Ruff 2025 style guide (#13906)

Closes #13371

crates/ruff_python_formatter/src/pattern/mod.rs

@@ -14,7 +14,6 @@ use crate::expression::parentheses::{
     optional_parentheses, parenthesized, NeedsParentheses, OptionalParentheses, Parentheses,
 };
 use crate::prelude::*;
-use crate::preview::is_join_implicit_concatenated_string_enabled;
 
 pub(crate) mod pattern_arguments;
 pub(crate) mod pattern_keyword;
@@ -227,7 +226,7 @@ pub(crate) fn can_pattern_omit_optional_parentheses(
     pattern: &Pattern,
     context: &PyFormatContext,
 ) -> bool {
-    let mut visitor = CanOmitOptionalParenthesesVisitor::new(context);
+    let mut visitor = CanOmitOptionalParenthesesVisitor::default();
     visitor.visit_pattern(pattern, context);
 
     if !visitor.any_parenthesized_expressions {
@@ -272,32 +271,16 @@ pub(crate) fn can_pattern_omit_optional_parentheses(
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
 struct CanOmitOptionalParenthesesVisitor<'input> {
     max_precedence: OperatorPrecedence,
     max_precedence_count: usize,
     any_parenthesized_expressions: bool,
-    join_implicit_concatenated_strings: bool,
     last: Option<&'input Pattern>,
     first: First<'input>,
 }
 
 impl<'a> CanOmitOptionalParenthesesVisitor<'a> {
-    fn new(context: &PyFormatContext) -> Self {
-        Self {
-            max_precedence: OperatorPrecedence::default(),
-            max_precedence_count: 0,
-            any_parenthesized_expressions: false,
-            // TODO: Derive default for `CanOmitOptionalParenthesesVisitor` when removing the `join_implicit_concatenated_strings`
-            //   preview style.
-            join_implicit_concatenated_strings: is_join_implicit_concatenated_string_enabled(
-                context,
-            ),
-            last: None,
-            first: First::default(),
-        }
-    }
-
     fn visit_pattern(&mut self, pattern: &'a Pattern, context: &PyFormatContext) {
         match pattern {
             Pattern::MatchSequence(_) | Pattern::MatchMapping(_) => {
@@ -305,27 +288,11 @@ impl<'a> CanOmitOptionalParenthesesVisitor<'a> {
             }
 
             Pattern::MatchValue(value) => match &*value.value {
-                Expr::StringLiteral(string) => {
-                    if !self.join_implicit_concatenated_strings {
-                        self.update_max_precedence(OperatorPrecedence::String, string.value.len());
-                    }
-                }
-                Expr::BytesLiteral(bytes) => {
-                    if !self.join_implicit_concatenated_strings {
-                        self.update_max_precedence(OperatorPrecedence::String, bytes.value.len());
-                    }
-                }
+                Expr::StringLiteral(_)  |
+                Expr::BytesLiteral(_) |
                 // F-strings are allowed according to python's grammar but fail with a syntax error at runtime.
                 // That's why we need to support them for formatting.
-                Expr::FString(string) => {
-                    if !self.join_implicit_concatenated_strings {
-                        self.update_max_precedence(
-                            OperatorPrecedence::String,
-                            string.value.as_slice().len(),
-                        );
-                    }
-                }
-
+                Expr::FString(_)  |
                 Expr::NumberLiteral(_) | Expr::Attribute(_) | Expr::UnaryOp(_) => {
                     // require no state update other than visit_pattern does.
                 }
@@ -397,8 +364,6 @@ enum OperatorPrecedence {
     None,
     Additive,
     Or,
-    // Implicit string concatenation
-    String,
 }
 
 #[derive(Copy, Clone, Debug, Default)]

crates/ruff_python_formatter/src/pattern/pattern_match_as.rs

@@ -5,7 +5,6 @@ use ruff_python_ast::PatternMatchAs;
 use crate::comments::dangling_comments;
 use crate::expression::parentheses::{NeedsParentheses, OptionalParentheses};
 use crate::prelude::*;
-use crate::preview::is_match_case_parentheses_enabled;
 
 #[derive(Default)]
 pub struct FormatPatternMatchAs;
@@ -55,16 +54,12 @@ impl NeedsParentheses for PatternMatchAs {
     fn needs_parentheses(
         &self,
         _parent: AnyNodeRef,
-        context: &PyFormatContext,
+        _context: &PyFormatContext,
     ) -> OptionalParentheses {
-        if is_match_case_parentheses_enabled(context) {
-            if self.name.is_some() {
-                OptionalParentheses::Multiline
-            } else {
-                OptionalParentheses::BestFit
-            }
-        } else {
+        if self.name.is_some() {
             OptionalParentheses::Multiline
+        } else {
+            OptionalParentheses::BestFit
         }
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_or.rs

@@ -8,7 +8,6 @@ use crate::expression::parentheses::{
     OptionalParentheses,
 };
 use crate::prelude::*;
-use crate::preview::is_match_case_parentheses_enabled;
 
 #[derive(Default)]
 pub struct FormatPatternMatchOr;
@@ -43,11 +42,7 @@ impl FormatNodeRule<PatternMatchOr> for FormatPatternMatchOr {
             Ok(())
         });
 
-        if is_match_case_parentheses_enabled(f.context()) {
-            in_parentheses_only_group(&inner).fmt(f)
-        } else {
-            inner.fmt(f)
-        }
+        in_parentheses_only_group(&inner).fmt(f)
     }
 }
 

crates/ruff_python_formatter/src/pattern/pattern_match_singleton.rs

@@ -3,7 +3,6 @@ use ruff_python_ast::{PatternMatchSingleton, Singleton};
 
 use crate::expression::parentheses::{NeedsParentheses, OptionalParentheses};
 use crate::prelude::*;
-use crate::preview::is_match_case_parentheses_enabled;
 
 #[derive(Default)]
 pub struct FormatPatternMatchSingleton;
@@ -22,12 +21,8 @@ impl NeedsParentheses for PatternMatchSingleton {
     fn needs_parentheses(
         &self,
         _parent: AnyNodeRef,
-        context: &PyFormatContext,
+        _context: &PyFormatContext,
     ) -> OptionalParentheses {
-        if is_match_case_parentheses_enabled(context) {
-            OptionalParentheses::BestFit
-        } else {
-            OptionalParentheses::Never
-        }
+        OptionalParentheses::BestFit
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_value.rs

@@ -3,7 +3,6 @@ use ruff_python_ast::PatternMatchValue;
 
 use crate::expression::parentheses::{NeedsParentheses, OptionalParentheses, Parentheses};
 use crate::prelude::*;
-use crate::preview::is_match_case_parentheses_enabled;
 
 #[derive(Default)]
 pub struct FormatPatternMatchValue;
@@ -21,10 +20,6 @@ impl NeedsParentheses for PatternMatchValue {
         parent: AnyNodeRef,
         context: &PyFormatContext,
     ) -> OptionalParentheses {
-        if is_match_case_parentheses_enabled(context) {
-            self.value.needs_parentheses(parent, context)
-        } else {
-            OptionalParentheses::Never
-        }
+        self.value.needs_parentheses(parent, context)
     }
 }