Add pyflakes.extend-generics setting (#4677)

crates/ruff/resources/test/fixtures/pyflakes/F401_15.py

@@ -0,0 +1,9 @@
+from typing import TYPE_CHECKING
+from django.db.models import ForeignKey
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+class Foo:
+    var = ForeignKey["Path"]()

crates/ruff/src/checkers/ast/mod.rs

@@ -3884,6 +3884,7 @@ where
                         value,
                         &self.semantic_model,
                         self.settings.typing_modules.iter().map(String::as_str),
+                        &self.settings.pyflakes.extend_generics,
                     ) {
                         Some(subscript) => {
                             match subscript {

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

@@ -3,6 +3,7 @@ pub(crate) mod cformat;
 pub(crate) mod fixes;
 pub(crate) mod format;
 pub(crate) mod rules;
+pub mod settings;
 
 #[cfg(test)]
 mod tests {
@@ -19,7 +20,7 @@ mod tests {
 
     use crate::linter::{check_path, LinterResult};
     use crate::registry::{AsRule, Linter, Rule};
-    use crate::settings::flags;
+    use crate::settings::{flags, Settings};
     use crate::test::test_path;
     use crate::{assert_messages, directives, settings};
 
@@ -38,6 +39,7 @@ mod tests {
     #[test_case(Rule::UnusedImport, Path::new("F401_12.py"))]
     #[test_case(Rule::UnusedImport, Path::new("F401_13.py"))]
     #[test_case(Rule::UnusedImport, Path::new("F401_14.py"))]
+    #[test_case(Rule::UnusedImport, Path::new("F401_15.py"))]
     #[test_case(Rule::ImportShadowedByLoopVar, Path::new("F402.py"))]
     #[test_case(Rule::UndefinedLocalWithImportStar, Path::new("F403.py"))]
     #[test_case(Rule::LateFutureImport, Path::new("F404.py"))]
@@ -252,6 +254,22 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn extend_generics() -> Result<()> {
+        let snapshot = "extend_immutable_calls".to_string();
+        let diagnostics = test_path(
+            Path::new("pyflakes/F401_15.py"),
+            &Settings {
+                pyflakes: super::settings::Settings {
+                    extend_generics: vec!["django.db.models.ForeignKey".to_string()],
+                },
+                ..Settings::for_rules(vec![Rule::UnusedImport])
+            },
+        )?;
+        assert_messages!(snapshot, diagnostics);
+        Ok(())
+    }
+
     /// A re-implementation of the Pyflakes test runner.
     /// Note that all tests marked with `#[ignore]` should be considered TODOs.
     fn flakes(contents: &str, expected: &[Rule]) {

crates/ruff/src/rules/pyflakes/rules/imports.rs

@@ -25,6 +25,10 @@ pub(crate) enum UnusedImportContext {
 /// If an import statement is used to check for the availability or existence
 /// of a module, consider using `importlib.util.find_spec` instead.
 ///
+/// ## Options
+///
+/// - `pyflakes.extend-generics`
+///
 /// ## Example
 /// ```python
 /// import numpy as np  # unused import

crates/ruff/src/rules/pyflakes/settings.rs

@@ -0,0 +1,47 @@
+//! Settings for the `Pyflakes` plugin.
+
+use serde::{Deserialize, Serialize};
+
+use ruff_macros::{CacheKey, CombineOptions, ConfigurationOptions};
+
+#[derive(
+    Debug, PartialEq, Eq, Default, Serialize, Deserialize, ConfigurationOptions, CombineOptions,
+)]
+#[serde(
+    deny_unknown_fields,
+    rename_all = "kebab-case",
+    rename = "PyflakesOptions"
+)]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct Options {
+    #[option(
+        default = r#"[]"#,
+        value_type = "list[str]",
+        example = "extend-generics = [\"django.db.models.ForeignKey\"]"
+    )]
+    /// Additional functions or classes to consider generic, such that any
+    /// subscripts should be treated as type annotation (e.g., `ForeignKey` in
+    /// `django.db.models.ForeignKey["User"]`.
+    pub extend_generics: Option<Vec<String>>,
+}
+
+#[derive(Debug, Default, CacheKey)]
+pub struct Settings {
+    pub extend_generics: Vec<String>,
+}
+
+impl From<Options> for Settings {
+    fn from(options: Options) -> Self {
+        Self {
+            extend_generics: options.extend_generics.unwrap_or_default(),
+        }
+    }
+}
+
+impl From<Settings> for Options {
+    fn from(settings: Settings) -> Self {
+        Self {
+            extend_generics: Some(settings.extend_generics),
+        }
+    }
+}

crates/ruff/src/rules/pyflakes/snapshots/ruff__rules__pyflakes__tests__F401_F401_15.py.snap

@@ -0,0 +1,22 @@
+---
+source: crates/ruff/src/rules/pyflakes/mod.rs
+---
+F401_15.py:5:25: F401 [*] `pathlib.Path` imported but unused
+  |
+5 | if TYPE_CHECKING:
+6 |     from pathlib import Path
+  |                         ^^^^ F401
+  |
+  = help: Remove unused import: `pathlib.Path`
+
+ℹ Suggested fix
+2 2 | from django.db.models import ForeignKey
+3 3 | 
+4 4 | if TYPE_CHECKING:
+5   |-    from pathlib import Path
+  5 |+    pass
+6 6 | 
+7 7 | 
+8 8 | class Foo:
+
+

crates/ruff/src/rules/pyflakes/snapshots/ruff__rules__pyflakes__tests__extend_immutable_calls.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff/src/rules/pyflakes/mod.rs
+---
+

crates/ruff/src/settings/configuration.rs

@@ -19,7 +19,7 @@ use crate::rules::{
     flake8_annotations, flake8_bandit, flake8_bugbear, flake8_builtins, flake8_comprehensions,
     flake8_errmsg, flake8_gettext, flake8_implicit_str_concat, flake8_import_conventions,
     flake8_pytest_style, flake8_quotes, flake8_self, flake8_tidy_imports, flake8_type_checking,
-    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pylint,
+    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pyflakes, pylint,
 };
 use crate::settings::options::Options;
 use crate::settings::types::{
@@ -89,6 +89,7 @@ pub struct Configuration {
     pub pep8_naming: Option<pep8_naming::settings::Options>,
     pub pycodestyle: Option<pycodestyle::settings::Options>,
     pub pydocstyle: Option<pydocstyle::settings::Options>,
+    pub pyflakes: Option<pyflakes::settings::Options>,
     pub pylint: Option<pylint::settings::Options>,
 }
 
@@ -241,6 +242,7 @@ impl Configuration {
             pep8_naming: options.pep8_naming,
             pycodestyle: options.pycodestyle,
             pydocstyle: options.pydocstyle,
+            pyflakes: options.pyflakes,
             pylint: options.pylint,
         })
     }
@@ -326,6 +328,7 @@ impl Configuration {
             pep8_naming: self.pep8_naming.combine(config.pep8_naming),
             pycodestyle: self.pycodestyle.combine(config.pycodestyle),
             pydocstyle: self.pydocstyle.combine(config.pydocstyle),
+            pyflakes: self.pyflakes.combine(config.pyflakes),
             pylint: self.pylint.combine(config.pylint),
         }
     }

crates/ruff/src/settings/defaults.rs

@@ -13,7 +13,7 @@ use crate::rules::{
     flake8_annotations, flake8_bandit, flake8_bugbear, flake8_builtins, flake8_comprehensions,
     flake8_errmsg, flake8_gettext, flake8_implicit_str_concat, flake8_import_conventions,
     flake8_pytest_style, flake8_quotes, flake8_self, flake8_tidy_imports, flake8_type_checking,
-    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pylint,
+    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pyflakes, pylint,
 };
 use crate::settings::types::FilePatternSet;
 
@@ -110,6 +110,7 @@ impl Default for Settings {
             pep8_naming: pep8_naming::settings::Settings::default(),
             pycodestyle: pycodestyle::settings::Settings::default(),
             pydocstyle: pydocstyle::settings::Settings::default(),
+            pyflakes: pyflakes::settings::Settings::default(),
             pylint: pylint::settings::Settings::default(),
         }
     }

crates/ruff/src/settings/mod.rs

@@ -19,7 +19,7 @@ use crate::rules::{
     flake8_annotations, flake8_bandit, flake8_bugbear, flake8_builtins, flake8_comprehensions,
     flake8_errmsg, flake8_gettext, flake8_implicit_str_concat, flake8_import_conventions,
     flake8_pytest_style, flake8_quotes, flake8_self, flake8_tidy_imports, flake8_type_checking,
-    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pylint,
+    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pyflakes, pylint,
 };
 use crate::settings::configuration::Configuration;
 use crate::settings::types::{FilePatternSet, PerFileIgnore, PythonVersion, SerializationFormat};
@@ -126,6 +126,7 @@ pub struct Settings {
     pub pep8_naming: pep8_naming::settings::Settings,
     pub pycodestyle: pycodestyle::settings::Settings,
     pub pydocstyle: pydocstyle::settings::Settings,
+    pub pyflakes: pyflakes::settings::Settings,
     pub pylint: pylint::settings::Settings,
 }
 
@@ -231,6 +232,7 @@ impl Settings {
             pep8_naming: config.pep8_naming.map(Into::into).unwrap_or_default(),
             pycodestyle: config.pycodestyle.map(Into::into).unwrap_or_default(),
             pydocstyle: config.pydocstyle.map(Into::into).unwrap_or_default(),
+            pyflakes: config.pyflakes.map(Into::into).unwrap_or_default(),
             pylint: config.pylint.map(Into::into).unwrap_or_default(),
         })
     }

crates/ruff/src/settings/options.rs

@@ -11,7 +11,7 @@ use crate::rules::{
     flake8_annotations, flake8_bandit, flake8_bugbear, flake8_builtins, flake8_comprehensions,
     flake8_errmsg, flake8_gettext, flake8_implicit_str_concat, flake8_import_conventions,
     flake8_pytest_style, flake8_quotes, flake8_self, flake8_tidy_imports, flake8_type_checking,
-    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pylint,
+    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pyflakes, pylint,
 };
 use crate::settings::types::{PythonVersion, SerializationFormat, Version};
 
@@ -539,6 +539,9 @@ pub struct Options {
     /// Options for the `pydocstyle` plugin.
     pub pydocstyle: Option<pydocstyle::settings::Options>,
     #[option_group]
+    /// Options for the `pyflakes` plugin.
+    pub pyflakes: Option<pyflakes::settings::Options>,
+    #[option_group]
     /// Options for the `pylint` plugin.
     pub pylint: Option<pylint::settings::Options>,
     // Tables are required to go last.

crates/ruff_python_semantic/src/analyze/typing.rs

@@ -1,7 +1,7 @@
 use rustpython_parser::ast::{self, Constant, Expr, Operator};
 
 use num_traits::identities::Zero;
-use ruff_python_ast::call_path::{from_unqualified_name, CallPath};
+use ruff_python_ast::call_path::{from_qualified_name, from_unqualified_name, CallPath};
 use ruff_python_stdlib::typing::{
     IMMUTABLE_GENERIC_TYPES, IMMUTABLE_TYPES, PEP_585_GENERICS, PEP_593_SUBSCRIPTS, SUBSCRIPTS,
 };
@@ -29,6 +29,7 @@ pub fn match_annotated_subscript<'a>(
     expr: &Expr,
     semantic_model: &SemanticModel,
     typing_modules: impl Iterator<Item = &'a str>,
+    extend_generics: &[String],
 ) -> Option<SubscriptKind> {
     if !matches!(expr, Expr::Name(_) | Expr::Attribute(_)) {
         return None;
@@ -37,7 +38,12 @@ pub fn match_annotated_subscript<'a>(
     semantic_model
         .resolve_call_path(expr)
         .and_then(|call_path| {
-            if SUBSCRIPTS.contains(&call_path.as_slice()) {
+            if SUBSCRIPTS.contains(&call_path.as_slice())
+                || extend_generics
+                    .iter()
+                    .map(|target| from_qualified_name(target))
+                    .any(|target| call_path == target)
+            {
                 return Some(SubscriptKind::AnnotatedSubscript);
             }
             if PEP_593_SUBSCRIPTS.contains(&call_path.as_slice()) {

crates/ruff_wasm/src/lib.rs

@@ -12,7 +12,7 @@ use ruff::rules::{
     flake8_annotations, flake8_bandit, flake8_bugbear, flake8_builtins, flake8_comprehensions,
     flake8_errmsg, flake8_gettext, flake8_implicit_str_concat, flake8_import_conventions,
     flake8_pytest_style, flake8_quotes, flake8_self, flake8_tidy_imports, flake8_type_checking,
-    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pylint,
+    flake8_unused_arguments, isort, mccabe, pep8_naming, pycodestyle, pydocstyle, pyflakes, pylint,
 };
 use ruff::settings::configuration::Configuration;
 use ruff::settings::options::Options;
@@ -158,6 +158,7 @@ pub fn defaultSettings() -> Result<JsValue, JsValue> {
         pep8_naming: Some(pep8_naming::settings::Settings::default().into()),
         pycodestyle: Some(pycodestyle::settings::Settings::default().into()),
         pydocstyle: Some(pydocstyle::settings::Settings::default().into()),
+        pyflakes: Some(pyflakes::settings::Settings::default().into()),
         pylint: Some(pylint::settings::Settings::default().into()),
     })?)
 }