[ruff] Skip singleton starred expressions for `incorrectly-parenthe…

…sized-tuple-in-subscript` (`RUF031`) (#16083)

The index in subscript access like `d[*y]` will not be linted or
autofixed with parentheses, even when
`lint.ruff.parenthesize-tuple-in-subscript = true`.

Closes #16077

crates/ruff_linter/resources/test/fixtures/ruff/RUF031.py

@@ -42,3 +42,7 @@
 type Y = typing.Literal[1, 2]
 Z: typing.TypeAlias = dict[int, int]
 class Foo(dict[str, int]): pass
+
+# Skip tuples of length one that are single-starred expressions
+# https://github.com/astral-sh/ruff/issues/16077
+d[*x]

crates/ruff_linter/resources/test/fixtures/ruff/RUF031_prefer_parens.py

@@ -42,3 +42,7 @@
 type Y = typing.Literal[1, 2]
 Z: typing.TypeAlias = dict[int, int]
 class Foo(dict[str, int]): pass
+
+# Skip tuples of length one that are single-starred expressions
+# https://github.com/astral-sh/ruff/issues/16077
+d[*x]

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

@@ -73,6 +73,12 @@ pub(crate) fn subscript_with_parenthesized_tuple(checker: &Checker, subscript: &
         return;
     }
 
+    // We should not handle single starred expressions
+    // (regardless of `prefer_parentheses`)
+    if matches!(&tuple_subscript.elts[..], &[Expr::Starred(_)]) {
+        return;
+    }
+
     // Adding parentheses in the presence of a slice leads to a syntax error.
     if prefer_parentheses && tuple_subscript.iter().any(Expr::is_slice_expr) {
         return;