[ruff] Avoid treating named expressions as static keys (RUF011) (#9494)

Closes https://github.com/astral-sh/ruff/issues/9487.

crates/ruff_linter/resources/test/fixtures/ruff/RUF011.py

@@ -10,6 +10,8 @@ constant = 5
 {value.attribute: value.upper() for value in data for constant in data}
 {constant[value]: value.upper() for value in data for constant in data}
 {value[constant]: value.upper() for value in data for constant in data}
+{local_id: token for token in tokens if (local_id := _extract_local_id(token)) is not None}
+{key: kwargs.get(key) for key in kwargs.keys() if not params.get(key)}
 
 # Errors
 {"key": value.upper() for value in data}
@@ -20,3 +22,5 @@ constant = 5
 {constant + constant: value.upper() for value in data}
 {constant.attribute: value.upper() for value in data}
 {constant[0]: value.upper() for value in data}
+{tokens: token for token in tokens}
+

crates/ruff_linter/src/rules/flake8_bugbear/rules/unused_loop_control_variable.rs

@@ -2,7 +2,7 @@ use ruff_diagnostics::{Diagnostic, Edit, Fix, FixAvailability, Violation};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast as ast;
 use ruff_python_ast::helpers;
-use ruff_python_ast::helpers::NameFinder;
+use ruff_python_ast::helpers::{NameFinder, StoredNameFinder};
 use ruff_python_ast::visitor::Visitor;
 use ruff_text_size::Ranged;
 
@@ -80,7 +80,7 @@ impl Violation for UnusedLoopControlVariable {
 /// B007
 pub(crate) fn unused_loop_control_variable(checker: &mut Checker, stmt_for: &ast::StmtFor) {
     let control_names = {
-        let mut finder = NameFinder::default();
+        let mut finder = StoredNameFinder::default();
         finder.visit_expr(stmt_for.target.as_ref());
         finder.names
     };

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

@@ -2,7 +2,7 @@ use rustc_hash::FxHashMap;
 
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::helpers::NameFinder;
+use ruff_python_ast::helpers::StoredNameFinder;
 use ruff_python_ast::visitor::Visitor;
 use ruff_python_ast::{self as ast, Expr};
 use ruff_text_size::Ranged;
@@ -51,9 +51,9 @@ impl Violation for StaticKeyDictComprehension {
 pub(crate) fn static_key_dict_comprehension(checker: &mut Checker, dict_comp: &ast::ExprDictComp) {
     // Collect the bound names in the comprehension's generators.
     let names = {
-        let mut visitor = NameFinder::default();
+        let mut visitor = StoredNameFinder::default();
         for generator in &dict_comp.generators {
-            visitor.visit_expr(&generator.target);
+            visitor.visit_comprehension(generator);
         }
         visitor.names
     };

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF011_RUF011.py.snap

@@ -1,80 +1,90 @@
 ---
 source: crates/ruff_linter/src/rules/ruff/mod.rs
 ---
-RUF011.py:15:2: RUF011 Dictionary comprehension uses static key: `"key"`
+RUF011.py:17:2: RUF011 Dictionary comprehension uses static key: `"key"`
    |
-14 | # Errors
+16 | # Errors
-15 | {"key": value.upper() for value in data}
+17 | {"key": value.upper() for value in data}
    |  ^^^^^ RUF011
-16 | {True: value.upper() for value in data}
+18 | {True: value.upper() for value in data}
-17 | {0: value.upper() for value in data}
+19 | {0: value.upper() for value in data}
    |
 
-RUF011.py:16:2: RUF011 Dictionary comprehension uses static key: `True`
+RUF011.py:18:2: RUF011 Dictionary comprehension uses static key: `True`
    |
-14 | # Errors
+16 | # Errors
-15 | {"key": value.upper() for value in data}
+17 | {"key": value.upper() for value in data}
-16 | {True: value.upper() for value in data}
+18 | {True: value.upper() for value in data}
    |  ^^^^ RUF011
-17 | {0: value.upper() for value in data}
+19 | {0: value.upper() for value in data}
-18 | {(1, "a"): value.upper() for value in data}  # Constant tuple
+20 | {(1, "a"): value.upper() for value in data}  # Constant tuple
    |
 
-RUF011.py:17:2: RUF011 Dictionary comprehension uses static key: `0`
+RUF011.py:19:2: RUF011 Dictionary comprehension uses static key: `0`
    |
-15 | {"key": value.upper() for value in data}
+17 | {"key": value.upper() for value in data}
-16 | {True: value.upper() for value in data}
+18 | {True: value.upper() for value in data}
-17 | {0: value.upper() for value in data}
+19 | {0: value.upper() for value in data}
    |  ^ RUF011
-18 | {(1, "a"): value.upper() for value in data}  # Constant tuple
+20 | {(1, "a"): value.upper() for value in data}  # Constant tuple
-19 | {constant: value.upper() for value in data}
+21 | {constant: value.upper() for value in data}
    |
 
-RUF011.py:18:2: RUF011 Dictionary comprehension uses static key: `(1, "a")`
+RUF011.py:20:2: RUF011 Dictionary comprehension uses static key: `(1, "a")`
    |
-16 | {True: value.upper() for value in data}
+18 | {True: value.upper() for value in data}
-17 | {0: value.upper() for value in data}
+19 | {0: value.upper() for value in data}
-18 | {(1, "a"): value.upper() for value in data}  # Constant tuple
+20 | {(1, "a"): value.upper() for value in data}  # Constant tuple
    |  ^^^^^^^^ RUF011
-19 | {constant: value.upper() for value in data}
+21 | {constant: value.upper() for value in data}
-20 | {constant + constant: value.upper() for value in data}
+22 | {constant + constant: value.upper() for value in data}
    |
 
-RUF011.py:19:2: RUF011 Dictionary comprehension uses static key: `constant`
+RUF011.py:21:2: RUF011 Dictionary comprehension uses static key: `constant`
    |
-17 | {0: value.upper() for value in data}
+19 | {0: value.upper() for value in data}
-18 | {(1, "a"): value.upper() for value in data}  # Constant tuple
+20 | {(1, "a"): value.upper() for value in data}  # Constant tuple
-19 | {constant: value.upper() for value in data}
+21 | {constant: value.upper() for value in data}
    |  ^^^^^^^^ RUF011
-20 | {constant + constant: value.upper() for value in data}
+22 | {constant + constant: value.upper() for value in data}
-21 | {constant.attribute: value.upper() for value in data}
+23 | {constant.attribute: value.upper() for value in data}
    |
 
-RUF011.py:20:2: RUF011 Dictionary comprehension uses static key: `constant + constant`
+RUF011.py:22:2: RUF011 Dictionary comprehension uses static key: `constant + constant`
    |
-18 | {(1, "a"): value.upper() for value in data}  # Constant tuple
+20 | {(1, "a"): value.upper() for value in data}  # Constant tuple
-19 | {constant: value.upper() for value in data}
+21 | {constant: value.upper() for value in data}
-20 | {constant + constant: value.upper() for value in data}
+22 | {constant + constant: value.upper() for value in data}
    |  ^^^^^^^^^^^^^^^^^^^ RUF011
-21 | {constant.attribute: value.upper() for value in data}
+23 | {constant.attribute: value.upper() for value in data}
-22 | {constant[0]: value.upper() for value in data}
+24 | {constant[0]: value.upper() for value in data}
    |
 
-RUF011.py:21:2: RUF011 Dictionary comprehension uses static key: `constant.attribute`
+RUF011.py:23:2: RUF011 Dictionary comprehension uses static key: `constant.attribute`
    |
-19 | {constant: value.upper() for value in data}
+21 | {constant: value.upper() for value in data}
-20 | {constant + constant: value.upper() for value in data}
+22 | {constant + constant: value.upper() for value in data}
-21 | {constant.attribute: value.upper() for value in data}
+23 | {constant.attribute: value.upper() for value in data}
    |  ^^^^^^^^^^^^^^^^^^ RUF011
-22 | {constant[0]: value.upper() for value in data}
+24 | {constant[0]: value.upper() for value in data}
+25 | {tokens: token for token in tokens}
    |
 
-RUF011.py:22:2: RUF011 Dictionary comprehension uses static key: `constant[0]`
+RUF011.py:24:2: RUF011 Dictionary comprehension uses static key: `constant[0]`
    |
-20 | {constant + constant: value.upper() for value in data}
+22 | {constant + constant: value.upper() for value in data}
-21 | {constant.attribute: value.upper() for value in data}
+23 | {constant.attribute: value.upper() for value in data}
-22 | {constant[0]: value.upper() for value in data}
+24 | {constant[0]: value.upper() for value in data}
    |  ^^^^^^^^^^^ RUF011
+25 | {tokens: token for token in tokens}
+   |
+
+RUF011.py:25:2: RUF011 Dictionary comprehension uses static key: `tokens`
+   |
+23 | {constant.attribute: value.upper() for value in data}
+24 | {constant[0]: value.upper() for value in data}
+25 | {tokens: token for token in tokens}
+   |  ^^^^^^ RUF011
    |
 
 

crates/ruff_python_ast/src/helpers.rs

@@ -914,6 +914,27 @@ where
     }
 }
 
+/// A [`Visitor`] to collect all stored [`Expr::Name`] nodes in an AST.
+#[derive(Debug, Default)]
+pub struct StoredNameFinder<'a> {
+    /// A map from identifier to defining expression.
+    pub names: FxHashMap<&'a str, &'a ast::ExprName>,
+}
+
+impl<'a, 'b> Visitor<'b> for StoredNameFinder<'a>
+where
+    'b: 'a,
+{
+    fn visit_expr(&mut self, expr: &'a Expr) {
+        if let Expr::Name(name) = expr {
+            if name.ctx.is_store() {
+                self.names.insert(&name.id, name);
+            }
+        }
+        crate::visitor::walk_expr(self, expr);
+    }
+}
+
 /// A [`StatementVisitor`] that collects all `return` statements in a function or method.
 #[derive(Default)]
 pub struct ReturnStatementVisitor<'a> {