Fix panic when formatting comments in unary expressions

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/unary.py

@@ -193,3 +193,19 @@ def foo():
         not (aaaaaaaaaaaaaaaaaaaaa[bbbbbbbb, ccccccc]) and dddddddddd < eeeeeeeeeeeeeee
     ):
         pass
+
+# Regression tests for https://github.com/astral-sh/ruff/issues/19226
+if '' and (not #
+0):
+    pass
+
+if '' and (not #
+(0)
+):
+    pass
+
+if '' and (not
+	(  #
+	0
+)):
+    pass

crates/ruff_python_formatter/src/comments/placement.rs

@@ -13,6 +13,7 @@ use std::cmp::Ordering;
 
 use crate::comments::visitor::{CommentPlacement, DecoratedComment};
 use crate::expression::expr_slice::{ExprSliceCommentSection, assign_comment_in_slice};
+use crate::expression::expr_unary_op::operand_start;
 use crate::expression::parentheses::is_expression_parenthesized;
 use crate::other::parameters::{
     assign_argument_separator_comment_placement, find_parameter_separators,
@@ -1907,24 +1908,9 @@ fn handle_unary_op_comment<'a>(
     unary_op: &'a ast::ExprUnaryOp,
     source: &str,
 ) -> CommentPlacement<'a> {
-    let mut tokenizer = SimpleTokenizer::new(
-        source,
-        TextRange::new(unary_op.start(), unary_op.operand.start()),
-    )
-    .skip_trivia();
-    let op_token = tokenizer.next();
-    debug_assert!(op_token.is_some_and(|token| matches!(
-        token.kind,
-        SimpleTokenKind::Tilde
-            | SimpleTokenKind::Not
-            | SimpleTokenKind::Plus
-            | SimpleTokenKind::Minus
-    )));
-    let up_to = tokenizer
-        .find(|token| token.kind == SimpleTokenKind::LParen)
-        .map_or(unary_op.operand.start(), |lparen| lparen.start());
-    if comment.end() < up_to {
-        CommentPlacement::leading(unary_op, comment)
+    let up_to = operand_start(unary_op, source);
+    if comment.end() < up_to && comment.line_position().is_end_of_line() {
+        CommentPlacement::dangling(unary_op, comment)
     } else {
         CommentPlacement::Default(comment)
     }

crates/ruff_python_formatter/src/expression/expr_unary_op.rs

@@ -1,6 +1,9 @@
 use ruff_python_ast::AnyNodeRef;
 use ruff_python_ast::ExprUnaryOp;
 use ruff_python_ast::UnaryOp;
+use ruff_python_ast::parenthesize::parenthesized_range;
+use ruff_python_trivia::{SimpleTokenKind, SimpleTokenizer};
+use ruff_text_size::{Ranged, TextRange, TextSize};
 
 use crate::comments::trailing_comments;
 use crate::expression::parentheses::{
@@ -39,19 +42,43 @@ impl FormatNodeRule<ExprUnaryOp> for FormatExprUnaryOp {
         // ```
         trailing_comments(dangling).fmt(f)?;
 
-        // Insert a line break if the operand has comments but itself is not parenthesized.
+        // Insert a line break if the operand has comments but itself is not parenthesized or if the
+        // operand is parenthesized but has a leading comment before the parentheses.
         // ```python
         // if (
         //  not
         //  # comment
-        //  a)
+        //  a):
+        //      pass
+        //
+        // if 1 and (
+        //     not
+        //     # comment
+        //     (
+        //         a
+        //     )
+        // ):
+        //     pass
         // ```
+        let parenthesized_operand_range = parenthesized_range(
+            operand.into(),
+            item.into(),
+            comments.ranges(),
+            f.context().source(),
+        );
+        let has_leading_comments_before_parens = parenthesized_operand_range.is_some_and(|range| {
+            comments
+                .leading(operand.as_ref())
+                .iter()
+                .any(|comment| comment.start() < range.start())
+        });
         if comments.has_leading(operand.as_ref())
             && !is_expression_parenthesized(
                 operand.as_ref().into(),
                 f.context().comments().ranges(),
                 f.context().source(),
             )
+            || has_leading_comments_before_parens
         {
             hard_line_break().fmt(f)?;
         } else if op.is_not() {
@@ -76,17 +103,51 @@ impl NeedsParentheses for ExprUnaryOp {
         context: &PyFormatContext,
     ) -> OptionalParentheses {
         if parent.is_expr_await() {
-            OptionalParentheses::Always
-        } else if is_expression_parenthesized(
+            return OptionalParentheses::Always;
+        }
+
+        if is_expression_parenthesized(
             self.operand.as_ref().into(),
             context.comments().ranges(),
             context.source(),
         ) {
-            OptionalParentheses::Never
-        } else if context.comments().has(self.operand.as_ref()) {
+            return OptionalParentheses::Never;
+        }
+
+        let operand_start = operand_start(self, context.source());
+        if context
+            .comments()
+            .dangling(self)
+            .iter()
+            .any(|comment| comment.end() < operand_start)
+        {
+            return OptionalParentheses::Multiline;
+        }
+
+        if context.comments().has(self.operand.as_ref()) {
             OptionalParentheses::Always
         } else {
             self.operand.needs_parentheses(self.into(), context)
         }
     }
 }
+
+/// Returns the start of `unary_op`'s operand, or its leading parenthesis, if it has one.
+pub(crate) fn operand_start(unary_op: &ExprUnaryOp, source: &str) -> TextSize {
+    let mut tokenizer = SimpleTokenizer::new(
+        source,
+        TextRange::new(unary_op.start(), unary_op.operand.start()),
+    )
+    .skip_trivia();
+    let op_token = tokenizer.next();
+    debug_assert!(op_token.is_some_and(|token| matches!(
+        token.kind,
+        SimpleTokenKind::Tilde
+            | SimpleTokenKind::Not
+            | SimpleTokenKind::Plus
+            | SimpleTokenKind::Minus
+    )));
+    tokenizer
+        .find(|token| token.kind == SimpleTokenKind::LParen)
+        .map_or(unary_op.operand.start(), |lparen| lparen.start())
+}

crates/ruff_python_formatter/tests/snapshots/format@expression__unary.py.snap

@@ -1,7 +1,6 @@
 ---
 source: crates/ruff_python_formatter/tests/fixtures.rs
 input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/unary.py
-snapshot_kind: text
 ---
 ## Input
 ```python
@@ -200,6 +199,22 @@ def foo():
         not (aaaaaaaaaaaaaaaaaaaaa[bbbbbbbb, ccccccc]) and dddddddddd < eeeeeeeeeeeeeee
     ):
         pass
+
+# Regression tests for https://github.com/astral-sh/ruff/issues/19226
+if '' and (not #
+0):
+    pass
+
+if '' and (not #
+(0)
+):
+    pass
+
+if '' and (not
+	(  #
+	0
+)):
+    pass
 ```
 
 ## Output
@@ -250,31 +265,35 @@ if +(
     pass
 
 if (
+    not
     # comment
-    not aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
 
 
 if (
+    ~
     # comment
-    ~aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
 
 if (
+    -
     # comment
-    -aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
 
 
 if (
+    +
     # comment
-    +aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
@@ -283,8 +302,9 @@ if (
 
 if (
     # unary comment
+    not
     # operand comment
-    not (
+    (
         # comment
         aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
         + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
@@ -318,31 +338,28 @@ if (
 
 ## Trailing operator comments
 
-if (  # comment
-    not aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+if (
+    not aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  # comment
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
 
 
 if (
-    # comment
-    ~aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    ~aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  # comment
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
 
 if (
-    # comment
-    -aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    -aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  # comment
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
 
 
 if (
-    # comment
-    +aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    +aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  # comment
     + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 ):
     pass
@@ -362,13 +379,14 @@ if (
     pass
 
 if (
+    not
     # comment
-    not a
+    a
 ):
     pass
 
-if (  # comment
-    not a
+if (
+    not a  # comment
 ):
     pass
 
@@ -385,9 +403,9 @@ if True:
 # Regression test for: https://github.com/astral-sh/ruff/issues/7448
 x = (
     # a
-    # b
+    not  # b
     # c
-    not (  # d
+    (  # d
         # e
         True
     )
@@ -415,4 +433,23 @@ def foo():
         not (aaaaaaaaaaaaaaaaaaaaa[bbbbbbbb, ccccccc]) and dddddddddd < eeeeeeeeeeeeeee
     ):
         pass
+
+
+# Regression tests for https://github.com/astral-sh/ruff/issues/19226
+if "" and (
+    not 0  #
+):
+    pass
+
+if "" and (
+    not (0)  #
+):
+    pass
+
+if "" and (
+    not (  #
+        0
+    )
+):
+    pass
 ```

crates/ruff_python_formatter/tests/snapshots/format@parentheses__expression_parentheses_comments.py.snap

@@ -1,7 +1,6 @@
 ---
 source: crates/ruff_python_formatter/tests/fixtures.rs
 input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/parentheses/expression_parentheses_comments.py
-snapshot_kind: text
 ---
 ## Input
 ```python
@@ -179,13 +178,13 @@ nested_parentheses4 = [
 
 x = (
     # unary comment
+    not
     # in-between comment
-    not (
+    (
         # leading inner
         "a"
     ),
-    # in-between comment
-    not (
+    not (  # in-between comment
         # leading inner
         "b"
     ),
@@ -194,17 +193,17 @@ x = (
         "c"
     ),
     # 1
-    # 2
-    not (  # 3
+    not (  # 2  # 3
         # 4
         "d"
     ),
 )
 
 if (
     # unary comment
+    not
     # in-between comment
-    not (
+    (
         # leading inner
         1
     )