Stabilize parenthesize_lambda_bodies

crates/ruff_python_formatter/src/expression/expr_lambda.rs

@@ -10,7 +10,6 @@ use crate::expression::parentheses::{
 use crate::expression::{CallChainLayout, has_own_parentheses};
 use crate::other::parameters::ParametersParentheses;
 use crate::prelude::*;
-use crate::preview::is_parenthesize_lambda_bodies_enabled;
 
 #[derive(Default)]
 pub struct FormatExprLambda {
@@ -31,7 +30,6 @@ impl FormatNodeRule<ExprLambda> for FormatExprLambda {
 
         let comments = f.context().comments().clone();
         let dangling = comments.dangling(item);
-        let preview = is_parenthesize_lambda_bodies_enabled(f.context());
 
         write!(f, [token("lambda")])?;
 
@@ -108,7 +106,7 @@ impl FormatNodeRule<ExprLambda> for FormatExprLambda {
             }
 
             // Try to keep the parameters on a single line, unless there are intervening comments.
-            if preview && !comments.contains_comments(parameters.into()) {
+            if !comments.contains_comments(parameters.into()) {
                 let mut buffer = RemoveSoftLinesBuffer::new(f);
                 write!(
                     buffer,
@@ -134,12 +132,6 @@ impl FormatNodeRule<ExprLambda> for FormatExprLambda {
 
         if dangling_header_comments.is_empty() {
             write!(f, [space()])?;
-        } else if !preview {
-            write!(f, [dangling_comments(dangling_header_comments)])?;
-        }
-
-        if !preview {
-            return body.format().fmt(f);
         }
 
         let fmt_body = FormatBody {

crates/ruff_python_formatter/src/preview.rs

@@ -13,10 +13,3 @@ pub(crate) const fn is_hug_parens_with_braces_and_square_brackets_enabled(
 ) -> bool {
     context.is_preview()
 }
-
-/// Returns `true` if the
-/// [`parenthesize_lambda_bodies`](https://github.com/astral-sh/ruff/pull/21385) preview style is
-/// enabled.
-pub(crate) const fn is_parenthesize_lambda_bodies_enabled(context: &PyFormatContext) -> bool {
-    context.is_preview()
-}

crates/ruff_python_formatter/src/statement/stmt_assign.rs

@@ -20,7 +20,6 @@ use crate::expression::{
 };
 use crate::other::interpolated_string::InterpolatedStringLayout;
 use crate::prelude::*;
-use crate::preview::is_parenthesize_lambda_bodies_enabled;
 use crate::statement::trailing_semicolon;
 use crate::string::StringLikeExtensions;
 use crate::string::implicit::{
@@ -1355,7 +1354,7 @@ fn is_attribute_with_parenthesized_value(target: &Expr, context: &PyFormatContex
     }
 }
 
-/// Like [`maybe_parenthesize_expression`] but with special handling for lambdas in preview.
+/// Like [`maybe_parenthesize_expression`] but with special handling for lambdas.
 fn maybe_parenthesize_value<'a>(
     expression: &'a Expr,
     parent: AnyNodeRef<'a>,
@@ -1372,8 +1371,7 @@ impl Format<PyFormatContext<'_>> for MaybeParenthesizeValue<'_> {
     fn fmt(&self, f: &mut PyFormatter) -> FormatResult<()> {
         let MaybeParenthesizeValue { expression, parent } = self;
 
-        if is_parenthesize_lambda_bodies_enabled(f.context())
-            && let Expr::Lambda(lambda) = expression
+        if let Expr::Lambda(lambda) = expression
             && !f.context().comments().has_leading(lambda)
         {
             parenthesize_if_expands(&lambda.format().with_options(ExprLambdaLayout::Assignment))

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

@@ -1,6 +1,5 @@
 ---
 source: crates/ruff_python_formatter/tests/fixtures.rs
-input_file: crates/ruff_python_formatter/resources/test/fixtures/black/cases/comments_in_blocks.py
 ---
 ## Input
 
@@ -123,29 +122,43 @@ if (
 ```diff
 --- Black
 +++ Ruff
-@@ -5,9 +5,9 @@
+@@ -5,23 +5,25 @@
  # - https://github.com/psf/black/issues/563
 
  (
 -    lambda
-+    lambda:
-     # a comment
+-    # a comment
 -    : None
-+    None
++    lambda: (
++        # a comment
++        None
++    )
  )
 
  (
-@@ -17,9 +17,8 @@
+-    lambda:
+-    # b comment
+-    None
++    lambda: (
++        # b comment
++        None
++    )
  )
 
  (
 -    lambda
-+    lambda:
-     # a comment
+-    # a comment
 -    :
-     # b comment
-     None
+-    # b comment
+-    None
++    lambda: (
++        # a comment
++        # b comment
++        None
++    )
  )
+
+ [
 ```
 
 ## Ruff Output
@@ -158,22 +171,25 @@ if (
 # - https://github.com/psf/black/issues/563
 
 (
-    lambda:
-    # a comment
-    None
+    lambda: (
+        # a comment
+        None
+    )
 )
 
 (
-    lambda:
-    # b comment
-    None
+    lambda: (
+        # b comment
+        None
+    )
 )
 
 (
-    lambda:
-    # a comment
-    # b comment
-    None
+    lambda: (
+        # a comment
+        # b comment
+        None
+    )
 )
 
 [