Allow starred arguments in B030 (#3871)

crates/ruff/resources/test/fixtures/flake8_bugbear/B030.py

@@ -28,6 +28,11 @@ except (ValueError, *(RuntimeError, (KeyError, TypeError))):  # error
     pass
 
 
+try:
+    pass
+except (*a, *(RuntimeError, (KeyError, TypeError))):  # error
+    pass
+
 try:
     pass
 except (ValueError, *(RuntimeError, TypeError)):  # ok
@@ -38,10 +43,36 @@ try:
 except (ValueError, *[RuntimeError, *(TypeError,)]):  # ok
     pass
 
+
+try:
+    pass
+except (*a, *b):  # ok
+    pass
+
+
+try:
+    pass
+except (*a, *(RuntimeError, TypeError)):  # ok
+    pass
+
+
+try:
+    pass
+except (*a, *(b, c)):  # ok
+    pass
+
+
+try:
+    pass
+except (*a, *(*b, *c)):  # ok
+    pass
+
+
 def what_to_catch():
     return ...
 
+
 try:
     pass
 except what_to_catch():  # ok
-    pass
+    pass

crates/ruff/src/rules/flake8_bugbear/rules/except_with_empty_tuple.rs

@@ -13,17 +13,17 @@ pub struct ExceptWithEmptyTuple;
 impl Violation for ExceptWithEmptyTuple {
     #[derive_message_formats]
     fn message(&self) -> String {
-        format!("Using except (): with an empty tuple does not handle/catch anything. Add exceptions to handle.")
+        format!("Using `except ():` with an empty tuple does not catch anything; add exceptions to handle")
     }
 }
 
 /// B029
 pub fn except_with_empty_tuple(checker: &mut Checker, excepthandler: &Excepthandler) {
     let ExcepthandlerKind::ExceptHandler { type_, .. } = &excepthandler.node;
-    if type_.is_none() {
+    let Some(type_) = type_ else {
         return;
-    }
-    let ExprKind::Tuple { elts, .. } = &type_.as_ref().unwrap().node else {
+    };
+    let ExprKind::Tuple { elts, .. } = &type_.node else {
         return;
     };
     if elts.is_empty() {

crates/ruff/src/rules/flake8_bugbear/rules/except_with_non_exception_classes.rs

@@ -33,7 +33,7 @@ fn flatten_starred_iterables(expr: &Expr) -> Vec<&Expr> {
                 ExprKind::Tuple { elts, .. } | ExprKind::List { elts, .. } => {
                     exprs_to_process.append(&mut elts.iter().collect());
                 }
-                _ => flattened_exprs.push(expr),
+                _ => flattened_exprs.push(value),
             },
             _ => flattened_exprs.push(expr),
         }
@@ -48,12 +48,17 @@ pub fn except_with_non_exception_classes(checker: &mut Checker, excepthandler: &
         return;
     };
     for expr in flatten_starred_iterables(type_) {
-        match expr.node {
-            ExprKind::Attribute { .. } | ExprKind::Name { .. } | ExprKind::Call { .. } => (),
-            _ => checker.diagnostics.push(Diagnostic::new(
+        if !matches!(
+            &expr.node,
+            ExprKind::Subscript { .. }
+                | ExprKind::Attribute { .. }
+                | ExprKind::Name { .. }
+                | ExprKind::Call { .. },
+        ) {
+            checker.diagnostics.push(Diagnostic::new(
                 ExceptWithNonExceptionClasses,
                 Range::from(expr),
-            )),
+            ));
         }
     }
 }

crates/ruff/src/rules/flake8_bugbear/snapshots/ruff__rules__flake8_bugbear__tests__B029_B029.py.snap

@@ -4,7 +4,7 @@ expression: diagnostics
 ---
 - kind:
     name: ExceptWithEmptyTuple
-    body: "Using except (): with an empty tuple does not handle/catch anything. Add exceptions to handle."
+    body: "Using `except ():` with an empty tuple does not catch anything; add exceptions to handle"
     suggestion: ~
     fixable: false
   location:
@@ -18,7 +18,7 @@ expression: diagnostics
   parent: ~
 - kind:
     name: ExceptWithEmptyTuple
-    body: "Using except (): with an empty tuple does not handle/catch anything. Add exceptions to handle."
+    body: "Using `except ():` with an empty tuple does not catch anything; add exceptions to handle"
     suggestion: ~
     fixable: false
   location:

crates/ruff/src/rules/flake8_bugbear/snapshots/ruff__rules__flake8_bugbear__tests__B030_B030.py.snap

@@ -58,4 +58,18 @@ expression: diagnostics
   fix:
     edits: []
   parent: ~
+- kind:
+    name: ExceptWithNonExceptionClasses
+    body: "`except` handlers should only be exception classes or tuples of exception classes"
+    suggestion: ~
+    fixable: false
+  location:
+    row: 33
+    column: 28
+  end_location:
+    row: 33
+    column: 49
+  fix:
+    edits: []
+  parent: ~