Create dedicated is_*_enabled functions for each preview style (#8988)

crates/ruff_python_formatter/src/context.rs

@@ -74,6 +74,11 @@ impl<'a> PyFormatContext<'a> {
             ..self
         }
     }
+
+    /// Returns `true` if preview mode is enabled.
+    pub(crate) const fn is_preview(&self) -> bool {
+        self.options.preview().is_enabled()
+    }
 }
 
 impl FormatContext for PyFormatContext<'_> {

crates/ruff_python_formatter/src/expression/binary_like.rs

@@ -3,7 +3,7 @@ use std::ops::{Deref, Index};
 
 use smallvec::SmallVec;
 
-use ruff_formatter::{write, FormatContext};
+use ruff_formatter::write;
 use ruff_python_ast::{
     Expr, ExprAttribute, ExprBinOp, ExprBoolOp, ExprCompare, ExprUnaryOp, UnaryOp,
 };
@@ -21,6 +21,7 @@ use crate::expression::parentheses::{
 use crate::expression::string::{AnyString, FormatString, StringLayout};
 use crate::expression::OperatorPrecedence;
 use crate::prelude::*;
+use crate::preview::is_fix_power_op_line_length_enabled;
 
 #[derive(Copy, Clone, Debug)]
 pub(super) enum BinaryLike<'a> {
@@ -719,7 +720,7 @@ impl Format<PyFormatContext<'_>> for FlatBinaryExpressionSlice<'_> {
                 {
                     hard_line_break().fmt(f)?;
                 } else if is_pow {
-                    if f.context().options().preview().is_enabled() {
+                    if is_fix_power_op_line_length_enabled(f.context()) {
                         in_parentheses_only_if_group_breaks(&space()).fmt(f)?;
                     }
                 } else {

crates/ruff_python_formatter/src/expression/mod.rs

@@ -21,7 +21,7 @@ use crate::expression::parentheses::{
     OptionalParentheses, Parentheses, Parenthesize,
 };
 use crate::prelude::*;
-use crate::PyFormatOptions;
+use crate::preview::is_hug_parens_with_braces_and_square_brackets_enabled;
 
 mod binary_like;
 pub(crate) mod expr_attribute;
@@ -129,7 +129,7 @@ impl FormatRule<Expr, PyFormatContext<'_>> for FormatExpr {
             let node_comments = comments.leading_dangling_trailing(expression);
             if !node_comments.has_leading() && !node_comments.has_trailing() {
                 parenthesized("(", &format_expr, ")")
-                    .with_indent(!is_expression_huggable(expression, f.options()))
+                    .with_indent(!is_expression_huggable(expression, f.context()))
                     .fmt(f)
             } else {
                 format_with_parentheses_comments(expression, &node_comments, f)
@@ -448,7 +448,7 @@ impl Format<PyFormatContext<'_>> for MaybeParenthesizeExpression<'_> {
             OptionalParentheses::Never => match parenthesize {
                 Parenthesize::IfBreaksOrIfRequired => {
                     parenthesize_if_expands(&expression.format().with_options(Parentheses::Never))
-                        .with_indent(!is_expression_huggable(expression, f.options()))
+                        .with_indent(!is_expression_huggable(expression, f.context()))
                         .fmt(f)
                 }
 
@@ -1061,8 +1061,8 @@ pub(crate) fn has_own_parentheses(
 ///     ]
 /// )
 /// ```
-pub(crate) fn is_expression_huggable(expr: &Expr, options: &PyFormatOptions) -> bool {
-    if !options.preview().is_enabled() {
+pub(crate) fn is_expression_huggable(expr: &Expr, context: &PyFormatContext) -> bool {
+    if !is_hug_parens_with_braces_and_square_brackets_enabled(context) {
         return false;
     }
 

crates/ruff_python_formatter/src/lib.rs

@@ -32,6 +32,7 @@ mod options;
 pub(crate) mod other;
 pub(crate) mod pattern;
 mod prelude;
+mod preview;
 mod shared_traits;
 pub(crate) mod statement;
 pub(crate) mod type_param;

crates/ruff_python_formatter/src/options.rs

@@ -119,7 +119,7 @@ impl PyFormatOptions {
         self.docstring_code
     }
 
-    pub fn preview(&self) -> PreviewMode {
+    pub const fn preview(&self) -> PreviewMode {
         self.preview
     }
 

crates/ruff_python_formatter/src/other/arguments.rs

@@ -9,6 +9,7 @@ use crate::expression::is_expression_huggable;
 use crate::expression::parentheses::{empty_parenthesized, parenthesized, Parentheses};
 use crate::other::commas;
 use crate::prelude::*;
+use crate::preview::is_hug_parens_with_braces_and_square_brackets_enabled;
 
 #[derive(Default)]
 pub struct FormatArguments;
@@ -177,8 +178,7 @@ fn is_single_argument_parenthesized(argument: &Expr, call_end: TextSize, source:
 /// Hugging should only be applied to single-argument collections, like lists, or starred versions
 /// of those collections.
 fn is_argument_huggable(item: &Arguments, context: &PyFormatContext) -> bool {
-    let options = context.options();
-    if !options.preview().is_enabled() {
+    if !is_hug_parens_with_braces_and_square_brackets_enabled(context) {
         return false;
     }
 
@@ -192,7 +192,7 @@ fn is_argument_huggable(item: &Arguments, context: &PyFormatContext) -> bool {
     };
 
     // If the expression itself isn't huggable, then we can't hug it.
-    if !is_expression_huggable(arg, options) {
+    if !is_expression_huggable(arg, context) {
         return false;
     }
 
@@ -202,6 +202,8 @@ fn is_argument_huggable(item: &Arguments, context: &PyFormatContext) -> bool {
         return false;
     }
 
+    let options = context.options();
+
     // If the expression has a trailing comma, then we can't hug it.
     if options.magic_trailing_comma().is_respect()
         && commas::has_magic_trailing_comma(TextRange::new(arg.end(), item.end()), options, context)

crates/ruff_python_formatter/src/preview.rs

@@ -0,0 +1,19 @@
+//! Helpers to test if a specific preview style is enabled or not.
+//!
+//! The motivation for these functions isn't to avoid code duplication but to ease promoting preview styles
+//! to stable. The challenge with directly using [`is_preview`](PyFormatContext::is_preview) is that it is unclear
+//! for which specific feature this preview check is for. Having named functions simplifies the promotion:
+//! Simply delete the function and let Rust tell you which checks you have to remove.
+use crate::PyFormatContext;
+
+/// Returns `true` if the [`fix_power_op_line_length`](https://github.com/astral-sh/ruff/issues/8938) preview style is enabled.
+pub(crate) const fn is_fix_power_op_line_length_enabled(context: &PyFormatContext) -> bool {
+    context.is_preview()
+}
+
+/// Returns `true` if the [`hug_parens_with_braces_and_square_brackets`](https://github.com/astral-sh/ruff/issues/8279) preview style is enabled.
+pub(crate) const fn is_hug_parens_with_braces_and_square_brackets_enabled(
+    context: &PyFormatContext,
+) -> bool {
+    context.is_preview()
+}