parens_for_long_if_clauses_in_case_block preview style

crates/ruff_python_formatter/src/expression/expr_named.rs

@@ -74,6 +74,7 @@ impl NeedsParentheses for ExprNamed {
             || parent.is_stmt_delete()
             || parent.is_stmt_for()
             || parent.is_stmt_function_def()
+            || parent.is_match_case()
         {
             OptionalParentheses::Always
         } else {

crates/ruff_python_formatter/src/other/match_case.rs

@@ -4,8 +4,12 @@ use ruff_python_ast::MatchCase;
 
 use crate::builders::parenthesize_if_expands;
 use crate::comments::SourceComment;
-use crate::expression::parentheses::{NeedsParentheses, OptionalParentheses, Parentheses};
+use crate::expression::maybe_parenthesize_expression;
+use crate::expression::parentheses::{
+    NeedsParentheses, OptionalParentheses, Parentheses, Parenthesize,
+};
 use crate::prelude::*;
+use crate::preview::parens_for_long_if_clauses_in_case_block;
 use crate::statement::clause::{clause_body, clause_header, ClauseHeader};
 
 #[derive(Default)]
@@ -58,7 +62,18 @@ impl FormatNodeRule<MatchCase> for FormatMatchCase {
                         }
 
                         if let Some(guard) = guard {
-                            write!(f, [space(), token("if"), space(), guard.format()])?;
+                            write!(f, [space(), token("if"), space(),])?;
+
+                            if parens_for_long_if_clauses_in_case_block(f.context()) {
+                                maybe_parenthesize_expression(
+                                    guard,
+                                    item,
+                                    Parenthesize::IfBreaksOrIfRequired,
+                                )
+                                .fmt(f)?;
+                            } else {
+                                guard.format().fmt(f)?;
+                            }
                         }
 
                         Ok(())

crates/ruff_python_formatter/src/preview.rs

@@ -22,3 +22,8 @@ pub(crate) fn is_f_string_formatting_enabled(context: &PyFormatContext) -> bool
 pub(crate) fn is_with_single_item_pre_39_enabled(context: &PyFormatContext) -> bool {
     context.is_preview()
 }
+
+/// Returns `true` if the [`parens_for_long_if_clauses_in_case_block`](https://github.com/psf/black/pull/4269) preview style is enabled.
+pub(crate) fn parens_for_long_if_clauses_in_case_block(context: &PyFormatContext) -> bool {
+    context.is_preview()
+}

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

@@ -69,20 +69,7 @@ match 1:
 ```diff
 --- Black
 +++ Ruff
-@@ -1,10 +1,10 @@
- match 1:
--    case _ if True:
-+    case _ if (True):
-         pass
- 
- 
- match 1:
--    case _ if True:
-+    case _ if (True):
-         pass
- 
- 
-@@ -25,27 +25,33 @@
+@@ -25,12 +25,16 @@
  
  
  match 1:
@@ -101,18 +88,7 @@ match 1:
          pass
  
  
- match 1:
--    case _ if True:  # this is a comment
-+    case _ if (True):  # this is a comment
-         pass
- 
- 
- match 1:
--    case _ if True:  # comment over the line limit unless parens are removed x
-+    case _ if (
-+        True
-+    ):  # comment over the line limit unless parens are removed x
-         pass
+@@ -45,7 +49,7 @@
  
  
  match 1:
@@ -129,12 +105,12 @@ match 1:
 
 ```python
 match 1:
-    case _ if (True):
+    case _ if True:
         pass
 
 
 match 1:
-    case _ if (True):
+    case _ if True:
         pass
 
 
@@ -169,14 +145,12 @@ match 1:
 
 
 match 1:
-    case _ if (True):  # this is a comment
+    case _ if True:  # this is a comment
         pass
 
 
 match 1:
-    case _ if (
-        True
-    ):  # comment over the line limit unless parens are removed x
+    case _ if True:  # comment over the line limit unless parens are removed x
         pass
 
 

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

@@ -1235,4 +1235,41 @@ match x:
 ```
 
 
-
+## Preview changes
+```diff
+--- Stable
++++ Preview
+@@ -82,7 +82,9 @@
+ 
+ 
+ match long_lines:
+-    case "this is a long line for if condition" if aaaaaaaaahhhhhhhh == 1 and bbbbbbaaaaaaaaaaa == 2:  # comment
++    case "this is a long line for if condition" if (
++        aaaaaaaaahhhhhhhh == 1 and bbbbbbaaaaaaaaaaa == 2
++    ):  # comment
+         pass
+ 
+     case "this is a long line for if condition with parentheses" if (
+@@ -90,7 +92,7 @@
+     ):  # comment
+         pass
+ 
+-    case "named expressions aren't special" if foo := 1:
++    case "named expressions aren't special" if (foo := 1):
+         pass
+ 
+     case "named expressions aren't that special" if (foo := 1):
+@@ -101,9 +103,9 @@
+     ):  # another comment
+         pass
+ 
+-    case {
+-        "long_long_long_key": str(long_long_long_key)
+-    } if value := "long long long long long long long long long long long value":
++    case {"long_long_long_key": str(long_long_long_key)} if (
++        value := "long long long long long long long long long long long value"
++    ):
+         pass
+ 
+ 
+```