,6 +4091,20 @@ mod tests {
         10 | foo([x=]x.y)
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+                self.x: int = 1
+                self.y: int = 2
+        x: MyClass = MyClass()
+
+        foo(x.x)
+        foo(x.y)
         ");
     }
 
@@ -3969,6 +4173,22 @@ mod tests {
         12 | foo([x=]val.y())
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+            def x() -> int:
+                return 1
+            def y() -> int:
+                return 2
+        val: MyClass = MyClass()
+
+        foo(val.x())
+        foo(val.y())
         ");
     }
 
@@ -4043,6 +4263,24 @@ mod tests {
         14 | foo([x=]val.y()[1])
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        from typing import List
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+            def x() -> List[int]:
+                return 1
+            def y() -> List[int]:
+                return 2
+        val: MyClass = MyClass()
+
+        foo(val.x()[0])
+        foo(val.y()[1])
         ");
     }
 
@@ -4193,6 +4431,17 @@ mod tests {
         7 | foo([x=]y[0])
           |      ^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        x: list[Unknown | int] = [1]
+        y: list[Unknown | int] = [2]
+
+        foo(x[0])
+        foo(y[0])
         "#);
     }
 
@@ -4378,6 +4627,15 @@ mod tests {
         5 | f[: Foo] = Foo([x=]1)
           |                 ^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class Foo:
+            def __init__(self, x: int): pass
+        Foo(1)
+        f: Foo = Foo(1)
         ");
     }
 
@@ -4450,6 +4708,15 @@ mod tests {
         5 | f[: Foo] = Foo([x=]1)
           |                 ^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class Foo:
+            def __new__(cls, x: int): pass
+        Foo(1)
+        f: Foo = Foo(1)
         ");
     }
 
@@ -5197,6 +5464,15 @@ mod tests {
           |         ^^^^^^^^^^^^^
         5 | my_func(x="hello")
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        from typing import LiteralString
+        def my_func(x: LiteralString):
+            y: LiteralString = x
+        my_func(x="hello")
         "#);
     }
 
@@ -5339,6 +5615,23 @@ mod tests {
         13 |     y[: Literal[1, 2, 3, "hello"] | None] = x
            |                                     ^^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def branch(cond: int):
+            if cond < 10:
+                x = 1
+            elif cond < 20:
+                x = 2
+            elif cond < 30:
+                x = 3
+            elif cond < 40:
+                x = "hello"
+            else:
+                x = None
+            y: Literal[1, 2, 3, "hello"] | None = x
         "#);
     }
 
@@ -5454,6 +5747,13 @@ mod tests {
         3 |     y[: type[list[str]]] = type(x)
           |                   ^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def f(x: list[str]):
+            y: type[list[str]] = type(x)
         "#);
     }
 
@@ -5493,6 +5793,16 @@ mod tests {
         6 | ab[: property] = F.whatever
           |      ^^^^^^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class F:
+            @property
+            def whatever(self): ...
+
+        ab: property = F.whatever
         ");
     }
 
@@ -5810,6 +6120,196 @@ mod tests {
         ");
     }
 
+    #[test]
+    fn test_function_signature_inlay_hint() {
+        let mut test = inlay_hint_test(
+            "
+                  def foo(x: int, *y: bool, z: str | int | list[str]): ...
+
+                  a = foo",
+        );
+
+        assert_snapshot!(test.inlay_hints(), @r#"
+        def foo(x: int, *y: bool, z: str | int | list[str]): ...
+
+        a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+        ---------------------------------------------
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:348:7
+            |
+        347 | @disjoint_base
+        348 | class int:
+            |       ^^^
+        349 |     """int([x]) -> integer
+        350 |     int(x, base=10) -> integer
+            |
+        info: Source
+         --> main2.py:4:16
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+            --> stdlib/builtins.pyi:2591:7
+             |
+        2590 | @final
+        2591 | class bool(int):
+             |       ^^^^
+        2592 |     """Returns True when the argument is true, False otherwise.
+        2593 |     The builtins True and False are the only two instances of the class bool.
+             |
+        info: Source
+         --> main2.py:4:25
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                         ^^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+         --> main2.py:4:37
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                     ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:348:7
+            |
+        347 | @disjoint_base
+        348 | class int:
+            |       ^^^
+        349 |     """int([x]) -> integer
+        350 |     int(x, base=10) -> integer
+            |
+        info: Source
+         --> main2.py:4:43
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                           ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+            --> stdlib/builtins.pyi:2802:7
+             |
+        2801 | @disjoint_base
+        2802 | class list(MutableSequence[_T]):
+             |       ^^^^
+        2803 |     """Built-in mutable sequence.
+             |
+        info: Source
+         --> main2.py:4:49
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                                 ^^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+         --> main2.py:4:54
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                                      ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main2.py:4:63
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                                               ^^^^^^^
+          |
+        "#);
+    }
+
+    #[test]
+    fn test_module_inlay_hint() {
+        let mut test = inlay_hint_test(
+            "
+                      import foo
+
+                      a = foo",
+        );
+
+        test.with_extra_file("foo.py", "'''Foo module'''");
+
+        assert_snapshot!(test.inlay_hints(), @r"
+        import foo
+
+        a[: <module 'foo'>] = foo
+        ---------------------------------------------
+        info[inlay-hint-location]: Inlay Hint Target
+         --> foo.py:1:1
+          |
+        1 | '''Foo module'''
+          | ^^^^^^^^^^^^^^^^
+          |
+        info: Source
+         --> main2.py:4:5
+          |
+        2 | import foo
+        3 |
+        4 | a[: <module 'foo'>] = foo
+          |     ^^^^^^^^^^^^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn test_literal_type_alias_inlay_hint() {
+        let mut test = inlay_hint_test(
+            "
+                        from typing import Literal
+
+                        a = Literal['a', 'b', 'c']",
+        );
+
+        assert_snapshot!(test.inlay_hints(), @r"
+        from typing import Literal
+
+        a[: <typing.Literal special form>] = Literal['a', 'b', 'c']
+        ");
+    }
+
     struct InlayHintLocationDiagnostic {
         source: FileRange,
         target: FileRange,
@@ -5847,4 +6347,31 @@ mod tests {
             main
         }
     }
+
+    struct InlayHintEditDiagnostic {
+        file_content: String,
+    }
+
+    impl InlayHintEditDiagnostic {
+        fn new(file_content: String) -> Self {
+            Self { file_content }
+        }
+    }
+
+    impl IntoDiagnostic for InlayHintEditDiagnostic {
+        fn into_diagnostic(self) -> Diagnostic {
+            let mut main = Diagnostic::new(
+                DiagnosticId::Lint(LintName::of("inlay-hint-edit")),
+                Severity::Info,
+                "File after edits".to_string(),
+            );
+
+            main.sub(SubDiagnostic::new(
+                SubDiagnosticSeverity::Info,
+                format!("{}\n{}", "Source", self.file_content),
+            ));
+
+            main
+        }
+    }
 }

crates/ty_ide/src/lib.rs

@@ -3,6 +3,7 @@
     reason = "Prefer System trait methods over std methods in ty crates"
 )]
 mod all_symbols;
+mod code_action;
 mod completion;
 mod doc_highlights;
 mod docstring;
@@ -27,13 +28,16 @@ mod symbols;
 mod workspace_symbols;
 
 pub use all_symbols::{AllSymbolInfo, all_symbols};
+pub use code_action::{QuickFix, code_actions};
 pub use completion::{Completion, CompletionKind, CompletionSettings, completion};
 pub use doc_highlights::document_highlights;
 pub use document_symbols::document_symbols;
 pub use goto::{goto_declaration, goto_definition, goto_type_definition};
 pub use goto_references::goto_references;
 pub use hover::hover;
-pub use inlay_hints::{InlayHintKind, InlayHintLabel, InlayHintSettings, inlay_hints};
+pub use inlay_hints::{
+    InlayHintKind, InlayHintLabel, InlayHintSettings, InlayHintTextEdit, inlay_hints,
+};
 pub use markup::MarkupKind;
 pub use references::ReferencesMode;
 pub use rename::{can_rename, rename};

crates/ty_ide/src/references.rs

@@ -122,10 +122,10 @@ fn references_for_file(
 ) {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     let mut finder = LocalReferencesFinder {
-        db,
-        file,
+        model: &model,
         target_definitions,
         references,
         mode,
@@ -157,8 +157,7 @@ fn is_symbol_externally_visible(goto_target: &GotoTarget<'_>) -> bool {
 
 /// AST visitor to find all references to a specific symbol by comparing semantic definitions
 struct LocalReferencesFinder<'a> {
-    db: &'a dyn Db,
-    file: File,
+    model: &'a SemanticModel<'a>,
     tokens: &'a Tokens,
     target_definitions: &'a [NavigationTarget],
     references: &'a mut Vec<ReferenceTarget>,
@@ -227,6 +226,22 @@ impl<'a> SourceOrderVisitor<'a> for LocalReferencesFinder<'a> {
                     self.check_identifier_reference(rest_name);
                 }
             }
+            AnyNodeRef::ExprStringLiteral(string_expr) if self.should_include_declaration() => {
+                // Highlight the sub-AST of a string annotation
+                if let Some((sub_ast, sub_model)) = self.model.enter_string_annotation(string_expr)
+                {
+                    let mut sub_finder = LocalReferencesFinder {
+                        model: &sub_model,
+                        target_definitions: self.target_definitions,
+                        references: self.references,
+                        mode: self.mode,
+                        tokens: sub_ast.tokens(),
+                        target_text: self.target_text,
+                        ancestors: Vec::new(),
+                    };
+                    sub_finder.visit_expr(sub_ast.expr());
+                }
+            }
             AnyNodeRef::Alias(alias) if self.should_include_declaration() => {
                 // Handle import alias declarations
                 if let Some(asname) = &alias.asname {
@@ -285,15 +300,13 @@ impl LocalReferencesFinder<'_> {
         // the node is fine here. Offsets matter only for import statements
         // where the identifier might be a multi-part module name.
         let offset = covering_node.node().start();
-
         if let Some(goto_target) =
-            GotoTarget::from_covering_node(covering_node, offset, self.tokens)
+            GotoTarget::from_covering_node(self.model, covering_node, offset, self.tokens)
         {
             // Get the definitions for this goto target
-            let model = SemanticModel::new(self.db, self.file);
             if let Some(current_definitions_nav) = goto_target
-                .get_definition_targets(&model, ImportAliasResolution::PreserveAliases)
-                .and_then(|definitions| definitions.declaration_targets(self.db))
+                .get_definition_targets(self.model, ImportAliasResolution::PreserveAliases)
+                .and_then(|definitions| definitions.declaration_targets(self.model.db()))
             {
                 let current_definitions: Vec<NavigationTarget> =
                     current_definitions_nav.into_iter().collect();
@@ -302,7 +315,7 @@ impl LocalReferencesFinder<'_> {
                     // Determine if this is a read or write reference
                     let kind = self.determine_reference_kind(covering_node);
                     let target =
-                        ReferenceTarget::new(self.file, covering_node.node().range(), kind);
+                        ReferenceTarget::new(self.model.file(), covering_node.node().range(), kind);
                     self.references.push(target);
                 }
             }

crates/ty_ide/src/rename.rs

@@ -12,7 +12,7 @@ pub fn can_rename(db: &dyn Db, file: File, offset: TextSize) -> Option<ruff_text
     let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the offset
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     // Don't allow renaming of import module components
     if matches!(
@@ -59,9 +59,10 @@ pub fn rename(
 ) -> Option<Vec<ReferenceTarget>> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the offset
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     // Clients shouldn't call us with an empty new name, but just in case...
     if new_name.is_empty() {
@@ -338,6 +339,162 @@ class DataProcessor:
         ");
     }
 
+    #[test]
+    fn rename_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
+    #[test]
+    fn rename_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
+    #[test]
+    fn rename_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
+    #[test]
+    fn rename_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
     #[test]
     fn test_cannot_rename_import_module_component() {
         // Test that we cannot rename parts of module names in import statements

crates/ty_ide/src/semantic_tokens.rs

@@ -187,9 +187,9 @@ impl Deref for SemanticTokens {
 /// Pass None to get tokens for the entire file.
 pub fn semantic_tokens(db: &dyn Db, file: File, range: Option<TextRange>) -> SemanticTokens {
     let parsed = parsed_module(db, file).load(db);
-    let semantic_model = SemanticModel::new(db, file);
+    let model = SemanticModel::new(db, file);
 
-    let mut visitor = SemanticTokenVisitor::new(&semantic_model, file, range);
+    let mut visitor = SemanticTokenVisitor::new(&model, range);
     visitor.visit_body(parsed.suite());
 
     SemanticTokens::new(visitor.tokens)
@@ -197,8 +197,7 @@ pub fn semantic_tokens(db: &dyn Db, file: File, range: Option<TextRange>) -> Sem
 
 /// AST visitor that collects semantic tokens.
 struct SemanticTokenVisitor<'db> {
-    semantic_model: &'db SemanticModel<'db>,
-    file: File,
+    model: &'db SemanticModel<'db>,
     tokens: Vec<SemanticToken>,
     in_class_scope: bool,
     in_type_annotation: bool,
@@ -207,14 +206,9 @@ struct SemanticTokenVisitor<'db> {
 }
 
 impl<'db> SemanticTokenVisitor<'db> {
-    fn new(
-        semantic_model: &'db SemanticModel<'db>,
-        file: File,
-        range_filter: Option<TextRange>,
-    ) -> Self {
+    fn new(model: &'db SemanticModel<'db>, range_filter: Option<TextRange>) -> Self {
         Self {
-            semantic_model,
-            file,
+            model,
             tokens: Vec::new(),
             in_class_scope: false,
             in_target_creating_definition: false,
@@ -265,7 +259,7 @@ impl<'db> SemanticTokenVisitor<'db> {
 
     fn classify_name(&self, name: &ast::ExprName) -> (SemanticTokenType, SemanticTokenModifier) {
         // First try to classify the token based on its definition kind.
-        let definition = definition_for_name(self.semantic_model.db(), self.file, name);
+        let definition = definition_for_name(self.model, name);
 
         if let Some(definition) = definition {
             let name_str = name.id.as_str();
@@ -275,7 +269,7 @@ impl<'db> SemanticTokenVisitor<'db> {
         }
 
         // Fall back to type-based classification.
-        let ty = name.inferred_type(self.semantic_model);
+        let ty = name.inferred_type(self.model);
         let name_str = name.id.as_str();
         self.classify_from_type_and_name_str(ty, name_str)
     }
@@ -286,7 +280,7 @@ impl<'db> SemanticTokenVisitor<'db> {
         name_str: &str,
     ) -> Option<(SemanticTokenType, SemanticTokenModifier)> {
         let mut modifiers = SemanticTokenModifier::empty();
-        let db = self.semantic_model.db();
+        let db = self.model.db();
         let model = SemanticModel::new(db, definition.file(db));
 
         match definition.kind(db) {
@@ -712,12 +706,12 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
                 for alias in &import.names {
                     if let Some(asname) = &alias.asname {
                         // For aliased imports (from X import Y as Z), classify Z based on what Y is
-                        let ty = alias.inferred_type(self.semantic_model);
+                        let ty = alias.inferred_type(self.model);
                         let (token_type, modifiers) = self.classify_from_alias_type(ty, asname);
                         self.add_token(asname, token_type, modifiers);
                     } else {
                         // For direct imports (from X import Y), use semantic classification
-                        let ty = alias.inferred_type(self.semantic_model);
+                        let ty = alias.inferred_type(self.model);
                         let (token_type, modifiers) =
                             self.classify_from_alias_type(ty, &alias.name);
                         self.add_token(&alias.name, token_type, modifiers);
@@ -837,7 +831,7 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
                 self.visit_expr(&attr.value);
 
                 // Then add token for the attribute name (e.g., 'path' in 'os.path')
-                let ty = expr.inferred_type(self.semantic_model);
+                let ty = expr.inferred_type(self.model);
                 let (token_type, modifiers) =
                     Self::classify_from_type_for_attribute(ty, &attr.attr);
                 self.add_token(&attr.attr, token_type, modifiers);
@@ -881,6 +875,17 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
 
                 self.visit_expr(&named.value);
             }
+            ast::Expr::StringLiteral(string_expr) => {
+                // Highlight the sub-AST of a string annotation
+                if let Some((sub_ast, sub_model)) = self.model.enter_string_annotation(string_expr)
+                {
+                    let mut sub_visitor = SemanticTokenVisitor::new(&sub_model, None);
+                    sub_visitor.visit_expr(sub_ast.expr());
+                    self.tokens.extend(sub_visitor.tokens);
+                } else {
+                    walk_expr(self, expr);
+                }
+            }
             _ => {
                 // For all other expression types, let the default visitor handle them
                 walk_expr(self, expr);
@@ -1061,6 +1066,17 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
             }
         }
     }
+
+    fn visit_comprehension(&mut self, comp: &ast::Comprehension) {
+        self.in_target_creating_definition = true;
+        self.visit_expr(&comp.target);
+        self.in_target_creating_definition = false;
+
+        self.visit_expr(&comp.iter);
+        for if_clause in &comp.ifs {
+            self.visit_expr(if_clause);
+        }
+    }
 }
 
 #[cfg(test)]
@@ -1564,6 +1580,50 @@ from mymodule import CONSTANT, my_function, MyClass
         "#);
     }
 
+    #[test]
+    fn test_str_annotation() {
+        let test = SemanticTokenTest::new(
+            r#"
+x: int = 1
+y: "int" = 1
+z = "int"
+w1: "int | str" = "hello"
+w2: "int | sr" = "hello"
+w3: "int | " = "hello"
+w4: "float"
+w5: "float
+"#,
+        );
+
+        let tokens = test.highlight_file();
+
+        assert_snapshot!(test.to_snapshot(&tokens), @r#"
+        "x" @ 1..2: Variable [definition]
+        "int" @ 4..7: Class
+        "1" @ 10..11: Number
+        "y" @ 12..13: Variable [definition]
+        "int" @ 16..19: Class
+        "1" @ 23..24: Number
+        "z" @ 25..26: Variable [definition]
+        "\"int\"" @ 29..34: String
+        "w1" @ 35..37: Variable [definition]
+        "int" @ 40..43: Class
+        "str" @ 46..49: Class
+        "\"hello\"" @ 53..60: String
+        "w2" @ 61..63: Variable [definition]
+        "int" @ 66..69: Class
+        "sr" @ 72..74: Variable
+        "\"hello\"" @ 78..85: String
+        "w3" @ 86..88: Variable [definition]
+        "\"int | \"" @ 90..98: String
+        "\"hello\"" @ 101..108: String
+        "w4" @ 109..111: Variable [definition]
+        "float" @ 114..119: Class
+        "w5" @ 121..123: Variable [definition]
+        "float" @ 126..131: Class
+        "#);
+    }
+
     #[test]
     fn test_attribute_classification() {
         let test = SemanticTokenTest::new(
@@ -2595,6 +2655,50 @@ with open("file.txt") as f:
         "#);
     }
 
+    #[test]
+    fn test_comprehensions() {
+        let test = SemanticTokenTest::new(
+            r#"
+list_comp = [x for x in range(10) if x % 2 == 0]
+set_comp = {x for x in range(10)}
+dict_comp = {k: v for k, v in zip(["a", "b"], [1, 2])}
+generator = (x for x in range(10))
+"#,
+        );
+
+        let tokens = test.highlight_file();
+        assert_snapshot!(test.to_snapshot(&tokens), @r#"
+        "list_comp" @ 1..10: Variable [definition]
+        "x" @ 14..15: Variable
+        "x" @ 20..21: Variable [definition]
+        "range" @ 25..30: Class
+        "10" @ 31..33: Number
+        "x" @ 38..39: Variable
+        "2" @ 42..43: Number
+        "0" @ 47..48: Number
+        "set_comp" @ 50..58: Variable [definition]
+        "x" @ 62..63: Variable
+        "x" @ 68..69: Variable [definition]
+        "range" @ 73..78: Class
+        "10" @ 79..81: Number
+        "dict_comp" @ 84..93: Variable [definition]
+        "k" @ 97..98: Variable
+        "v" @ 100..101: Variable
+        "k" @ 106..107: Variable [definition]
+        "v" @ 109..110: Variable [definition]
+        "zip" @ 114..117: Class
+        "\"a\"" @ 119..122: String
+        "\"b\"" @ 124..127: String
+        "1" @ 131..132: Number
+        "2" @ 134..135: Number
+        "generator" @ 139..148: Variable [definition]
+        "x" @ 152..153: Variable
+        "x" @ 158..159: Variable [definition]
+        "range" @ 163..168: Class
+        "10" @ 169..171: Number
+        "#);
+    }
+
     /// Regression test for <https://github.com/astral-sh/ty/issues/1406>
     #[test]
     fn test_invalid_kwargs() {

crates/ty_ide/src/signature_help.rs

@@ -74,7 +74,7 @@ pub fn signature_help(db: &dyn Db, file: File, offset: TextSize) -> Option<Signa
 
     // Get signature details from the semantic analyzer.
     let signature_details: Vec<CallSignatureDetails<'_>> =
-        call_signature_details(db, &model, call_expr);
+        call_signature_details(&model, call_expr);
 
     if signature_details.is_empty() {
         return None;

crates/ty_ide/src/stub_mapping.rs

@@ -11,12 +11,12 @@ use crate::cached_vendored_root;
 /// other language server providers (like hover, completion, and signature help) to find
 /// docstrings for functions that resolve to stubs.
 pub(crate) struct StubMapper<'db> {
-    db: &'db dyn crate::Db,
+    db: &'db dyn ty_python_semantic::Db,
     cached_vendored_root: Option<SystemPathBuf>,
 }
 
 impl<'db> StubMapper<'db> {
-    pub(crate) fn new(db: &'db dyn crate::Db) -> Self {
+    pub(crate) fn new(db: &'db dyn ty_python_semantic::Db) -> Self {
         let cached_vendored_root = cached_vendored_root(db);
         Self {
             db,

crates/ty_ide/src/symbols.rs

@@ -23,11 +23,12 @@ use crate::completion::CompletionKind;
 pub struct QueryPattern {
     re: Option<Regex>,
     original: String,
+    original_is_exact: bool,
 }
 
 impl QueryPattern {
     /// Create a new query pattern from a literal search string given.
-    pub fn new(literal_query_string: &str) -> QueryPattern {
+    pub fn fuzzy(literal_query_string: &str) -> QueryPattern {
         let mut pattern = "(?i)".to_string();
         for ch in literal_query_string.chars() {
             pattern.push_str(&regex::escape(ch.encode_utf8(&mut [0; 4])));
@@ -41,6 +42,16 @@ impl QueryPattern {
         QueryPattern {
             re: Regex::new(&pattern).ok(),
             original: literal_query_string.to_string(),
+            original_is_exact: false,
+        }
+    }
+
+    /// Create a new query
+    pub fn exactly(symbol: &str) -> QueryPattern {
+        QueryPattern {
+            re: None,
+            original: symbol.to_string(),
+            original_is_exact: true,
         }
     }
 
@@ -49,6 +60,7 @@ impl QueryPattern {
         QueryPattern {
             re: None,
             original: String::new(),
+            original_is_exact: false,
         }
     }
 
@@ -59,6 +71,8 @@ impl QueryPattern {
     pub fn is_match_symbol_name(&self, symbol_name: &str) -> bool {
         if let Some(ref re) = self.re {
             re.is_match(symbol_name)
+        } else if self.original_is_exact {
+            symbol_name == self.original
         } else {
             // This is a degenerate case. The only way
             // we should get here is if the query string
@@ -75,13 +89,13 @@ impl QueryPattern {
     /// incorrectly. That is, it's possible that this query will match all
     /// inputs but this still returns `false`.
     pub fn will_match_everything(&self) -> bool {
-        self.re.is_none()
+        self.re.is_none() && self.original.is_empty()
     }
 }
 
 impl From<&str> for QueryPattern {
     fn from(literal_query_string: &str) -> QueryPattern {
-        QueryPattern::new(literal_query_string)
+        QueryPattern::fuzzy(literal_query_string)
     }
 }
 
@@ -565,7 +579,7 @@ impl SourceOrderVisitor<'_> for SymbolVisitor {
 #[cfg(test)]
 mod tests {
     fn matches(query: &str, symbol: &str) -> bool {
-        super::QueryPattern::new(query).is_match_symbol_name(symbol)
+        super::QueryPattern::fuzzy(query).is_match_symbol_name(symbol)
     }
 
     #[test]

crates/ty_ide/src/workspace_symbols.rs

@@ -12,7 +12,7 @@ pub fn workspace_symbols(db: &dyn Db, query: &str) -> Vec<WorkspaceSymbolInfo> {
 
     let project = db.project();
 
-    let query = QueryPattern::new(query);
+    let query = QueryPattern::fuzzy(query);
     let files = project.files(db);
     let results = std::sync::Mutex::new(Vec::new());
     {

crates/ty_python_semantic/Cargo.toml

@@ -13,6 +13,7 @@ license = { workspace = true }
 [dependencies]
 ruff_db = { workspace = true }
 ruff_annotate_snippets = { workspace = true }
+ruff_diagnostics = { workspace = true }
 ruff_index = { workspace = true, features = ["salsa"] }
 ruff_macros = { workspace = true }
 ruff_memory_usage = { workspace = true }

crates/ty_python_semantic/resources/corpus/classliteral_decorators_cycle.py

@@ -0,0 +1,26 @@
+try:
+    type name_4 = name_1
+finally:
+    from .. import name_3
+
+try:
+    pass
+except* 0:
+    pass
+else:
+    def name_1() -> name_4:
+        pass
+
+    @name_1
+    def name_3():
+        pass
+finally:
+    try:
+        pass
+    except* 0:
+        assert name_3
+    finally:
+
+        @name_3
+        class name_1:
+            pass

crates/ty_python_semantic/resources/corpus/cyclic_reassignment.py

@@ -0,0 +1,5 @@
+class foo[_: foo](object): ...
+
+[_] = (foo,) = foo
+
+def foo(): ...

crates/ty_python_semantic/resources/corpus/cyclic_type_alias.py

@@ -0,0 +1,20 @@
+name_3: Foo = 0
+name_4 = 0
+
+if _0:
+    type name_3 = name_5
+    type name_4 = name_3
+
+_1: name_3
+
+def name_1(_2: name_4):
+    pass
+
+match 0:
+    case name_1._3:
+        pass
+    case 1:
+        type name_5 = name_4
+    case name_5:
+        pass
+name_3 = name_5

crates/ty_python_semantic/resources/mdtest/annotations/literal_string.md

@@ -35,6 +35,8 @@ bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
 
 `LiteralString` cannot be parameterized.
 
+<!-- snapshot-diagnostics -->
+
 ```py
 from typing_extensions import LiteralString
 
@@ -42,7 +44,6 @@ from typing_extensions import LiteralString
 a: LiteralString[str]
 
 # error: [invalid-type-form]
-# error: [unresolved-reference] "Name `foo` used when not defined"
 b: LiteralString["foo"]
 ```
 

crates/ty_python_semantic/resources/mdtest/assignment/annotations.md

@@ -222,10 +222,10 @@ reveal_type(r)  # revealed: dict[int | str, int | str]
 ## Incorrect collection literal assignments are complained about
 
 ```py
-# error: [invalid-assignment] "Object of type `list[Unknown | int]` is not assignable to `list[str]`"
+# error: [invalid-assignment] "Object of type `list[str | int]` is not assignable to `list[str]`"
 a: list[str] = [1, 2, 3]
 
-# error: [invalid-assignment] "Object of type `set[Unknown | int | str]` is not assignable to `set[int]`"
+# error: [invalid-assignment] "Object of type `set[int | str]` is not assignable to `set[int]`"
 b: set[int] = {1, 2, "3"}
 ```
 
@@ -422,7 +422,7 @@ reveal_type(d)  # revealed: list[int | tuple[int, int]]
 e: list[int] = f(True)
 reveal_type(e)  # revealed: list[int]
 
-# error: [invalid-assignment] "Object of type `list[str]` is not assignable to `list[int]`"
+# error: [invalid-assignment] "Object of type `list[int | str]` is not assignable to `list[int]`"
 g: list[int] = f("a")
 
 # error: [invalid-assignment] "Object of type `list[str]` is not assignable to `tuple[int]`"
@@ -459,12 +459,12 @@ reveal_type(b)  # revealed: TD
 
 # error: [missing-typed-dict-key] "Missing required key 'x' in TypedDict `TD` constructor"
 # error: [invalid-key] "Unknown key "y" for TypedDict `TD`"
-# error: [invalid-assignment] "Object of type `Unknown | dict[Unknown | str, Unknown | int]` is not assignable to `TD`"
+# error: [invalid-assignment] "Object of type `TD | dict[Unknown | str, Unknown | int]` is not assignable to `TD`"
 c: TD = f([{"y": 0}, {"x": 1}])
 
 # error: [missing-typed-dict-key] "Missing required key 'x' in TypedDict `TD` constructor"
 # error: [invalid-key] "Unknown key "y" for TypedDict `TD`"
-# error: [invalid-assignment] "Object of type `Unknown | dict[Unknown | str, Unknown | int]` is not assignable to `TD | None`"
+# error: [invalid-assignment] "Object of type `TD | None | dict[Unknown | str, Unknown | int]` is not assignable to `TD | None`"
 c: TD | None = f([{"y": 0}, {"x": 1}])
 ```
 

crates/ty_python_semantic/resources/mdtest/attributes.md

@@ -2383,6 +2383,34 @@ class B:
 
 reveal_type(B().x)  # revealed: Unknown | Literal[1]
 reveal_type(A().x)  # revealed: Unknown | Literal[1]
+
+class Base:
+    def flip(self) -> "Sub":
+        return Sub()
+
+class Sub(Base):
+    # error: [invalid-method-override]
+    def flip(self) -> "Base":
+        return Base()
+
+class C2:
+    def __init__(self, x: Sub):
+        self.x = x
+
+    def replace_with(self, other: "C2"):
+        self.x = other.x.flip()
+
+reveal_type(C2(Sub()).x)  # revealed: Unknown | Base
+
+class C3:
+    def __init__(self, x: Sub):
+        self.x = [x]
+
+    def replace_with(self, other: "C3"):
+        self.x = [self.x[0].flip()]
+
+# TODO: should be `Unknown | list[Unknown | Sub] | list[Unknown | Base]`
+reveal_type(C3(Sub()).x)  # revealed: Unknown | list[Unknown | Sub] | list[Divergent]
 ```
 
 And cycles between many attributes:
@@ -2432,6 +2460,30 @@ class ManyCycles:
         reveal_type(self.x5)  # revealed: Unknown | int
         reveal_type(self.x6)  # revealed: Unknown | int
         reveal_type(self.x7)  # revealed: Unknown | int
+
+class ManyCycles2:
+    def __init__(self: "ManyCycles2"):
+        self.x1 = [0]
+        self.x2 = [1]
+        self.x3 = [1]
+
+    def f1(self: "ManyCycles2"):
+        # TODO: should be Unknown | list[Unknown | int] | list[Divergent]
+        reveal_type(self.x3)  # revealed: Unknown | list[Unknown | int] | list[Divergent] | list[Divergent]
+
+        self.x1 = [self.x2] + [self.x3]
+        self.x2 = [self.x1] + [self.x3]
+        self.x3 = [self.x1] + [self.x2]
+
+    def f2(self: "ManyCycles2"):
+        self.x1 = self.x2 + self.x3
+        self.x2 = self.x1 + self.x3
+        self.x3 = self.x1 + self.x2
+
+    def f3(self: "ManyCycles2"):
+        self.x1 = self.x2 + self.x3
+        self.x2 = self.x1 + self.x3
+        self.x3 = self.x1 + self.x2
 ```
 
 This case additionally tests our union/intersection simplification logic:
@@ -2611,12 +2663,18 @@ reveal_type(Answer.__members__)  # revealed: MappingProxyType[str, Unknown]
 
 ## Divergent inferred implicit instance attribute types
 
+If an implicit attribute is defined recursively and type inference diverges, the divergent part is
+filled in with the dynamic type `Divergent`. Types containing `Divergent` can be seen as "cheap"
+recursive types: they are not true recursive types based on recursive type theory, so no unfolding
+is performed when you use them.
+
 ```py
 class C:
     def f(self, other: "C"):
         self.x = (other.x, 1)
 
 reveal_type(C().x)  # revealed: Unknown | tuple[Divergent, Literal[1]]
+reveal_type(C().x[0])  # revealed: Unknown | Divergent
 ```
 
 This also works if the tuple is not constructed directly:
@@ -2655,11 +2713,11 @@ And it also works for homogeneous tuples:
 def make_homogeneous_tuple(x: T) -> tuple[T, ...]:
     return (x, x)
 
-class E:
-    def f(self, other: "E"):
+class F:
+    def f(self, other: "F"):
         self.x = make_homogeneous_tuple(other.x)
 
-reveal_type(E().x)  # revealed: Unknown | tuple[Divergent, ...]
+reveal_type(F().x)  # revealed: Unknown | tuple[Divergent, ...]
 ```
 
 ## Attributes of standard library modules that aren't yet defined

crates/ty_python_semantic/resources/mdtest/bidirectional.md

@@ -268,8 +268,8 @@ class A:
 
 A(f(1))
 
-# error: [invalid-argument-type] "Argument to function `__new__` is incorrect: Expected `list[int | str]`, found `list[list[Unknown]]`"
-# error: [invalid-argument-type] "Argument to bound method `__init__` is incorrect: Expected `list[int | None]`, found `list[list[Unknown]]`"
+# error: [invalid-argument-type] "Argument to function `__new__` is incorrect: Expected `list[int | str]`, found `list[int | None | list[Unknown]] & list[int | str | list[Unknown]] & list[list[Unknown]]`"
+# error: [invalid-argument-type] "Argument to bound method `__init__` is incorrect: Expected `list[int | None]`, found `list[int | None | list[Unknown]] & list[int | str | list[Unknown]] & list[list[Unknown]]`"
 A(f([]))
 ```
 

crates/ty_python_semantic/resources/mdtest/call/builtins.md

@@ -57,7 +57,7 @@ type("Foo", Base, {})
 # error: [invalid-argument-type] "Argument to class `type` is incorrect: Expected `tuple[type, ...]`, found `tuple[Literal[1], Literal[2]]`"
 type("Foo", (1, 2), {})
 
-# error: [invalid-argument-type] "Argument to class `type` is incorrect: Expected `dict[str, Any]`, found `dict[Unknown | bytes, Unknown | int]`"
+# error: [invalid-argument-type] "Argument to class `type` is incorrect: Expected `dict[str, Any]`, found `dict[str | bytes, Any]`"
 type("Foo", (Base,), {b"attr": 1})
 ```
 

crates/ty_python_semantic/resources/mdtest/call/callables_as_descriptors.md

@@ -237,4 +237,26 @@ class Matrix:
 Matrix() < Matrix()
 ```
 
+## `self`-binding behaviour of function-like `Callable`s
+
+Binding the `self` parameter of a function-like `Callable` creates a new `Callable` that is also
+function-like:
+
+`main.py`:
+
+```py
+from typing import Callable
+
+def my_lossy_decorator(fn: Callable[..., int]) -> Callable[..., int]:
+    return fn
+
+class MyClass:
+    @my_lossy_decorator
+    def method(self) -> int:
+        return 42
+
+reveal_type(MyClass().method)  # revealed: (...) -> int
+reveal_type(MyClass().method.__name__)  # revealed: str
+```
+
 [`tensorbase`]: https://github.com/pytorch/pytorch/blob/f3913ea641d871f04fa2b6588a77f63efeeb9f10/torch/_tensor.py#L1084-L1092

crates/ty_python_semantic/resources/mdtest/call/union.md

@@ -277,6 +277,6 @@ def _(flag: bool):
     x = f({"x": 1})
     reveal_type(x)  # revealed: int
 
-    # error: [invalid-argument-type] "Argument to function `f` is incorrect: Expected `T`, found `dict[Unknown | str, Unknown | int]`"
+    # error: [invalid-argument-type] "Argument to function `f` is incorrect: Expected `T`, found `dict[str, int] & dict[Unknown | str, Unknown | int]`"
     f({"y": 1})
 ```

crates/ty_python_semantic/resources/mdtest/cycle.md

@@ -32,6 +32,39 @@ reveal_type(p.x)  # revealed: Unknown | int
 reveal_type(p.y)  # revealed: Unknown | int
 ```
 
+## Self-referential bare type alias
+
+```toml
+[environment]
+python-version = "3.12"  # typing.TypeAliasType
+```
+
+```py
+from typing import Union, TypeAliasType, Sequence, Mapping
+
+A = list["A" | None]
+
+def f(x: A):
+    # TODO: should be `list[A | None]`?
+    reveal_type(x)  # revealed: list[Divergent]
+    # TODO: should be `A | None`?
+    reveal_type(x[0])  # revealed: Divergent
+
+JSONPrimitive = Union[str, int, float, bool, None]
+JSONValue = TypeAliasType("JSONValue", 'Union[JSONPrimitive, Sequence["JSONValue"], Mapping[str, "JSONValue"]]')
+```
+
+## Self-referential legacy type variables
+
+```py
+from typing import Generic, TypeVar
+
+B = TypeVar("B", bound="Base")
+
+class Base(Generic[B]):
+    pass
+```
+
 ## Parameter default values
 
 This is a regression test for <https://github.com/astral-sh/ty/issues/1402>. When a parameter has a

crates/ty_python_semantic/resources/mdtest/diagnostics/same_names.md

@@ -171,7 +171,7 @@ class Config:
 import generic_a
 import generic_b
 
-# TODO should be error: [invalid-assignment] "Object of type `<class 'generic_b.Container[int]'>` is not assignable to `type[generic_a.Container[int]]`"
+# error: [invalid-assignment] "Object of type `<class 'generic_b.Container[int]'>` is not assignable to `type[generic_a.Container[int]]`"
 container: type[generic_a.Container[int]] = generic_b.Container[int]
 ```
 

crates/ty_python_semantic/resources/mdtest/generics/legacy/classes.md

@@ -145,8 +145,8 @@ reveal_type(C[Literal[5]]())  # revealed: C[Literal[5]]
 The specialization must match the generic types:
 
 ```py
-# error: [too-many-positional-arguments] "Too many positional arguments to class `C`: expected 1, got 2"
-reveal_type(C[int, int]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Too many type arguments to class `C`: expected 1, got 2"
+reveal_type(C[int, int]())  # revealed: C[Unknown]
 ```
 
 If the type variable has an upper bound, the specialized type must satisfy that bound:
@@ -164,13 +164,11 @@ class IntSubclass(int): ...
 reveal_type(Bounded[int]())  # revealed: Bounded[int]
 reveal_type(Bounded[IntSubclass]())  # revealed: Bounded[IntSubclass]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument to class `Bounded` is incorrect: Expected `int`, found `str`"
-reveal_type(Bounded[str]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `str` is not assignable to upper bound `int` of type variable `BoundedT@Bounded`"
+reveal_type(Bounded[str]())  # revealed: Bounded[Unknown]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error:  [invalid-argument-type] "Argument to class `Bounded` is incorrect: Expected `int`, found `int | str`"
-reveal_type(Bounded[int | str]())  # revealed: Unknown
+# error:  [invalid-type-arguments] "Type `int | str` is not assignable to upper bound `int` of type variable `BoundedT@Bounded`"
+reveal_type(Bounded[int | str]())  # revealed: Bounded[Unknown]
 
 reveal_type(BoundedByUnion[int]())  # revealed: BoundedByUnion[int]
 reveal_type(BoundedByUnion[IntSubclass]())  # revealed: BoundedByUnion[IntSubclass]
@@ -197,9 +195,8 @@ reveal_type(Constrained[str]())  # revealed: Constrained[str]
 # TODO: revealed: Unknown
 reveal_type(Constrained[int | str]())  # revealed: Constrained[int | str]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument to class `Constrained` is incorrect: Expected `int | str`, found `object`"
-reveal_type(Constrained[object]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `object` does not satisfy constraints `int`, `str` of type variable `ConstrainedT@Constrained`"
+reveal_type(Constrained[object]())  # revealed: Constrained[Unknown]
 ```
 
 If the type variable has a default, it can be omitted:
@@ -273,7 +270,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -289,7 +286,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -308,7 +305,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -327,7 +324,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 
 class D(Generic[T]):
@@ -338,7 +335,7 @@ class D(Generic[T]):
 
 reveal_type(D(1))  # revealed: D[int]
 
-# error: [invalid-assignment] "Object of type `D[str]` is not assignable to `D[int]`"
+# error: [invalid-assignment] "Object of type `D[int | str]` is not assignable to `D[int]`"
 wrong_innards: D[int] = D("five")
 ```
 
@@ -454,7 +451,7 @@ reveal_type(C(1, 1))  # revealed: C[int]
 reveal_type(C(1, "string"))  # revealed: C[int]
 reveal_type(C(1, True))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five", 1)
 ```
 
@@ -732,6 +729,14 @@ class Base(Generic[T]): ...
 class Sub(Base["Sub"]): ...
 
 reveal_type(Sub)  # revealed: <class 'Sub'>
+
+U = TypeVar("U")
+
+class Base2(Generic[T, U]): ...
+
+# TODO: no error
+# error: [unsupported-base] "Unsupported class base with type `<class 'Base2[Sub2, U@Sub2]'> | <class 'Base2[Sub2[Unknown], U@Sub2]'>`"
+class Sub2(Base2["Sub2", U]): ...
 ```
 
 #### Without string forward references
@@ -756,6 +761,8 @@ from typing_extensions import Generic, TypeVar
 
 T = TypeVar("T")
 
+# TODO: no error "Unsupported class base with type `<class 'list[Derived[T@Derived]]'> | <class 'list[@Todo]'>`"
+# error: [unsupported-base]
 class Derived(list[Derived[T]], Generic[T]): ...
 ```
 

crates/ty_python_semantic/resources/mdtest/generics/legacy/variables.md

@@ -444,6 +444,22 @@ class G(Generic[T]):
 reveal_type(G[list[G]]().x)  # revealed: list[G[Unknown]]
 ```
 
+An invalid specialization in a recursive bound doesn't cause a panic:
+
+```py
+from typing import TypeVar, Generic
+
+# error: [invalid-type-arguments]
+T = TypeVar("T", bound="Node[int]")
+
+class Node(Generic[T]):
+    pass
+
+# error: [invalid-type-arguments]
+def _(n: Node[str]):
+    reveal_type(n)  # revealed: Node[Unknown]
+```
+
 ### Defaults
 
 ```toml

crates/ty_python_semantic/resources/mdtest/generics/pep695/aliases.md

@@ -61,8 +61,8 @@ def _(a: C[int], b: C[Literal[5]]):
 The specialization must match the generic types:
 
 ```py
-# error: [too-many-positional-arguments] "Too many positional arguments: expected 1, got 2"
-reveal_type(C[int, int])  # revealed: Unknown
+# error: [invalid-type-arguments] "Too many type arguments: expected 1, got 2"
+reveal_type(C[int, int])  # revealed: C[Unknown]
 ```
 
 And non-generic types cannot be specialized:
@@ -88,13 +88,11 @@ class IntSubclass(int): ...
 reveal_type(Bounded[int])  # revealed: Bounded[int]
 reveal_type(Bounded[IntSubclass])  # revealed: Bounded[IntSubclass]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument is incorrect: Expected `int`, found `str`"
-reveal_type(Bounded[str])  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `str` is not assignable to upper bound `int` of type variable `T@Bounded`"
+reveal_type(Bounded[str])  # revealed: Bounded[Unknown]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument is incorrect: Expected `int`, found `int | str`"
-reveal_type(Bounded[int | str])  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `int | str` is not assignable to upper bound `int` of type variable `T@Bounded`"
+reveal_type(Bounded[int | str])  # revealed: Bounded[Unknown]
 
 reveal_type(BoundedByUnion[int])  # revealed: BoundedByUnion[int]
 reveal_type(BoundedByUnion[IntSubclass])  # revealed: BoundedByUnion[IntSubclass]
@@ -119,9 +117,8 @@ reveal_type(Constrained[str])  # revealed: Constrained[str]
 # TODO: revealed: Unknown
 reveal_type(Constrained[int | str])  # revealed: Constrained[int | str]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument is incorrect: Expected `int | str`, found `object`"
-reveal_type(Constrained[object])  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `object` does not satisfy constraints `int`, `str` of type variable `T@Constrained`"
+reveal_type(Constrained[object])  # revealed: Constrained[Unknown]
 ```
 
 If the type variable has a default, it can be omitted:

crates/ty_python_semantic/resources/mdtest/generics/pep695/classes.md

@@ -135,8 +135,8 @@ reveal_type(C[Literal[5]]())  # revealed: C[Literal[5]]
 The specialization must match the generic types:
 
 ```py
-# error: [too-many-positional-arguments] "Too many positional arguments to class `C`: expected 1, got 2"
-reveal_type(C[int, int]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Too many type arguments to class `C`: expected 1, got 2"
+reveal_type(C[int, int]())  # revealed: C[Unknown]
 ```
 
 If the type variable has an upper bound, the specialized type must satisfy that bound:
@@ -149,13 +149,11 @@ class IntSubclass(int): ...
 reveal_type(Bounded[int]())  # revealed: Bounded[int]
 reveal_type(Bounded[IntSubclass]())  # revealed: Bounded[IntSubclass]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument to class `Bounded` is incorrect: Expected `int`, found `str`"
-reveal_type(Bounded[str]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `str` is not assignable to upper bound `int` of type variable `T@Bounded`"
+reveal_type(Bounded[str]())  # revealed: Bounded[Unknown]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument to class `Bounded` is incorrect: Expected `int`, found `int | str`"
-reveal_type(Bounded[int | str]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `int | str` is not assignable to upper bound `int` of type variable `T@Bounded`"
+reveal_type(Bounded[int | str]())  # revealed: Bounded[Unknown]
 
 reveal_type(BoundedByUnion[int]())  # revealed: BoundedByUnion[int]
 reveal_type(BoundedByUnion[IntSubclass]())  # revealed: BoundedByUnion[IntSubclass]
@@ -180,9 +178,8 @@ reveal_type(Constrained[str]())  # revealed: Constrained[str]
 # TODO: revealed: Unknown
 reveal_type(Constrained[int | str]())  # revealed: Constrained[int | str]
 
-# TODO: update this diagnostic to talk about type parameters and specializations
-# error: [invalid-argument-type] "Argument to class `Constrained` is incorrect: Expected `int | str`, found `object`"
-reveal_type(Constrained[object]())  # revealed: Unknown
+# error: [invalid-type-arguments] "Type `object` does not satisfy constraints `int`, `str` of type variable `T@Constrained`"
+reveal_type(Constrained[object]())  # revealed: Constrained[Unknown]
 ```
 
 If the type variable has a default, it can be omitted:
@@ -249,7 +246,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -263,7 +260,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -280,7 +277,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -297,7 +294,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 
 class D[T]:
@@ -310,7 +307,7 @@ class D[T]:
 
 reveal_type(D(1))  # revealed: D[int]
 
-# error: [invalid-assignment] "Object of type `D[str]` is not assignable to `D[int]`"
+# error: [invalid-assignment] "Object of type `D[int | str]` is not assignable to `D[int]`"
 wrong_innards: D[int] = D("five")
 ```
 
@@ -395,7 +392,7 @@ reveal_type(C(1, 1))  # revealed: C[int]
 reveal_type(C(1, "string"))  # revealed: C[int]
 reveal_type(C(1, True))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five", 1)
 ```
 

crates/ty_python_semantic/resources/mdtest/generics/pep695/variables.md

@@ -834,6 +834,18 @@ class G[T: list[G]]:
 reveal_type(G[list[G]]().x)  # revealed: list[G[Unknown]]
 ```
 
+An invalid specialization in a recursive bound doesn't cause a panic:
+
+```py
+# error: [invalid-type-arguments]
+class Node[T: "Node[int]"]:
+    pass
+
+# error: [invalid-type-arguments]
+def _(n: Node[str]):
+    reveal_type(n)  # revealed: Node[Unknown]
+```
+
 ### Defaults
 
 Defaults can be generic, but can only refer to earlier typevars:

crates/ty_python_semantic/resources/mdtest/generics/specialize_constrained.md

@@ -22,8 +22,10 @@ from ty_extensions import ConstraintSet, generic_context
 # fmt: off
 
 def unbounded[T]():
-    # revealed: ty_extensions.Specialization[T@unbounded = object]
+    # revealed: ty_extensions.Specialization[T@unbounded = Unknown]
     reveal_type(generic_context(unbounded).specialize_constrained(ConstraintSet.always()))
+    # revealed: ty_extensions.Specialization[T@unbounded = object]
+    reveal_type(generic_context(unbounded).specialize_constrained(ConstraintSet.range(Never, T, object)))
     # revealed: None
     reveal_type(generic_context(unbounded).specialize_constrained(ConstraintSet.never()))
 
@@ -88,6 +90,7 @@ that makes the test succeed.
 from typing import Any
 
 def bounded_by_gradual[T: Any]():
+    # TODO: revealed: ty_extensions.Specialization[T@bounded_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@bounded_by_gradual = object]
     reveal_type(generic_context(bounded_by_gradual).specialize_constrained(ConstraintSet.always()))
     # revealed: None
@@ -168,12 +171,16 @@ from typing import Any
 # fmt: off
 
 def constrained_by_gradual[T: (Base, Any)]():
+    # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Unknown]
+    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
+    reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.always()))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = object]
-    reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.always()))
+    reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, object)))
     # revealed: None
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.never()))
 
+    # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, Base)))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
@@ -181,14 +188,14 @@ def constrained_by_gradual[T: (Base, Any)]():
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, Unrelated)))
 
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
-    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Super]
+    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, Super)))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Super]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Super, T, Super)))
 
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
-    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = object]
+    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Sub, T, object)))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Sub]
@@ -288,7 +295,7 @@ class Unrelated: ...
 # fmt: off
 
 def mutually_bound[T: Base, U]():
-    # revealed: ty_extensions.Specialization[T@mutually_bound = Base, U@mutually_bound = object]
+    # revealed: ty_extensions.Specialization[T@mutually_bound = Base, U@mutually_bound = Unknown]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.always()))
     # revealed: None
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.never()))
@@ -296,7 +303,7 @@ def mutually_bound[T: Base, U]():
     # revealed: ty_extensions.Specialization[T@mutually_bound = Base, U@mutually_bound = Base]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.range(Never, U, T)))
 
-    # revealed: ty_extensions.Specialization[T@mutually_bound = Sub, U@mutually_bound = object]
+    # revealed: ty_extensions.Specialization[T@mutually_bound = Sub, U@mutually_bound = Unknown]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.range(Never, T, Sub)))
     # revealed: ty_extensions.Specialization[T@mutually_bound = Sub, U@mutually_bound = Sub]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.range(Never, T, Sub) & ConstraintSet.range(Never, U, T)))

crates/ty_python_semantic/resources/mdtest/ide_support/all_members.md

@@ -153,6 +153,12 @@ static_assert(has_member(D, "meta_base_attr"))
 static_assert(has_member(D, "meta_attr"))
 static_assert(has_member(D, "base_attr"))
 static_assert(has_member(D, "class_attr"))
+
+def f(x: type[D]):
+    static_assert(has_member(x, "meta_base_attr"))
+    static_assert(has_member(x, "meta_attr"))
+    static_assert(has_member(x, "base_attr"))
+    static_assert(has_member(x, "class_attr"))
 ```
 
 ### Generic classes
@@ -170,6 +176,40 @@ static_assert(has_member(C[int], "base_attr"))
 static_assert(has_member(C[int](), "base_attr"))
 ```
 
+Generic classes can also have metaclasses:
+
+```py
+class Meta(type):
+    FOO = 42
+
+class E(Generic[T], metaclass=Meta): ...
+
+static_assert(has_member(E[int], "FOO"))
+
+def f(x: type[E[str]]):
+    static_assert(has_member(x, "FOO"))
+```
+
+### `type[Any]` and `Any`
+
+`type[Any]` has all members of `type`.
+
+```py
+from typing import Any
+from ty_extensions import has_member, static_assert
+
+def f(x: type[Any]):
+    static_assert(has_member(x, "__base__"))
+    static_assert(has_member(x, "__qualname__"))
+```
+
+`Any` has all members of `object`, since it is a subtype of `object`:
+
+```py
+def f(x: Any):
+    static_assert(has_member(x, "__repr__"))
+```
+
 ### Other instance-like types
 
 ```py

crates/ty_python_semantic/resources/mdtest/implicit_type_aliases.md

@@ -11,17 +11,36 @@ valid type for use in a type expression:
 ```py
 MyInt = int
 
+reveal_type(MyInt)  # revealed: <class 'int'>
+reveal_type(MyInt(1))  # revealed: int
+
 def f(x: MyInt):
     reveal_type(x)  # revealed: int
 
 f(1)
 ```
 
+This also works for generic aliases:
+
+```py
+ListOfStr = list[str]
+
+reveal_type(ListOfStr)  # revealed: <class 'list[str]'>
+reveal_type(ListOfStr(["a", "b"]))  # revealed: list[str]
+
+def g(x: ListOfStr):
+    reveal_type(x)  # revealed: list[str]
+
+g(["a", "b"])
+```
+
 ## None
 
 ```py
 MyNone = None
 
+reveal_type(MyNone)  # revealed: None
+
 def g(x: MyNone):
     reveal_type(x)  # revealed: None
 
@@ -215,6 +234,13 @@ def _(int_or_int: IntOrInt, list_of_int_or_list_of_int: ListOfIntOrListOfInt):
     reveal_type(list_of_int_or_list_of_int)  # revealed: list[int]
 ```
 
+`types.UnionType` instances can not be instantiated:
+
+```py
+# error: [call-non-callable] "Object of type `UnionType` is not callable"
+IntOrStr()
+```
+
 `NoneType` has no special or-operator behavior, so this is an error:
 
 ```py
@@ -619,7 +645,7 @@ def _(weird: IntLiteral1[int]):
 
 ## `Annotated`
 
-Basic usage:
+### Basic usage
 
 ```py
 from typing import Annotated
@@ -646,10 +672,61 @@ class C:
 reveal_type(C().old)  # revealed: @Todo(Generic specialization of typing.Annotated)
 ```
 
+### Special members
+
+The `__origin__` attribute on an instance of `Annotated` can be used to access the underlying type.
+We currently do not model this precisely:
+
+```py
+from typing import Annotated
+
+StrWithMetadata = Annotated[str, "metadata", 1, 2, 3]
+
+reveal_type(StrWithMetadata.__origin__)  # revealed: type | TypeAliasType
+```
+
+At runtime, the `__metadata__` attribute contains the metadata elements `('metadata', 1, 2, 3)`, but
+we do not model the type of this attribute precisely:
+
+```py
+reveal_type(StrWithMetadata.__metadata__)  # revealed: Any
+```
+
+### Attribute access and instantiation
+
+A class can be instantiated through an `Annotated` alias, and attributes can be accessed on the
+created instance:
+
+```py
+from __future__ import annotations
+from typing import Annotated, Union
+
+class Foo:
+    attribute: int = 1
+
+FooWithMetadata = Annotated[Foo, "metadata"]
+
+c = FooWithMetadata()
+
+reveal_type(c)  # revealed: Foo
+reveal_type(c.attribute)  # revealed: int
+```
+
+However, accessing attributes on the alias itself currently yields `Any`, instead of the attribute's
+type:
+
+```py
+reveal_type(FooWithMetadata.attribute)  # revealed: Any
+```
+
+### Error cases
+
 If the metadata argument is missing, we emit an error (because this code fails at runtime), but
 still use the first element as the type, when used in annotations:
 
 ```py
+from typing import Annotated
+
 # error: [invalid-type-form] "Special form `typing.Annotated` expected at least 2 arguments (one type and at least one metadata element)"
 WronglyAnnotatedInt = Annotated[int]
 

crates/ty_python_semantic/resources/mdtest/import/cyclic.md

@@ -38,7 +38,7 @@ See: <https://github.com/astral-sh/ty/issues/113>
 from pkg.sub import A
 
 # TODO: This should be `<class 'A'>`
-reveal_type(A)  # revealed: Never
+reveal_type(A)  # revealed: Divergent
 ```
 
 `pkg/outer.py`:

crates/ty_python_semantic/resources/mdtest/liskov.md

@@ -523,3 +523,63 @@ class Baz(NamedTuple):
 class Spam(Baz):
     def _asdict(self) -> tuple[int, ...]: ...  # error: [invalid-method-override]
 ```
+
+## Staticmethods and classmethods
+
+Methods decorated with `@staticmethod` or `@classmethod` are checked in much the same way as other
+methods.
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+class Parent:
+    def instance_method(self, x: int) -> int: ...
+    @classmethod
+    def class_method(cls, x: int) -> int: ...
+    @staticmethod
+    def static_method(x: int) -> int: ...
+
+class BadChild1(Parent):
+    @staticmethod
+    def instance_method(self, x: int) -> int: ...  # error: [invalid-method-override]
+    # TODO: we should emit `invalid-method-override` here.
+    # Although the method has the same signature as `Parent.class_method`
+    # when accessed on instances, it does not have the same signature as
+    # `Parent.class_method` when accessed on the class object itself
+    def class_method(cls, x: int) -> int: ...
+    def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+
+class BadChild2(Parent):
+    # TODO: we should emit `invalid-method-override` here.
+    # Although the method has the same signature as `Parent.class_method`
+    # when accessed on instances, it does not have the same signature as
+    # `Parent.class_method` when accessed on the class object itself.
+    #
+    # Note that whereas `BadChild1.class_method` is reported as a Liskov violation by
+    # mypy, pyright and pyrefly, pyright is the only one of those three to report a
+    # Liskov violation on this method as of 2025-11-23.
+    @classmethod
+    def instance_method(self, x: int) -> int: ...
+    @staticmethod
+    def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+    @classmethod
+    def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+
+class BadChild3(Parent):
+    @classmethod
+    def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+    @staticmethod
+    def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+
+class GoodChild1(Parent):
+    @classmethod
+    def class_method(cls, x: int) -> int: ...
+    @staticmethod
+    def static_method(x: int) -> int: ...
+
+class GoodChild2(Parent):
+    @classmethod
+    def class_method(cls, x: object) -> bool: ...
+    @staticmethod
+    def static_method(x: object) -> bool: ...
+```

crates/ty_python_semantic/resources/mdtest/override.md

@@ -0,0 +1,314 @@
+# `typing.override`
+
+## Basics
+
+Decorating a method with `typing.override` decorator is an explicit indication to a type checker
+that the method is intended to override a method on a superclass. If the decorated method does not
+in fact override anything, a type checker should report a diagnostic on that method.
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+from typing_extensions import override, Callable, TypeVar
+
+def lossy_decorator(fn: Callable) -> Callable: ...
+
+class A:
+    @override
+    def __repr__(self): ...  # fine: overrides `object.__repr__`
+
+class Parent:
+    def foo(self): ...
+    @property
+    def my_property1(self) -> int: ...
+    @property
+    def my_property2(self) -> int: ...
+    baz = None
+    @classmethod
+    def class_method1(cls) -> int: ...
+    @staticmethod
+    def static_method1() -> int: ...
+    @classmethod
+    def class_method2(cls) -> int: ...
+    @staticmethod
+    def static_method2() -> int: ...
+    @lossy_decorator
+    def decorated_1(self): ...
+    @lossy_decorator
+    def decorated_2(self): ...
+    @lossy_decorator
+    def decorated_3(self): ...
+
+class Child(Parent):
+    @override
+    def foo(self): ...  # fine: overrides `Parent.foo`
+    @property
+    @override
+    def my_property1(self) -> int: ...  # fine: overrides `Parent.my_property1`
+    @override
+    @property
+    def my_property2(self) -> int: ...  # fine: overrides `Parent.my_property2`
+    @override
+    def baz(self): ...  # fine: overrides `Parent.baz`
+    @classmethod
+    @override
+    def class_method1(cls) -> int: ...  # fine: overrides `Parent.class_method1`
+    @staticmethod
+    @override
+    def static_method1() -> int: ...  # fine: overrides `Parent.static_method1`
+    @override
+    @classmethod
+    def class_method2(cls) -> int: ...  # fine: overrides `Parent.class_method2`
+    @override
+    @staticmethod
+    def static_method2() -> int: ...  # fine: overrides `Parent.static_method2`
+    @override
+    def decorated_1(self): ...  # fine: overrides `Parent.decorated_1`
+    @override
+    @lossy_decorator
+    def decorated_2(self): ...  # fine: overrides `Parent.decorated_2`
+    @lossy_decorator
+    @override
+    def decorated_3(self): ...  # fine: overrides `Parent.decorated_3`
+
+class OtherChild(Parent): ...
+
+class Grandchild(OtherChild):
+    @override
+    def foo(self): ...  # fine: overrides `Parent.foo`
+    @override
+    @property
+    def bar(self) -> int: ...  # fine: overrides `Parent.bar`
+    @override
+    def baz(self): ...  # fine: overrides `Parent.baz`
+    @classmethod
+    @override
+    def class_method1(cls) -> int: ...  # fine: overrides `Parent.class_method1`
+    @staticmethod
+    @override
+    def static_method1() -> int: ...  # fine: overrides `Parent.static_method1`
+    @override
+    @classmethod
+    def class_method2(cls) -> int: ...  # fine: overrides `Parent.class_method2`
+    @override
+    @staticmethod
+    def static_method2() -> int: ...  # fine: overrides `Parent.static_method2`
+    @override
+    def decorated_1(self): ...  # fine: overrides `Parent.decorated_1`
+    @override
+    @lossy_decorator
+    def decorated_2(self): ...  # fine: overrides `Parent.decorated_2`
+    @lossy_decorator
+    @override
+    def decorated_3(self): ...  # fine: overrides `Parent.decorated_3`
+
+class Invalid:
+    @override
+    def ___reprrr__(self): ...  # error: [invalid-explicit-override]
+    @override
+    @classmethod
+    def foo(self): ...  # error: [invalid-explicit-override]
+    @classmethod
+    @override
+    def bar(self): ...  # error: [invalid-explicit-override]
+    @staticmethod
+    @override
+    def baz(): ...  # error: [invalid-explicit-override]
+    @override
+    @staticmethod
+    def eggs(): ...  # error: [invalid-explicit-override]
+    @property
+    @override
+    def bad_property1(self) -> int: ...  # TODO: should emit `invalid-explicit-override` here
+    @override
+    @property
+    def bad_property2(self) -> int: ...  # TODO: should emit `invalid-explicit-override` here
+    @lossy_decorator
+    @override
+    def lossy(self): ...  # TODO: should emit `invalid-explicit-override` here
+    @override
+    @lossy_decorator
+    def lossy2(self): ...  # TODO: should emit `invalid-explicit-override` here
+
+# TODO: all overrides in this class should cause us to emit *Liskov* violations,
+# but not `@override` violations
+class LiskovViolatingButNotOverrideViolating(Parent):
+    @override
+    @property
+    def foo(self) -> int: ...
+    @override
+    def my_property1(self) -> int: ...
+    @staticmethod
+    @override
+    def class_method1() -> int: ...
+    @classmethod
+    @override
+    def static_method1(cls) -> int: ...
+
+# Diagnostic edge case: `override` is very far away from the method definition in the source code:
+
+T = TypeVar("T")
+
+def identity(x: T) -> T: ...
+
+class Foo:
+    @override
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    def bar(self): ...  # error: [invalid-explicit-override]
+```
+
+## Overloads
+
+The typing spec states that for an overloaded method, `@override` should only be applied to the
+implementation function. However, we nonetheless respect the decorator in this situation, even
+though we also emit `invalid-overload` on these methods.
+
+```py
+from typing_extensions import override, overload
+
+class Spam:
+    @overload
+    def foo(self, x: str) -> str: ...
+    @overload
+    def foo(self, x: int) -> int: ...
+    @override
+    def foo(self, x: str | int) -> str | int:  # error: [invalid-explicit-override]
+        return x
+
+    @overload
+    @override
+    def bar(self, x: str) -> str: ...
+    @overload
+    @override
+    def bar(self, x: int) -> int: ...
+    @override
+    # error: [invalid-overload] "`@override` decorator should be applied only to the overload implementation"
+    # error: [invalid-overload] "`@override` decorator should be applied only to the overload implementation"
+    # error: [invalid-explicit-override]
+    def bar(self, x: str | int) -> str | int:
+        return x
+
+    @overload
+    @override
+    def baz(self, x: str) -> str: ...
+    @overload
+    def baz(self, x: int) -> int: ...
+    # error: [invalid-overload] "`@override` decorator should be applied only to the overload implementation"
+    # error: [invalid-explicit-override]
+    def baz(self, x: str | int) -> str | int:
+        return x
+```
+
+In a stub file, `@override` should always be applied to the first overload. Even if it isn't, we
+always emit `invalid-explicit-override` diagnostics on the first overload.
+
+`module.pyi`:
+
+```pyi
+from typing_extensions import override, overload
+
+class Spam:
+    @overload
+    def foo(self, x: str) -> str: ...  # error: [invalid-explicit-override]
+    @overload
+    @override
+    # error: [invalid-overload]  "`@override` decorator should be applied only to the first overload"
+    def foo(self, x: int) -> int: ...
+
+    @overload
+    @override
+    def bar(self, x: str) -> str: ...  # error: [invalid-explicit-override]
+    @overload
+    @override
+    # error: [invalid-overload]  "`@override` decorator should be applied only to the first overload"
+    def bar(self, x: int) -> int: ...
+
+    @overload
+    @override
+    def baz(self, x: str) -> str: ...  # error: [invalid-explicit-override]
+    @overload
+    def baz(self, x: int) -> int: ...
+```
+
+## Classes inheriting from `Any`
+
+```py
+from typing_extensions import Any, override
+from does_not_exist import SomethingUnknown  # error: [unresolved-import]
+
+class Parent1(Any): ...
+class Parent2(SomethingUnknown): ...
+
+class Child1(Parent1):
+    @override
+    def bar(self): ...  # fine
+
+class Child2(Parent2):
+    @override
+    def bar(self): ...  # fine
+```
+
+## Override of a synthesized method
+
+```pyi
+from typing_extensions import NamedTuple, TypedDict, override, Any, Self
+from dataclasses import dataclass
+
+@dataclass(order=True)
+class ParentDataclass:
+    x: int
+
+class Child(ParentDataclass):
+    @override
+    def __lt__(self, other: ParentDataclass) -> bool: ...  # fine
+
+class MyNamedTuple(NamedTuple):
+    x: int
+
+    @override
+    # TODO: this raises an exception at runtime (which we should emit a diagnostic for).
+    # It shouldn't be an `invalid-explicit-override` diagnostic, however.
+    def _asdict(self, /) -> dict[str, Any]: ...
+
+class MyNamedTupleParent(NamedTuple):
+    x: int
+
+class MyNamedTupleChild(MyNamedTupleParent):
+    @override
+    def _asdict(self, /) -> dict[str, Any]: ...  # fine
+
+class MyTypedDict(TypedDict):
+    x: int
+
+    @override
+    # TODO: it's invalid to define a method on a `TypedDict` class,
+    # so we should emit a diagnostic here.
+    # It shouldn't be an `invalid-explicit-override` diagnostic, however.
+    def copy(self) -> Self: ...
+
+class Grandparent(Any): ...
+
+class Parent(Grandparent, NamedTuple):  # error: [invalid-named-tuple]
+    x: int
+
+class Child(Parent):
+    @override
+    def foo(self): ...  # fine because `Any` is in the MRO
+```

crates/ty_python_semantic/resources/mdtest/pep613_type_aliases.md

@@ -144,17 +144,46 @@ def _(x: IntOrStr):
 ## Cyclic
 
 ```py
-from typing import TypeAlias
+from typing import TypeAlias, TypeVar, Union
+from types import UnionType
 
 RecursiveTuple: TypeAlias = tuple[int | "RecursiveTuple", str]
 
 def _(rec: RecursiveTuple):
+    # TODO should be `tuple[int | RecursiveTuple, str]`
     reveal_type(rec)  # revealed: tuple[Divergent, str]
 
 RecursiveHomogeneousTuple: TypeAlias = tuple[int | "RecursiveHomogeneousTuple", ...]
 
 def _(rec: RecursiveHomogeneousTuple):
+    # TODO should be `tuple[int | RecursiveHomogeneousTuple, ...]`
     reveal_type(rec)  # revealed: tuple[Divergent, ...]
+
+ClassInfo: TypeAlias = type | UnionType | tuple["ClassInfo", ...]
+reveal_type(ClassInfo)  # revealed: types.UnionType
+
+def my_isinstance(obj: object, classinfo: ClassInfo) -> bool:
+    # TODO should be `type | UnionType | tuple[ClassInfo, ...]`
+    reveal_type(classinfo)  # revealed: type | UnionType | tuple[Divergent, ...]
+    return isinstance(obj, classinfo)
+
+K = TypeVar("K")
+V = TypeVar("V")
+NestedDict: TypeAlias = dict[K, Union[V, "NestedDict[K, V]"]]
+
+def _(nested: NestedDict[str, int]):
+    # TODO should be `dict[str, int | NestedDict[str, int]]`
+    reveal_type(nested)  # revealed: @Todo(specialized generic alias in type expression)
+
+my_isinstance(1, int)
+my_isinstance(1, int | str)
+my_isinstance(1, (int, str))
+my_isinstance(1, (int, (str, float)))
+my_isinstance(1, (int, (str | float)))
+# error: [invalid-argument-type]
+my_isinstance(1, 1)
+# TODO should be an invalid-argument-type error
+my_isinstance(1, (int, (str, 1)))
 ```
 
 ## Conditionally imported on Python < 3.10

crates/ty_python_semantic/resources/mdtest/pep695_type_aliases.md

@@ -106,6 +106,29 @@ def _(flag: bool):
 ```py
 type ListOrSet[T] = list[T] | set[T]
 reveal_type(ListOrSet.__type_params__)  # revealed: tuple[TypeVar | ParamSpec | TypeVarTuple, ...]
+type Tuple1[T] = tuple[T]
+
+def _(cond: bool):
+    Generic = ListOrSet if cond else Tuple1
+
+    def _(x: Generic[int]):
+        reveal_type(x)  # revealed: list[int] | set[int] | tuple[int]
+
+try:
+    class Foo[T]:
+        x: T
+        def foo(self) -> T:
+            return self.x
+
+    ...
+except Exception:
+    class Foo[T]:
+        x: T
+        def foo(self) -> T:
+            return self.x
+
+def f(x: Foo[int]):
+    reveal_type(x.foo())  # revealed: int
 ```
 
 ## In unions and intersections
@@ -244,6 +267,47 @@ def f(x: IntOr, y: OrInt):
         reveal_type(x)  # revealed: Never
     if not isinstance(y, int):
         reveal_type(y)  # revealed: Never
+
+# error: [cyclic-type-alias-definition] "Cyclic definition of `Itself`"
+type Itself = Itself
+
+def foo(
+    # this is a very strange thing to do, but this is a regression test to ensure it doesn't panic
+    Itself: Itself,
+):
+    x: Itself
+    reveal_type(Itself)  # revealed: Divergent
+
+# A type alias defined with invalid recursion behaves as a dynamic type.
+foo(42)
+foo("hello")
+
+# error: [cyclic-type-alias-definition] "Cyclic definition of `A`"
+type A = B
+# error: [cyclic-type-alias-definition] "Cyclic definition of `B`"
+type B = A
+
+def bar(B: B):
+    x: B
+    reveal_type(B)  # revealed: Divergent
+
+# error: [cyclic-type-alias-definition] "Cyclic definition of `G`"
+type G[T] = G[T]
+# error: [cyclic-type-alias-definition] "Cyclic definition of `H`"
+type H[T] = I[T]
+# error: [cyclic-type-alias-definition] "Cyclic definition of `I`"
+type I[T] = H[T]
+
+# It's not possible to create an element of this type, but it's not an error for now
+type DirectRecursiveList[T] = list[DirectRecursiveList[T]]
+
+# TODO: this should probably be a cyclic-type-alias-definition error
+type Foo[T] = list[T] | Bar[T]
+type Bar[T] = int | Foo[T]
+
+def _(x: Bar[int]):
+    # TODO: should be `int | list[int]`
+    reveal_type(x)  # revealed: int | list[int] | Any
 ```
 
 ### With legacy generic
@@ -327,7 +391,7 @@ class C(P[T]):
     pass
 
 reveal_type(C[int]())  # revealed: C[int]
-reveal_type(C())  # revealed: C[Divergent]
+reveal_type(C())  # revealed: C[C[Divergent]]
 ```
 
 ### Union inside generic

crates/ty_python_semantic/resources/mdtest/regression/1377_iteration_count_mismatch.md

@@ -2,10 +2,7 @@
 
 Regression test for <https://github.com/astral-sh/ty/issues/1377>.
 
-The code is an excerpt from <https://github.com/Gobot1234/steam.py> that is minimal enough to
-trigger the iteration count mismatch bug in Salsa.
-
-<!-- expect-panic: execute: too many cycle iterations -->
+The code is an excerpt from <https://github.com/Gobot1234/steam.py>.
 
 ```toml
 [environment]

crates/ty_python_semantic/resources/mdtest/snapshots/assignment_diagnosti…_-_Subscript_assignment…_-_Misspelled_key_for_`…_(7cf0fa634e2a2d59).snap

@@ -34,5 +34,11 @@ error[invalid-key]: Unknown key "Retries" for TypedDict `Config`
   |     TypedDict `Config`
   |
 info: rule `invalid-key` is enabled by default
+4 |     retries: int
+5 | 
+6 | def _(config: Config) -> None:
+  -     config["Retries"] = 30.0  # error: [invalid-key]
+7 +     config["retries"] = 30.0  # error: [invalid-key]
+note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/assignment_diagnosti…_-_Subscript_assignment…_-_Unknown_key_for_all_…_(8a0f0e8ceccc51b2).snap

@@ -42,6 +42,12 @@ error[invalid-key]: Unknown key "surname" for TypedDict `Person`
    |     TypedDict `Person` in union type `Person | Animal`
    |
 info: rule `invalid-key` is enabled by default
+11 | def _(being: Person | Animal) -> None:
+12 |     # error: [invalid-key]
+13 |     # error: [invalid-key]
+   -     being["surname"] = "unknown"
+14 +     being["name"] = "unknown"
+note: This is an unsafe fix and may change runtime behavior
 
 ```
 
@@ -57,5 +63,11 @@ error[invalid-key]: Unknown key "surname" for TypedDict `Animal`
    |     TypedDict `Animal` in union type `Person | Animal`
    |
 info: rule `invalid-key` is enabled by default
+11 | def _(being: Person | Animal) -> None:
+12 |     # error: [invalid-key]
+13 |     # error: [invalid-key]
+   -     being["surname"] = "unknown"
+14 +     being["name"] = "unknown"
+note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/invalid.md_-_Tests_for_invalid_ty…_-_Diagnostics_for_comm…_-_Module-literal_used_…_(652fec4fd4a6c63a).snap

@@ -34,29 +34,37 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/annotations/invalid.md
 # Diagnostics
 
 ```
-error[invalid-type-form]: Variable of type `<module 'datetime'>` is not allowed in a type expression
+error[invalid-type-form]: Module `datetime` is not valid in a type expression
  --> src/foo.py:3:10
   |
 1 | import datetime
 2 |
 3 | def f(x: datetime): ...  # error: [invalid-type-form]
-  |          ^^^^^^^^
+  |          ^^^^^^^^ Did you mean to use the module's member `datetime.datetime`?
   |
-info: Did you mean to use the module's member `datetime.datetime` instead?
 info: rule `invalid-type-form` is enabled by default
+1 | import datetime
+2 | 
+  - def f(x: datetime): ...  # error: [invalid-type-form]
+3 + def f(x: datetime.datetime): ...  # error: [invalid-type-form]
+note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
-error[invalid-type-form]: Variable of type `<module 'PIL.Image'>` is not allowed in a type expression
+error[invalid-type-form]: Module `PIL.Image` is not valid in a type expression
  --> src/bar.py:3:10
   |
 1 | from PIL import Image
 2 |
 3 | def g(x: Image): ...  # error: [invalid-type-form]
-  |          ^^^^^
+  |          ^^^^^ Did you mean to use the module's member `Image.Image`?
   |
-info: Did you mean to use the module's member `Image.Image` instead?
 info: rule `invalid-type-form` is enabled by default
+1 | from PIL import Image
+2 | 
+  - def g(x: Image): ...  # error: [invalid-type-form]
+3 + def g(x: Image.Image): ...  # error: [invalid-type-form]
+note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/invalid_assignment.m…_-_Invalid_assignment_d…_-_Multiple_targets_(e20ddfd7a91affb0).snap

@@ -23,13 +23,13 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_assi
 # Diagnostics
 
 ```
-error[invalid-assignment]: Object of type `tuple[Literal["a"], Literal["b"]]` is not assignable to `int`
+error[invalid-assignment]: Object of type `Literal["a"]` is not assignable to `int`
  --> src/mdtest_snippet.py:4:1
   |
 2 | y: str
 3 |
 4 | x, y = ("a", "b")  # error: [invalid-assignment]
-  | -      ^^^^^^^^^^ Incompatible value of type `tuple[Literal["a"], Literal["b"]]`
+  | -      ^^^^^^^^^^ Incompatible value of type `Literal["a"]`
   | |
   | Declared type `int`
 5 |
@@ -40,13 +40,13 @@ info: rule `invalid-assignment` is enabled by default
 ```
 
 ```
-error[invalid-assignment]: Object of type `tuple[Literal[0], Literal[0]]` is not assignable to `str`
+error[invalid-assignment]: Object of type `Literal[0]` is not assignable to `str`
  --> src/mdtest_snippet.py:6:4
   |
 4 | x, y = ("a", "b")  # error: [invalid-assignment]
 5 |
 6 | x, y = (0, 0)  # error: [invalid-assignment]
-  |    -   ^^^^^^ Incompatible value of type `tuple[Literal[0], Literal[0]]`
+  |    -   ^^^^^^ Incompatible value of type `Literal[0]`
   |    |
   |    Declared type `str`
   |

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Staticmethods_and_cl…_(49e28aae6fdd1291).snap

@@ -0,0 +1,220 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Staticmethods and classmethods
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## mdtest_snippet.pyi
+
+```
+ 1 | class Parent:
+ 2 |     def instance_method(self, x: int) -> int: ...
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+ 7 | 
+ 8 | class BadChild1(Parent):
+ 9 |     @staticmethod
+10 |     def instance_method(self, x: int) -> int: ...  # error: [invalid-method-override]
+11 |     # TODO: we should emit `invalid-method-override` here.
+12 |     # Although the method has the same signature as `Parent.class_method`
+13 |     # when accessed on instances, it does not have the same signature as
+14 |     # `Parent.class_method` when accessed on the class object itself
+15 |     def class_method(cls, x: int) -> int: ...
+16 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+17 | 
+18 | class BadChild2(Parent):
+19 |     # TODO: we should emit `invalid-method-override` here.
+20 |     # Although the method has the same signature as `Parent.class_method`
+21 |     # when accessed on instances, it does not have the same signature as
+22 |     # `Parent.class_method` when accessed on the class object itself.
+23 |     #
+24 |     # Note that whereas `BadChild1.class_method` is reported as a Liskov violation by
+25 |     # mypy, pyright and pyrefly, pyright is the only one of those three to report a
+26 |     # Liskov violation on this method as of 2025-11-23.
+27 |     @classmethod
+28 |     def instance_method(self, x: int) -> int: ...
+29 |     @staticmethod
+30 |     def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+31 |     @classmethod
+32 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+33 | 
+34 | class BadChild3(Parent):
+35 |     @classmethod
+36 |     def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+37 |     @staticmethod
+38 |     def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+39 | 
+40 | class GoodChild1(Parent):
+41 |     @classmethod
+42 |     def class_method(cls, x: int) -> int: ...
+43 |     @staticmethod
+44 |     def static_method(x: int) -> int: ...
+45 | 
+46 | class GoodChild2(Parent):
+47 |     @classmethod
+48 |     def class_method(cls, x: object) -> bool: ...
+49 |     @staticmethod
+50 |     def static_method(x: object) -> bool: ...
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `instance_method`
+  --> src/mdtest_snippet.pyi:10:9
+   |
+ 8 | class BadChild1(Parent):
+ 9 |     @staticmethod
+10 |     def instance_method(self, x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.instance_method`
+11 |     # TODO: we should emit `invalid-method-override` here.
+12 |     # Although the method has the same signature as `Parent.class_method`
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Parent:
+ 2 |     def instance_method(self, x: int) -> int: ...
+   |         ------------------------------------ `Parent.instance_method` defined here
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+   |
+info: `BadChild1.instance_method` is a staticmethod but `Parent.instance_method` is an instance method
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `static_method`
+  --> src/mdtest_snippet.pyi:16:9
+   |
+14 |     # `Parent.class_method` when accessed on the class object itself
+15 |     def class_method(cls, x: int) -> int: ...
+16 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.static_method`
+17 |
+18 | class BadChild2(Parent):
+   |
+  ::: src/mdtest_snippet.pyi:6:9
+   |
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |         ---------------------------- `Parent.static_method` defined here
+ 7 |
+ 8 | class BadChild1(Parent):
+   |
+info: `BadChild1.static_method` is an instance method but `Parent.static_method` is a staticmethod
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `class_method`
+  --> src/mdtest_snippet.pyi:30:9
+   |
+28 |     def instance_method(self, x: int) -> int: ...
+29 |     @staticmethod
+30 |     def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.class_method`
+31 |     @classmethod
+32 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+   |
+  ::: src/mdtest_snippet.pyi:4:9
+   |
+ 2 |     def instance_method(self, x: int) -> int: ...
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+   |         -------------------------------- `Parent.class_method` defined here
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |
+info: `BadChild2.class_method` is a staticmethod but `Parent.class_method` is a classmethod
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `static_method`
+  --> src/mdtest_snippet.pyi:32:9
+   |
+30 |     def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+31 |     @classmethod
+32 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.static_method`
+33 |
+34 | class BadChild3(Parent):
+   |
+  ::: src/mdtest_snippet.pyi:6:9
+   |
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |         ---------------------------- `Parent.static_method` defined here
+ 7 |
+ 8 | class BadChild1(Parent):
+   |
+info: `BadChild2.static_method` is a classmethod but `Parent.static_method` is a staticmethod
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `class_method`
+  --> src/mdtest_snippet.pyi:36:9
+   |
+34 | class BadChild3(Parent):
+35 |     @classmethod
+36 |     def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.class_method`
+37 |     @staticmethod
+38 |     def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+   |
+  ::: src/mdtest_snippet.pyi:4:9
+   |
+ 2 |     def instance_method(self, x: int) -> int: ...
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+   |         -------------------------------- `Parent.class_method` defined here
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `static_method`
+  --> src/mdtest_snippet.pyi:38:9
+   |
+36 |     def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+37 |     @staticmethod
+38 |     def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.static_method`
+39 |
+40 | class GoodChild1(Parent):
+   |
+  ::: src/mdtest_snippet.pyi:6:9
+   |
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |         ---------------------------- `Parent.static_method` defined here
+ 7 |
+ 8 | class BadChild1(Parent):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/literal_string.md_-_`LiteralString`_-_Usages_-_Parameterized_(ec84ce49ea235791).snap

@@ -0,0 +1,52 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: literal_string.md - `LiteralString` - Usages - Parameterized
+mdtest path: crates/ty_python_semantic/resources/mdtest/annotations/literal_string.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | from typing_extensions import LiteralString
+2 | 
+3 | # error: [invalid-type-form]
+4 | a: LiteralString[str]
+5 | 
+6 | # error: [invalid-type-form]
+7 | b: LiteralString["foo"]
+```
+
+# Diagnostics
+
+```
+error[invalid-type-form]: `LiteralString` expects no type parameter
+ --> src/mdtest_snippet.py:4:4
+  |
+3 | # error: [invalid-type-form]
+4 | a: LiteralString[str]
+  |    ^^^^^^^^^^^^^^^^^^
+5 |
+6 | # error: [invalid-type-form]
+  |
+info: rule `invalid-type-form` is enabled by default
+
+```
+
+```
+error[invalid-type-form]: `LiteralString` expects no type parameter
+ --> src/mdtest_snippet.py:7:4
+  |
+6 | # error: [invalid-type-form]
+7 | b: LiteralString["foo"]
+  |    -------------^^^^^^^
+  |    |
+  |    Did you mean `Literal`?
+  |
+info: rule `invalid-type-form` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/mro.md_-_Method_Resolution_Or…_-_`__bases__`_lists_wi…_(ea7ebc83ec359b54).snap

@@ -312,6 +312,15 @@ info[unused-ignore-comment]: Unused blanket `type: ignore` directive
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 73 | ): ...
    |
+help: Remove the unused suppression comment
+69 | class D(
+70 |     A,
+71 |     # error: [unused-ignore-comment]
+   -     A,  # type: ignore[duplicate-base]
+72 +     A,
+73 | ): ...
+74 | 
+75 | # error: [duplicate-base]
 
 ```
 
@@ -356,5 +365,13 @@ info[unused-ignore-comment]: Unused blanket `type: ignore` directive
 82 |
 83 | # fmt: on
    |
+help: Remove the unused suppression comment
+78 |     A
+79 | ):
+80 |     # error: [unused-ignore-comment]
+   -     x: int  # type: ignore[duplicate-base]
+81 +     x: int
+82 | 
+83 | # fmt: on
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/override.md_-_`typing.override`_-_Basics_(b7c220f8171f11f0).snap

@@ -0,0 +1,293 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: override.md - `typing.override` - Basics
+mdtest path: crates/ty_python_semantic/resources/mdtest/override.md
+---
+
+# Python source files
+
+## mdtest_snippet.pyi
+
+```
+  1 | from typing_extensions import override, Callable, TypeVar
+  2 | 
+  3 | def lossy_decorator(fn: Callable) -> Callable: ...
+  4 | 
+  5 | class A:
+  6 |     @override
+  7 |     def __repr__(self): ...  # fine: overrides `object.__repr__`
+  8 | 
+  9 | class Parent:
+ 10 |     def foo(self): ...
+ 11 |     @property
+ 12 |     def my_property1(self) -> int: ...
+ 13 |     @property
+ 14 |     def my_property2(self) -> int: ...
+ 15 |     baz = None
+ 16 |     @classmethod
+ 17 |     def class_method1(cls) -> int: ...
+ 18 |     @staticmethod
+ 19 |     def static_method1() -> int: ...
+ 20 |     @classmethod
+ 21 |     def class_method2(cls) -> int: ...
+ 22 |     @staticmethod
+ 23 |     def static_method2() -> int: ...
+ 24 |     @lossy_decorator
+ 25 |     def decorated_1(self): ...
+ 26 |     @lossy_decorator
+ 27 |     def decorated_2(self): ...
+ 28 |     @lossy_decorator
+ 29 |     def decorated_3(self): ...
+ 30 | 
+ 31 | class Child(Parent):
+ 32 |     @override
+ 33 |     def foo(self): ...  # fine: overrides `Parent.foo`
+ 34 |     @property
+ 35 |     @override
+ 36 |     def my_property1(self) -> int: ...  # fine: overrides `Parent.my_property1`
+ 37 |     @override
+ 38 |     @property
+ 39 |     def my_property2(self) -> int: ...  # fine: overrides `Parent.my_property2`
+ 40 |     @override
+ 41 |     def baz(self): ...  # fine: overrides `Parent.baz`
+ 42 |     @classmethod
+ 43 |     @override
+ 44 |     def class_method1(cls) -> int: ...  # fine: overrides `Parent.class_method1`
+ 45 |     @staticmethod
+ 46 |     @override
+ 47 |     def static_method1() -> int: ...  # fine: overrides `Parent.static_method1`
+ 48 |     @override
+ 49 |     @classmethod
+ 50 |     def class_method2(cls) -> int: ...  # fine: overrides `Parent.class_method2`
+ 51 |     @override
+ 52 |     @staticmethod
+ 53 |     def static_method2() -> int: ...  # fine: overrides `Parent.static_method2`
+ 54 |     @override
+ 55 |     def decorated_1(self): ...  # fine: overrides `Parent.decorated_1`
+ 56 |     @override
+ 57 |     @lossy_decorator
+ 58 |     def decorated_2(self): ...  # fine: overrides `Parent.decorated_2`
+ 59 |     @lossy_decorator
+ 60 |     @override
+ 61 |     def decorated_3(self): ...  # fine: overrides `Parent.decorated_3`
+ 62 | 
+ 63 | class OtherChild(Parent): ...
+ 64 | 
+ 65 | class Grandchild(OtherChild):
+ 66 |     @override
+ 67 |     def foo(self): ...  # fine: overrides `Parent.foo`
+ 68 |     @override
+ 69 |     @property
+ 70 |     def bar(self) -> int: ...  # fine: overrides `Parent.bar`
+ 71 |     @override
+ 72 |     def baz(self): ...  # fine: overrides `Parent.baz`
+ 73 |     @classmethod
+ 74 |     @override
+ 75 |     def class_method1(cls) -> int: ...  # fine: overrides `Parent.class_method1`
+ 76 |     @staticmethod
+ 77 |     @override
+ 78 |     def static_method1() -> int: ...  # fine: overrides `Parent.static_method1`
+ 79 |     @override
+ 80 |     @classmethod
+ 81 |     def class_method2(cls) -> int: ...  # fine: overrides `Parent.class_method2`
+ 82 |     @override
+ 83 |     @staticmethod
+ 84 |     def static_method2() -> int: ...  # fine: overrides `Parent.static_method2`
+ 85 |     @override
+ 86 |     def decorated_1(self): ...  # fine: overrides `Parent.decorated_1`
+ 87 |     @override
+ 88 |     @lossy_decorator
+ 89 |     def decorated_2(self): ...  # fine: overrides `Parent.decorated_2`
+ 90 |     @lossy_decorator
+ 91 |     @override
+ 92 |     def decorated_3(self): ...  # fine: overrides `Parent.decorated_3`
+ 93 | 
+ 94 | class Invalid:
+ 95 |     @override
+ 96 |     def ___reprrr__(self): ...  # error: [invalid-explicit-override]
+ 97 |     @override
+ 98 |     @classmethod
+ 99 |     def foo(self): ...  # error: [invalid-explicit-override]
+100 |     @classmethod
+101 |     @override
+102 |     def bar(self): ...  # error: [invalid-explicit-override]
+103 |     @staticmethod
+104 |     @override
+105 |     def baz(): ...  # error: [invalid-explicit-override]
+106 |     @override
+107 |     @staticmethod
+108 |     def eggs(): ...  # error: [invalid-explicit-override]
+109 |     @property
+110 |     @override
+111 |     def bad_property1(self) -> int: ...  # TODO: should emit `invalid-explicit-override` here
+112 |     @override
+113 |     @property
+114 |     def bad_property2(self) -> int: ...  # TODO: should emit `invalid-explicit-override` here
+115 |     @lossy_decorator
+116 |     @override
+117 |     def lossy(self): ...  # TODO: should emit `invalid-explicit-override` here
+118 |     @override
+119 |     @lossy_decorator
+120 |     def lossy2(self): ...  # TODO: should emit `invalid-explicit-override` here
+121 | 
+122 | # TODO: all overrides in this class should cause us to emit *Liskov* violations,
+123 | # but not `@override` violations
+124 | class LiskovViolatingButNotOverrideViolating(Parent):
+125 |     @override
+126 |     @property
+127 |     def foo(self) -> int: ...
+128 |     @override
+129 |     def my_property1(self) -> int: ...
+130 |     @staticmethod
+131 |     @override
+132 |     def class_method1() -> int: ...
+133 |     @classmethod
+134 |     @override
+135 |     def static_method1(cls) -> int: ...
+136 | 
+137 | # Diagnostic edge case: `override` is very far away from the method definition in the source code:
+138 | 
+139 | T = TypeVar("T")
+140 | 
+141 | def identity(x: T) -> T: ...
+142 | 
+143 | class Foo:
+144 |     @override
+145 |     @identity
+146 |     @identity
+147 |     @identity
+148 |     @identity
+149 |     @identity
+150 |     @identity
+151 |     @identity
+152 |     @identity
+153 |     @identity
+154 |     @identity
+155 |     @identity
+156 |     @identity
+157 |     @identity
+158 |     @identity
+159 |     @identity
+160 |     @identity
+161 |     @identity
+162 |     @identity
+163 |     def bar(self): ...  # error: [invalid-explicit-override]
+```
+
+# Diagnostics
+
+```
+error[invalid-explicit-override]: Method `___reprrr__` is decorated with `@override` but does not override anything
+  --> src/mdtest_snippet.pyi:95:5
+   |
+94 | class Invalid:
+95 |     @override
+   |     ---------
+96 |     def ___reprrr__(self): ...  # error: [invalid-explicit-override]
+   |         ^^^^^^^^^^^
+97 |     @override
+98 |     @classmethod
+   |
+info: No `___reprrr__` definitions were found on any superclasses of `Invalid`
+info: rule `invalid-explicit-override` is enabled by default
+
+```
+
+```
+error[invalid-explicit-override]: Method `foo` is decorated with `@override` but does not override anything
+   --> src/mdtest_snippet.pyi:97:5
+    |
+ 95 |     @override
+ 96 |     def ___reprrr__(self): ...  # error: [invalid-explicit-override]
+ 97 |     @override
+    |     ---------
+ 98 |     @classmethod
+ 99 |     def foo(self): ...  # error: [invalid-explicit-override]
+    |         ^^^
+100 |     @classmethod
+101 |     @override
+    |
+info: No `foo` definitions were found on any superclasses of `Invalid`
+info: rule `invalid-explicit-override` is enabled by default
+
+```
+
+```
+error[invalid-explicit-override]: Method `bar` is decorated with `@override` but does not override anything
+   --> src/mdtest_snippet.pyi:101:5
+    |
+ 99 |     def foo(self): ...  # error: [invalid-explicit-override]
+100 |     @classmethod
+101 |     @override
+    |     ---------
+102 |     def bar(self): ...  # error: [invalid-explicit-override]
+    |         ^^^
+103 |     @staticmethod
+104 |     @override
+    |
+info: No `bar` definitions were found on any superclasses of `Invalid`
+info: rule `invalid-explicit-override` is enabled by default
+
+```
+
+```
+error[invalid-explicit-override]: Method `baz` is decorated with `@override` but does not override anything
+   --> src/mdtest_snippet.pyi:104:5
+    |
+102 |     def bar(self): ...  # error: [invalid-explicit-override]
+103 |     @staticmethod
+104 |     @override
+    |     ---------
+105 |     def baz(): ...  # error: [invalid-explicit-override]
+    |         ^^^
+106 |     @override
+107 |     @staticmethod
+    |
+info: No `baz` definitions were found on any superclasses of `Invalid`
+info: rule `invalid-explicit-override` is enabled by default
+
+```
+
+```
+error[invalid-explicit-override]: Method `eggs` is decorated with `@override` but does not override anything
+   --> src/mdtest_snippet.pyi:106:5
+    |
+104 |     @override
+105 |     def baz(): ...  # error: [invalid-explicit-override]
+106 |     @override
+    |     ---------
+107 |     @staticmethod
+108 |     def eggs(): ...  # error: [invalid-explicit-override]
+    |         ^^^^
+109 |     @property
+110 |     @override
+    |
+info: No `eggs` definitions were found on any superclasses of `Invalid`
+info: rule `invalid-explicit-override` is enabled by default
+
+```
+
+```
+error[invalid-explicit-override]: Method `bar` is decorated with `@override` but does not override anything
+   --> src/mdtest_snippet.pyi:163:9
+    |
+161 |     @identity
+162 |     @identity
+163 |     def bar(self): ...  # error: [invalid-explicit-override]
+    |         ^^^
+    |
+   ::: src/mdtest_snippet.pyi:144:5
+    |
+143 | class Foo:
+144 |     @override
+    |     ---------
+145 |     @identity
+146 |     @identity
+    |
+info: No `bar` definitions were found on any superclasses of `Foo`
+info: rule `invalid-explicit-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/ty_ignore.md_-_Suppressing_errors_w…_-_Multiple_unused_comm…_(7cbe4a1d9893a05).snap

@@ -0,0 +1,109 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: ty_ignore.md - Suppressing errors with `ty: ignore` - Multiple unused comments
+mdtest path: crates/ty_python_semantic/resources/mdtest/suppressions/ty_ignore.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive"
+2 | a = 10 / 2  # ty: ignore[division-by-zero, unresolved-reference]
+3 | 
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+5 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'unresolved-reference'"
+6 | a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero, unresolved-reference]
+7 | 
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+9 | a = 10 / 0  # ty: ignore[invalid-assignment, unresolved-reference, division-by-zero]
+```
+
+# Diagnostics
+
+```
+info[unused-ignore-comment]: Unused `ty: ignore` directive
+ --> src/mdtest_snippet.py:2:13
+  |
+1 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive"
+2 | a = 10 / 2  # ty: ignore[division-by-zero, unresolved-reference]
+  |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+3 |
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+  |
+help: Remove the unused suppression comment
+1 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive"
+  - a = 10 / 2  # ty: ignore[division-by-zero, unresolved-reference]
+2 + a = 10 / 2
+3 | 
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+5 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'unresolved-reference'"
+
+```
+
+```
+info[unused-ignore-comment]: Unused `ty: ignore` directive: 'invalid-assignment'
+ --> src/mdtest_snippet.py:6:26
+  |
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+5 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'unresolved-reference'"
+6 | a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero, unresolved-reference]
+  |                          ^^^^^^^^^^^^^^^^^^
+7 |
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+  |
+help: Remove the unused suppression code
+3 | 
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+5 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'unresolved-reference'"
+  - a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero, unresolved-reference]
+6 + a = 10 / 0  # ty: ignore[division-by-zero, unresolved-reference]
+7 | 
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+9 | a = 10 / 0  # ty: ignore[invalid-assignment, unresolved-reference, division-by-zero]
+
+```
+
+```
+info[unused-ignore-comment]: Unused `ty: ignore` directive: 'unresolved-reference'
+ --> src/mdtest_snippet.py:6:64
+  |
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+5 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'unresolved-reference'"
+6 | a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero, unresolved-reference]
+  |                                                                ^^^^^^^^^^^^^^^^^^^^
+7 |
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+  |
+help: Remove the unused suppression code
+3 | 
+4 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment'"
+5 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'unresolved-reference'"
+  - a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero, unresolved-reference]
+6 + a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero]
+7 | 
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+9 | a = 10 / 0  # ty: ignore[invalid-assignment, unresolved-reference, division-by-zero]
+
+```
+
+```
+info[unused-ignore-comment]: Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'
+ --> src/mdtest_snippet.py:9:26
+  |
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+9 | a = 10 / 0  # ty: ignore[invalid-assignment, unresolved-reference, division-by-zero]
+  |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  |
+help: Remove the unused suppression codes
+6 | a = 10 / 0  # ty: ignore[invalid-assignment, division-by-zero, unresolved-reference]
+7 | 
+8 | # error: [unused-ignore-comment] "Unused `ty: ignore` directive: 'invalid-assignment', 'unresolved-reference'"
+  - a = 10 / 0  # ty: ignore[invalid-assignment, unresolved-reference, division-by-zero]
+9 + a = 10 / 0  # ty: ignore[division-by-zero]
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/type_ignore.md_-_Suppressing_errors_w…_-_Nested_comments_(6e4dc67270e388d2).snap

@@ -0,0 +1,72 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: type_ignore.md - Suppressing errors with `type: ignore` - Nested comments
+mdtest path: crates/ty_python_semantic/resources/mdtest/suppressions/type_ignore.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | # fmt: off
+ 2 | a = test /
+ 3 |   + 2  # fmt: skip # type: ignore
+ 4 | 
+ 5 | a = test /
+ 6 |   + 2  # type: ignore # fmt: skip
+ 7 | 
+ 8 | a = (3
+ 9 |   # error: [unused-ignore-comment]
+10 |   + 2)  # ty:ignore[division-by-zero] # fmt: skip
+11 | 
+12 | a = (3
+13 |   # error: [unused-ignore-comment]
+14 |   + 2)  # fmt: skip # ty:ignore[division-by-zero]
+```
+
+# Diagnostics
+
+```
+info[unused-ignore-comment]: Unused `ty: ignore` directive
+  --> src/mdtest_snippet.py:10:9
+   |
+ 8 | a = (3
+ 9 |   # error: [unused-ignore-comment]
+10 |   + 2)  # ty:ignore[division-by-zero] # fmt: skip
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+11 |
+12 | a = (3
+   |
+help: Remove the unused suppression comment
+7  | 
+8  | a = (3
+9  |   # error: [unused-ignore-comment]
+   -   + 2)  # ty:ignore[division-by-zero] # fmt: skip
+10 +   + 2)  # fmt: skip
+11 | 
+12 | a = (3
+13 |   # error: [unused-ignore-comment]
+
+```
+
+```
+info[unused-ignore-comment]: Unused `ty: ignore` directive
+  --> src/mdtest_snippet.py:14:21
+   |
+12 | a = (3
+13 |   # error: [unused-ignore-comment]
+14 |   + 2)  # fmt: skip # ty:ignore[division-by-zero]
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: Remove the unused suppression comment
+11 | 
+12 | a = (3
+13 |   # error: [unused-ignore-comment]
+   -   + 2)  # fmt: skip # ty:ignore[division-by-zero]
+14 +   + 2)  # fmt: skip 
+
+```