Format Slice Expressions (#5047)

This formats slice expressions and subscript expressions.

Spaces around the colons follows the same rules as black
(https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#slices):
```python
e00 = "e"[:]
e01 = "e"[:1]
e02 = "e"[: a()]
e10 = "e"[1:]
e11 = "e"[1:1]
e12 = "e"[1 : a()]
e20 = "e"[a() :]
e21 = "e"[a() : 1]
e22 = "e"[a() : a()]
e200 = "e"[a() : :]
e201 = "e"[a() :: 1]
e202 = "e"[a() :: a()]
e210 = "e"[a() : 1 :]
```

Comment placement is different due to our very different infrastructure.
If we have explicit bounds (e.g. `x[1:2]`) all comments get assigned as
leading or trailing to the bound expression. If a bound is missing
`[:]`, comments get marked as dangling and placed in the same section as
they were originally in:
```python
x = "x"[ # a
      # b
    :  # c
      # d
]
```
to
```python
x = "x"[
    # a
    # b
    :
    # c
    # d
]
```
Except for the potential trailing end-of-line comments, all comments get
formatted on their own line. This can be improved by keeping end-of-line
comments after the opening bracket or after a colon as such but the
changes were already complex enough.

I added tests for comment placement and spaces.

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/slice.py

@@ -0,0 +1,82 @@
+# Handle comments both when lower and upper exist and when they don't
+a1 = "a"[
+    # a
+    1  # b
+    :  # c
+    2  # d
+]
+a2 = "a"[
+    # a
+      # b
+    :  # c
+      # d
+]
+
+# Check all places where comments can exist
+b1 = "b"[ # a
+    # b
+    1 # c
+    # d
+    : # e
+    # f
+    2 # g
+    # h
+    : # i
+    # j
+    3 # k
+    # l
+]
+
+# Handle the spacing from the colon correctly with upper leading comments
+c1 = "c"[
+    1
+    :  # e
+    # f
+    2
+]
+c2 = "c"[
+    1
+    :  # e
+    2
+]
+c3 = "c"[
+    1
+    :
+    # f
+    2
+]
+c4 = "c"[
+    1
+    : # f
+    2
+]
+
+# End of line comments
+d1 = "d"[ # comment
+    :
+]
+d2 = "d"[  # comment
+    1:
+]
+d3 = "d"[
+    1  # comment
+    :
+]
+
+# Spacing around the colon(s)
+def a():
+    ...
+
+e00 = "e"[:]
+e01 = "e"[:1]
+e02 = "e"[: a()]
+e10 = "e"[1:]
+e11 = "e"[1:1]
+e12 = "e"[1 : a()]
+e20 = "e"[a() :]
+e21 = "e"[a() : 1]
+e22 = "e"[a() : a()]
+e200 = "e"[a() :: ]
+e201 = "e"[a() :: 1]
+e202 = "e"[a() :: a()]
+e210 = "e"[a() : 1 :]

crates/ruff_python_formatter/src/comments/placement.rs

@@ -1,16 +1,14 @@
-use std::cmp::Ordering;
+use crate::comments::visitor::{CommentPlacement, DecoratedComment};
-
+use crate::comments::CommentLinePosition;
-use ruff_text_size::{TextRange, TextSize};
+use crate::expression::expr_slice::{assign_comment_in_slice, ExprSliceCommentSection};
-use rustpython_parser::ast::Ranged;
+use crate::trivia::{first_non_trivia_token_rev, SimpleTokenizer, Token, TokenKind};
-
+use ruff_python_ast::node::{AnyNodeRef, AstNode};
-use ruff_python_ast::node::AnyNodeRef;
 use ruff_python_ast::source_code::Locator;
 use ruff_python_ast::whitespace;
 use ruff_python_whitespace::{PythonWhitespace, UniversalNewlines};
-
+use ruff_text_size::{TextRange, TextSize};
-use crate::comments::visitor::{CommentPlacement, DecoratedComment};
+use rustpython_parser::ast::{Expr, ExprSlice, Ranged};
-use crate::comments::CommentLinePosition;
+use std::cmp::Ordering;
-use crate::trivia::{SimpleTokenizer, Token, TokenKind};
 
 /// Implements the custom comment placement logic.
 pub(super) fn place_comment<'a>(
@@ -30,6 +28,7 @@ pub(super) fn place_comment<'a>(
         handle_trailing_binary_expression_left_or_operator_comment,
         handle_leading_function_with_decorators_comment,
         handle_dict_unpacking_comment,
+        handle_slice_comments,
     ];
     for handler in HANDLERS {
         comment = match handler(comment, locator) {
@@ -837,6 +836,87 @@ fn handle_module_level_own_line_comment_before_class_or_function_comment<'a>(
     }
 }
 
+/// Handles the attaching comments left or right of the colon in a slice as trailing comment of the
+/// preceding node or leading comment of the following node respectively.
+/// ```python
+/// a = "input"[
+///     1 # c
+///     # d
+///     :2
+/// ]
+/// ```
+fn handle_slice_comments<'a>(
+    comment: DecoratedComment<'a>,
+    locator: &Locator,
+) -> CommentPlacement<'a> {
+    let expr_slice = match comment.enclosing_node() {
+        AnyNodeRef::ExprSlice(expr_slice) => expr_slice,
+        AnyNodeRef::ExprSubscript(expr_subscript) => {
+            if expr_subscript.value.end() < expr_subscript.slice.start() {
+                if let Expr::Slice(expr_slice) = expr_subscript.slice.as_ref() {
+                    expr_slice
+                } else {
+                    return CommentPlacement::Default(comment);
+                }
+            } else {
+                return CommentPlacement::Default(comment);
+            }
+        }
+        _ => return CommentPlacement::Default(comment),
+    };
+
+    let ExprSlice {
+        range: _,
+        lower,
+        upper,
+        step,
+    } = expr_slice;
+
+    // Check for `foo[ # comment`, but only if they are on the same line
+    let after_lbracket = matches!(
+        first_non_trivia_token_rev(comment.slice().start(), locator.contents()),
+        Some(Token {
+            kind: TokenKind::LBracket,
+            ..
+        })
+    );
+    if comment.line_position().is_end_of_line() && after_lbracket {
+        // Keep comments after the opening bracket there by formatting them outside the
+        // soft block indent
+        // ```python
+        // "a"[ # comment
+        //     1:
+        // ]
+        // ```
+        debug_assert!(
+            matches!(comment.enclosing_node(), AnyNodeRef::ExprSubscript(_)),
+            "{:?}",
+            comment.enclosing_node()
+        );
+        return CommentPlacement::dangling(comment.enclosing_node(), comment);
+    }
+
+    let assignment =
+        assign_comment_in_slice(comment.slice().range(), locator.contents(), expr_slice);
+    let node = match assignment {
+        ExprSliceCommentSection::Lower => lower,
+        ExprSliceCommentSection::Upper => upper,
+        ExprSliceCommentSection::Step => step,
+    };
+
+    if let Some(node) = node {
+        if comment.slice().start() < node.start() {
+            CommentPlacement::leading(node.as_ref().into(), comment)
+        } else {
+            // If a trailing comment is an end of line comment that's fine because we have a node
+            // ahead of it
+            CommentPlacement::trailing(node.as_ref().into(), comment)
+        }
+    } else {
+        CommentPlacement::dangling(expr_slice.as_any_node_ref(), comment)
+    }
+}
+
 /// Finds the offset of the `/` that separates the positional only and arguments from the other arguments.
 /// Returns `None` if the positional only separator `/` isn't present in the specified range.
 fn find_pos_only_slash_offset(

crates/ruff_python_formatter/src/expression/expr_slice.rs

@@ -1,24 +1,262 @@
+use crate::comments::{dangling_comments, Comments, SourceComment};
 use crate::expression::parentheses::{
     default_expression_needs_parentheses, NeedsParentheses, Parentheses, Parenthesize,
 };
-use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+use crate::trivia::Token;
-
+use crate::trivia::{first_non_trivia_token, TokenKind};
-use crate::comments::Comments;
+use crate::{AsFormat, FormatNodeRule, PyFormatter};
-use ruff_formatter::{write, Buffer, FormatResult};
+use ruff_formatter::prelude::{hard_line_break, line_suffix_boundary, space, text};
+use ruff_formatter::{write, Buffer, Format, FormatError, FormatResult};
+use ruff_python_ast::node::AstNode;
+use ruff_python_ast::prelude::{Expr, Ranged};
+use ruff_text_size::TextRange;
 use rustpython_parser::ast::ExprSlice;
 
 #[derive(Default)]
 pub struct FormatExprSlice;
 
 impl FormatNodeRule<ExprSlice> for FormatExprSlice {
-    fn fmt_fields(&self, _item: &ExprSlice, f: &mut PyFormatter) -> FormatResult<()> {
+    /// This implementation deviates from black in that comments are attached to the section of the
+    /// slice they originate in
+    fn fmt_fields(&self, item: &ExprSlice, f: &mut PyFormatter) -> FormatResult<()> {
+        // `[lower:upper:step]`
+        let ExprSlice {
+            range,
+            lower,
+            upper,
+            step,
+        } = item;
+
+        let (first_colon, second_colon) =
+            find_colons(f.context().contents(), *range, lower, upper)?;
+
+        // Handle comment placement
+        // In placements.rs, we marked comment for None nodes a dangling and associated all others
+        // as leading or dangling wrt to a node. That means we either format a node and only have
+        // to handle newlines and spacing, or the node is None and we insert the corresponding
+        // slice of dangling comments
+        let comments = f.context().comments().clone();
+        let slice_dangling_comments = comments.dangling_comments(item.as_any_node_ref());
+        // Put the dangling comments (where the nodes are missing) into buckets
+        let first_colon_partition_index = slice_dangling_comments
+            .partition_point(|x| x.slice().start() < first_colon.range.start());
+        let (dangling_lower_comments, dangling_upper_step_comments) =
+            slice_dangling_comments.split_at(first_colon_partition_index);
+        let (dangling_upper_comments, dangling_step_comments) =
+            if let Some(second_colon) = &second_colon {
+                let second_colon_partition_index = dangling_upper_step_comments
+                    .partition_point(|x| x.slice().start() < second_colon.range.start());
+                dangling_upper_step_comments.split_at(second_colon_partition_index)
+            } else {
+                // Without a second colon they remaining dangling comments belong between the first
+                // colon and the closing parentheses
+                (dangling_upper_step_comments, [].as_slice())
+            };
+
+        // Ensure there a no dangling comments for a node if the node is present
+        debug_assert!(lower.is_none() || dangling_lower_comments.is_empty());
+        debug_assert!(upper.is_none() || dangling_upper_comments.is_empty());
+        debug_assert!(step.is_none() || dangling_step_comments.is_empty());
+
+        // Handle spacing around the colon(s)
+        // https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#slices
+        let lower_simple = lower.as_ref().map_or(true, |expr| is_simple_expr(expr));
+        let upper_simple = upper.as_ref().map_or(true, |expr| is_simple_expr(expr));
+        let step_simple = step.as_ref().map_or(true, |expr| is_simple_expr(expr));
+        let all_simple = lower_simple && upper_simple && step_simple;
+
+        // lower
+        if let Some(lower) = lower {
+            write!(f, [lower.format(), line_suffix_boundary()])?;
+        } else {
+            dangling_comments(dangling_lower_comments).fmt(f)?;
+        }
+
+        // First colon
+        // The spacing after the colon depends on both the lhs and the rhs:
+        // ```
+        // e00 = x[:]
+        // e01 = x[:1]
+        // e02 = x[: a()]
+        // e10 = x[1:]
+        // e11 = x[1:1]
+        // e12 = x[1 : a()]
+        // e20 = x[a() :]
+        // e21 = x[a() : 1]
+        // e22 = x[a() : a()]
+        // e200 = "e"[a() : :]
+        // e201 = "e"[a() :: 1]
+        // e202 = "e"[a() :: a()]
+        // ```
+        if !all_simple {
+            space().fmt(f)?;
+        }
+        text(":").fmt(f)?;
+        // No upper node, no need for a space, e.g. `x[a() :]`
+        if !all_simple && upper.is_some() {
+            space().fmt(f)?;
+        }
+
+        // Upper
+        if let Some(upper) = upper {
+            let upper_leading_comments = comments.leading_comments(upper.as_ref());
+            leading_comments_spacing(f, upper_leading_comments)?;
+            write!(f, [upper.format(), line_suffix_boundary()])?;
+        } else {
+            if let Some(first) = dangling_upper_comments.first() {
+                // Here the spacing for end-of-line comments works but own line comments need
+                // explicit spacing
+                if first.line_position().is_own_line() {
+                    hard_line_break().fmt(f)?;
+                }
+            }
+            dangling_comments(dangling_upper_comments).fmt(f)?;
+        }
+
+        // (optionally) step
+        if second_colon.is_some() {
+            // Same spacing rules as for the first colon, except for the strange case when the
+            // second colon exists, but neither upper nor step
+            // ```
+            // e200 = "e"[a() : :]
+            // e201 = "e"[a() :: 1]
+            // e202 = "e"[a() :: a()]
+            // ```
+            if !all_simple && (upper.is_some() || step.is_none()) {
+                space().fmt(f)?;
+            }
+            text(":").fmt(f)?;
+            // No step node, no need for a space
+            if !all_simple && step.is_some() {
+                space().fmt(f)?;
+            }
+            if let Some(step) = step {
+                let step_leading_comments = comments.leading_comments(step.as_ref());
+                leading_comments_spacing(f, step_leading_comments)?;
+                step.format().fmt(f)?;
+            } else {
+                if !dangling_step_comments.is_empty() {
+                    // Put the colon and comments on their own lines
                     write!(
                         f,
-            [not_yet_implemented_custom_text(
+                        [hard_line_break(), dangling_comments(dangling_step_comments)]
-                "NOT_IMPLEMENTED_start:NOT_IMPLEMENTED_end"
+                    )?;
-            )]
-        )
                 }
+            }
+        } else {
+            debug_assert!(step.is_none(), "step can't exist without a second colon");
+        }
+        Ok(())
+    }
+}
+
+/// We're in a slice, so we know there's a first colon, but with have to look into the source
+/// to find out whether there is a second one, too, e.g. `[1:2]` and `[1:10:2]`.
+///
+/// Returns the first and optionally the second colon.
+pub(crate) fn find_colons(
+    contents: &str,
+    range: TextRange,
+    lower: &Option<Box<Expr>>,
+    upper: &Option<Box<Expr>>,
+) -> FormatResult<(Token, Option<Token>)> {
+    let after_lower = lower
+        .as_ref()
+        .map_or(range.start(), |lower| lower.range().end());
+    let first_colon =
+        first_non_trivia_token(after_lower, contents).ok_or(FormatError::SyntaxError)?;
+    if first_colon.kind != TokenKind::Colon {
+        return Err(FormatError::SyntaxError);
+    }
+
+    let after_upper = upper
+        .as_ref()
+        .map_or(first_colon.end(), |upper| upper.range().end());
+    // At least the closing bracket must exist, so there must be a token there
+    let next_token =
+        first_non_trivia_token(after_upper, contents).ok_or(FormatError::SyntaxError)?;
+    let second_colon = if next_token.kind == TokenKind::Colon {
+        debug_assert!(
+            next_token.range.start() < range.end(),
+            "The next token in a slice must either be a colon or the closing bracket"
+        );
+        Some(next_token)
+    } else {
+        None
+    };
+    Ok((first_colon, second_colon))
+}
+
+/// Determines whether this expression needs a space around the colon
+/// <https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#slices>
+fn is_simple_expr(expr: &Expr) -> bool {
+    matches!(expr, Expr::Constant(_) | Expr::Name(_))
+}
+
+pub(crate) enum ExprSliceCommentSection {
+    Lower,
+    Upper,
+    Step,
+}
+
+/// Assigns a comment to lower/upper/step in `[lower:upper:step]`.
+///
+/// ```python
+/// "sliceable"[
+///     # lower comment
+///     :
+///     # upper comment
+///     :
+///     # step comment
+/// ]
+/// ```
+pub(crate) fn assign_comment_in_slice(
+    comment: TextRange,
+    contents: &str,
+    expr_slice: &ExprSlice,
+) -> ExprSliceCommentSection {
+    let ExprSlice {
+        range,
+        lower,
+        upper,
+        step: _,
+    } = expr_slice;
+
+    let (first_colon, second_colon) = find_colons(contents, *range, lower, upper)
+        .expect("SyntaxError when trying to parse slice");
+
+    if comment.start() < first_colon.range.start() {
+        ExprSliceCommentSection::Lower
+    } else {
+        // We are to the right of the first colon
+        if let Some(second_colon) = second_colon {
+            if comment.start() < second_colon.range.start() {
+                ExprSliceCommentSection::Upper
+            } else {
+                ExprSliceCommentSection::Step
+            }
+        } else {
+            // No second colon means there is no step
+            ExprSliceCommentSection::Upper
+        }
+    }
+}
+
+/// Manual spacing for the leading comments of upper and step
+fn leading_comments_spacing(
+    f: &mut PyFormatter,
+    leading_comments: &[SourceComment],
+) -> FormatResult<()> {
+    if let Some(first) = leading_comments.first() {
+        if first.line_position().is_own_line() {
+            // Insert a newline after the colon so the comment ends up on its own line
+            hard_line_break().fmt(f)?;
+        } else {
+            // Insert the two spaces between the colon and the end-of-line comment after the colon
+            write!(f, [space(), space()])?;
+        }
+    }
+    Ok(())
 }
 
 impl NeedsParentheses for ExprSlice {

crates/ruff_python_formatter/src/expression/expr_subscript.rs

@@ -1,24 +1,52 @@
+use crate::comments::{trailing_comments, Comments};
 use crate::expression::parentheses::{
     default_expression_needs_parentheses, NeedsParentheses, Parentheses, Parenthesize,
 };
-use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+use crate::{AsFormat, FormatNodeRule, PyFormatter};
-
+use ruff_formatter::prelude::{group, soft_block_indent, text};
-use crate::comments::Comments;
+use ruff_formatter::{format_args, write, Buffer, FormatResult};
-use ruff_formatter::{write, Buffer, FormatResult};
+use ruff_python_ast::node::AstNode;
 use rustpython_parser::ast::ExprSubscript;
 
 #[derive(Default)]
 pub struct FormatExprSubscript;
 
 impl FormatNodeRule<ExprSubscript> for FormatExprSubscript {
-    fn fmt_fields(&self, _item: &ExprSubscript, f: &mut PyFormatter) -> FormatResult<()> {
+    fn fmt_fields(&self, item: &ExprSubscript, f: &mut PyFormatter) -> FormatResult<()> {
+        let ExprSubscript {
+            range: _,
+            value,
+            slice,
+            ctx: _,
+        } = item;
+
+        let comments = f.context().comments().clone();
+        let dangling_comments = comments.dangling_comments(item.as_any_node_ref());
+        debug_assert!(
+            dangling_comments.len() <= 1,
+            "The subscript expression must have at most a single comment, the one after the bracket"
+        );
+
         write!(
             f,
-            [not_yet_implemented_custom_text(
+            [group(&format_args![
-                "NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]"
+                value.format(),
-            )]
+                text("["),
+                trailing_comments(dangling_comments),
+                soft_block_indent(&slice.format()),
+                text("]")
+            ])]
         )
     }
+
+    fn fmt_dangling_comments(
+        &self,
+        _node: &ExprSubscript,
+        _f: &mut PyFormatter,
+    ) -> FormatResult<()> {
+        // Handled inside of `fmt_fields`
+        Ok(())
+    }
 }
 
 impl NeedsParentheses for ExprSubscript {
@@ -28,6 +56,9 @@ impl NeedsParentheses for ExprSubscript {
         source: &str,
         comments: &Comments,
     ) -> Parentheses {
-        default_expression_needs_parentheses(self.into(), parenthesize, source, comments)
+        match default_expression_needs_parentheses(self.into(), parenthesize, source, comments) {
+            Parentheses::Optional => Parentheses::Never,
+            parentheses => parentheses,
+        }
     }
 }

crates/ruff_python_formatter/src/expression/expr_unary_op.rs

@@ -2,10 +2,10 @@ use crate::comments::{trailing_comments, Comments};
 use crate::expression::parentheses::{
     default_expression_needs_parentheses, NeedsParentheses, Parentheses, Parenthesize,
 };
-use crate::prelude::*;
 use crate::trivia::{SimpleTokenizer, TokenKind};
-use crate::FormatNodeRule;
+use crate::{AsFormat, FormatNodeRule, PyFormatter};
-use ruff_formatter::FormatContext;
+use ruff_formatter::prelude::{hard_line_break, space, text};
+use ruff_formatter::{Format, FormatContext, FormatResult};
 use ruff_python_ast::prelude::UnaryOp;
 use ruff_text_size::{TextLen, TextRange};
 use rustpython_parser::ast::{ExprUnaryOp, Ranged};

crates/ruff_python_formatter/src/lib.rs

@@ -273,36 +273,7 @@ if True:
 
         let formatted_code = printed.as_code();
 
-        let reformatted = match format_module(formatted_code) {
+        ensure_stability_when_formatting_twice(formatted_code);
-            Ok(reformatted) => reformatted,
-            Err(err) => {
-                panic!(
-                    "Expected formatted code to be valid syntax: {err}:\
-                    \n---\n{formatted_code}---\n",
-                );
-            }
-        };
-
-        if reformatted.as_code() != formatted_code {
-            let diff = TextDiff::from_lines(formatted_code, reformatted.as_code())
-                .unified_diff()
-                .header("Formatted once", "Formatted twice")
-                .to_string();
-            panic!(
-                r#"Reformatting the formatted code a second time resulted in formatting changes.
----
-{diff}---
-
-Formatted once:
----
-{formatted_code}---
-
-Formatted twice:
----
-{}---"#,
-                reformatted.as_code()
-            );
-        }
 
         if formatted_code == expected_output {
             // Black and Ruff formatting matches. Delete any existing snapshot files because the Black output
@@ -374,6 +345,8 @@ Formatted twice:
         let reformatted =
             format_module(formatted_code).unwrap_or_else(|err| panic!("Expected formatted code to be valid syntax but it contains syntax errors: {err}\n{formatted_code}"));
 
+        ensure_stability_when_formatting_twice(formatted_code);
+
         if reformatted.as_code() != formatted_code {
             let diff = TextDiff::from_lines(formatted_code, reformatted.as_code())
                 .unified_diff()
@@ -406,6 +379,40 @@ Formatted twice:
         Ok(())
     }
 
+    /// Format another time and make sure that there are no changes anymore
+    fn ensure_stability_when_formatting_twice(formatted_code: &str) {
+        let reformatted = match format_module(formatted_code) {
+            Ok(reformatted) => reformatted,
+            Err(err) => {
+                panic!(
+                    "Expected formatted code to be valid syntax: {err}:\
+                    \n---\n{formatted_code}---\n",
+                );
+            }
+        };
+
+        if reformatted.as_code() != formatted_code {
+            let diff = TextDiff::from_lines(formatted_code, reformatted.as_code())
+                .unified_diff()
+                .header("Formatted once", "Formatted twice")
+                .to_string();
+            panic!(
+                r#"Reformatting the formatted code a second time resulted in formatting changes.
+---
+{diff}---
+
+Formatted once:
+---
+{formatted_code}---
+
+Formatted twice:
+---
+{}---"#,
+                reformatted.as_code()
+            );
+        }
+    }
+
     /// Use this test to debug the formatting of some snipped
     #[ignore]
     #[test]

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__attribute_access_on_number_literals_py.snap

@@ -73,9 +73,8 @@ y = 100(no)
 +if 10 .NOT_IMPLEMENTED_attr:
      ...
  
--y = 100[no]
+ y = 100[no]
 -y = 100(no)
-+y = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
 +y = NOT_IMPLEMENTED_call()
 ```
 
@@ -102,7 +101,7 @@ x = -100.0000J
 if 10 .NOT_IMPLEMENTED_attr:
     ...
 
-y = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+y = 100[no]
 y = NOT_IMPLEMENTED_call()
 ```
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments2_py.snap

@@ -264,32 +264,30 @@ instruction()#comment with bad spacing
      if typedargslist:
 -        parameters.children = [children[0], body, children[-1]]  # (1  # )1
 -        parameters.children = [
--            children[0],
 +        parameters.NOT_IMPLEMENTED_attr = [
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # (1
++            children[0],  # (1
-             body,
++            body,
--            children[-1],  # type: ignore
++            children[-1],  # )1
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # )1
 +        ]
 +        parameters.NOT_IMPLEMENTED_attr = [
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
+             children[0],
-+            body,
+             body,
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # type: ignore
+             children[-1],  # type: ignore
          ]
      else:
 -        parameters.children = [
 -            parameters.children[0],  # (2 what if this was actually long
 +        parameters.NOT_IMPLEMENTED_attr = [
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # (2 what if this was actually long
++            parameters.NOT_IMPLEMENTED_attr[0],  # (2 what if this was actually long
              body,
 -            parameters.children[-1],  # )2
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # )2
++            parameters.NOT_IMPLEMENTED_attr[-1],  # )2
          ]
 -        parameters.children = [parameters.what_if_this_was_actually_long.children[0], body, parameters.children[-1]]  # type: ignore
 +        parameters.NOT_IMPLEMENTED_attr = [
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
++            parameters.NOT_IMPLEMENTED_attr.NOT_IMPLEMENTED_attr[0],
 +            body,
-+            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
++            parameters.NOT_IMPLEMENTED_attr[-1],
 +        ]  # type: ignore
      if (
 -        self._proc is not None
@@ -460,25 +458,25 @@ else:
 def inline_comments_in_brackets_ruin_everything():
     if typedargslist:
         parameters.NOT_IMPLEMENTED_attr = [
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # (1
+            children[0],  # (1
             body,
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # )1
+            children[-1],  # )1
         ]
         parameters.NOT_IMPLEMENTED_attr = [
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
+            children[0],
             body,
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # type: ignore
+            children[-1],  # type: ignore
         ]
     else:
         parameters.NOT_IMPLEMENTED_attr = [
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # (2 what if this was actually long
+            parameters.NOT_IMPLEMENTED_attr[0],  # (2 what if this was actually long
             body,
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # )2
+            parameters.NOT_IMPLEMENTED_attr[-1],  # )2
         ]
         parameters.NOT_IMPLEMENTED_attr = [
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
+            parameters.NOT_IMPLEMENTED_attr.NOT_IMPLEMENTED_attr[0],
             body,
-            NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
+            parameters.NOT_IMPLEMENTED_attr[-1],
         ]  # type: ignore
     if (
         NOT_IMPLEMENTED_left < NOT_IMPLEMENTED_right

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments6_py.snap

@@ -153,12 +153,9 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
  
      tup = (
          another_element,
-@@ -84,35 +85,22 @@
+@@ -86,33 +87,20 @@
- 
- 
  def func(
--    a=some_list[0],  # type: int
+     a=some_list[0],  # type: int
-+    a=NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # type: int
  ):  # type: () -> int
 -    c = call(
 -        0.0123,
@@ -293,7 +290,7 @@ def f(
 
 
 def func(
-    a=NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],  # type: int
+    a=some_list[0],  # type: int
 ):  # type: () -> int
     c = NOT_IMPLEMENTED_call()
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__expression_py.snap

@@ -276,7 +276,7 @@ last_call()
  Name
  None
  True
-@@ -30,203 +31,178 @@
+@@ -30,134 +31,120 @@
  -1
  ~int and not v1 ^ 123 + v2 | True
  (~int) and (not ((v1 ^ (123 + v2)) | True))
@@ -297,13 +297,6 @@ last_call()
 -(str or None) if True else (str or bytes or None)
 -str or None if (1 if True else 2) else str or bytes or None
 -(str or None) if (1 if True else 2) else (str or bytes or None)
--(
--    (super_long_variable_name or None)
--    if (1 if super_long_test_name else 2)
--    else (str or bytes or None)
--)
--{"2.7": dead, "3.7": (long_live or die_hard)}
--{"2.7": dead, "3.7": (long_live or die_hard), **{"3.6": verygood}}
 ++really ** -confusing ** ~operator**-precedence
 +flags & ~select.NOT_IMPLEMENTED_attr and NOT_IMPLEMENTED_left < NOT_IMPLEMENTED_right
 +lambda x: True
@@ -328,9 +321,7 @@ last_call()
 +    "NOT_YET_IMPLEMENTED_STRING": (long_live or die_hard),
 +    **{"NOT_YET_IMPLEMENTED_STRING": verygood},
 +}
- {**a, **b, **c}
++{**a, **b, **c}
--{"2.7", "3.6", "3.7", "3.8", "3.9", ("4.0" if gilectomy else "3.10")}
--({"a": "b"}, (True or False), (+value), "string", b"bytes") or None
 +{
 +    "NOT_YET_IMPLEMENTED_STRING",
 +    "NOT_YET_IMPLEMENTED_STRING",
@@ -339,7 +330,16 @@ last_call()
 +    "NOT_YET_IMPLEMENTED_STRING",
 +    (NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false),
 +}
-+(
+ (
+-    (super_long_variable_name or None)
+-    if (1 if super_long_test_name else 2)
+-    else (str or bytes or None)
+-)
+-{"2.7": dead, "3.7": (long_live or die_hard)}
+-{"2.7": dead, "3.7": (long_live or die_hard), **{"3.6": verygood}}
+-{**a, **b, **c}
+-{"2.7", "3.6", "3.7", "3.8", "3.9", ("4.0" if gilectomy else "3.10")}
+-({"a": "b"}, (True or False), (+value), "string", b"bytes") or None
 +    {"NOT_YET_IMPLEMENTED_STRING": "NOT_YET_IMPLEMENTED_STRING"},
 +    (True or False),
 +    (+value),
@@ -352,7 +352,12 @@ last_call()
  (1, 2, 3)
  []
  [1, 2, 3, 4, 5, 6, 7, 8, 9, (10 or A), (11 or B), (12 or C)]
--[
++[1, 2, 3]
++[NOT_YET_IMPLEMENTED_ExprStarred]
++[NOT_YET_IMPLEMENTED_ExprStarred]
++[NOT_YET_IMPLEMENTED_ExprStarred, 4, 5]
++[4, NOT_YET_IMPLEMENTED_ExprStarred, 5]
+ [
 -    1,
 -    2,
 -    3,
@@ -369,12 +374,7 @@ last_call()
 -    *a,
 -    5,
 -]
-+[1, 2, 3]
+-[
-+[NOT_YET_IMPLEMENTED_ExprStarred]
-+[NOT_YET_IMPLEMENTED_ExprStarred]
-+[NOT_YET_IMPLEMENTED_ExprStarred, 4, 5]
-+[4, NOT_YET_IMPLEMENTED_ExprStarred, 5]
- [
      this_is_a_very_long_variable_which_will_force_a_delimiter_split,
      element,
      another,
@@ -393,6 +393,33 @@ last_call()
 -{i: j for i, j in ((1, "a"), (2, "b"), (3, "c"))}
 -{a: b * 2 for a, b in dictionary.items()}
 -{a: b * -2 for a, b in dictionary.items()}
+-{
+-    k: v
+-    for k, v in this_is_a_very_long_variable_which_will_cause_a_trailing_comma_which_breaks_the_comprehension
+-}
+-Python3 > Python2 > COBOL
+-Life is Life
+-call()
+-call(arg)
+-call(kwarg="hey")
+-call(arg, kwarg="hey")
+-call(arg, another, kwarg="hey", **kwargs)
+-call(
+-    this_is_a_very_long_variable_which_will_force_a_delimiter_split,
+-    arg,
+-    another,
+-    kwarg="hey",
+-    **kwargs,
+-)  # note: no trailing comma pre-3.6
+-call(*gidgets[:2])
+-call(a, *gidgets[:2])
+-call(**self.screen_kwargs)
+-call(b, **self.screen_kwargs)
+-lukasz.langa.pl
+-call.me(maybe)
+-(1).real
+-(1.0).real
+-....__class__
 +NOT_YET_IMPLEMENTED_ExprSetComp
 +NOT_YET_IMPLEMENTED_ExprSetComp
 +NOT_YET_IMPLEMENTED_ExprSetComp
@@ -423,81 +450,22 @@ last_call()
 +1 .NOT_IMPLEMENTED_attr
 +1.0 .NOT_IMPLEMENTED_attr
 +....NOT_IMPLEMENTED_attr
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ list[str]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ dict[str, int]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ tuple[str, ...]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ tuple[str, int, float, dict[str, int]]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ tuple[
-+NOT_YET_IMPLEMENTED_StmtAnnAssign
-+NOT_YET_IMPLEMENTED_StmtAnnAssign
-+NOT_YET_IMPLEMENTED_StmtAnnAssign
-+NOT_YET_IMPLEMENTED_StmtAnnAssign  # type: ignore
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
- {
--    k: v
--    for k, v in this_is_a_very_long_variable_which_will_cause_a_trailing_comma_which_breaks_the_comprehension
-+    "NOT_YET_IMPLEMENTED_STRING": dead,
-+    "NOT_YET_IMPLEMENTED_STRING": long_live or die_hard,
- }
--Python3 > Python2 > COBOL
--Life is Life
--call()
--call(arg)
--call(kwarg="hey")
--call(arg, kwarg="hey")
--call(arg, another, kwarg="hey", **kwargs)
--call(
--    this_is_a_very_long_variable_which_will_force_a_delimiter_split,
--    arg,
--    another,
--    kwarg="hey",
--    **kwargs,
--)  # note: no trailing comma pre-3.6
--call(*gidgets[:2])
--call(a, *gidgets[:2])
--call(**self.screen_kwargs)
--call(b, **self.screen_kwargs)
--lukasz.langa.pl
--call.me(maybe)
--(1).real
--(1.0).real
--....__class__
--list[str]
--dict[str, int]
--tuple[str, ...]
--tuple[str, int, float, dict[str, int]]
--tuple[
 -    str,
 -    int,
 -    float,
 -    dict[str, int],
--]
++    (
++        str,
++        int,
++        float,
++        dict[str, int],
++    )
+ ]
 -very_long_variable_name_filters: t.List[
 -    t.Tuple[str, t.Union[str, t.List[t.Optional[str]]]],
 -]
@@ -510,35 +478,43 @@ last_call()
 -xxxx_xxx_xxxx_xxxxx_xxxx_xxx: Callable[..., List[SomeClass]] = classmethod(
 -    sync(async_xxxx_xxx_xxxx_xxxxx_xxxx_xxx.__func__)
 -)  # type: ignore
--slice[0]
++NOT_YET_IMPLEMENTED_StmtAnnAssign
--slice[0:1]
++NOT_YET_IMPLEMENTED_StmtAnnAssign
--slice[0:1:2]
++NOT_YET_IMPLEMENTED_StmtAnnAssign
--slice[:]
++NOT_YET_IMPLEMENTED_StmtAnnAssign  # type: ignore
+ slice[0]
+ slice[0:1]
+ slice[0:1:2]
+ slice[:]
 -slice[:-1]
--slice[1:]
++slice[ : -1]
+ slice[1:]
 -slice[::-1]
--slice[d :: d + 1]
++slice[ :: -1]
--slice[:c, c - 1]
+ slice[d :: d + 1]
--numpy[:, 0:1]
+ slice[:c, c - 1]
+ numpy[:, 0:1]
 -numpy[:, :-1]
--numpy[0, :]
++numpy[:,  : -1]
--numpy[:, i]
+ numpy[0, :]
--numpy[0, :2]
+ numpy[:, i]
--numpy[:N, 0]
+ numpy[0, :2]
--numpy[:2, :4]
+@@ -171,62 +158,58 @@
--numpy[2:4, 1:5]
+ numpy[1 : c + 1, c]
--numpy[4:, 2:]
+ numpy[-(c + 1) :, d]
--numpy[:, (0, 1, 2, 5)]
+ numpy[:, l[-2]]
--numpy[0, [0]]
--numpy[:, [i]]
--numpy[1 : c + 1, c]
--numpy[-(c + 1) :, d]
--numpy[:, l[-2]]
 -numpy[:, ::-1]
 -numpy[np.newaxis, :]
 -(str or None) if (sys.version_info[0] > (3,)) else (str or bytes or None)
 -{"2.7": dead, "3.7": long_live or die_hard}
 -{"2.7", "3.6", "3.7", "3.8", "3.9", "4.0" if gilectomy else "3.10"}
++numpy[:,  :: -1]
++numpy[np.NOT_IMPLEMENTED_attr, :]
++NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
++{
++    "NOT_YET_IMPLEMENTED_STRING": dead,
++    "NOT_YET_IMPLEMENTED_STRING": long_live or die_hard,
++}
 +{
 +    "NOT_YET_IMPLEMENTED_STRING",
 +    "NOT_YET_IMPLEMENTED_STRING",
@@ -585,7 +561,13 @@ last_call()
 -g = 1, *"ten"
 -what_is_up_with_those_new_coord_names = (coord_names + set(vars_to_create)) + set(
 -    vars_to_remove
--)
++e = NOT_IMPLEMENTED_call()
++f = 1, NOT_YET_IMPLEMENTED_ExprStarred
++g = 1, NOT_YET_IMPLEMENTED_ExprStarred
++what_is_up_with_those_new_coord_names = (
++    (coord_names + NOT_IMPLEMENTED_call())
++    + NOT_IMPLEMENTED_call()
+ )
 -what_is_up_with_those_new_coord_names = (coord_names | set(vars_to_create)) - set(
 -    vars_to_remove
 -)
@@ -596,13 +578,7 @@ last_call()
 -    )
 -    .order_by(models.Customer.id.asc())
 -    .all()
-+e = NOT_IMPLEMENTED_call()
+-)
-+f = 1, NOT_YET_IMPLEMENTED_ExprStarred
-+g = 1, NOT_YET_IMPLEMENTED_ExprStarred
-+what_is_up_with_those_new_coord_names = (
-+    (coord_names + NOT_IMPLEMENTED_call())
-+    + NOT_IMPLEMENTED_call()
- )
 -result = (
 -    session.query(models.Customer.id)
 -    .filter(
@@ -625,7 +601,7 @@ last_call()
  mapping = {
      A: 0.25 * (10.0 / 12),
      B: 0.1 * (10.0 / 12),
-@@ -236,64 +212,38 @@
+@@ -236,64 +219,38 @@
  
  
  def gen():
@@ -714,7 +690,7 @@ last_call()
  ):
      return True
  if (
-@@ -327,24 +277,44 @@
+@@ -327,24 +284,44 @@
  ):
      return True
  if (
@@ -771,7 +747,7 @@ last_call()
  ):
      return True
  (
-@@ -363,8 +333,9 @@
+@@ -363,8 +340,9 @@
  bbbb >> bbbb * bbbb
  (
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
@@ -908,41 +884,48 @@ NOT_IMPLEMENTED_call()
 1 .NOT_IMPLEMENTED_attr
 1.0 .NOT_IMPLEMENTED_attr
 ....NOT_IMPLEMENTED_attr
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+list[str]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+dict[str, int]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+tuple[str, ...]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+tuple[str, int, float, dict[str, int]]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+tuple[
+    (
+        str,
+        int,
+        float,
+        dict[str, int],
+    )
+]
 NOT_YET_IMPLEMENTED_StmtAnnAssign
 NOT_YET_IMPLEMENTED_StmtAnnAssign
 NOT_YET_IMPLEMENTED_StmtAnnAssign
 NOT_YET_IMPLEMENTED_StmtAnnAssign  # type: ignore
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[0]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[0:1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[0:1:2]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[:]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ : -1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[1:]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ :: -1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[d :: d + 1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[:c, c - 1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:, 0:1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:,  : -1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[0, :]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:, i]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[0, :2]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:N, 0]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:2, :4]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[2:4, 1:5]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[4:, 2:]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:, (0, 1, 2, 5)]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[0, [0]]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:, [i]]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[1 : c + 1, c]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[-(c + 1) :, d]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:, l[-2]]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[:,  :: -1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+numpy[np.NOT_IMPLEMENTED_attr, :]
 NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
 {
     "NOT_YET_IMPLEMENTED_STRING": dead,

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtonoff_py.snap

@@ -273,7 +273,7 @@ d={'a':1,
 +    debug: bool = False,
 +    **kwargs,
 +) -> str:
-+    return NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++    return text[number : -1]
 +
 +
  # fmt: on
@@ -296,7 +296,7 @@ d={'a':1,
  
  
  def spaces_types(
-@@ -51,76 +70,61 @@
+@@ -51,76 +70,71 @@
      d: dict = {},
      e: bool = True,
      f: int = -1,
@@ -323,15 +323,22 @@ d={'a':1,
  
  
  def subscriptlist():
--    atom[
+     atom[
--        # fmt: off
+         # fmt: off
 -        'some big and',
 -        'complex subscript',
 -        # fmt: on
 -        goes + here,
 -        andhere,
--    ]
++        (
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++            "NOT_YET_IMPLEMENTED_STRING",
++            "NOT_YET_IMPLEMENTED_STRING",
++            # fmt: on
++            goes
++            + here,
++            andhere,
++        )
+     ]
  
  
  def import_as_names():
@@ -390,7 +397,7 @@ d={'a':1,
      # fmt: off
  
      # hey, that won't work
-@@ -130,13 +134,15 @@
+@@ -130,13 +144,15 @@
  
  
  def on_and_off_broken():
@@ -411,7 +418,7 @@ d={'a':1,
      # fmt: on
      # fmt: off
      # ...but comments still get reformatted even though they should not be
-@@ -145,80 +151,21 @@
+@@ -145,80 +161,21 @@
  
  def long_lines():
      if True:
@@ -551,7 +558,7 @@ def function_signature_stress_test(
     debug: bool = False,
     **kwargs,
 ) -> str:
-    return NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    return text[number : -1]
 
 
 # fmt: on
@@ -595,7 +602,17 @@ something = {
 
 
 def subscriptlist():
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    atom[
+        # fmt: off
+        (
+            "NOT_YET_IMPLEMENTED_STRING",
+            "NOT_YET_IMPLEMENTED_STRING",
+            # fmt: on
+            goes
+            + here,
+            andhere,
+        )
+    ]
 
 
 def import_as_names():

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__function_py.snap

@@ -167,7 +167,7 @@ def __await__(): return (yield)
      **kwargs,
  ) -> str:
 -    return text[number:-1]
-+    return NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++    return text[number : -1]
  
  
 -def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
@@ -330,7 +330,7 @@ def function_signature_stress_test(
     debug: bool = False,
     **kwargs,
 ) -> str:
-    return NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    return text[number : -1]
 
 
 def spaces(

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__function_trailing_comma_py.snap

@@ -94,7 +94,7 @@ some_module.some_function(
      }
      tup = (
          1,
-@@ -24,45 +24,18 @@
+@@ -24,45 +24,23 @@
  def f(
      a: int = 1,
  ):
@@ -106,7 +106,9 @@ some_module.some_function(
 -    call2(
 -        arg=[1, 2, 3],
 -    )
--    x = {
++    NOT_IMPLEMENTED_call()
++    NOT_IMPLEMENTED_call()
+     x = {
 -        "a": 1,
 -        "b": 2,
 -    }["a"]
@@ -123,9 +125,11 @@ some_module.some_function(
 -            "h": 8,
 -        }["a"]
 -    ):
-+    NOT_IMPLEMENTED_call()
++        "NOT_YET_IMPLEMENTED_STRING": 1,
-+    NOT_IMPLEMENTED_call()
++        "NOT_YET_IMPLEMENTED_STRING": 2,
-+    x = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++    }[
++        "NOT_YET_IMPLEMENTED_STRING"
++    ]
 +    if NOT_IMPLEMENTED_left < NOT_IMPLEMENTED_right:
          pass
  
@@ -133,7 +137,7 @@ some_module.some_function(
 -def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> (
 -    Set["xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"]
 -):
-+def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
++def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> Set["NOT_YET_IMPLEMENTED_STRING"]:
      json = {
 -        "k": {
 -            "k2": {
@@ -148,7 +152,7 @@ some_module.some_function(
      }
  
  
-@@ -80,35 +53,16 @@
+@@ -80,35 +58,16 @@
      pass
  
  
@@ -221,12 +225,17 @@ def f(
 ):
     NOT_IMPLEMENTED_call()
     NOT_IMPLEMENTED_call()
-    x = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    x = {
+        "NOT_YET_IMPLEMENTED_STRING": 1,
+        "NOT_YET_IMPLEMENTED_STRING": 2,
+    }[
+        "NOT_YET_IMPLEMENTED_STRING"
+    ]
     if NOT_IMPLEMENTED_left < NOT_IMPLEMENTED_right:
         pass
 
 
-def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
+def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> Set["NOT_YET_IMPLEMENTED_STRING"]:
     json = {
         "NOT_YET_IMPLEMENTED_STRING": {
             "NOT_YET_IMPLEMENTED_STRING": {"NOT_YET_IMPLEMENTED_STRING": [1]},

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__one_element_subscript_py.snap

@@ -25,25 +25,28 @@ list_of_types = [tuple[int,],]
 ```diff
 --- Black
 +++ Ruff
-@@ -1,22 +1,12 @@
+@@ -1,22 +1,17 @@
  # We should not treat the trailing comma
  # in a single-element subscript.
 -a: tuple[int,]
 -b = tuple[int,]
 +NOT_YET_IMPLEMENTED_StmtAnnAssign
-+b = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++b = tuple[(int,)]
  
  # The magic comma still applies to multi-element subscripts.
 -c: tuple[
 -    int,
 -    int,
 -]
--d = tuple[
--    int,
--    int,
--]
 +NOT_YET_IMPLEMENTED_StmtAnnAssign
-+d = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ d = tuple[
+-    int,
+-    int,
++    (
++        int,
++        int,
++    )
+ ]
  
  # Magic commas still work as expected for non-subscripts.
 -small_list = [
@@ -53,7 +56,7 @@ list_of_types = [tuple[int,],]
 -    tuple[int,],
 -]
 +small_list = [1]
-+list_of_types = [NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]]
++list_of_types = [tuple[(int,)]]
 ```
 
 ## Ruff Output
@@ -62,15 +65,20 @@ list_of_types = [tuple[int,],]
 # We should not treat the trailing comma
 # in a single-element subscript.
 NOT_YET_IMPLEMENTED_StmtAnnAssign
-b = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+b = tuple[(int,)]
 
 # The magic comma still applies to multi-element subscripts.
 NOT_YET_IMPLEMENTED_StmtAnnAssign
-d = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+d = tuple[
+    (
+        int,
+        int,
+    )
+]
 
 # Magic commas still work as expected for non-subscripts.
 small_list = [1]
-list_of_types = [NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]]
+list_of_types = [tuple[(int,)]]
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__power_op_spacing_py.snap

@@ -92,7 +92,7 @@ return np.divide(
 -j = super().name ** 5
 -k = [(2**idx, value) for idx, value in pairs]
 -l = mod.weights_[0] == pytest.approx(0.95**100, abs=0.001)
-+d = 5 ** NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++d = 5 ** f["NOT_YET_IMPLEMENTED_STRING"]
 +e = NOT_IMPLEMENTED_call()
 +f = NOT_IMPLEMENTED_call() ** 5
 +g = a.NOT_IMPLEMENTED_attr**c.NOT_IMPLEMENTED_attr
@@ -125,7 +125,7 @@ return np.divide(
 -j = super().name ** 5.0
 -k = [(2.0**idx, value) for idx, value in pairs]
 -l = mod.weights_[0] == pytest.approx(0.95**100, abs=0.001)
-+d = 5.0 ** NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++d = 5.0 ** f["NOT_YET_IMPLEMENTED_STRING"]
 +e = NOT_IMPLEMENTED_call()
 +f = NOT_IMPLEMENTED_call() ** 5.0
 +g = a.NOT_IMPLEMENTED_attr**c.NOT_IMPLEMENTED_attr
@@ -181,7 +181,7 @@ def function_dont_replace_spaces():
 a = 5**~4
 b = 5 ** NOT_IMPLEMENTED_call()
 c = -(5**2)
-d = 5 ** NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+d = 5 ** f["NOT_YET_IMPLEMENTED_STRING"]
 e = NOT_IMPLEMENTED_call()
 f = NOT_IMPLEMENTED_call() ** 5
 g = a.NOT_IMPLEMENTED_attr**c.NOT_IMPLEMENTED_attr
@@ -200,7 +200,7 @@ r = x**y
 a = 5.0**~4.0
 b = 5.0 ** NOT_IMPLEMENTED_call()
 c = -(5.0**2.0)
-d = 5.0 ** NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+d = 5.0 ** f["NOT_YET_IMPLEMENTED_STRING"]
 e = NOT_IMPLEMENTED_call()
 f = NOT_IMPLEMENTED_call() ** 5.0
 g = a.NOT_IMPLEMENTED_attr**c.NOT_IMPLEMENTED_attr

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__prefer_rhs_split_reformatted_py.snap

@@ -40,7 +40,7 @@ xxxxxxxxx_yyy_zzzzzzzz[xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxx
 -xxxxxxxxx_yyy_zzzzzzzz[
 -    xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxxx=1)
 -] = 1
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key] = 1
++xxxxxxxxx_yyy_zzzzzzzz[NOT_IMPLEMENTED_call(), NOT_IMPLEMENTED_call()] = 1
 ```
 
 ## Ruff Output
@@ -61,7 +61,7 @@ xxxxxxxxx_yyy_zzzzzzzz[xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxx
 
 # Make when when the left side of assignment plus the opening paren "... = (" is
 # exactly line length limit + 1, it won't be split like that.
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key] = 1
+xxxxxxxxx_yyy_zzzzzzzz[NOT_IMPLEMENTED_call(), NOT_IMPLEMENTED_call()] = 1
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__return_annotation_brackets_py.snap

@@ -123,35 +123,36 @@ def foo() -> tuple[int, int, int,]:
      return 2
  
  
-@@ -95,26 +99,14 @@
+@@ -99,22 +103,22 @@
- 
- 
- # Return type with commas
--def foo() -> tuple[int, int, int]:
-+def foo() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
      return 2
  
  
 -def foo() -> (
 -    tuple[
--        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
++def foo() -> tuple[
--        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
++    (
--        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+         loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+         loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+         loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
 -    ]
 -):
-+def foo() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
++    )
++]:
      return 2
  
  
  # Magic trailing comma example
 -def foo() -> (
 -    tuple[
--        int,
++def foo() -> tuple[
--        int,
++    (
--        int,
+         int,
+         int,
+         int,
 -    ]
 -):
-+def foo() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
++    )
++]:
      return 2
 ```
 
@@ -259,16 +260,28 @@ def foo() -> (
 
 
 # Return type with commas
-def foo() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
+def foo() -> tuple[int, int, int]:
     return 2
 
 
-def foo() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
+def foo() -> tuple[
+    (
+        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+    )
+]:
     return 2
 
 
 # Magic trailing comma example
-def foo() -> NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]:
+def foo() -> tuple[
+    (
+        int,
+        int,
+        int,
+    )
+]:
     return 2
 ```
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__skip_magic_trailing_comma_py.snap

@@ -60,26 +60,31 @@ func(
 ```diff
 --- Black
 +++ Ruff
-@@ -1,25 +1,30 @@
+@@ -1,25 +1,35 @@
  # We should not remove the trailing comma in a single-element subscript.
 -a: tuple[int,]
 -b = tuple[int,]
 +NOT_YET_IMPLEMENTED_StmtAnnAssign
-+b = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++b = tuple[(int,)]
  
  # But commas in multiple element subscripts should be removed.
 -c: tuple[int, int]
 -d = tuple[int, int]
 +NOT_YET_IMPLEMENTED_StmtAnnAssign
-+d = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++d = tuple[
++    (
++        int,
++        int,
++    )
++]
  
  # Remove commas for non-subscripts.
  small_list = [1]
 -list_of_types = [tuple[int,]]
-+list_of_types = [NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]]
++list_of_types = [tuple[(int,)]]
  small_set = {1}
 -set_of_types = {tuple[int,]}
-+set_of_types = {NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]}
++set_of_types = {tuple[(int,)]}
  
  # Except single element tuples
  small_tuple = (1,)
@@ -108,17 +113,22 @@ func(
 ```py
 # We should not remove the trailing comma in a single-element subscript.
 NOT_YET_IMPLEMENTED_StmtAnnAssign
-b = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+b = tuple[(int,)]
 
 # But commas in multiple element subscripts should be removed.
 NOT_YET_IMPLEMENTED_StmtAnnAssign
-d = NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+d = tuple[
+    (
+        int,
+        int,
+    )
+]
 
 # Remove commas for non-subscripts.
 small_list = [1]
-list_of_types = [NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]]
+list_of_types = [tuple[(int,)]]
 small_set = {1}
-set_of_types = {NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]}
+set_of_types = {tuple[(int,)]}
 
 # Except single element tuples
 small_tuple = (1,)

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__slices_py.snap

@@ -76,158 +76,137 @@ x[
 ```diff
 --- Black
 +++ Ruff
-@@ -1,59 +1,48 @@
+@@ -1,33 +1,33 @@
 -slice[a.b : c.d]
--slice[d :: d + 1]
++slice[a.NOT_IMPLEMENTED_attr : c.NOT_IMPLEMENTED_attr]
--slice[d + 1 :: d]
+ slice[d :: d + 1]
--slice[d::d]
+ slice[d + 1 :: d]
--slice[0]
+ slice[d::d]
--slice[-1]
+ slice[0]
+ slice[-1]
 -slice[:-1]
 -slice[::-1]
--slice[:c, c - 1]
++slice[ : -1]
--slice[c, c + 1, d::]
++slice[ :: -1]
--slice[ham[c::d] :: 1]
+ slice[:c, c - 1]
--slice[ham[cheese**2 : -1] : 1 : 1, ham[1:2]]
+ slice[c, c + 1, d::]
+ slice[ham[c::d] :: 1]
+ slice[ham[cheese**2 : -1] : 1 : 1, ham[1:2]]
 -slice[:-1:]
 -slice[lambda: None : lambda: None]
 -slice[lambda x, y, *args, really=2, **kwargs: None :, None::]
--slice[1 or 2 : True and False]
++slice[ : -1 :]
++slice[lambda x: True : lambda x: True]
++slice[lambda x: True :, None::]
+ slice[1 or 2 : True and False]
 -slice[not so_simple : 1 < val <= 10]
 -slice[(1 for i in range(42)) : x]
 -slice[:: [i for i in range(42)]]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++slice[not so_simple : NOT_IMPLEMENTED_left < NOT_IMPLEMENTED_right]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++slice[(i for i in []) : x]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++slice[ :: [i for i in []]]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
  
  
  async def f():
 -    slice[await x : [i async for i in arange(42)] : 42]
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++    slice[await x : [i for i in []] : 42]
  
  
  # These are from PEP-8:
--ham[1:9], ham[1:9:3], ham[:9:3], ham[1::3], ham[1:9:]
+ ham[1:9], ham[1:9:3], ham[:9:3], ham[1::3], ham[1:9:]
--ham[lower:upper], ham[lower:upper:], ham[lower::step]
+ ham[lower:upper], ham[lower:upper:], ham[lower::step]
-+(
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+)
-+(
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-+)
  # ham[lower+offset : upper+offset]
 -ham[: upper_fn(x) : step_fn(x)], ham[:: step_fn(x)]
--ham[lower + offset : upper + offset]
++ham[ : NOT_IMPLEMENTED_call() : NOT_IMPLEMENTED_call()], ham[ :: NOT_IMPLEMENTED_call()]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key], NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ ham[lower + offset : upper + offset]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
  
--slice[::, ::]
+ slice[::, ::]
--slice[
+@@ -50,10 +50,14 @@
--    # A
+ slice[
--    :
+     # A
--    # B
+     1
--    :
--    # C
--]
--slice[
--    # A
--    1:
--    # B
--    2:
--    # C
--    3
--]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
- 
--slice[
--    # A
--    1
 -    + 2 :
--    # B
++    + 2 : 
+     # B
 -    3 :
--    # C
++    3 : 
--    4
+     # C
--]
+     4
+ ]
 -x[1:2:3]  # A  # B  # C
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++x[
-+NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++    1:  # A
++    2:  # B
++    3  # C
++]
 ```
 
 ## Ruff Output
 
 ```py
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[a.NOT_IMPLEMENTED_attr : c.NOT_IMPLEMENTED_attr]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[d :: d + 1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[d + 1 :: d]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[d::d]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[0]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[-1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ : -1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ :: -1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[:c, c - 1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[c, c + 1, d::]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ham[c::d] :: 1]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ham[cheese**2 : -1] : 1 : 1, ham[1:2]]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ : -1 :]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[lambda x: True : lambda x: True]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[lambda x: True :, None::]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[1 or 2 : True and False]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[not so_simple : NOT_IMPLEMENTED_left < NOT_IMPLEMENTED_right]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[(i for i in []) : x]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[ :: [i for i in []]]
 
 
 async def f():
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    slice[await x : [i for i in []] : 42]
 
 
 # These are from PEP-8:
-(
+ham[1:9], ham[1:9:3], ham[:9:3], ham[1::3], ham[1:9:]
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
+ham[lower:upper], ham[lower:upper:], ham[lower::step]
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-)
-(
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-    NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key],
-)
 # ham[lower+offset : upper+offset]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key], NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ham[ : NOT_IMPLEMENTED_call() : NOT_IMPLEMENTED_call()], ham[ :: NOT_IMPLEMENTED_call()]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+ham[lower + offset : upper + offset]
 
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[::, ::]
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    # A
+    :
+    # B
+    :
+    # C
+]
+slice[
+    # A
+    1:
+    # B
+    2:
+    # C
+    3
+]
 
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+slice[
-NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    # A
+    1
+    + 2 : 
+    # B
+    3 : 
+    # C
+    4
+]
+x[
+    1:  # A
+    2:  # B
+    3  # C
+]
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__trailing_commas_in_leading_parts_py.snap

@@ -46,7 +46,7 @@ assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
 ```diff
 --- Black
 +++ Ruff
-@@ -1,50 +1,26 @@
+@@ -1,50 +1,30 @@
 -zero(
 -    one,
 -).two(
@@ -86,7 +86,11 @@ assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
 -        },
 -        api_key=api_key,
 -    )["extensions"]["sdk"]["token"]
-+    return NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
++    return NOT_IMPLEMENTED_call()["NOT_YET_IMPLEMENTED_STRING"][
++        "NOT_YET_IMPLEMENTED_STRING"
++    ][
++        "NOT_YET_IMPLEMENTED_STRING"
++    ]
  
  
  # Edge case where a bug in a working-in-progress version of
@@ -126,7 +130,11 @@ NOT_IMPLEMENTED_call()
 
 # Example from https://github.com/psf/black/issues/3229
 def refresh_token(self, device_family, refresh_token, api_key):
-    return NOT_IMPLEMENTED_value[NOT_IMPLEMENTED_key]
+    return NOT_IMPLEMENTED_call()["NOT_YET_IMPLEMENTED_STRING"][
+        "NOT_YET_IMPLEMENTED_STRING"
+    ][
+        "NOT_YET_IMPLEMENTED_STRING"
+    ]
 
 
 # Edge case where a bug in a working-in-progress version of

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__ruff_test__expression__slice_py.snap

@@ -0,0 +1,177 @@
+---
+source: crates/ruff_python_formatter/src/lib.rs
+expression: snapshot
+---
+## Input
+```py
+# Handle comments both when lower and upper exist and when they don't
+a1 = "a"[
+    # a
+    1  # b
+    :  # c
+    2  # d
+]
+a2 = "a"[
+    # a
+      # b
+    :  # c
+      # d
+]
+
+# Check all places where comments can exist
+b1 = "b"[ # a
+    # b
+    1 # c
+    # d
+    : # e
+    # f
+    2 # g
+    # h
+    : # i
+    # j
+    3 # k
+    # l
+]
+
+# Handle the spacing from the colon correctly with upper leading comments
+c1 = "c"[
+    1
+    :  # e
+    # f
+    2
+]
+c2 = "c"[
+    1
+    :  # e
+    2
+]
+c3 = "c"[
+    1
+    :
+    # f
+    2
+]
+c4 = "c"[
+    1
+    : # f
+    2
+]
+
+# End of line comments
+d1 = "d"[ # comment
+    :
+]
+d2 = "d"[  # comment
+    1:
+]
+d3 = "d"[
+    1  # comment
+    :
+]
+
+# Spacing around the colon(s)
+def a():
+    ...
+
+e00 = "e"[:]
+e01 = "e"[:1]
+e02 = "e"[: a()]
+e10 = "e"[1:]
+e11 = "e"[1:1]
+e12 = "e"[1 : a()]
+e20 = "e"[a() :]
+e21 = "e"[a() : 1]
+e22 = "e"[a() : a()]
+e200 = "e"[a() :: ]
+e201 = "e"[a() :: 1]
+e202 = "e"[a() :: a()]
+e210 = "e"[a() : 1 :]
+```
+
+
+
+## Output
+```py
+# Handle comments both when lower and upper exist and when they don't
+a1 = "NOT_YET_IMPLEMENTED_STRING"[
+    # a
+    1  # b
+    :  # c
+    2  # d
+]
+a2 = "NOT_YET_IMPLEMENTED_STRING"[
+    # a
+    # b
+    :  # c
+    # d
+]
+
+# Check all places where comments can exist
+b1 = "NOT_YET_IMPLEMENTED_STRING"[  # a
+    # b
+    1  # c
+    # d
+    :  # e
+    # f
+    2  # g
+    # h
+    :  # i
+    # j
+    3  # k
+    # l
+]
+
+# Handle the spacing from the colon correctly with upper leading comments
+c1 = "NOT_YET_IMPLEMENTED_STRING"[
+    1:  # e
+    # f
+    2
+]
+c2 = "NOT_YET_IMPLEMENTED_STRING"[
+    1:  # e
+    2
+]
+c3 = "NOT_YET_IMPLEMENTED_STRING"[
+    1:
+    # f
+    2
+]
+c4 = "NOT_YET_IMPLEMENTED_STRING"[
+    1:  # f
+    2
+]
+
+# End of line comments
+d1 = "NOT_YET_IMPLEMENTED_STRING"[  # comment
+    :
+]
+d2 = "NOT_YET_IMPLEMENTED_STRING"[  # comment
+    1:
+]
+d3 = "NOT_YET_IMPLEMENTED_STRING"[
+    1  # comment
+    :
+]
+
+
+# Spacing around the colon(s)
+def a():
+    ...
+
+
+e00 = "NOT_YET_IMPLEMENTED_STRING"[:]
+e01 = "NOT_YET_IMPLEMENTED_STRING"[:1]
+e02 = "NOT_YET_IMPLEMENTED_STRING"[ : NOT_IMPLEMENTED_call()]
+e10 = "NOT_YET_IMPLEMENTED_STRING"[1:]
+e11 = "NOT_YET_IMPLEMENTED_STRING"[1:1]
+e12 = "NOT_YET_IMPLEMENTED_STRING"[1 : NOT_IMPLEMENTED_call()]
+e20 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() :]
+e21 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() : 1]
+e22 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() : NOT_IMPLEMENTED_call()]
+e200 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() : :]
+e201 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() :: 1]
+e202 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() :: NOT_IMPLEMENTED_call()]
+e210 = "NOT_YET_IMPLEMENTED_STRING"[NOT_IMPLEMENTED_call() : 1 :]
+```
+
+

crates/ruff_python_formatter/src/trivia.rs

@@ -112,9 +112,8 @@ impl Token {
         self.range.start()
     }
 
-    #[allow(unused)]
     pub(crate) const fn end(&self) -> TextSize {
-        self.range.start()
+        self.range.end()
     }
 }