In stable, retain blanket exemption

Author: charliermarsh

crates/ruff_linter/resources/test/fixtures/flake8_self/SLF001_2.py

@@ -1,45 +1,43 @@
-# https://github.com/astral-sh/ruff/issues/24275
-
 class C:
-    def false_positive(this):
-        this._x = 0  # fine
+    def non_self_named_method_receiver(this):
+        this._x = 0  # stable: fine, preview: fine
 
     @classmethod
-    def false_positive_2(that):
-        return that._x  # fine
+    def non_self_named_classmethod_receiver(that):
+        return that._x  # stable: fine, preview: fine
 
-    def false_negative_1(this, self):
-        self._x = 1  # error
+    def non_receiver_named_self_parameter(this, self):
+        self._x = 1  # stable: fine, preview: error
 
     @classmethod
-    def false_positive_3(self):
-        return self._x  # fine
+    def classmethod_named_self(self):
+        return self._x  # stable: fine, preview: fine
 
     @staticmethod
-    def false_negative_3(self):
-        return self._x  # error
+    def staticmethod_named_self(self):
+        return self._x  # stable: fine, preview: error
 
 
-def false_negative_4(self):
-    return self._x  # error
+def top_level_self_parameter(self):
+    return self._x  # stable: fine, preview: error
 
 
-def false_negative_5():
+def local_self_binding():
     self = C()
-    return self._x  # error
+    return self._x  # stable: fine, preview: error
 
 
 self = C()
 
 
-def false_negative_6():
-    return self._x  # error
+def global_self_binding():
+    return self._x  # stable: fine, preview: error
 
 
-def false_negative_7(cls):
-    return cls._x  # error
+def top_level_cls_parameter(cls):
+    return cls._x  # stable: fine, preview: error
 
 
-def false_negative_8():
+def local_mcs_binding():
     mcs = C
-    return mcs._x  # error
+    return mcs._x  # stable: fine, preview: error

crates/ruff_linter/src/preview.rs

@@ -218,6 +218,11 @@ pub(crate) const fn is_refined_submodule_import_match_enabled(settings: &LinterS
     settings.preview.is_enabled()
 }
 
+// https://github.com/astral-sh/ruff/issues/24275
+pub(crate) const fn is_slf001_self_cls_mcs_enforcement_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
 // https://github.com/astral-sh/ruff/pull/20660
 pub(crate) const fn is_type_var_default_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()

crates/ruff_linter/src/rules/flake8_self/mod.rs

@@ -8,6 +8,7 @@ mod tests {
 
     use crate::registry::Rule;
     use crate::rules::flake8_self;
+    use crate::settings::types::PreviewMode;
     use crate::test::test_path;
     use crate::{assert_diagnostics, settings};
     use anyhow::Result;
@@ -27,6 +28,20 @@ mod tests {
         Ok(())
     }
 
+    #[test_case(Rule::PrivateMemberAccess, Path::new("SLF001_2.py"))]
+    fn preview_rules(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!("preview__{}_{}", rule_code.name(), path.to_string_lossy());
+        let diagnostics = test_path(
+            Path::new("flake8_self").join(path).as_path(),
+            &settings::LinterSettings {
+                preview: PreviewMode::Enabled,
+                ..settings::LinterSettings::for_rule(rule_code)
+            },
+        )?;
+        assert_diagnostics!(snapshot, diagnostics);
+        Ok(())
+    }
+
     #[test]
     fn ignore_names() -> Result<()> {
         let diagnostics = test_path(
@@ -47,6 +62,7 @@ mod tests {
         let diagnostics = test_path(
             Path::new("flake8_self/SLF001_custom_decorators.py"),
             &settings::LinterSettings {
+                preview: PreviewMode::Enabled,
                 pep8_naming: crate::rules::pep8_naming::settings::Settings {
                     classmethod_decorators: vec!["custom_classmethod".to_string()],
                     staticmethod_decorators: vec!["custom_staticmethod".to_string()],

crates/ruff_linter/src/rules/flake8_self/rules/private_member_access.rs

@@ -10,6 +10,7 @@ use ruff_text_size::Ranged;
 
 use crate::Violation;
 use crate::checkers::ast::Checker;
+use crate::preview::is_slf001_self_cls_mcs_enforcement_enabled;
 use crate::rules::pylint::helpers::is_dunder_operator_method;
 
 /// ## What it does
@@ -77,6 +78,7 @@ pub(crate) fn private_member_access(checker: &Checker, expr: &Expr) {
 
     let semantic = checker.semantic();
     let current_scope = semantic.current_scope();
+    let enforce_self_cls_mcs = is_slf001_self_cls_mcs_enforcement_enabled(checker.settings());
 
     if semantic.in_annotation() {
         return;
@@ -118,6 +120,13 @@ pub(crate) fn private_member_access(checker: &Checker, expr: &Expr) {
         }
     }
 
+    if !enforce_self_cls_mcs
+        && let Some(name) = UnqualifiedName::from_expr(value)
+        && matches!(name.segments(), ["self" | "cls" | "mcs"])
+    {
+        return;
+    }
+
     if let Expr::Name(name) = value.as_ref() {
         // Ignore accesses on class members from _within_ the class.
         if semantic
@@ -134,7 +143,12 @@ pub(crate) fn private_member_access(checker: &Checker, expr: &Expr) {
             return;
         }
 
-        if is_same_class_instance(checker, name) {
+        if is_same_class_instance(
+            name,
+            semantic,
+            &checker.settings().pep8_naming.classmethod_decorators,
+            &checker.settings().pep8_naming.staticmethod_decorators,
+        ) {
             return;
         }
     }
@@ -171,12 +185,21 @@ pub(crate) fn private_member_access(checker: &Checker, expr: &Expr) {
 ///
 /// This function is intentionally naive and does not handle more complex cases.
 /// It is expected to be expanded overtime, possibly when type-aware APIs are available.
-fn is_same_class_instance(checker: &Checker, name: &ast::ExprName) -> bool {
-    if is_method_receiver(checker, name) {
+fn is_same_class_instance(
+    name: &ast::ExprName,
+    semantic: &SemanticModel,
+    classmethod_decorators: &[String],
+    staticmethod_decorators: &[String],
+) -> bool {
+    if is_method_receiver(
+        name,
+        semantic,
+        classmethod_decorators,
+        staticmethod_decorators,
+    ) {
         return true;
     }
 
-    let semantic = checker.semantic();
     let Some(binding_id) = semantic.resolve_name(name) else {
         return false;
     };
@@ -185,9 +208,14 @@ fn is_same_class_instance(checker: &Checker, name: &ast::ExprName) -> bool {
     typing::check_type::<SameClassInstanceChecker>(binding, semantic)
 }
 
-fn is_method_receiver(checker: &Checker, name: &ast::ExprName) -> bool {
-    let semantic = checker.semantic();
-
+/// Return `true` if `name` resolves to the first parameter of a syntactic
+/// method receiver, including class methods and `__new__`.
+fn is_method_receiver(
+    name: &ast::ExprName,
+    semantic: &SemanticModel,
+    classmethod_decorators: &[String],
+    staticmethod_decorators: &[String],
+) -> bool {
     let Some(binding_id) = semantic.resolve_name(name) else {
         return false;
     };
@@ -225,8 +253,8 @@ fn is_method_receiver(checker: &Checker, name: &ast::ExprName) -> bool {
             &function.decorator_list,
             parent_scope,
             semantic,
-            &checker.settings().pep8_naming.classmethod_decorators,
-            &checker.settings().pep8_naming.staticmethod_decorators,
+            classmethod_decorators,
+            staticmethod_decorators,
         ),
         function_type::FunctionType::Method
             | function_type::FunctionType::ClassMethod

crates/ruff_linter/src/rules/flake8_self/snapshots/ruff_linter__rules__flake8_self__tests__preview__private-member-access_SLF001_2.py.snap

@@ -0,0 +1,63 @@
+---
+source: crates/ruff_linter/src/rules/flake8_self/mod.rs
+---
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:10:9
+   |
+ 9 |     def non_receiver_named_self_parameter(this, self):
+10 |         self._x = 1  # stable: fine, preview: error
+   |         ^^^^^^^
+11 |
+12 |     @classmethod
+   |
+
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:18:16
+   |
+16 |     @staticmethod
+17 |     def staticmethod_named_self(self):
+18 |         return self._x  # stable: fine, preview: error
+   |                ^^^^^^^
+   |
+
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:22:12
+   |
+21 | def top_level_self_parameter(self):
+22 |     return self._x  # stable: fine, preview: error
+   |            ^^^^^^^
+   |
+
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:27:12
+   |
+25 | def local_self_binding():
+26 |     self = C()
+27 |     return self._x  # stable: fine, preview: error
+   |            ^^^^^^^
+   |
+
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:34:12
+   |
+33 | def global_self_binding():
+34 |     return self._x  # stable: fine, preview: error
+   |            ^^^^^^^
+   |
+
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:38:12
+   |
+37 | def top_level_cls_parameter(cls):
+38 |     return cls._x  # stable: fine, preview: error
+   |            ^^^^^^
+   |
+
+SLF001 Private member accessed: `_x`
+  --> SLF001_2.py:43:12
+   |
+41 | def local_mcs_binding():
+42 |     mcs = C
+43 |     return mcs._x  # stable: fine, preview: error
+   |            ^^^^^^
+   |

crates/ruff_linter/src/rules/flake8_self/snapshots/ruff_linter__rules__flake8_self__tests__private-member-access_SLF001_2.py.snap

@@ -1,63 +1,4 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_self/mod.rs
 ---
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:12:9
-   |
-11 |     def false_negative_1(this, self):
-12 |         self._x = 1  # error
-   |         ^^^^^^^
-13 |
-14 |     @classmethod
-   |
 
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:20:16
-   |
-18 |     @staticmethod
-19 |     def false_negative_3(self):
-20 |         return self._x  # error
-   |                ^^^^^^^
-   |
-
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:24:12
-   |
-23 | def false_negative_4(self):
-24 |     return self._x  # error
-   |            ^^^^^^^
-   |
-
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:29:12
-   |
-27 | def false_negative_5():
-28 |     self = C()
-29 |     return self._x  # error
-   |            ^^^^^^^
-   |
-
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:36:12
-   |
-35 | def false_negative_6():
-36 |     return self._x  # error
-   |            ^^^^^^^
-   |
-
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:40:12
-   |
-39 | def false_negative_7(cls):
-40 |     return cls._x  # error
-   |            ^^^^^^
-   |
-
-SLF001 Private member accessed: `_x`
-  --> SLF001_2.py:45:12
-   |
-43 | def false_negative_8():
-44 |     mcs = C
-45 |     return mcs._x  # error
-   |            ^^^^^^
-   |