Respect `fmt: skip` for compound statements on single line (#20633)

Closes #11216

Essentially the approach is to implement `Format` for a new struct
`FormatClause` which is just a clause header _and_ its body. We then
have the information we need to see whether there is a skip suppression
comment on the last child in the body and it all fits on one line.

crates/ruff_python_formatter/resources/test/fixtures/ruff/fmt_skip/compound_one_liners.py

@@ -0,0 +1,149 @@
+# Test cases for fmt: skip on compound statements that fit on one line
+
+# Basic single-line compound statements
+def simple_func(): return "hello"  # fmt: skip
+if True: print("condition met")  # fmt: skip
+for i in range(5): print(i)  # fmt: skip
+while x < 10: x += 1  # fmt: skip
+
+# With expressions that would normally trigger formatting
+def long_params(a, b, c, d, e, f, g): return a + b + c + d + e + f + g  # fmt: skip
+if some_very_long_condition_that_might_wrap: do_something_else_that_is_long()  # fmt: skip
+
+# Nested compound statements (outer should be preserved)
+if True:
+    for i in range(10): print(i)  # fmt: skip
+
+# Multiple statements in body (should not apply - multiline)
+if True:
+    x = 1
+    y   =   2  # fmt: skip
+
+# With decorators - decorated function on one line
+@overload
+def decorated_func(x: int) -> str: return str(x)  # fmt: skip
+
+@property
+def prop_method(self): return self._value  # fmt: skip
+
+# Class definitions on one line
+class SimpleClass: pass  # fmt: skip
+class GenericClass(Generic[T]): pass  # fmt: skip
+
+# Try/except blocks
+try: risky_operation()  # fmt: skip
+except ValueError: handle_error()  # fmt: skip
+except: handle_any_error()  # fmt: skip
+else: success_case()  # fmt: skip
+finally: cleanup()  # fmt: skip
+
+# Match statements (Python 3.10+)
+match value:
+    case 1: print("one")  # fmt: skip
+    case _: print("other")  # fmt: skip
+
+# With statements
+with open("file.txt") as f: content = f.read()  # fmt: skip
+with context_manager() as cm: result = cm.process()  # fmt: skip
+
+# Async variants
+async def async_func(): return await some_call()  # fmt: skip
+async for item in async_iterator(): await process(item)  # fmt: skip
+async with async_context() as ctx: await ctx.work()  # fmt: skip
+
+# Complex expressions that would normally format
+def complex_expr(): return [x for x in range(100) if x % 2 == 0 and x > 50]  # fmt: skip
+if condition_a and condition_b or (condition_c and not condition_d): execute_complex_logic()  # fmt: skip
+
+# Edge case: comment positioning
+def func_with_comment():  # some comment
+    return "value"  # fmt: skip
+
+# Edge case: multiple fmt: skip (only last one should matter)
+def multiple_skip(): return "test"  # fmt: skip  # fmt: skip
+
+# Should NOT be affected (already multiline)
+def multiline_func():
+    return "this should format normally"
+
+if long_condition_that_spans \
+   and continues_on_next_line:
+    print("multiline condition")
+
+# Mix of skipped and non-skipped
+for i in range(10): print(f"item {i}")  # fmt: skip
+for j in range(5):
+    print(f"formatted item {j}")
+
+# With trailing comma that would normally be removed
+def trailing_comma_func(a, b, c,): return a + b + c  # fmt: skip
+
+# Dictionary/list comprehensions
+def dict_comp(): return {k: v for k, v in items.items() if v is not None}  # fmt: skip
+def list_comp(): return [x * 2 for x in numbers if x > threshold_value]  # fmt: skip
+
+# Lambda in one-liner
+def with_lambda(): return lambda x, y, z: x + y + z if all([x, y, z]) else None  # fmt: skip
+
+# String formatting that would normally be reformatted
+def format_string(): return f"Hello {name}, you have {count} items in your cart totaling ${total:.2f}"  # fmt: skip
+
+# loop else clauses
+for i in range(2): print(i) # fmt: skip
+else: print("this") # fmt: skip
+
+
+while foo(): print(i) # fmt: skip
+else: print("this") # fmt: skip
+
+# again but only the first skip
+for i in range(2): print(i) # fmt: skip
+else: print("this")
+
+
+while foo(): print(i) # fmt: skip
+else: print("this")
+
+# again but only the second skip
+for i in range(2): print(i)
+else: print("this") # fmt: skip
+
+
+while foo(): print(i)
+else: print("this") # fmt: skip
+
+# multiple statements in body
+if True: print("this"); print("that") # fmt: skip
+
+# Examples with more comments
+
+try: risky_operation()  # fmt: skip
+# leading 1
+except ValueError: handle_error()  # fmt: skip
+# leading 2
+except: handle_any_error()  # fmt: skip
+# leading 3
+else: success_case()  # fmt: skip
+# leading 4
+finally: cleanup()  # fmt: skip
+# trailing
+
+# multi-line before colon (should remain as is)
+if (
+	long_condition
+):  a     +     b # fmt: skip
+
+# over-indented comment example
+# See https://github.com/astral-sh/ruff/pull/20633#issuecomment-3453288910
+# and https://github.com/astral-sh/ruff/pull/21185
+
+for x in it: foo()
+    # comment
+else: bar() # fmt: skip
+
+
+if this(
+    'is a long',
+    # commented
+    'condition'
+): with_a_skip # fmt: skip

crates/ruff_python_formatter/src/other/except_handler_except_handler.rs

@@ -7,7 +7,7 @@ use crate::expression::maybe_parenthesize_expression;
 use crate::expression::parentheses::Parenthesize;
 use crate::prelude::*;
 use crate::preview::is_remove_parens_around_except_types_enabled;
-use crate::statement::clause::{ClauseHeader, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Copy, Clone, Default)]
@@ -55,10 +55,8 @@ impl FormatNodeRule<ExceptHandlerExceptHandler> for FormatExceptHandlerExceptHan
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(
                 ClauseHeader::ExceptHandler(item),
-                    dangling_comments,
                 &format_with(|f: &mut PyFormatter| {
                     write!(
                         f,
@@ -83,18 +81,14 @@ impl FormatNodeRule<ExceptHandlerExceptHandler> for FormatExceptHandlerExceptHan
                         // ```
                         Some(Expr::Tuple(tuple))
                             if f.options().target_version() >= PythonVersion::PY314
-                                    && is_remove_parens_around_except_types_enabled(
+                                && is_remove_parens_around_except_types_enabled(f.context())
-                                        f.context(),
-                                    )
                                 && name.is_none() =>
                         {
                             write!(
                                 f,
                                 [
                                     space(),
-                                        tuple
+                                    tuple.format().with_options(TupleParentheses::NeverPreserve)
-                                            .format()
-                                            .with_options(TupleParentheses::NeverPreserve)
                                 ]
                             )?;
                         }
@@ -119,13 +113,10 @@ impl FormatNodeRule<ExceptHandlerExceptHandler> for FormatExceptHandlerExceptHan
 
                     Ok(())
                 }),
-                ),
+                dangling_comments,
-                clause_body(
                 body,
                 SuiteKind::other(self.last_suite_in_statement),
-                    dangling_comments
+            )]
-                ),
-            ]
         )
     }
 }

crates/ruff_python_formatter/src/other/match_case.rs

@@ -5,7 +5,7 @@ use crate::expression::maybe_parenthesize_expression;
 use crate::expression::parentheses::Parenthesize;
 use crate::pattern::maybe_parenthesize_pattern;
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Default)]
@@ -46,23 +46,18 @@ impl FormatNodeRule<MatchCase> for FormatMatchCase {
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(
                 ClauseHeader::MatchCase(item),
-                    dangling_item_comments,
                 &format_args![
                     token("case"),
                     space(),
                     maybe_parenthesize_pattern(pattern, item),
                     format_guard
                 ],
-                ),
+                dangling_item_comments,
-                clause_body(
                 body,
                 SuiteKind::other(self.last_suite_in_statement),
-                    dangling_item_comments
+            )]
-                ),
-            ]
         )
     }
 }

crates/ruff_python_formatter/src/statement/clause.rs

@@ -5,11 +5,12 @@ use ruff_python_ast::{
     StmtIf, StmtMatch, StmtTry, StmtWhile, StmtWith, Suite,
 };
 use ruff_python_trivia::{SimpleToken, SimpleTokenKind, SimpleTokenizer};
+use ruff_source_file::LineRanges;
 use ruff_text_size::{Ranged, TextRange, TextSize};
 
 use crate::comments::{SourceComment, leading_alternate_branch_comments, trailing_comments};
 use crate::statement::suite::{SuiteKind, as_only_an_ellipsis};
-use crate::verbatim::write_suppressed_clause_header;
+use crate::verbatim::{verbatim_text, write_suppressed_clause_header};
 use crate::{has_skip_comment, prelude::*};
 
 /// The header of a compound statement clause.
@@ -36,7 +37,41 @@ pub(crate) enum ClauseHeader<'a> {
     OrElse(ElseClause<'a>),
 }
 
-impl ClauseHeader<'_> {
+impl<'a> ClauseHeader<'a> {
+    /// Returns the last child in the clause body immediately following this clause header.
+    ///
+    /// For most clauses, this is the last statement in
+    /// the primary body. For clauses like `try`, it specifically returns the last child
+    /// in the `try` body, not the `except`/`else`/`finally` clauses.
+    ///
+    /// This is similar to [`ruff_python_ast::AnyNodeRef::last_child_in_body`]
+    /// but restricted to the clause.
+    pub(crate) fn last_child_in_clause(self) -> Option<AnyNodeRef<'a>> {
+        match self {
+            ClauseHeader::Class(StmtClassDef { body, .. })
+            | ClauseHeader::Function(StmtFunctionDef { body, .. })
+            | ClauseHeader::If(StmtIf { body, .. })
+            | ClauseHeader::ElifElse(ElifElseClause { body, .. })
+            | ClauseHeader::Try(StmtTry { body, .. })
+            | ClauseHeader::MatchCase(MatchCase { body, .. })
+            | ClauseHeader::For(StmtFor { body, .. })
+            | ClauseHeader::While(StmtWhile { body, .. })
+            | ClauseHeader::With(StmtWith { body, .. })
+            | ClauseHeader::ExceptHandler(ExceptHandlerExceptHandler { body, .. })
+            | ClauseHeader::OrElse(
+                ElseClause::Try(StmtTry { orelse: body, .. })
+                | ElseClause::For(StmtFor { orelse: body, .. })
+                | ElseClause::While(StmtWhile { orelse: body, .. }),
+            )
+            | ClauseHeader::TryFinally(StmtTry {
+                finalbody: body, ..
+            }) => body.last().map(AnyNodeRef::from),
+            ClauseHeader::Match(StmtMatch { cases, .. }) => cases
+                .last()
+                .and_then(|case| case.body.last().map(AnyNodeRef::from)),
+        }
+    }
+
     /// The range from the clause keyword up to and including the final colon.
     pub(crate) fn range(self, source: &str) -> FormatResult<TextRange> {
         let keyword_range = self.first_keyword_range(source)?;
@@ -338,6 +373,28 @@ impl ClauseHeader<'_> {
     }
 }
 
+impl<'a> From<ClauseHeader<'a>> for AnyNodeRef<'a> {
+    fn from(value: ClauseHeader<'a>) -> Self {
+        match value {
+            ClauseHeader::Class(stmt_class_def) => stmt_class_def.into(),
+            ClauseHeader::Function(stmt_function_def) => stmt_function_def.into(),
+            ClauseHeader::If(stmt_if) => stmt_if.into(),
+            ClauseHeader::ElifElse(elif_else_clause) => elif_else_clause.into(),
+            ClauseHeader::Try(stmt_try) => stmt_try.into(),
+            ClauseHeader::ExceptHandler(except_handler_except_handler) => {
+                except_handler_except_handler.into()
+            }
+            ClauseHeader::TryFinally(stmt_try) => stmt_try.into(),
+            ClauseHeader::Match(stmt_match) => stmt_match.into(),
+            ClauseHeader::MatchCase(match_case) => match_case.into(),
+            ClauseHeader::For(stmt_for) => stmt_for.into(),
+            ClauseHeader::While(stmt_while) => stmt_while.into(),
+            ClauseHeader::With(stmt_with) => stmt_with.into(),
+            ClauseHeader::OrElse(else_clause) => else_clause.into(),
+        }
+    }
+}
+
 #[derive(Copy, Clone)]
 pub(crate) enum ElseClause<'a> {
     Try(&'a StmtTry),
@@ -345,6 +402,16 @@ pub(crate) enum ElseClause<'a> {
     While(&'a StmtWhile),
 }
 
+impl<'a> From<ElseClause<'a>> for AnyNodeRef<'a> {
+    fn from(value: ElseClause<'a>) -> Self {
+        match value {
+            ElseClause::Try(stmt_try) => stmt_try.into(),
+            ElseClause::For(stmt_for) => stmt_for.into(),
+            ElseClause::While(stmt_while) => stmt_while.into(),
+        }
+    }
+}
+
 pub(crate) struct FormatClauseHeader<'a, 'ast> {
     header: ClauseHeader<'a>,
     /// How to format the clause header
@@ -378,22 +445,6 @@ where
     }
 }
 
-impl<'a> FormatClauseHeader<'a, '_> {
-    /// Sets the leading comments that precede an alternate branch.
-    #[must_use]
-    pub(crate) fn with_leading_comments<N>(
-        mut self,
-        comments: &'a [SourceComment],
-        last_node: Option<N>,
-    ) -> Self
-    where
-        N: Into<AnyNodeRef<'a>>,
-    {
-        self.leading_comments = Some((comments, last_node.map(Into::into)));
-        self
-    }
-}
-
 impl<'ast> Format<PyFormatContext<'ast>> for FormatClauseHeader<'_, 'ast> {
     fn fmt(&self, f: &mut Formatter<PyFormatContext<'ast>>) -> FormatResult<()> {
         if let Some((leading_comments, last_node)) = self.leading_comments {
@@ -423,13 +474,13 @@ impl<'ast> Format<PyFormatContext<'ast>> for FormatClauseHeader<'_, 'ast> {
     }
 }
 
-pub(crate) struct FormatClauseBody<'a> {
+struct FormatClauseBody<'a> {
     body: &'a Suite,
     kind: SuiteKind,
     trailing_comments: &'a [SourceComment],
 }
 
-pub(crate) fn clause_body<'a>(
+fn clause_body<'a>(
     body: &'a Suite,
     kind: SuiteKind,
     trailing_comments: &'a [SourceComment],
@@ -465,6 +516,84 @@ impl Format<PyFormatContext<'_>> for FormatClauseBody<'_> {
     }
 }
 
+pub(crate) struct FormatClause<'a, 'ast> {
+    header: ClauseHeader<'a>,
+    /// How to format the clause header
+    header_formatter: Argument<'a, PyFormatContext<'ast>>,
+    /// Leading comments coming before the branch, together with the previous node, if any. Only relevant
+    /// for alternate branches.
+    leading_comments: Option<(&'a [SourceComment], Option<AnyNodeRef<'a>>)>,
+    /// The trailing comments coming after the colon.
+    trailing_colon_comment: &'a [SourceComment],
+    body: &'a Suite,
+    kind: SuiteKind,
+}
+
+impl<'a, 'ast> FormatClause<'a, 'ast> {
+    /// Sets the leading comments that precede an alternate branch.
+    #[must_use]
+    pub(crate) fn with_leading_comments<N>(
+        mut self,
+        comments: &'a [SourceComment],
+        last_node: Option<N>,
+    ) -> Self
+    where
+        N: Into<AnyNodeRef<'a>>,
+    {
+        self.leading_comments = Some((comments, last_node.map(Into::into)));
+        self
+    }
+
+    fn clause_header(&self) -> FormatClauseHeader<'a, 'ast> {
+        FormatClauseHeader {
+            header: self.header,
+            formatter: self.header_formatter,
+            leading_comments: self.leading_comments,
+            trailing_colon_comment: self.trailing_colon_comment,
+        }
+    }
+
+    fn clause_body(&self) -> FormatClauseBody<'a> {
+        clause_body(self.body, self.kind, self.trailing_colon_comment)
+    }
+}
+
+/// Formats a clause, handling the case where the compound
+/// statement lies on a single line with `# fmt: skip` and
+/// should be suppressed.
+pub(crate) fn clause<'a, 'ast, Content>(
+    header: ClauseHeader<'a>,
+    header_formatter: &'a Content,
+    trailing_colon_comment: &'a [SourceComment],
+    body: &'a Suite,
+    kind: SuiteKind,
+) -> FormatClause<'a, 'ast>
+where
+    Content: Format<PyFormatContext<'ast>>,
+{
+    FormatClause {
+        header,
+        header_formatter: Argument::new(header_formatter),
+        leading_comments: None,
+        trailing_colon_comment,
+        body,
+        kind,
+    }
+}
+
+impl<'ast> Format<PyFormatContext<'ast>> for FormatClause<'_, 'ast> {
+    fn fmt(&self, f: &mut Formatter<PyFormatContext<'ast>>) -> FormatResult<()> {
+        match should_suppress_clause(self, f)? {
+            SuppressClauseHeader::Yes {
+                last_child_in_clause,
+            } => write_suppressed_clause(self, f, last_child_in_clause),
+            SuppressClauseHeader::No => {
+                write!(f, [self.clause_header(), self.clause_body()])
+            }
+        }
+    }
+}
+
 /// Finds the range of `keyword` starting the search at `start_position`.
 ///
 /// If the start position is at the end of the previous statement, the
@@ -587,3 +716,96 @@ fn colon_range(after_keyword_or_condition: TextSize, source: &str) -> FormatResu
         }
     }
 }
+
+fn should_suppress_clause<'a>(
+    clause: &FormatClause<'a, '_>,
+    f: &mut Formatter<PyFormatContext<'_>>,
+) -> FormatResult<SuppressClauseHeader<'a>> {
+    let source = f.context().source();
+
+    let Some(last_child_in_clause) = clause.header.last_child_in_clause() else {
+        return Ok(SuppressClauseHeader::No);
+    };
+
+    // Early return if we don't have a skip comment
+    // to avoid computing header range in the common case
+    if !has_skip_comment(
+        f.context().comments().trailing(last_child_in_clause),
+        source,
+    ) {
+        return Ok(SuppressClauseHeader::No);
+    }
+
+    let clause_start = clause.header.range(source)?.end();
+
+    let clause_range = TextRange::new(clause_start, last_child_in_clause.end());
+
+    // Only applies to clauses on a single line
+    if source.contains_line_break(clause_range) {
+        return Ok(SuppressClauseHeader::No);
+    }
+
+    Ok(SuppressClauseHeader::Yes {
+        last_child_in_clause,
+    })
+}
+
+#[cold]
+fn write_suppressed_clause(
+    clause: &FormatClause,
+    f: &mut Formatter<PyFormatContext<'_>>,
+    last_child_in_clause: AnyNodeRef,
+) -> FormatResult<()> {
+    if let Some((leading_comments, last_node)) = clause.leading_comments {
+        leading_alternate_branch_comments(leading_comments, last_node).fmt(f)?;
+    }
+
+    let header = clause.header;
+    let clause_start = header.first_keyword_range(f.context().source())?.start();
+
+    let comments = f.context().comments().clone();
+
+    let clause_end = last_child_in_clause.end();
+
+    // Write the outer comments and format the node as verbatim
+    write!(
+        f,
+        [
+            source_position(clause_start),
+            verbatim_text(TextRange::new(clause_start, clause_end)),
+            source_position(clause_end),
+            trailing_comments(comments.trailing(last_child_in_clause)),
+            hard_line_break()
+        ]
+    )?;
+
+    // We mark comments in the header as formatted as in
+    // the implementation of [`write_suppressed_clause_header`].
+    //
+    // Note that the header may be multi-line and contain
+    // various comments since we only require that the range
+    // starting at the _colon_ and ending at the `# fmt: skip`
+    // fits on one line.
+    header.visit(&mut |child| {
+        for comment in comments.leading_trailing(child) {
+            comment.mark_formatted();
+        }
+        comments.mark_verbatim_node_comments_formatted(child);
+    });
+
+    // Similarly we mark the comments in the body as formatted.
+    // Note that the trailing comments for the last child in the
+    // body have already been handled above.
+    for stmt in clause.body {
+        comments.mark_verbatim_node_comments_formatted(stmt.into());
+    }
+
+    Ok(())
+}
+
+enum SuppressClauseHeader<'a> {
+    No,
+    Yes {
+        last_child_in_clause: AnyNodeRef<'a>,
+    },
+}

crates/ruff_python_formatter/src/statement/stmt_class_def.rs

@@ -8,7 +8,7 @@ use crate::comments::format::{
 };
 use crate::comments::{SourceComment, leading_comments, trailing_comments};
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Default)]
@@ -65,9 +65,8 @@ impl FormatNodeRule<StmtClassDef> for FormatStmtClassDef {
                     decorators: decorator_list,
                     leading_definition_comments,
                 },
-                clause_header(
+                clause(
                     ClauseHeader::Class(item),
-                    trailing_definition_comments,
                     &format_with(|f| {
                         write!(f, [token("class"), space(), name.format()])?;
 
@@ -132,8 +131,10 @@ impl FormatNodeRule<StmtClassDef> for FormatStmtClassDef {
 
                         Ok(())
                     }),
+                    trailing_definition_comments,
+                    body,
+                    SuiteKind::Class,
                 ),
-                clause_body(body, SuiteKind::Class, trailing_definition_comments),
             ]
         )?;
 

crates/ruff_python_formatter/src/statement/stmt_for.rs

@@ -6,7 +6,7 @@ use crate::expression::expr_tuple::TupleParentheses;
 use crate::expression::maybe_parenthesize_expression;
 use crate::expression::parentheses::Parenthesize;
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, ElseClause, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, ElseClause, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Debug)]
@@ -50,10 +50,8 @@ impl FormatNodeRule<StmtFor> for FormatStmtFor {
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(
                 ClauseHeader::For(item),
-                    trailing_condition_comments,
                 &format_args![
                     is_async.then_some(format_args![token("async"), space()]),
                     token("for"),
@@ -64,13 +62,10 @@ impl FormatNodeRule<StmtFor> for FormatStmtFor {
                     space(),
                     maybe_parenthesize_expression(iter, item, Parenthesize::IfBreaks),
                 ],
-                ),
+                trailing_condition_comments,
-                clause_body(
                 body,
                 SuiteKind::other(orelse.is_empty()),
-                    trailing_condition_comments
+            ),]
-                ),
-            ]
         )?;
 
         if orelse.is_empty() {
@@ -84,15 +79,14 @@ impl FormatNodeRule<StmtFor> for FormatStmtFor {
 
             write!(
                 f,
-                [
+                [clause(
-                    clause_header(
                     ClauseHeader::OrElse(ElseClause::For(item)),
-                        trailing,
                     &token("else"),
+                    trailing,
+                    orelse,
+                    SuiteKind::other(true),
                 )
-                    .with_leading_comments(leading, body.last()),
+                .with_leading_comments(leading, body.last())]
-                    clause_body(orelse, SuiteKind::other(true), trailing),
-                ]
             )?;
         }
 

crates/ruff_python_formatter/src/statement/stmt_function_def.rs

@@ -4,7 +4,7 @@ use crate::comments::format::{
 use crate::expression::maybe_parenthesize_expression;
 use crate::expression::parentheses::{Parentheses, Parenthesize};
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, clause};
 use crate::statement::stmt_class_def::FormatDecorators;
 use crate::statement::suite::SuiteKind;
 use ruff_formatter::write;
@@ -60,12 +60,13 @@ impl FormatNodeRule<StmtFunctionDef> for FormatStmtFunctionDef {
                     decorators: decorator_list,
                     leading_definition_comments,
                 },
-                clause_header(
+                clause(
                     ClauseHeader::Function(item),
-                    trailing_definition_comments,
                     &format_with(|f| format_function_header(f, item)),
+                    trailing_definition_comments,
+                    body,
+                    SuiteKind::Function,
                 ),
-                clause_body(body, SuiteKind::Function, trailing_definition_comments),
             ]
         )?;
 

crates/ruff_python_formatter/src/statement/stmt_if.rs

@@ -5,7 +5,7 @@ use ruff_text_size::Ranged;
 use crate::expression::maybe_parenthesize_expression;
 use crate::expression::parentheses::Parenthesize;
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Default)]
@@ -26,22 +26,17 @@ impl FormatNodeRule<StmtIf> for FormatStmtIf {
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(
                 ClauseHeader::If(item),
-                    trailing_colon_comment,
                 &format_args![
                     token("if"),
                     space(),
                     maybe_parenthesize_expression(test, item, Parenthesize::IfBreaks),
                 ],
-                ),
+                trailing_colon_comment,
-                clause_body(
                 body,
                 SuiteKind::other(elif_else_clauses.is_empty()),
-                    trailing_colon_comment
+            )]
-                ),
-            ]
         )?;
 
         let mut last_node = body.last().unwrap().into();
@@ -81,9 +76,8 @@ pub(crate) fn format_elif_else_clause(
     write!(
         f,
         [
-            clause_header(
+            clause(
                 ClauseHeader::ElifElse(item),
-                trailing_colon_comment,
                 &format_with(|f: &mut PyFormatter| {
                     f.options()
                         .source_map_generation()
@@ -103,9 +97,11 @@ pub(crate) fn format_elif_else_clause(
                         token("else").fmt(f)
                     }
                 }),
+                trailing_colon_comment,
+                body,
+                suite_kind,
             )
             .with_leading_comments(leading_comments, last_node),
-            clause_body(body, suite_kind, trailing_colon_comment),
             f.options()
                 .source_map_generation()
                 .is_enabled()

crates/ruff_python_formatter/src/statement/stmt_try.rs

@@ -9,7 +9,7 @@ use crate::other::except_handler_except_handler::{
     ExceptHandlerKind, FormatExceptHandlerExceptHandler,
 };
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, ElseClause, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, ElseClause, clause};
 use crate::statement::suite::SuiteKind;
 use crate::statement::{FormatRefWithRule, Stmt};
 
@@ -154,15 +154,14 @@ fn format_case<'a>(
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(header, trailing_case_comments, &token(kind.keyword()))
+                header,
-                    .with_leading_comments(leading_case_comments, previous_node),
+                &token(kind.keyword()),
-                clause_body(
+                trailing_case_comments,
                 body,
                 SuiteKind::other(last_suite_in_statement),
-                    trailing_case_comments
+            )
-                ),
+            .with_leading_comments(leading_case_comments, previous_node),]
-            ]
         )?;
         (Some(last), rest)
     } else {

crates/ruff_python_formatter/src/statement/stmt_while.rs

@@ -5,7 +5,7 @@ use ruff_text_size::Ranged;
 use crate::expression::maybe_parenthesize_expression;
 use crate::expression::parentheses::Parenthesize;
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, ElseClause, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, ElseClause, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Default)]
@@ -33,22 +33,17 @@ impl FormatNodeRule<StmtWhile> for FormatStmtWhile {
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(
                 ClauseHeader::While(item),
-                    trailing_condition_comments,
                 &format_args![
                     token("while"),
                     space(),
                     maybe_parenthesize_expression(test, item, Parenthesize::IfBreaks),
-                    ]
+                ],
-                ),
+                trailing_condition_comments,
-                clause_body(
                 body,
                 SuiteKind::other(orelse.is_empty()),
-                    trailing_condition_comments
+            )]
-                ),
-            ]
         )?;
 
         if !orelse.is_empty() {
@@ -60,15 +55,14 @@ impl FormatNodeRule<StmtWhile> for FormatStmtWhile {
 
             write!(
                 f,
-                [
+                [clause(
-                    clause_header(
                     ClauseHeader::OrElse(ElseClause::While(item)),
+                    &token("else"),
                     trailing,
-                        &token("else")
+                    orelse,
+                    SuiteKind::other(true),
                 )
-                    .with_leading_comments(leading, body.last()),
+                .with_leading_comments(leading, body.last()),]
-                    clause_body(orelse, SuiteKind::other(true), trailing),
-                ]
             )?;
         }
 

crates/ruff_python_formatter/src/statement/stmt_with.rs

@@ -13,7 +13,7 @@ use crate::expression::parentheses::{
 use crate::other::commas;
 use crate::other::with_item::WithItemLayout;
 use crate::prelude::*;
-use crate::statement::clause::{ClauseHeader, clause_body, clause_header};
+use crate::statement::clause::{ClauseHeader, clause};
 use crate::statement::suite::SuiteKind;
 
 #[derive(Default)]
@@ -46,10 +46,8 @@ impl FormatNodeRule<StmtWith> for FormatStmtWith {
 
         write!(
             f,
-            [
+            [clause(
-                clause_header(
                 ClauseHeader::With(with_stmt),
-                    colon_comments,
                 &format_with(|f| {
                     write!(
                         f,
@@ -88,9 +86,8 @@ impl FormatNodeRule<StmtWith> for FormatStmtWith {
 
                         WithItemsLayout::ParenthesizeIfExpands => {
                             parenthesize_if_expands(&format_with(|f| {
-                                    let mut joiner = f.join_comma_separated(
+                                let mut joiner =
-                                        with_stmt.body.first().unwrap().start(),
+                                    f.join_comma_separated(with_stmt.body.first().unwrap().start());
-                                    );
 
                                 for item in &with_stmt.items {
                                     joiner.entry_with_line_separator(
@@ -120,9 +117,8 @@ impl FormatNodeRule<StmtWith> for FormatStmtWith {
                         WithItemsLayout::Parenthesized => parenthesized(
                             "(",
                             &format_with(|f: &mut PyFormatter| {
-                                    let mut joiner = f.join_comma_separated(
+                                let mut joiner =
-                                        with_stmt.body.first().unwrap().start(),
+                                    f.join_comma_separated(with_stmt.body.first().unwrap().start());
-                                    );
 
                                 for item in &with_stmt.items {
                                     joiner.entry(
@@ -142,10 +138,11 @@ impl FormatNodeRule<StmtWith> for FormatStmtWith {
                         .with_dangling_comments(parenthesized_comments)
                         .fmt(f),
                     }
-                    })
+                }),
-                ),
+                colon_comments,
-                clause_body(&with_stmt.body, SuiteKind::other(true), colon_comments)
+                &with_stmt.body,
-            ]
+                SuiteKind::other(true),
+            )]
         )
     }
 }

crates/ruff_python_formatter/tests/snapshots/black_compatibility@cases__fmtskip10.py.snap

@@ -20,24 +20,16 @@ b = [c for c in "A very long string that would normally generate some kind of co
 ```diff
 --- Black
 +++ Ruff
-@@ -1,8 +1,14 @@
+@@ -1,8 +1,10 @@
--def foo(): return "mock"  # fmt: skip
+ def foo(): return "mock"  # fmt: skip
--if True: print("yay")  # fmt: skip
--for i in range(10): print(i)  # fmt: skip
-+def foo():
-+    return "mock"  # fmt: skip
 +
 +
-+if True:
+ if True: print("yay")  # fmt: skip
-+    print("yay")  # fmt: skip
+ for i in range(10): print(i)  # fmt: skip
-+for i in range(10):
-+    print(i)  # fmt: skip
  
 -j =     1 # fmt: skip
--while j < 10: j += 1  # fmt: skip
 +j =     1  # fmt: skip
-+while j < 10:
+ while j < 10: j += 1  # fmt: skip
-+    j += 1  # fmt: skip
  
 -b = [c for c in "A very long string that would normally generate some kind of collapse, since it is this long"] # fmt: skip
 +b = [c for c in "A very long string that would normally generate some kind of collapse, since it is this long"]  # fmt: skip
@@ -46,18 +38,14 @@ b = [c for c in "A very long string that would normally generate some kind of co
 ## Ruff Output
 
 ```python
-def foo():
+def foo(): return "mock"  # fmt: skip
-    return "mock"  # fmt: skip
 
 
-if True:
+if True: print("yay")  # fmt: skip
-    print("yay")  # fmt: skip
+for i in range(10): print(i)  # fmt: skip
-for i in range(10):
-    print(i)  # fmt: skip
 
 j =     1  # fmt: skip
-while j < 10:
+while j < 10: j += 1  # fmt: skip
-    j += 1  # fmt: skip
 
 b = [c for c in "A very long string that would normally generate some kind of collapse, since it is this long"]  # fmt: skip
 ```

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

@@ -0,0 +1,341 @@
+---
+source: crates/ruff_python_formatter/tests/fixtures.rs
+input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/fmt_skip/compound_one_liners.py
+---
+## Input
+```python
+# Test cases for fmt: skip on compound statements that fit on one line
+
+# Basic single-line compound statements
+def simple_func(): return "hello"  # fmt: skip
+if True: print("condition met")  # fmt: skip
+for i in range(5): print(i)  # fmt: skip
+while x < 10: x += 1  # fmt: skip
+
+# With expressions that would normally trigger formatting
+def long_params(a, b, c, d, e, f, g): return a + b + c + d + e + f + g  # fmt: skip
+if some_very_long_condition_that_might_wrap: do_something_else_that_is_long()  # fmt: skip
+
+# Nested compound statements (outer should be preserved)
+if True:
+    for i in range(10): print(i)  # fmt: skip
+
+# Multiple statements in body (should not apply - multiline)
+if True:
+    x = 1
+    y   =   2  # fmt: skip
+
+# With decorators - decorated function on one line
+@overload
+def decorated_func(x: int) -> str: return str(x)  # fmt: skip
+
+@property
+def prop_method(self): return self._value  # fmt: skip
+
+# Class definitions on one line
+class SimpleClass: pass  # fmt: skip
+class GenericClass(Generic[T]): pass  # fmt: skip
+
+# Try/except blocks
+try: risky_operation()  # fmt: skip
+except ValueError: handle_error()  # fmt: skip
+except: handle_any_error()  # fmt: skip
+else: success_case()  # fmt: skip
+finally: cleanup()  # fmt: skip
+
+# Match statements (Python 3.10+)
+match value:
+    case 1: print("one")  # fmt: skip
+    case _: print("other")  # fmt: skip
+
+# With statements
+with open("file.txt") as f: content = f.read()  # fmt: skip
+with context_manager() as cm: result = cm.process()  # fmt: skip
+
+# Async variants
+async def async_func(): return await some_call()  # fmt: skip
+async for item in async_iterator(): await process(item)  # fmt: skip
+async with async_context() as ctx: await ctx.work()  # fmt: skip
+
+# Complex expressions that would normally format
+def complex_expr(): return [x for x in range(100) if x % 2 == 0 and x > 50]  # fmt: skip
+if condition_a and condition_b or (condition_c and not condition_d): execute_complex_logic()  # fmt: skip
+
+# Edge case: comment positioning
+def func_with_comment():  # some comment
+    return "value"  # fmt: skip
+
+# Edge case: multiple fmt: skip (only last one should matter)
+def multiple_skip(): return "test"  # fmt: skip  # fmt: skip
+
+# Should NOT be affected (already multiline)
+def multiline_func():
+    return "this should format normally"
+
+if long_condition_that_spans \
+   and continues_on_next_line:
+    print("multiline condition")
+
+# Mix of skipped and non-skipped
+for i in range(10): print(f"item {i}")  # fmt: skip
+for j in range(5):
+    print(f"formatted item {j}")
+
+# With trailing comma that would normally be removed
+def trailing_comma_func(a, b, c,): return a + b + c  # fmt: skip
+
+# Dictionary/list comprehensions
+def dict_comp(): return {k: v for k, v in items.items() if v is not None}  # fmt: skip
+def list_comp(): return [x * 2 for x in numbers if x > threshold_value]  # fmt: skip
+
+# Lambda in one-liner
+def with_lambda(): return lambda x, y, z: x + y + z if all([x, y, z]) else None  # fmt: skip
+
+# String formatting that would normally be reformatted
+def format_string(): return f"Hello {name}, you have {count} items in your cart totaling ${total:.2f}"  # fmt: skip
+
+# loop else clauses
+for i in range(2): print(i) # fmt: skip
+else: print("this") # fmt: skip
+
+
+while foo(): print(i) # fmt: skip
+else: print("this") # fmt: skip
+
+# again but only the first skip
+for i in range(2): print(i) # fmt: skip
+else: print("this")
+
+
+while foo(): print(i) # fmt: skip
+else: print("this")
+
+# again but only the second skip
+for i in range(2): print(i)
+else: print("this") # fmt: skip
+
+
+while foo(): print(i)
+else: print("this") # fmt: skip
+
+# multiple statements in body
+if True: print("this"); print("that") # fmt: skip
+
+# Examples with more comments
+
+try: risky_operation()  # fmt: skip
+# leading 1
+except ValueError: handle_error()  # fmt: skip
+# leading 2
+except: handle_any_error()  # fmt: skip
+# leading 3
+else: success_case()  # fmt: skip
+# leading 4
+finally: cleanup()  # fmt: skip
+# trailing
+
+# multi-line before colon (should remain as is)
+if (
+	long_condition
+):  a     +     b # fmt: skip
+
+# over-indented comment example
+# See https://github.com/astral-sh/ruff/pull/20633#issuecomment-3453288910
+# and https://github.com/astral-sh/ruff/pull/21185
+
+for x in it: foo()
+    # comment
+else: bar() # fmt: skip
+
+
+if this(
+    'is a long',
+    # commented
+    'condition'
+): with_a_skip # fmt: skip
+```
+
+## Output
+```python
+# Test cases for fmt: skip on compound statements that fit on one line
+
+# Basic single-line compound statements
+def simple_func(): return "hello"  # fmt: skip
+
+
+if True: print("condition met")  # fmt: skip
+for i in range(5): print(i)  # fmt: skip
+while x < 10: x += 1  # fmt: skip
+
+
+# With expressions that would normally trigger formatting
+def long_params(a, b, c, d, e, f, g): return a + b + c + d + e + f + g  # fmt: skip
+
+
+if some_very_long_condition_that_might_wrap: do_something_else_that_is_long()  # fmt: skip
+
+# Nested compound statements (outer should be preserved)
+if True:
+    for i in range(10): print(i)  # fmt: skip
+
+# Multiple statements in body (should not apply - multiline)
+if True:
+    x = 1
+    y   =   2  # fmt: skip
+
+
+# With decorators - decorated function on one line
+@overload
+def decorated_func(x: int) -> str: return str(x)  # fmt: skip
+
+
+@property
+def prop_method(self): return self._value  # fmt: skip
+
+
+# Class definitions on one line
+class SimpleClass: pass  # fmt: skip
+
+
+class GenericClass(Generic[T]): pass  # fmt: skip
+
+
+# Try/except blocks
+try: risky_operation()  # fmt: skip
+except ValueError: handle_error()  # fmt: skip
+except: handle_any_error()  # fmt: skip
+else: success_case()  # fmt: skip
+finally: cleanup()  # fmt: skip
+
+# Match statements (Python 3.10+)
+match value:
+    case 1: print("one")  # fmt: skip
+    case _: print("other")  # fmt: skip
+
+# With statements
+with open("file.txt") as f: content = f.read()  # fmt: skip
+with context_manager() as cm: result = cm.process()  # fmt: skip
+
+
+# Async variants
+async def async_func(): return await some_call()  # fmt: skip
+
+
+async for item in async_iterator(): await process(item)  # fmt: skip
+async with async_context() as ctx: await ctx.work()  # fmt: skip
+
+
+# Complex expressions that would normally format
+def complex_expr(): return [x for x in range(100) if x % 2 == 0 and x > 50]  # fmt: skip
+
+
+if condition_a and condition_b or (condition_c and not condition_d): execute_complex_logic()  # fmt: skip
+
+
+# Edge case: comment positioning
+def func_with_comment():  # some comment
+    return "value"  # fmt: skip
+
+
+# Edge case: multiple fmt: skip (only last one should matter)
+def multiple_skip(): return "test"  # fmt: skip  # fmt: skip
+
+
+# Should NOT be affected (already multiline)
+def multiline_func():
+    return "this should format normally"
+
+
+if long_condition_that_spans and continues_on_next_line:
+    print("multiline condition")
+
+# Mix of skipped and non-skipped
+for i in range(10): print(f"item {i}")  # fmt: skip
+for j in range(5):
+    print(f"formatted item {j}")
+
+
+# With trailing comma that would normally be removed
+def trailing_comma_func(a, b, c,): return a + b + c  # fmt: skip
+
+
+# Dictionary/list comprehensions
+def dict_comp(): return {k: v for k, v in items.items() if v is not None}  # fmt: skip
+
+
+def list_comp(): return [x * 2 for x in numbers if x > threshold_value]  # fmt: skip
+
+
+# Lambda in one-liner
+def with_lambda(): return lambda x, y, z: x + y + z if all([x, y, z]) else None  # fmt: skip
+
+
+# String formatting that would normally be reformatted
+def format_string(): return f"Hello {name}, you have {count} items in your cart totaling ${total:.2f}"  # fmt: skip
+
+
+# loop else clauses
+for i in range(2): print(i)  # fmt: skip
+else: print("this")  # fmt: skip
+
+
+while foo(): print(i)  # fmt: skip
+else: print("this")  # fmt: skip
+
+# again but only the first skip
+for i in range(2): print(i)  # fmt: skip
+else:
+    print("this")
+
+
+while foo(): print(i)  # fmt: skip
+else:
+    print("this")
+
+# again but only the second skip
+for i in range(2):
+    print(i)
+else: print("this")  # fmt: skip
+
+
+while foo():
+    print(i)
+else: print("this")  # fmt: skip
+
+# multiple statements in body
+if True: print("this"); print("that")  # fmt: skip
+
+# Examples with more comments
+
+try: risky_operation()  # fmt: skip
+# leading 1
+except ValueError: handle_error()  # fmt: skip
+# leading 2
+except: handle_any_error()  # fmt: skip
+# leading 3
+else: success_case()  # fmt: skip
+# leading 4
+finally: cleanup()  # fmt: skip
+# trailing
+
+# multi-line before colon (should remain as is)
+if (
+	long_condition
+):  a     +     b  # fmt: skip
+
+# over-indented comment example
+# See https://github.com/astral-sh/ruff/pull/20633#issuecomment-3453288910
+# and https://github.com/astral-sh/ruff/pull/21185
+
+for x in it:
+    foo()
+# comment
+else: bar()  # fmt: skip
+
+
+if this(
+    'is a long',
+    # commented
+    'condition'
+): with_a_skip  # fmt: skip
+```

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

@@ -1,7 +1,6 @@
 ---
 source: crates/ruff_python_formatter/tests/fixtures.rs
 input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/fmt_skip/docstrings.py
-snapshot_kind: text
 ---
 ## Input
 ```python