Improve error messages for except* (B025, B029, B030, B904) #14791

crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B025.py

@@ -1,6 +1,6 @@
 """
 Should emit:
-B025 - on lines 15, 22, 31
+B025 - on lines 15, 22, 31, 40, 47, 56
 """
 
 import pickle
@@ -36,3 +36,28 @@
     a = 2
 except (OSError, TypeError):
     a = 2
+
+try:
+    a = 1
+except* ValueError:
+    a = 2
+except* ValueError:
+    a = 2
+
+try:
+    a = 1
+except* pickle.PickleError:
+    a = 2
+except* ValueError:
+    a = 2
+except* pickle.PickleError:
+    a = 2
+
+try:
+    a = 1
+except* (ValueError, TypeError):
+    a = 2
+except* ValueError:
+    a = 2
+except* (OSError, TypeError):
+    a = 2

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

@@ -1435,6 +1435,7 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             handlers,
             orelse,
             finalbody,
+            is_star,
             ..
         }) => {
             if checker.enabled(Rule::TooManyNestedBlocks) {
@@ -1459,7 +1460,7 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
                 Rule::DuplicateHandlerException,
                 Rule::DuplicateTryBlockException,
             ]) {
-                flake8_bugbear::rules::duplicate_exceptions(checker, handlers);
+                flake8_bugbear::rules::duplicate_exceptions(checker, handlers, *is_star);
             }
             if checker.enabled(Rule::RedundantTupleInExceptionHandler) {
                 flake8_bugbear::rules::redundant_tuple_in_exception_handler(checker, handlers);

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

@@ -42,13 +42,19 @@ use crate::registry::Rule;
 #[derive(ViolationMetadata)]
 pub(crate) struct DuplicateTryBlockException {
     name: String,
+    is_star: bool,
 }
 
 impl Violation for DuplicateTryBlockException {
     #[derive_message_formats]
     fn message(&self) -> String {
-        let DuplicateTryBlockException { name } = self;
-        format!("try-except block with duplicate exception `{name}`")
+        let DuplicateTryBlockException { name, is_star } = self;
+        let star = if *is_star {
+            "*".to_string()
+        } else {
+            String::new()
+        };
+        format!("try-except{star} block with duplicate exception `{name}`")
     }
 }
 
@@ -170,7 +176,11 @@ fn duplicate_handler_exceptions<'a>(
 }
 
 /// B025
-pub(crate) fn duplicate_exceptions(checker: &mut Checker, handlers: &[ExceptHandler]) {
+pub(crate) fn duplicate_exceptions(
+    checker: &mut Checker,
+    handlers: &[ExceptHandler],
+    is_star: bool,
+) {
     let mut seen: FxHashSet<UnqualifiedName> = FxHashSet::default();
     let mut duplicates: FxHashMap<UnqualifiedName, Vec<&Expr>> = FxHashMap::default();
     for handler in handlers {
@@ -210,6 +220,7 @@ pub(crate) fn duplicate_exceptions(checker: &mut Checker, handlers: &[ExceptHand
                 checker.diagnostics.push(Diagnostic::new(
                     DuplicateTryBlockException {
                         name: name.segments().join("."),
+                        is_star,
                     },
                     expr.range(),
                 ));