[flake8-bugbear] Add fix for duplicate-value (B033)

crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B033.py

@@ -2,7 +2,7 @@
 # Errors.
 ###
 incorrect_set = {"value1", 23, 5, "value1"}
-incorrect_set = {1, 1}
+incorrect_set = {1, 1, 2, 1}
 
 ###
 # Non-errors.

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

@@ -980,9 +980,9 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 flake8_pie::rules::unnecessary_spread(checker, dict);
             }
         }
-        Expr::Set(ast::ExprSet { elts, range: _ }) => {
+        Expr::Set(ast::ExprSet { elts, range }) => {
             if checker.enabled(Rule::DuplicateValue) {
-                flake8_bugbear::rules::duplicate_value(checker, elts);
+                flake8_bugbear::rules::duplicate_value(checker, elts, *range);
             }
         }
         Expr::Yield(_) => {

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

@@ -1,10 +1,10 @@
-use ruff_python_ast::Expr;
+use ruff_python_ast::{Expr, ExprSet};
 use rustc_hash::FxHashSet;
 
-use ruff_diagnostics::{Diagnostic, Violation};
+use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast::comparable::ComparableExpr;
-use ruff_text_size::Ranged;
+use ruff_text_size::{Ranged, TextRange};
 
 use crate::checkers::ast::Checker;
 
@@ -30,29 +30,65 @@ pub struct DuplicateValue {
     value: String,
 }
 
-impl Violation for DuplicateValue {
+impl AlwaysFixableViolation for DuplicateValue {
     #[derive_message_formats]
     fn message(&self) -> String {
         let DuplicateValue { value } = self;
         format!("Sets should not contain duplicate item `{value}`")
     }
+
+    fn fix_title(&self) -> String {
+        let DuplicateValue { value } = self;
+        format!("Remove duplicate item `{value}`")
+    }
 }
 
 /// B033
-pub(crate) fn duplicate_value(checker: &mut Checker, elts: &Vec<Expr>) {
+pub(crate) fn duplicate_value(checker: &mut Checker, elts: &[Expr], range: TextRange) {
     let mut seen_values: FxHashSet<ComparableExpr> = FxHashSet::default();
-    for elt in elts {
+    let mut duplicate_indices: Vec<usize> = Vec::new();
+    let mut unique_indices: Vec<usize> = Vec::new();
+
+    for (index, elt) in elts.iter().enumerate() {
         if elt.is_literal_expr() {
             let comparable_value: ComparableExpr = elt.into();
 
-            if !seen_values.insert(comparable_value) {
-                checker.diagnostics.push(Diagnostic::new(
-                    DuplicateValue {
-                        value: checker.generator().expr(elt),
-                    },
-                    elt.range(),
-                ));
+            if seen_values.insert(comparable_value) {
+                unique_indices.push(index);
+            } else {
+                duplicate_indices.push(index);
             }
-        };
+        } else {
+            unique_indices.push(index);
+        }
+    }
+
+    if duplicate_indices.is_empty() {
+        return;
+    }
+
+    let fix = Fix::safe_edit(Edit::range_replacement(
+        checker.generator().expr(&Expr::Set(ExprSet {
+            elts: unique_indices
+                .into_iter()
+                .map(|index| elts[index].clone())
+                .collect(),
+            range: TextRange::default(),
+        })),
+        range,
+    ));
+
+    for index in duplicate_indices {
+        let elt = &elts[index];
+        let mut diagnostic = Diagnostic::new(
+            DuplicateValue {
+                value: checker.generator().expr(elt),
+            },
+            elt.range(),
+        );
+
+        diagnostic.set_fix(fix.clone());
+
+        checker.diagnostics.push(diagnostic);
     }
 }

crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B033_B033.py.snap

@@ -1,23 +1,66 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs
 ---
-B033.py:4:35: B033 Sets should not contain duplicate item `"value1"`
+B033.py:4:35: B033 [*] Sets should not contain duplicate item `"value1"`
   |
 2 | # Errors.
 3 | ###
 4 | incorrect_set = {"value1", 23, 5, "value1"}
   |                                   ^^^^^^^^ B033
-5 | incorrect_set = {1, 1}
+5 | incorrect_set = {1, 1, 2, 1}
   |
+  = help: Remove duplicate item `"value1"`
 
-B033.py:5:21: B033 Sets should not contain duplicate item `1`
+ℹ Safe fix
+1 1 | ###
+2 2 | # Errors.
+3 3 | ###
+4   |-incorrect_set = {"value1", 23, 5, "value1"}
+  4 |+incorrect_set = {"value1", 23, 5}
+5 5 | incorrect_set = {1, 1, 2, 1}
+6 6 | 
+7 7 | ###
+
+B033.py:5:21: B033 [*] Sets should not contain duplicate item `1`
   |
 3 | ###
 4 | incorrect_set = {"value1", 23, 5, "value1"}
-5 | incorrect_set = {1, 1}
+5 | incorrect_set = {1, 1, 2, 1}
   |                     ^ B033
 6 | 
 7 | ###
   |
+  = help: Remove duplicate item `1`
+
+ℹ Safe fix
+2 2 | # Errors.
+3 3 | ###
+4 4 | incorrect_set = {"value1", 23, 5, "value1"}
+5   |-incorrect_set = {1, 1, 2, 1}
+  5 |+incorrect_set = {1, 2}
+6 6 | 
+7 7 | ###
+8 8 | # Non-errors.
+
+B033.py:5:27: B033 [*] Sets should not contain duplicate item `1`
+  |
+3 | ###
+4 | incorrect_set = {"value1", 23, 5, "value1"}
+5 | incorrect_set = {1, 1, 2, 1}
+  |                           ^ B033
+6 | 
+7 | ###
+  |
+  = help: Remove duplicate item `1`
+
+ℹ Safe fix
+2 2 | # Errors.
+3 3 | ###
+4 4 | incorrect_set = {"value1", 23, 5, "value1"}
+5   |-incorrect_set = {1, 1, 2, 1}
+  5 |+incorrect_set = {1, 2}
+6 6 | 
+7 7 | ###
+8 8 | # Non-errors.