Leading, Dangling, and Trailing comments formatting (#4785)

crates/ruff_formatter/src/source_code.rs

@@ -1,4 +1,4 @@
-use ruff_text_size::TextRange;
+use ruff_text_size::{TextRange, TextSize};
 use std::fmt::{Debug, Formatter};
 
 /// The source code of a document that gets formatted
@@ -68,9 +68,17 @@ impl SourceCodeSlice {
         &code.text[self.range]
     }
 
-    pub fn range(&self) -> TextRange {
+    pub const fn range(&self) -> TextRange {
         self.range
     }
+
+    pub const fn start(&self) -> TextSize {
+        self.range.start()
+    }
+
+    pub const fn end(&self) -> TextSize {
+        self.range.end()
+    }
 }
 
 impl Debug for SourceCodeSlice {

crates/ruff_python_formatter/src/comments/format.rs

@@ -0,0 +1,180 @@
+use crate::context::NodeLevel;
+use crate::prelude::*;
+use crate::trivia::{lines_after, lines_before};
+use ruff_formatter::{format_args, write};
+use ruff_python_ast::node::AnyNodeRef;
+use ruff_python_ast::prelude::AstNode;
+
+/// Formats the leading comments of a node.
+pub(crate) fn leading_comments<T>(node: &T) -> FormatLeadingComments
+where
+    T: AstNode,
+{
+    FormatLeadingComments {
+        node: node.as_any_node_ref(),
+    }
+}
+
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct FormatLeadingComments<'a> {
+    node: AnyNodeRef<'a>,
+}
+
+impl Format<PyFormatContext<'_>> for FormatLeadingComments<'_> {
+    fn fmt(&self, f: &mut PyFormatter) -> FormatResult<()> {
+        let comments = f.context().comments().clone();
+
+        for comment in comments.leading_comments(self.node) {
+            let slice = comment.slice();
+
+            let lines_after_comment = lines_after(f.context().contents(), slice.end());
+            write!(
+                f,
+                [
+                    source_text_slice(slice.range(), ContainsNewlines::No),
+                    empty_lines(lines_after_comment)
+                ]
+            )?;
+
+            comment.mark_formatted();
+        }
+
+        Ok(())
+    }
+}
+
+/// Formats the trailing comments of `node`
+pub(crate) fn trailing_comments<T>(node: &T) -> FormatTrailingComments
+where
+    T: AstNode,
+{
+    FormatTrailingComments {
+        node: node.as_any_node_ref(),
+    }
+}
+
+pub(crate) struct FormatTrailingComments<'a> {
+    node: AnyNodeRef<'a>,
+}
+
+impl Format<PyFormatContext<'_>> for FormatTrailingComments<'_> {
+    fn fmt(&self, f: &mut Formatter<PyFormatContext<'_>>) -> FormatResult<()> {
+        let comments = f.context().comments().clone();
+        let mut has_empty_lines_before = false;
+
+        for trailing in comments.trailing_comments(self.node) {
+            let slice = trailing.slice();
+            let content = source_text_slice(slice.range(), ContainsNewlines::No);
+
+            let lines_before_comment = lines_before(f.context().contents(), slice.start());
+            has_empty_lines_before |= lines_before_comment > 0;
+
+            if has_empty_lines_before {
+                // A trailing comment at the end of a body or list
+                // ```python
+                // def test():
+                //      pass
+                //
+                //      # Some comment
+                // ```
+                write!(
+                    f,
+                    [
+                        line_suffix(&format_with(|f| {
+                            write!(f, [empty_lines(lines_before_comment), content])
+                        })),
+                        expand_parent()
+                    ]
+                )?;
+            } else {
+                write!(
+                    f,
+                    [
+                        line_suffix(&format_args![space(), space(), content]),
+                        expand_parent()
+                    ]
+                )?;
+            }
+
+            trailing.mark_formatted();
+        }
+
+        Ok(())
+    }
+}
+
+/// Formats the dangling comments of `node`.
+pub(crate) fn dangling_comments<T>(node: &T) -> FormatDanglingComments
+where
+    T: AstNode,
+{
+    FormatDanglingComments {
+        node: node.as_any_node_ref(),
+    }
+}
+
+pub(crate) struct FormatDanglingComments<'a> {
+    node: AnyNodeRef<'a>,
+}
+
+impl Format<PyFormatContext<'_>> for FormatDanglingComments<'_> {
+    fn fmt(&self, f: &mut Formatter<PyFormatContext>) -> FormatResult<()> {
+        let comments = f.context().comments().clone();
+
+        let dangling_comments = comments.dangling_comments(self.node);
+
+        let mut first = true;
+        for comment in dangling_comments {
+            if first && comment.position().is_end_of_line() {
+                write!(f, [space(), space()])?;
+            }
+
+            write!(
+                f,
+                [
+                    source_text_slice(comment.slice().range(), ContainsNewlines::No),
+                    empty_lines(lines_after(f.context().contents(), comment.slice().end()))
+                ]
+            )?;
+
+            comment.mark_formatted();
+
+            first = false;
+        }
+
+        Ok(())
+    }
+}
+
+// Helper that inserts the appropriate number of empty lines before a comment, depending on the node level.
+// Top level: Up to two empty lines
+// parenthesized: A single empty line
+// other: Up to a single empty line
+const fn empty_lines(lines: u32) -> FormatEmptyLines {
+    FormatEmptyLines { lines }
+}
+
+#[derive(Copy, Clone, Debug)]
+struct FormatEmptyLines {
+    lines: u32,
+}
+
+impl Format<PyFormatContext<'_>> for FormatEmptyLines {
+    fn fmt(&self, f: &mut Formatter<PyFormatContext>) -> FormatResult<()> {
+        match f.context().node_level() {
+            NodeLevel::TopLevel => match self.lines {
+                0 | 1 => write!(f, [hard_line_break()]),
+                2 => write!(f, [empty_line()]),
+                _ => write!(f, [empty_line(), empty_line()]),
+            },
+
+            NodeLevel::Statement => match self.lines {
+                0 | 1 => write!(f, [hard_line_break()]),
+                _ => write!(f, [empty_line()]),
+            },
+
+            // Remove all whitespace in parenthesized expressions
+            NodeLevel::Parenthesized => write!(f, [hard_line_break()]),
+        }
+    }
+}

crates/ruff_python_formatter/src/comments/mod.rs

@@ -93,6 +93,7 @@ use std::fmt::Debug;
 use std::rc::Rc;
 
 mod debug;
+mod format;
 mod map;
 mod node_key;
 mod placement;
@@ -102,6 +103,7 @@ use crate::comments::debug::{DebugComment, DebugComments};
 use crate::comments::map::MultiMap;
 use crate::comments::node_key::NodeRefEqualityKey;
 use crate::comments::visitor::CommentsVisitor;
+pub(crate) use format::{dangling_comments, leading_comments, trailing_comments};
 use ruff_formatter::{SourceCode, SourceCodeSlice};
 use ruff_python_ast::node::AnyNodeRef;
 use ruff_python_ast::source_code::CommentRanges;

crates/ruff_python_formatter/src/context.rs

@@ -8,6 +8,7 @@ pub struct PyFormatContext<'a> {
     options: SimpleFormatOptions,
     contents: &'a str,
     comments: Comments<'a>,
+    node_level: NodeLevel,
 }
 
 impl<'a> PyFormatContext<'a> {
@@ -20,6 +21,7 @@ impl<'a> PyFormatContext<'a> {
             options,
             contents,
             comments,
+            node_level: NodeLevel::TopLevel,
         }
     }
 
@@ -33,6 +35,15 @@ impl<'a> PyFormatContext<'a> {
         Locator::new(self.contents)
     }
 
+    #[allow(unused)]
+    pub(crate) fn set_node_level(&mut self, level: NodeLevel) {
+        self.node_level = level;
+    }
+
+    pub(crate) fn node_level(&self) -> NodeLevel {
+        self.node_level
+    }
+
     #[allow(unused)]
     pub(crate) fn comments(&self) -> &Comments<'a> {
         &self.comments
@@ -56,7 +67,24 @@ impl Debug for PyFormatContext<'_> {
         f.debug_struct("PyFormatContext")
             .field("options", &self.options)
             .field("comments", &self.comments.debug(self.source_code()))
+            .field("node_level", &self.node_level)
             .field("source", &self.contents)
             .finish()
     }
 }
+
+/// What's the enclosing level of the outer node.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Default)]
+pub(crate) enum NodeLevel {
+    /// Formatting statements on the module level.
+    #[default]
+    TopLevel,
+
+    /// Formatting nodes that are enclosed by a statement.
+    #[allow(unused)]
+    Statement,
+
+    /// Formatting nodes that are enclosed in a parenthesized expression.
+    #[allow(unused)]
+    Parenthesized,
+}

crates/ruff_python_formatter/src/lib.rs

@@ -14,7 +14,7 @@ use ruff_formatter::{
 use ruff_python_ast::node::AstNode;
 use ruff_python_ast::source_code::{CommentRanges, CommentRangesBuilder, Locator};
 
-use crate::comments::Comments;
+use crate::comments::{dangling_comments, leading_comments, trailing_comments, Comments};
 use crate::context::PyFormatContext;
 
 pub mod cli;
@@ -57,31 +57,31 @@ where
     /// Formats the node's fields.
     fn fmt_fields(&self, item: &N, f: &mut PyFormatter) -> FormatResult<()>;
 
-    /// Formats the [leading comments](crate::comments#leading-comments) of the node.
+    /// Formats the [leading comments](comments#leading-comments) of the node.
     ///
     /// You may want to override this method if you want to manually handle the formatting of comments
     /// inside of the `fmt_fields` method or customize the formatting of the leading comments.
-    fn fmt_leading_comments(&self, _node: &N, _f: &mut PyFormatter) -> FormatResult<()> {
+    fn fmt_leading_comments(&self, node: &N, f: &mut PyFormatter) -> FormatResult<()> {
-        Ok(())
+        leading_comments(node).fmt(f)
     }
 
-    /// Formats the [dangling comments](rome_formatter::comments#dangling-comments) of the node.
+    /// Formats the [dangling comments](comments#dangling-comments) of the node.
     ///
     /// You should override this method if the node handled by this rule can have dangling comments because the
     /// default implementation formats the dangling comments at the end of the node, which isn't ideal but ensures that
     /// no comments are dropped.
     ///
     /// A node can have dangling comments if all its children are tokens or if all node childrens are optional.
-    fn fmt_dangling_comments(&self, _node: &N, _f: &mut PyFormatter) -> FormatResult<()> {
+    fn fmt_dangling_comments(&self, node: &N, f: &mut PyFormatter) -> FormatResult<()> {
-        Ok(())
+        dangling_comments(node).fmt(f)
     }
 
-    /// Formats the [trailing comments](rome_formatter::comments#trailing-comments) of the node.
+    /// Formats the [trailing comments](comments#trailing-comments) of the node.
     ///
     /// You may want to override this method if you want to manually handle the formatting of comments
     /// inside of the `fmt_fields` method or customize the formatting of the trailing comments.
-    fn fmt_trailing_comments(&self, _node: &N, _f: &mut PyFormatter) -> FormatResult<()> {
+    fn fmt_trailing_comments(&self, node: &N, f: &mut PyFormatter) -> FormatResult<()> {
-        Ok(())
+        trailing_comments(node).fmt(f)
     }
 }
 
@@ -180,8 +180,10 @@ if    True:
     print( "hi" )
 # trailing
 "#;
-        let expected = r#"if    True:
+        let expected = r#"# preceding
+if    True:
     print( "hi" )
+# trailing
 "#;
         let actual = format_module(input)?.as_code().to_string();
         assert_eq!(expected, actual);

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__collections_py.snap

@@ -84,23 +84,23 @@ if True:
 ```diff
 --- Black
 +++ Ruff
-@@ -1,99 +1,57 @@
+@@ -1,99 +1,61 @@
  import core, time, a
 -
  from . import A, B, C
 -
--# keeps existing trailing comma
+ # keeps existing trailing comma
  from foo import (
      bar,
  )
 -
--# also keeps existing structure
+ # also keeps existing structure
  from foo import (
      baz,
      qux,
  )
 -
--# `as` works as well
+ # `as` works as well
  from foo import (
      xyzzy as magic,
  )
@@ -155,9 +155,9 @@ if True:
 -    % bar
 -)
 -
--# looping over a 1-tuple should also not get wrapped
 +y = {"oneple": (1,),}
 +assert False, ("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa wraps %s" % bar)
+ # looping over a 1-tuple should also not get wrapped
  for x in (1,):
      pass
  for (x,) in (1,), (2,), (3,):
@@ -211,13 +211,16 @@ if True:
 ```py
 import core, time, a
 from . import A, B, C
+# keeps existing trailing comma
 from foo import (
     bar,
 )
+# also keeps existing structure
 from foo import (
     baz,
     qux,
 )
+# `as` works as well
 from foo import (
     xyzzy as magic,
 )
@@ -241,6 +244,7 @@ nested_long_lines = ["aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "bbbbbbbbbbbbbb
 x = {"oneple": (1,)}
 y = {"oneple": (1,),}
 assert False, ("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa wraps %s" % bar)
+# looping over a 1-tuple should also not get wrapped
 for x in (1,):
     pass
 for (x,) in (1,), (2,), (3,):

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments2_py.snap

@@ -178,7 +178,7 @@ instruction()#comment with bad spacing
 ```diff
 --- Black
 +++ Ruff
-@@ -1,39 +1,36 @@
+@@ -1,39 +1,38 @@
  from com.my_lovely_company.my_lovely_team.my_lovely_project.my_lovely_component import (
 -    MyLovelyCompanyTeamProjectComponent,  # NOT DRY
 +    MyLovelyCompanyTeamProjectComponent  # NOT DRY
@@ -188,8 +188,8 @@ instruction()#comment with bad spacing
 +    MyLovelyCompanyTeamProjectComponent as component  # DRY
  )
 -
--# Please keep __all__ alphabetized within each category.
+ # Please keep __all__ alphabetized within each category.
--
+ 
  __all__ = [
      # Super-special typing primitives.
 -    "Any",
@@ -238,7 +238,7 @@ instruction()#comment with bad spacing
      # builtin types and objects
      type,
      object,
-@@ -47,21 +44,20 @@
+@@ -47,21 +46,21 @@
      Cheese("Wensleydale"),
      SubBytes(b"spam"),
  ]
@@ -254,7 +254,7 @@ instruction()#comment with bad spacing
 -    # add_compiler(compilers[(7.1, 64)])
 -
 -
--# Comment before function.
+ # Comment before function.
  def inline_comments_in_brackets_ruin_everything():
      if typedargslist:
 -        parameters.children = [children[0], body, children[-1]]  # (1  # )1
@@ -267,7 +267,7 @@ instruction()#comment with bad spacing
              children[0],
              body,
              children[-1],  # type: ignore
-@@ -73,49 +69,42 @@
+@@ -73,49 +72,42 @@
              parameters.children[-1],  # )2
          ]
          parameters.children = [parameters.what_if_this_was_actually_long.children[0], body, parameters.children[-1]]  # type: ignore
@@ -340,7 +340,7 @@ instruction()#comment with bad spacing
      ]
      lcomp2 = [
          # hello
-@@ -127,7 +116,7 @@
+@@ -127,7 +119,7 @@
      ]
      lcomp3 = [
          # This one is actually too long to fit in a single line.
@@ -349,7 +349,7 @@ instruction()#comment with bad spacing
          # yup
          for element in collection.select_elements()
          # right
-@@ -140,34 +129,18 @@
+@@ -140,34 +132,26 @@
              # and round and round we go
          # and round and round we go
  
@@ -374,7 +374,7 @@ instruction()#comment with bad spacing
 -)  # type: Final
 -
 -
-+CONFIG_FILES = [CONFIG_FILE, ] + SHARED_CONFIG_FILES + USER_CONFIG_FILES
++CONFIG_FILES = [CONFIG_FILE, ] + SHARED_CONFIG_FILES + USER_CONFIG_FILES  # type: Final
  class Test:
      def _init_host(self, parsed) -> None:
 -        if parsed.hostname is None or not parsed.hostname.strip():  # type: ignore
@@ -383,16 +383,16 @@ instruction()#comment with bad spacing
              pass
 -
 -
--#######################
+ #######################
--### SECTION COMMENT ###
+ ### SECTION COMMENT ###
--#######################
+ #######################
--
+ 
--
+ 
 -instruction()  # comment with bad spacing
--
++instruction()  #comment with bad spacing
--# END COMMENTS
+ 
--# MORE END COMMENTS
+ # END COMMENTS
-+instruction()
+ # MORE END COMMENTS
 ```
 
 ## Ruff Output
@@ -404,6 +404,8 @@ from com.my_lovely_company.my_lovely_team.my_lovely_project.my_lovely_component
 from com.my_lovely_company.my_lovely_team.my_lovely_project.my_lovely_component import (
     MyLovelyCompanyTeamProjectComponent as component  # DRY
 )
+# Please keep __all__ alphabetized within each category.
+
 __all__ = [
     # Super-special typing primitives.
     'Any',
@@ -450,6 +452,7 @@ else:
     # for compiler in compilers.values():
          # add_compiler(compiler)
     add_compiler(compilers[(7.0, 32)])
+# Comment before function.
 def inline_comments_in_brackets_ruin_everything():
     if typedargslist:
         parameters.children = [
@@ -537,13 +540,21 @@ short
             Leaf(token.NEWLINE, '\n')  # FIXME: \r\n?
         ],
     )
-CONFIG_FILES = [CONFIG_FILE, ] + SHARED_CONFIG_FILES + USER_CONFIG_FILES
+CONFIG_FILES = [CONFIG_FILE, ] + SHARED_CONFIG_FILES + USER_CONFIG_FILES  # type: Final
 class Test:
     def _init_host(self, parsed) -> None:
         if (parsed.hostname is None or  # type: ignore
                 not parsed.hostname.strip()):
             pass
-instruction()
+#######################
+### SECTION COMMENT ###
+#######################
+
+
+instruction()  #comment with bad spacing
+
+# END COMMENTS
+# MORE END COMMENTS
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments3_py.snap

@@ -1,180 +0,0 @@
----
-source: crates/ruff_python_formatter/src/lib.rs
-expression: snapshot
-input_file: crates/ruff_python_formatter/resources/test/fixtures/black/simple_cases/comments3.py
----
-## Input
-
-```py
-# The percent-percent comments are Spyder IDE cells.
-
-
-# %%
-def func():
-    x = """
-    a really long string
-    """
-    lcomp3 = [
-        # This one is actually too long to fit in a single line.
-        element.split("\n", 1)[0]
-        # yup
-        for element in collection.select_elements()
-        # right
-        if element is not None
-    ]
-    # Capture each of the exceptions in the MultiError along with each of their causes and contexts
-    if isinstance(exc_value, MultiError):
-        embedded = []
-        for exc in exc_value.exceptions:
-            if exc not in _seen:
-                embedded.append(
-                    # This should be left alone (before)
-                    traceback.TracebackException.from_exception(
-                        exc,
-                        limit=limit,
-                        lookup_lines=lookup_lines,
-                        capture_locals=capture_locals,
-                        # copy the set of _seen exceptions so that duplicates
-                        # shared between sub-exceptions are not omitted
-                        _seen=set(_seen),
-                    )
-                    # This should be left alone (after)
-                )
-
-    # everything is fine if the expression isn't nested
-    traceback.TracebackException.from_exception(
-        exc,
-        limit=limit,
-        lookup_lines=lookup_lines,
-        capture_locals=capture_locals,
-        # copy the set of _seen exceptions so that duplicates
-        # shared between sub-exceptions are not omitted
-        _seen=set(_seen),
-    )
-
-
-# %%
-```
-
-## Black Differences
-
-```diff
---- Black
-+++ Ruff
-@@ -1,7 +1,3 @@
--# The percent-percent comments are Spyder IDE cells.
--
--
--# %%
- def func():
-     x = """
-     a really long string
-@@ -43,6 +39,3 @@
-         # shared between sub-exceptions are not omitted
-         _seen=set(_seen),
-     )
--
--
--# %%
-```
-
-## Ruff Output
-
-```py
-def func():
-    x = """
-    a really long string
-    """
-    lcomp3 = [
-        # This one is actually too long to fit in a single line.
-        element.split("\n", 1)[0]
-        # yup
-        for element in collection.select_elements()
-        # right
-        if element is not None
-    ]
-    # Capture each of the exceptions in the MultiError along with each of their causes and contexts
-    if isinstance(exc_value, MultiError):
-        embedded = []
-        for exc in exc_value.exceptions:
-            if exc not in _seen:
-                embedded.append(
-                    # This should be left alone (before)
-                    traceback.TracebackException.from_exception(
-                        exc,
-                        limit=limit,
-                        lookup_lines=lookup_lines,
-                        capture_locals=capture_locals,
-                        # copy the set of _seen exceptions so that duplicates
-                        # shared between sub-exceptions are not omitted
-                        _seen=set(_seen),
-                    )
-                    # This should be left alone (after)
-                )
-
-    # everything is fine if the expression isn't nested
-    traceback.TracebackException.from_exception(
-        exc,
-        limit=limit,
-        lookup_lines=lookup_lines,
-        capture_locals=capture_locals,
-        # copy the set of _seen exceptions so that duplicates
-        # shared between sub-exceptions are not omitted
-        _seen=set(_seen),
-    )
-```
-
-## Black Output
-
-```py
-# The percent-percent comments are Spyder IDE cells.
-
-
-# %%
-def func():
-    x = """
-    a really long string
-    """
-    lcomp3 = [
-        # This one is actually too long to fit in a single line.
-        element.split("\n", 1)[0]
-        # yup
-        for element in collection.select_elements()
-        # right
-        if element is not None
-    ]
-    # Capture each of the exceptions in the MultiError along with each of their causes and contexts
-    if isinstance(exc_value, MultiError):
-        embedded = []
-        for exc in exc_value.exceptions:
-            if exc not in _seen:
-                embedded.append(
-                    # This should be left alone (before)
-                    traceback.TracebackException.from_exception(
-                        exc,
-                        limit=limit,
-                        lookup_lines=lookup_lines,
-                        capture_locals=capture_locals,
-                        # copy the set of _seen exceptions so that duplicates
-                        # shared between sub-exceptions are not omitted
-                        _seen=set(_seen),
-                    )
-                    # This should be left alone (after)
-                )
-
-    # everything is fine if the expression isn't nested
-    traceback.TracebackException.from_exception(
-        exc,
-        limit=limit,
-        lookup_lines=lookup_lines,
-        capture_locals=capture_locals,
-        # copy the set of _seen exceptions so that duplicates
-        # shared between sub-exceptions are not omitted
-        _seen=set(_seen),
-    )
-
-
-# %%
-```
-
-

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments5_py.snap

@@ -86,22 +86,19 @@ if __name__ == "__main__":
 ```diff
 --- Black
 +++ Ruff
-@@ -1,13 +1,6 @@
+@@ -1,11 +1,6 @@
  while True:
      if something.changed:
--        do.stuff()  # trailing comment
+         do.stuff()  # trailing comment
 -        # Comment belongs to the `if` block.
 -    # This one belongs to the `while` block.
 -
 -    # Should this one, too?  I guess so.
 -
--# This one is properly standalone now.
+ # This one is properly standalone now.
--
+ 
-+        do.stuff()
  for i in range(100):
-     # first we do this
+@@ -15,27 +10,18 @@
-     if i % 33 == 0:
-@@ -15,31 +8,17 @@
  
      # then we do this
      print(i)
@@ -120,41 +117,37 @@ if __name__ == "__main__":
  import sys
 -
 -
--# leading function comment
+ # leading function comment
  def wat():
      ...
 -    # trailing function comment
 -
 -
--# SECTION COMMENT
+ # SECTION COMMENT
--
+ 
--
+ 
--# leading 1
+@@ -47,8 +33,6 @@
- @deco1
- # leading 2
- @deco2(with_args=True)
-@@ -47,27 +26,14 @@
  @deco3
  def decorated1():
      ...
 -
 -
--# leading 1
+ # leading 1
  @deco1
  # leading 2
- @deco2(with_args=True)
+@@ -56,18 +40,12 @@
  # leading function comment
  def decorated1():
      ...
 -
 -
--# Note: this is fixed in
+ # Note: this is fixed in
--# Preview.empty_lines_before_class_or_def_with_leading_comments.
+ # Preview.empty_lines_before_class_or_def_with_leading_comments.
--# In the current style, the user will have to split those lines by hand.
+ # In the current style, the user will have to split those lines by hand.
  some_instruction
 -
 -
--# This comment should be split from `some_instruction` by two lines but isn't.
+ # This comment should be split from `some_instruction` by two lines but isn't.
  def g():
      ...
 -
@@ -168,7 +161,9 @@ if __name__ == "__main__":
 ```py
 while True:
     if something.changed:
-        do.stuff()
+        do.stuff()  # trailing comment
+# This one is properly standalone now.
+
 for i in range(100):
     # first we do this
     if i % 33 == 0:
@@ -185,8 +180,13 @@ try:
 except OSError:
     print("problems")
 import sys
+# leading function comment
 def wat():
     ...
+# SECTION COMMENT
+
+
+# leading 1
 @deco1
 # leading 2
 @deco2(with_args=True)
@@ -194,13 +194,18 @@ def wat():
 @deco3
 def decorated1():
     ...
+# leading 1
 @deco1
 # leading 2
 @deco2(with_args=True)
 # leading function comment
 def decorated1():
     ...
+# Note: this is fixed in
+# Preview.empty_lines_before_class_or_def_with_leading_comments.
+# In the current style, the user will have to split those lines by hand.
 some_instruction
+# This comment should be split from `some_instruction` by two lines but isn't.
 def g():
     ...
 if __name__ == "__main__":

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments6_py.snap

@@ -131,7 +131,7 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
 ```diff
 --- Black
 +++ Ruff
-@@ -1,18 +1,11 @@
+@@ -1,18 +1,12 @@
  from typing import Any, Tuple
 -
 -
@@ -141,7 +141,7 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
      pass
 -
 -
--# test type comments
+ # test type comments
  def f(a, b, c, d, e, f, g, h, i):
      # type: (int, int, int, int, int, int, int, int, int) -> None
      pass
@@ -150,7 +150,7 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
  def f(
      a,  # type: int
      b,  # type: int
-@@ -26,8 +19,6 @@
+@@ -26,8 +20,6 @@
  ):
      # type: (...) -> None
      pass
@@ -159,7 +159,7 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
  def f(
      arg,  # type: int
      *args,  # type: *Any
-@@ -36,8 +27,6 @@
+@@ -36,8 +28,6 @@
  ):
      # type: (...) -> None
      pass
@@ -168,14 +168,12 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
  def f(
      a,  # type: int
      b,  # type: int
-@@ -66,23 +55,17 @@
+@@ -67,22 +57,16 @@
-         + element
          + another_element
          + another_element_with_long_name
--    )  # type: int
+     )  # type: int
 -
 -
-+    )
  def f(
      x,  # not a type comment
      y,  # type: int
@@ -193,7 +191,7 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
  def func(
      a=some_list[0],  # type: int
  ):  # type: () -> int
-@@ -102,17 +85,12 @@
+@@ -102,17 +86,12 @@
      c = call(
          "aaaaaaaa", "aaaaaaaa", "aaaaaaaa", "aaaaaaaa", "aaaaaaaa", "aaaaaaaa", "aaaaaaaa"  # type: ignore
      )
@@ -203,16 +201,14 @@ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*ite
      "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
  )
 -
--AAAAAAAAAAAAA = [AAAAAAAAAAAAA] + SHARED_AAAAAAAAAAAAA + USER_AAAAAAAAAAAAA + AAAAAAAAAAAAA  # type: ignore
+ AAAAAAAAAAAAA = [AAAAAAAAAAAAA] + SHARED_AAAAAAAAAAAAA + USER_AAAAAAAAAAAAA + AAAAAAAAAAAAA  # type: ignore
 -
-+AAAAAAAAAAAAA = [AAAAAAAAAAAAA] + SHARED_AAAAAAAAAAAAA + USER_AAAAAAAAAAAAA + AAAAAAAAAAAAA
  call_to_some_function_asdf(
      foo,
      [AAAAAAAAAAAAAAAAAAAAAAA, AAAAAAAAAAAAAAAAAAAAAAA, AAAAAAAAAAAAAAAAAAAAAAA, BBBBBBBBBBBB],  # type: ignore
  )
 -
--aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*items)))  # type: ignore[arg-type]
+ aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*items)))  # type: ignore[arg-type]
-+aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*items)))
 ```
 
 ## Ruff Output
@@ -223,6 +219,7 @@ def f(
     a,  # type: int
 ):
     pass
+# test type comments
 def f(a, b, c, d, e, f, g, h, i):
     # type: (int, int, int, int, int, int, int, int, int) -> None
     pass
@@ -275,7 +272,7 @@ def f(
         + element
         + another_element
         + another_element_with_long_name
-    )
+    )  # type: int
 def f(
     x,  # not a type comment
     y,  # type: int
@@ -308,12 +305,12 @@ def func(
 result = (  # aaa
     "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 )
-AAAAAAAAAAAAA = [AAAAAAAAAAAAA] + SHARED_AAAAAAAAAAAAA + USER_AAAAAAAAAAAAA + AAAAAAAAAAAAA
+AAAAAAAAAAAAA = [AAAAAAAAAAAAA] + SHARED_AAAAAAAAAAAAA + USER_AAAAAAAAAAAAA + AAAAAAAAAAAAA  # type: ignore
 call_to_some_function_asdf(
     foo,
     [AAAAAAAAAAAAAAAAAAAAAAA, AAAAAAAAAAAAAAAAAAAAAAA, AAAAAAAAAAAAAAAAAAAAAAA, BBBBBBBBBBBB],  # type: ignore
 )
-aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*items)))
+aaaaaaaaaaaaa, bbbbbbbbb = map(list, map(itertools.chain.from_iterable, zip(*items)))  # type: ignore[arg-type]
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments8_py.snap

@@ -19,18 +19,24 @@ input_file: crates/ruff_python_formatter/resources/test/fixtures/black/simple_ca
 ```diff
 --- Black
 +++ Ruff
-@@ -1,6 +0,0 @@
+@@ -2,5 +2,5 @@
--# The percent-percent comments are Spyder IDE cells.
+ # Both `#%%`` and `# %%` are accepted, so `black` standardises
--# Both `#%%`` and `# %%` are accepted, so `black` standardises
+ # to the latter.
--# to the latter.
+ 
--
--# %%
 -# %%
++#%%
+ # %%
 ```
 
 ## Ruff Output
 
 ```py
+# The percent-percent comments are Spyder IDE cells.
+# Both `#%%`` and `# %%` are accepted, so `black` standardises
+# to the latter.
+
+#%%
+# %%
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments9_py.snap

@@ -152,13 +152,13 @@ def bar():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,61 +1,23 @@
+@@ -1,60 +1,35 @@
--# Test for https://github.com/psf/black/issues/246.
+ # Test for https://github.com/psf/black/issues/246.
--
+ 
  some = statement
 -
 -
--# This comment should be split from the statement above by two lines.
+ # This comment should be split from the statement above by two lines.
  def function():
      pass
 -
@@ -166,9 +166,9 @@ def bar():
  some = statement
 -
 -
--# This multiline comments section
+ # This multiline comments section
--# should be split from the statement
+ # should be split from the statement
--# above by two lines.
+ # above by two lines.
  def function():
      pass
 -
@@ -176,7 +176,7 @@ def bar():
  some = statement
 -
 -
--# This comment should be split from the statement above by two lines.
+ # This comment should be split from the statement above by two lines.
  async def async_function():
      pass
 -
@@ -184,16 +184,16 @@ def bar():
  some = statement
 -
 -
--# This comment should be split from the statement above by two lines.
+ # This comment should be split from the statement above by two lines.
  class MyClass:
      pass
 -
 -
  some = statement
--# This should be stick to the statement above
+ # This should be stick to the statement above
+ 
 -
--
+ # This should be split from the above by two lines
--# This should be split from the above by two lines
  class MyClassWithComplexLeadingComments:
      pass
 -
@@ -202,7 +202,7 @@ def bar():
      """A docstring."""
 -
 -
--# Leading comment after a class with just a docstring
+ # Leading comment after a class with just a docstring
  class MyClassAfterAnotherClassWithDocstring:
      pass
 -
@@ -210,11 +210,10 @@ def bar():
  some = statement
 -
 -
--# leading 1
+ # leading 1
  @deco1
  # leading 2
- # leading 2 extra
+@@ -65,11 +40,7 @@
-@@ -65,12 +27,7 @@
  # leading 4
  def decorated():
      pass
@@ -223,11 +222,10 @@ def bar():
  some = statement
 -
 -
--# leading 1
+ # leading 1
  @deco1
  # leading 2
- @deco2(with_args=True)
+@@ -80,11 +51,7 @@
-@@ -80,12 +37,7 @@
  # leading 4
  def decorated_with_split_leading_comments():
      pass
@@ -236,11 +234,10 @@ def bar():
  some = statement
 -
 -
--# leading 1
+ # leading 1
  @deco1
  # leading 2
- @deco2(with_args=True)
+@@ -95,66 +62,44 @@
-@@ -95,66 +47,42 @@
  # leading 4 that already has an empty line
  def decorated_with_split_leading_comments():
      pass
@@ -284,7 +281,7 @@ def bar():
          pass
 -
 -
--# Regression test for https://github.com/psf/black/issues/3454.
+ # Regression test for https://github.com/psf/black/issues/3454.
  def foo():
      pass
 -    # Trailing comment that belongs to this function
@@ -296,7 +293,7 @@ def bar():
      pass
 -
 -
--# Regression test for https://github.com/psf/black/issues/3454.
+ # Regression test for https://github.com/psf/black/issues/3454.
  def foo():
      pass
 -    # Trailing comment that belongs to this function.
@@ -312,26 +309,39 @@ def bar():
 ## Ruff Output
 
 ```py
+# Test for https://github.com/psf/black/issues/246.
+
 some = statement
+# This comment should be split from the statement above by two lines.
 def function():
     pass
 some = statement
+# This multiline comments section
+# should be split from the statement
+# above by two lines.
 def function():
     pass
 some = statement
+# This comment should be split from the statement above by two lines.
 async def async_function():
     pass
 some = statement
+# This comment should be split from the statement above by two lines.
 class MyClass:
     pass
 some = statement
+# This should be stick to the statement above
+
+# This should be split from the above by two lines
 class MyClassWithComplexLeadingComments:
     pass
 class ClassWithDocstring:
     """A docstring."""
+# Leading comment after a class with just a docstring
 class MyClassAfterAnotherClassWithDocstring:
     pass
 some = statement
+# leading 1
 @deco1
 # leading 2
 # leading 2 extra
@@ -342,6 +352,7 @@ some = statement
 def decorated():
     pass
 some = statement
+# leading 1
 @deco1
 # leading 2
 @deco2(with_args=True)
@@ -352,6 +363,7 @@ some = statement
 def decorated_with_split_leading_comments():
     pass
 some = statement
+# leading 1
 @deco1
 # leading 2
 @deco2(with_args=True)
@@ -389,12 +401,14 @@ class MyClass:
     # More comments.
     def first_method(self):
         pass
+# Regression test for https://github.com/psf/black/issues/3454.
 def foo():
     pass
 @decorator1
 @decorator2  # fmt: skip
 def bar():
     pass
+# Regression test for https://github.com/psf/black/issues/3454.
 def foo():
     pass
 @decorator1

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments_non_breaking_space_py.snap

@@ -54,11 +54,11 @@ def function(a:int=42):
 -    """This docstring is already formatted
 -    a
 -    b
-+result = 1
++result = 1  # A simple comment
-+result = (    1, )
++result = (    1, )  # Another one
-+result = 1
++result = 1  # type: ignore
-+result = 1
++result = 1  # This comment is talking about type: ignore
-+square = Square(4)
++square = Square(4)  # type: Optional[Square]
 +def function(a:int=42):
 +    """ This docstring is already formatted
 +       a
@@ -76,11 +76,11 @@ def function(a:int=42):
 from .config import (  ConfigTypeAttributes,    Int,    Path,    # String,
     # DEFAULT_TYPE_ATTRIBUTES,
 )
-result = 1
+result = 1  # A simple comment
-result = (    1, )
+result = (    1, )  # Another one
-result = 1
+result = 1  # type: ignore
-result = 1
+result = 1  # This comment is talking about type: ignore
-square = Square(4)
+square = Square(4)  # type: Optional[Square]
 def function(a:int=42):
     """ This docstring is already formatted
        a

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__comments_py.snap

@@ -109,14 +109,7 @@ async def wat():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,34 +1,20 @@
+@@ -8,27 +8,19 @@
--#!/usr/bin/env python3
--# fmt: on
--# Some license here.
--#
--# Has many lines. Many, many lines.
--# Many, many, many lines.
- """Module docstring.
  
  Possibly also many, many lines.
  """
@@ -125,9 +118,8 @@ async def wat():
  import sys
 -
  import a
--from b.c import X  # some noqa comment
+ from b.c import X  # some noqa comment
 -
-+from b.c import X
  try:
      import fast
  except ImportError:
@@ -145,50 +137,46 @@ async def wat():
  def function(default=None):
      """Docstring comes first.
  
-@@ -45,16 +31,7 @@
+@@ -45,12 +37,8 @@
  
      # This return is also commented for some reason.
      return default
 -
 -
--# Explains why we use global state.
+ # Explains why we use global state.
  GLOBAL_STATE = {"a": a(1), "b": a(2), "c": a(3)}
 -
 -
--# Another comment!
+ # Another comment!
--# This time two lines.
+ # This time two lines.
--
--
- class Foo:
-     """Docstring for class Foo.  Example from Sphinx docs."""
  
-@@ -73,11 +50,6 @@
+@@ -73,8 +61,6 @@
  
          self.spam = 4
          """Docstring for instance attribute spam."""
 -
 -
--#' <h1>This is pweave!</h1>
+ #' <h1>This is pweave!</h1>
--
+ 
--
+ 
- @fast(really=True)
+@@ -93,4 +79,4 @@
- async def wat():
+ 
-     # This comment, for some reason \
+ # Some closing comments.
-@@ -89,8 +61,3 @@
+ # Maybe Vim or Emacs directives for formatting.
-         print("A OK", file=sys.stdout)
-         # Comment between things.
-         print()
--
--
--# Some closing comments.
--# Maybe Vim or Emacs directives for formatting.
 -# Who knows.
 \ No newline at end of file
++# Who knows.
 ```
 
 ## Ruff Output
 
 ```py
+#!/usr/bin/env python3
+# fmt: on
+# Some license here.
+#
+# Has many lines. Many, many lines.
+# Many, many, many lines.
 """Module docstring.
 
 Possibly also many, many lines.
@@ -196,7 +184,7 @@ Possibly also many, many lines.
 import os.path
 import sys
 import a
-from b.c import X
+from b.c import X  # some noqa comment
 try:
     import fast
 except ImportError:
@@ -222,7 +210,12 @@ def function(default=None):
 
     # This return is also commented for some reason.
     return default
+# Explains why we use global state.
 GLOBAL_STATE = {"a": a(1), "b": a(2), "c": a(3)}
+# Another comment!
+# This time two lines.
+
+
 class Foo:
     """Docstring for class Foo.  Example from Sphinx docs."""
 
@@ -241,6 +234,9 @@ class Foo:
 
         self.spam = 4
         """Docstring for instance attribute spam."""
+#' <h1>This is pweave!</h1>
+
+
 @fast(really=True)
 async def wat():
     # This comment, for some reason \
@@ -252,6 +248,11 @@ async def wat():
         print("A OK", file=sys.stdout)
         # Comment between things.
         print()
+
+
+# Some closing comments.
+# Maybe Vim or Emacs directives for formatting.
+# Who knows.
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__docstring_no_extra_empty_line_before_eof_py.snap

@@ -1,43 +0,0 @@
----
-source: crates/ruff_python_formatter/src/lib.rs
-expression: snapshot
-input_file: crates/ruff_python_formatter/resources/test/fixtures/black/simple_cases/docstring_no_extra_empty_line_before_eof.py
----
-## Input
-
-```py
-# Make sure when the file ends with class's docstring,
-# It doesn't add extra blank lines.
-class ClassWithDocstring:
-    """A docstring."""
-```
-
-## Black Differences
-
-```diff
---- Black
-+++ Ruff
-@@ -1,4 +1,2 @@
--# Make sure when the file ends with class's docstring,
--# It doesn't add extra blank lines.
- class ClassWithDocstring:
-     """A docstring."""
-```
-
-## Ruff Output
-
-```py
-class ClassWithDocstring:
-    """A docstring."""
-```
-
-## Black Output
-
-```py
-# Make sure when the file ends with class's docstring,
-# It doesn't add extra blank lines.
-class ClassWithDocstring:
-    """A docstring."""
-```
-
-

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__docstring_py.snap

@@ -234,7 +234,7 @@ def stable_quote_normalization_with_immediate_inner_single_quote(self):
 ```diff
 --- Black
 +++ Ruff
-@@ -1,219 +1,155 @@
+@@ -1,219 +1,157 @@
  class MyClass:
 +  """ Multiline
 +  class docstring
@@ -349,11 +349,11 @@ def stable_quote_normalization_with_immediate_inner_single_quote(self):
 +    - And the closing quote is too deep
      """
 -    pass
--
 +  pass
 +def single_line():
 +    """But with a newline after it!
  
+-
 -def over_indent():
 -    """
 -    This has a shallow indent
@@ -387,22 +387,22 @@ def stable_quote_normalization_with_immediate_inner_single_quote(self):
 +  """
 +  "hey yah" """
  def and_this():
--    '''
++  ''' 
++  "hey yah"'''
++def multiline_whitespace():
++    '''
++    
++    
++    
++    
+     '''
 -    "hey yah"'''
 -
 -
-+  ''' 
+-def multiline_whitespace():
-+  "hey yah"'''
- def multiline_whitespace():
 -    """ """
 -
 -
-+    '''
-+    
-+    
-+    
-+    
-+    '''
  def oneline_whitespace():
 -    """ """
 -
@@ -453,13 +453,13 @@ def stable_quote_normalization_with_immediate_inner_single_quote(self):
 -
  def docstring_with_inline_tabs_and_tab_indentation():
 -    """hey
--
++	"""hey
+ 
 -    tab	separated	value
 -            tab at start of line and then a tab	separated	value
 -                                    multiple tabs at the beginning	and	inline
 -                            mixed tabs and spaces at beginning. next line has mixed tabs and spaces only.
-+	"""hey
+-
- 
 -    line ends with some tabs
 -    """
 -    pass
@@ -490,9 +490,9 @@ def stable_quote_normalization_with_immediate_inner_single_quote(self):
 -    hey there \ """
 -
 -
--# Regression test for #3425
 +  '''
 +  hey there \ '''
+ # Regression test for #3425
  def multiline_backslash_really_long_dont_crash():
      """
      hey there hello guten tag hi hoow are you ola zdravstvuyte ciao como estas ca va \ """
@@ -509,7 +509,7 @@ def stable_quote_normalization_with_immediate_inner_single_quote(self):
      "I'm sorry Dave\u2001"
 -
 -
--# the space below is actually a \u2001, removed in output
+ # the space below is actually a \u2001, removed in output
  def my_god_its_full_of_stars_2():
 -    "I'm sorry Dave"
 -
@@ -675,6 +675,7 @@ def multiline_backslash_1():
 def multiline_backslash_2():
   '''
   hey there \ '''
+# Regression test for #3425
 def multiline_backslash_really_long_dont_crash():
     """
     hey there hello guten tag hi hoow are you ola zdravstvuyte ciao como estas ca va \ """
@@ -683,6 +684,7 @@ def multiline_backslash_3():
   already escaped \\ '''
 def my_god_its_full_of_stars_1():
     "I'm sorry Dave\u2001"
+# the space below is actually a \u2001, removed in output
 def my_god_its_full_of_stars_2():
     "I'm sorry Dave "
 def docstring_almost_at_line_limit():

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__empty_lines_py.snap

@@ -105,11 +105,11 @@ def g():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,11 +1,8 @@
+@@ -1,11 +1,9 @@
  """Docstring."""
 -
 -
--# leading comment
+ # leading comment
  def f():
 -    NO = ""
 -    SPACE = " "
@@ -120,7 +120,7 @@ def g():
  
      t = leaf.type
      p = leaf.parent  # trailing comment
-@@ -16,14 +13,19 @@
+@@ -16,14 +14,19 @@
      if t == token.COMMENT:  # another trailing comment
          return DOUBLESPACE
  
@@ -140,16 +140,16 @@ def g():
          if prevp.type == token.EQUAL:
              if prevp.parent and prevp.parent.type in {
                  syms.typedargslist,
-@@ -43,17 +45,10 @@
+@@ -43,17 +46,14 @@
                  syms.dictsetmaker,
              }:
                  return NO
 -
 -
--###############################################################################
+ ###############################################################################
--# SECTION BECAUSE SECTIONS
+ # SECTION BECAUSE SECTIONS
--###############################################################################
+ ###############################################################################
--
+ 
 -
  def g():
 -    NO = ""
@@ -161,7 +161,7 @@ def g():
  
      t = leaf.type
      p = leaf.parent
-@@ -67,7 +62,7 @@
+@@ -67,7 +67,7 @@
          return DOUBLESPACE
  
      # Another comment because more comments
@@ -176,6 +176,7 @@ def g():
 
 ```py
 """Docstring."""
+# leading comment
 def f():
     NO = ''
     SPACE = ' '
@@ -222,6 +223,10 @@ def f():
                 syms.dictsetmaker,
             }:
                 return NO
+###############################################################################
+# SECTION BECAUSE SECTIONS
+###############################################################################
+
 def g():
     NO = ''
     SPACE = ' '

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__expression_py.snap

@@ -401,7 +401,7 @@ last_call()
 +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)
++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)
@@ -437,7 +437,7 @@ last_call()
 -)  # type: ignore
 +xxxx_xxx_xxxx_xxxxx_xxxx_xxx: Callable[
 +    ..., List[SomeClass]
-+] = classmethod(sync(async_xxxx_xxx_xxxx_xxxxx_xxxx_xxx.__func__))
++] = classmethod(sync(async_xxxx_xxx_xxxx_xxxxx_xxxx_xxx.__func__))  # type: ignore
  slice[0]
  slice[0:1]
  slice[0:1:2]
@@ -510,7 +510,7 @@ last_call()
  Ø = set()
  authors.łukasz.say_thanks()
  mapping = {
-@@ -233,138 +170,82 @@
+@@ -233,138 +170,83 @@
      C: 0.1 * (10.0 / 12),
      D: 0.1 * (10.0 / 12),
  }
@@ -682,7 +682,7 @@ last_call()
 -)
 +aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ^bbbb.a & aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa^aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  last_call()
--# standalone comment at ENDMARKER
+ # standalone comment at ENDMARKER
 ```
 
 ## Ruff Output
@@ -773,7 +773,7 @@ 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)
+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)
@@ -801,7 +801,7 @@ xxxx_xxx_xxxx_xxxxx_xxxx_xxx: Callable[..., List[SomeClass]] = classmethod(  # t
 )
 xxxx_xxx_xxxx_xxxxx_xxxx_xxx: Callable[
     ..., List[SomeClass]
-] = classmethod(sync(async_xxxx_xxx_xxxx_xxxxx_xxxx_xxx.__func__))
+] = classmethod(sync(async_xxxx_xxx_xxxx_xxxxx_xxxx_xxx.__func__))  # type: ignore
 slice[0]
 slice[0:1]
 slice[0:1:2]
@@ -939,6 +939,7 @@ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa >> aaaaaaaaaaaaa
 bbbb >> bbbb * bbbb
 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ^bbbb.a & aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa^aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 last_call()
+# standalone comment at ENDMARKER
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtonoff2_py.snap

@@ -53,21 +53,16 @@ def test_calculate_fades():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,13 +1,6 @@
+@@ -1,8 +1,6 @@
  import pytest
 -
  TmSt = 1
  TmEx = 2
 -
--# fmt: off
+ # fmt: off
--
--# Test data:
--#   Position, Volume, State, TmSt/TmEx/None, [call, [arg1...]]
--
- @pytest.mark.parametrize('test', [
  
-     # Test don't manage the volume
+ # Test data:
-@@ -17,24 +10,18 @@
+@@ -17,19 +15,15 @@
  ])
  def test_fader(test):
      pass
@@ -87,11 +82,6 @@ def test_calculate_fades():
  def test_calculate_fades():
      calcs = [
          # one is zero/none
-         (0, 4, 0, 0, 10,        0, 0, 6, 10),
-         (None, 4, 0, 0, 10,     0, 0, 6, 10),
-     ]
--
--# fmt: on
 ```
 
 ## Ruff Output
@@ -100,6 +90,11 @@ def test_calculate_fades():
 import pytest
 TmSt = 1
 TmEx = 2
+# fmt: off
+
+# Test data:
+#   Position, Volume, State, TmSt/TmEx/None, [call, [arg1...]]
+
 @pytest.mark.parametrize('test', [
 
     # Test don't manage the volume
@@ -124,6 +119,8 @@ def test_calculate_fades():
         (0, 4, 0, 0, 10,        0, 0, 6, 10),
         (None, 4, 0, 0, 10,     0, 0, 6, 10),
     ]
+
+# fmt: on
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtonoff3_py.snap

@@ -30,21 +30,10 @@ x = [
 ```diff
 --- Black
 +++ Ruff
-@@ -1,15 +1,11 @@
+@@ -12,4 +12,6 @@
--# fmt: off
- x = [
-     1, 2,
-     3, 4,
  ]
--# fmt: on
+ # fmt: on
--
+ 
--# fmt: off
- x = [
-     1, 2,
-     3, 4,
- ]
--# fmt: on
--
 -x = [1, 2, 3, 4]
 +x = [
 +    1, 2, 3, 4
@@ -54,14 +43,20 @@ x = [
 ## Ruff Output
 
 ```py
+# fmt: off
 x = [
     1, 2,
     3, 4,
 ]
+# fmt: on
+
+# fmt: off
 x = [
     1, 2,
     3, 4,
 ]
+# fmt: on
+
 x = [
     1, 2, 3, 4
 ]

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtonoff4_py.snap

@@ -26,10 +26,7 @@ def f(): pass
 ```diff
 --- Black
 +++ Ruff
-@@ -1,20 +1,11 @@
+@@ -4,17 +4,9 @@
--# fmt: off
- @test([
-     1, 2,
      3, 4,
  ])
  # fmt: on
@@ -58,6 +55,7 @@ def f(): pass
 ## Ruff Output
 
 ```py
+# fmt: off
 @test([
     1, 2,
     3, 4,

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtonoff5_py.snap

@@ -97,62 +97,53 @@ elif   unformatted:
 ```diff
 --- Black
 +++ Ruff
-@@ -1,4 +1,3 @@
+@@ -9,8 +9,6 @@
--# Regression test for https://github.com/psf/black/issues/3129.
- setup(
-     entry_points={
-         # fmt: off
-@@ -9,9 +8,6 @@
              ]  # Includes an formatted indentation.
      },
  )
 -
 -
--# Regression test for https://github.com/psf/black/issues/2015.
+ # Regression test for https://github.com/psf/black/issues/2015.
  run(
      # fmt: off
-     [
+@@ -22,8 +20,6 @@
-@@ -22,9 +18,6 @@
      + path,
      check=True,
  )
 -
 -
--# Regression test for https://github.com/psf/black/issues/3026.
+ # Regression test for https://github.com/psf/black/issues/3026.
  def test_func():
      # yapf: disable
-     if  unformatted(  args  ):
+@@ -34,8 +30,6 @@
-@@ -34,9 +27,6 @@
          return True
  
      return False
 -
 -
--# Regression test for https://github.com/psf/black/issues/2567.
+ # Regression test for https://github.com/psf/black/issues/2567.
  if True:
      # fmt: off
-     for _ in range( 1 ):
+@@ -44,9 +38,7 @@
-@@ -44,10 +34,7 @@
          print ( "This won't be formatted" )
      print ( "This won't be formatted either" )
  else:
 -    print("This will be formatted")
 -
 -
--# Regression test for https://github.com/psf/black/issues/3184.
 +    print ( "This will be formatted" )
+ # Regression test for https://github.com/psf/black/issues/3184.
  class A:
      async def call(param):
-         if param:
+@@ -61,27 +53,18 @@
-@@ -61,27 +48,16 @@
              elif param[0:4] in ("ZZZZ",):
                  print ( "This won't be formatted either" )
  
 -        print("This will be formatted")
 -
 -
--# Regression test for https://github.com/psf/black/issues/2985.
 +        print ( "This will be formatted" )
+ # Regression test for https://github.com/psf/black/issues/2985.
  class Named(t.Protocol):
      # fmt: off
      @property
@@ -166,8 +157,8 @@ elif   unformatted:
 -    # fmt: on
 -
 -
--# Regression test for https://github.com/psf/black/issues/3436.
 +    def  this_will_be_formatted ( self, **kwargs ) -> Named: ...
+ # Regression test for https://github.com/psf/black/issues/3436.
  if x:
      return x
  # fmt: off
@@ -181,6 +172,7 @@ elif   unformatted:
 ## Ruff Output
 
 ```py
+# Regression test for https://github.com/psf/black/issues/3129.
 setup(
     entry_points={
         # fmt: off
@@ -191,6 +183,7 @@ setup(
             ]  # Includes an formatted indentation.
     },
 )
+# Regression test for https://github.com/psf/black/issues/2015.
 run(
     # fmt: off
     [
@@ -201,6 +194,7 @@ run(
     + path,
     check=True,
 )
+# Regression test for https://github.com/psf/black/issues/3026.
 def test_func():
     # yapf: disable
     if  unformatted(  args  ):
@@ -210,6 +204,7 @@ def test_func():
         return True
 
     return False
+# Regression test for https://github.com/psf/black/issues/2567.
 if True:
     # fmt: off
     for _ in range( 1 ):
@@ -218,6 +213,7 @@ if True:
     print ( "This won't be formatted either" )
 else:
     print ( "This will be formatted" )
+# Regression test for https://github.com/psf/black/issues/3184.
 class A:
     async def call(param):
         if param:
@@ -232,12 +228,14 @@ class A:
                 print ( "This won't be formatted either" )
 
         print ( "This will be formatted" )
+# Regression test for https://github.com/psf/black/issues/2985.
 class Named(t.Protocol):
     # fmt: off
     @property
     def  this_wont_be_formatted ( self ) -> str: ...
 class Factory(t.Protocol):
     def  this_will_be_formatted ( self, **kwargs ) -> Named: ...
+# Regression test for https://github.com/psf/black/issues/3436.
 if x:
     return x
 # fmt: off

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtonoff_py.snap

@@ -199,8 +199,8 @@ d={'a':1,
 ```diff
 --- Black
 +++ Ruff
-@@ -1,22 +1,11 @@
+@@ -1,20 +1,17 @@
--#!/usr/bin/env python3
+ #!/usr/bin/env python3
  import asyncio
  import sys
 -
@@ -208,28 +208,25 @@ d={'a':1,
 -
 -from library import some_connection, some_decorator
 -
--# fmt: off
 +from library import some_connection, \
 +                    some_decorator
+ # fmt: off
  from third_party import (X,
                           Y, Z)
--# fmt: on
+ # fmt: on
 -f"trigger 3.6 mode"
--# Comment 1
--
--# Comment 2
--
--
--# fmt: off
 +f'trigger 3.6 mode'
+ # Comment 1
+ 
+ # Comment 2
+-
+ 
+ # fmt: off
  def func_no_args():
-   a; b; c
+@@ -39,72 +36,41 @@
-   if True: raise RuntimeError
-@@ -38,73 +27,41 @@
- )
  def function_signature_stress_test(number:int,no_annotation=None,text:str='default',* ,debug:bool=False,**kwargs) -> str:
   return text[number:-1]
--# fmt: on
+ # fmt: on
 -def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
 -    offset = attr.ib(default=attr.Factory(lambda: _r.uniform(1, 2)))
 -    assert task._cancel_stack[: len(old_stack)] == old_stack
@@ -308,7 +305,7 @@ d={'a':1,
  def example(session):
      # fmt: off
      result = session\
-@@ -113,9 +70,6 @@
+@@ -113,9 +79,6 @@
                  models.Customer.email == email_address)\
          .order_by(models.Customer.id.asc())\
          .all()
@@ -318,23 +315,23 @@ d={'a':1,
  def off_and_on_without_data():
      """All comments here are technically on the same prefix.
  
-@@ -123,12 +77,12 @@
+@@ -123,12 +86,12 @@
      """
      # fmt: off
  
 -    # hey, that won't work
  
--    # fmt: on
--    pass
 +        #hey, that won't work
- 
++
- 
++
-+    # fmt: on
+     # fmt: on
-+    pass
+     pass
+-
+-
  def on_and_off_broken():
      """Another known limitation."""
      # fmt: on
-@@ -137,21 +91,10 @@
+@@ -137,21 +100,10 @@
      and_=indeed . it  is  not  formatted
      because . the . handling . inside . generate_ignored_nodes()
      now . considers . multiple . fmt . directives . within . one . prefix
@@ -357,7 +354,7 @@ d={'a':1,
          )
          # fmt: off
          a = (
-@@ -182,24 +125,19 @@
+@@ -182,24 +134,19 @@
          re.MULTILINE|re.VERBOSE
          # fmt: on
      )
@@ -372,7 +369,7 @@ d={'a':1,
 +        (1, 2, 3, 4),
 +        (5, 6, 7, 8),
 +        (9, 10, 11, 12)
-+    }
++    }  # yapf: disable
  cfg.rule(
 -    "Default",
 -    "address",
@@ -391,32 +388,36 @@ d={'a':1,
      # fmt: off
      xxxxxxx_xxxxxxxxxxxx={
          "xxxxxxxx": {
-@@ -214,11 +152,9 @@
+@@ -214,7 +161,7 @@
          },
      },
      # fmt: on
 -    xxxxxxxxxx_xxxxxxxxxxx_xxxxxxx_xxxxxxxxx=5,
 +    xxxxxxxxxx_xxxxxxxxxxx_xxxxxxx_xxxxxxxxx=5
  )
--# fmt: off
+ # fmt: off
  yield  'hello'
--# No formatting to the end of the file
- l=[1,2,3]
- d={'a':1,
-    'b':2}
 ```
 
 ## Ruff Output
 
 ```py
+#!/usr/bin/env python3
 import asyncio
 import sys
 from third_party import X, Y, Z
 from library import some_connection, \
                     some_decorator
+# fmt: off
 from third_party import (X,
                          Y, Z)
+# fmt: on
 f'trigger 3.6 mode'
+# Comment 1
+
+# Comment 2
+
+# fmt: off
 def func_no_args():
   a; b; c
   if True: raise RuntimeError
@@ -438,6 +439,7 @@ many_args=[1,2,3]
 )
 def function_signature_stress_test(number:int,no_annotation=None,text:str='default',* ,debug:bool=False,**kwargs) -> str:
  return text[number:-1]
+# fmt: on
 def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r''):
  offset = attr.ib(default=attr.Factory( lambda: _r.uniform(1, 2)))
  assert task._cancel_stack[:len(old_stack)] == old_stack
@@ -542,7 +544,7 @@ def single_literal_yapf_disable():
         (1, 2, 3, 4),
         (5, 6, 7, 8),
         (9, 10, 11, 12)
-    }
+    }  # yapf: disable
 cfg.rule(
     "Default", "address",
     xxxx_xxxx=["xxx-xxxxxx-xxxxxxxxxx"],
@@ -565,7 +567,9 @@ cfg.rule(
     # fmt: on
     xxxxxxxxxx_xxxxxxxxxxx_xxxxxxx_xxxxxxxxx=5
 )
+# fmt: off
 yield  'hello'
+# No formatting to the end of the file
 l=[1,2,3]
 d={'a':1,
    'b':2}

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip2_py.snap

@@ -22,14 +22,13 @@ l3 = ["I have", "trailing comma", "so I should be braked",]
 -    "into multiple lines",
 -    "because it is way too long",
 -]
--l2 = ["But this list shouldn't", "even though it also has", "way too many characters in it"]  # fmt: skip
++l1 = ["This list should be broken up", "into multiple lines", "because it is way too long"]
+ l2 = ["But this list shouldn't", "even though it also has", "way too many characters in it"]  # fmt: skip
 -l3 = [
 -    "I have",
 -    "trailing comma",
 -    "so I should be braked",
 -]
-+l1 = ["This list should be broken up", "into multiple lines", "because it is way too long"]
-+l2 = ["But this list shouldn't", "even though it also has", "way too many characters in it"]
 +l3 = ["I have", "trailing comma", "so I should be braked",]
 ```
 
@@ -37,7 +36,7 @@ l3 = ["I have", "trailing comma", "so I should be braked",]
 
 ```py
 l1 = ["This list should be broken up", "into multiple lines", "because it is way too long"]
-l2 = ["But this list shouldn't", "even though it also has", "way too many characters in it"]
+l2 = ["But this list shouldn't", "even though it also has", "way too many characters in it"]  # fmt: skip
 l3 = ["I have", "trailing comma", "so I should be braked",]
 ```
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip3_py.snap

@@ -20,15 +20,14 @@ f = ["This is a very long line that should be formatted into a clearer line ", "
 ```diff
 --- Black
 +++ Ruff
-@@ -1,10 +1,5 @@
+@@ -1,10 +1,7 @@
 -a = 3
--# fmt: off
 +a  =    3
+ # fmt: off
  b,    c = 1, 2
--d =    6  # fmt: skip
+ d =    6  # fmt: skip
-+d =    6
  e = 5
--# fmt: on
+ # fmt: on
 -f = [
 -    "This is a very long line that should be formatted into a clearer line ",
 -    "by rearranging.",
@@ -40,9 +39,11 @@ f = ["This is a very long line that should be formatted into a clearer line ", "
 
 ```py
 a  =    3
+# fmt: off
 b,    c = 1, 2
-d =    6
+d =    6  # fmt: skip
 e = 5
+# fmt: on
 f = ["This is a very long line that should be formatted into a clearer line ", "by rearranging."]
 ```
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip4_py.snap

@@ -16,15 +16,15 @@ l = [1, 2, 3,]
 ```diff
 --- Black
 +++ Ruff
-@@ -1,7 +1,2 @@
+@@ -1,7 +1,3 @@
 -a = 2
--# fmt: skip
++a =   2
+ # fmt: skip
 -l = [
 -    1,
 -    2,
 -    3,
 -]
-+a =   2
 +l = [1, 2, 3,]
 ```
 
@@ -32,6 +32,7 @@ l = [1, 2, 3,]
 
 ```py
 a =   2
+# fmt: skip
 l = [1, 2, 3,]
 ```
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip6_py.snap

@@ -1,49 +0,0 @@
----
-source: crates/ruff_python_formatter/src/lib.rs
-expression: snapshot
-input_file: crates/ruff_python_formatter/resources/test/fixtures/black/simple_cases/fmtskip6.py
----
-## Input
-
-```py
-class A:
-    def f(self):
-        for line in range(10):
-            if True:
-                pass  # fmt: skip
-```
-
-## Black Differences
-
-```diff
---- Black
-+++ Ruff
-@@ -2,4 +2,4 @@
-     def f(self):
-         for line in range(10):
-             if True:
--                pass  # fmt: skip
-+                pass
-```
-
-## Ruff Output
-
-```py
-class A:
-    def f(self):
-        for line in range(10):
-            if True:
-                pass
-```
-
-## Black Output
-
-```py
-class A:
-    def f(self):
-        for line in range(10):
-            if True:
-                pass  # fmt: skip
-```
-
-

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip7_py.snap

@@ -23,18 +23,18 @@ d = "thisisasuperlongstringthisisasuperlongstringthisisasuperlongstringthisisasu
 -c = 9  # fmt: skip
 -d = "thisisasuperlongstringthisisasuperlongstringthisisasuperlongstringthisisasuperlongstring"  # fmt:skip
 +a =     "this is some code"
-+b =     5
++b =     5  #fmt:skip
-+c = 9
++c = 9  #fmt: skip
-+d = "thisisasuperlongstringthisisasuperlongstringthisisasuperlongstringthisisasuperlongstring"
++d = "thisisasuperlongstringthisisasuperlongstringthisisasuperlongstringthisisasuperlongstring"  #fmt:skip
 ```
 
 ## Ruff Output
 
 ```py
 a =     "this is some code"
-b =     5
+b =     5  #fmt:skip
-c = 9
+c = 9  #fmt: skip
-d = "thisisasuperlongstringthisisasuperlongstringthisisasuperlongstringthisisasuperlongstring"
+d = "thisisasuperlongstringthisisasuperlongstringthisisasuperlongstringthisisasuperlongstring"  #fmt:skip
 ```
 
 ## Black Output

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip8_py.snap

@@ -75,35 +75,32 @@ async def test_async_with():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,17 +1,9 @@
+@@ -2,15 +2,10 @@
--# Make sure a leading comment is not removed.
  def some_func(  unformatted,  args  ):  # fmt: skip
      print("I am some_func")
      return 0
 -    # Make sure this comment is not removed.
 -
 -
--# Make sure a leading comment is not removed.
+ # Make sure a leading comment is not removed.
  async def some_async_func(  unformatted,   args):  # fmt: skip
      print("I am some_async_func")
      await asyncio.sleep(1)
 -
 -
--# Make sure a leading comment is not removed.
+ # Make sure a leading comment is not removed.
  class SomeClass(  Unformatted,  SuperClasses  ):  # fmt: skip
      def some_method(  self,  unformatted,  args  ):  # fmt: skip
-         print("I am some_method")
+@@ -20,8 +15,6 @@
-@@ -20,9 +12,6 @@
      async def some_async_method(  self,  unformatted,  args  ):  # fmt: skip
          print("I am some_async_method")
          await asyncio.sleep(1)
 -
 -
--# Make sure a leading comment is not removed.
+ # Make sure a leading comment is not removed.
  if  unformatted_call(  args  ):  # fmt: skip
      print("First branch")
-     # Make sure this is not removed.
+@@ -30,33 +23,21 @@
-@@ -30,33 +19,21 @@
      print("Second branch")
  else  :  # fmt: skip
      print("Last branch")
@@ -142,12 +139,15 @@ async def test_async_with():
 ## Ruff Output
 
 ```py
+# Make sure a leading comment is not removed.
 def some_func(  unformatted,  args  ):  # fmt: skip
     print("I am some_func")
     return 0
+# Make sure a leading comment is not removed.
 async def some_async_func(  unformatted,   args):  # fmt: skip
     print("I am some_async_func")
     await asyncio.sleep(1)
+# Make sure a leading comment is not removed.
 class SomeClass(  Unformatted,  SuperClasses  ):  # fmt: skip
     def some_method(  self,  unformatted,  args  ):  # fmt: skip
         print("I am some_method")
@@ -156,6 +156,7 @@ class SomeClass(  Unformatted,  SuperClasses  ):  # fmt: skip
     async def some_async_method(  self,  unformatted,  args  ):  # fmt: skip
         print("I am some_async_method")
         await asyncio.sleep(1)
+# Make sure a leading comment is not removed.
 if  unformatted_call(  args  ):  # fmt: skip
     print("First branch")
     # Make sure this is not removed.

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__fmtskip_py.snap

@@ -1,42 +0,0 @@
----
-source: crates/ruff_python_formatter/src/lib.rs
-expression: snapshot
-input_file: crates/ruff_python_formatter/resources/test/fixtures/black/simple_cases/fmtskip.py
----
-## Input
-
-```py
-a, b = 1, 2
-c =    6  # fmt: skip
-d = 5
-```
-
-## Black Differences
-
-```diff
---- Black
-+++ Ruff
-@@ -1,3 +1,3 @@
- a, b = 1, 2
--c =    6  # fmt: skip
-+c =    6
- d = 5
-```
-
-## Ruff Output
-
-```py
-a, b = 1, 2
-c =    6
-d = 5
-```
-
-## Black Output
-
-```py
-a, b = 1, 2
-c =    6  # fmt: skip
-d = 5
-```
-
-

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__function_py.snap

@@ -108,8 +108,8 @@ def __await__(): return (yield)
 ```diff
 --- Black
 +++ Ruff
-@@ -1,100 +1,51 @@
+@@ -1,100 +1,52 @@
--#!/usr/bin/env python3
+ #!/usr/bin/env python3
  import asyncio
  import sys
 -
@@ -244,7 +244,7 @@ def __await__(): return (yield)
                  # trailing standalone comment
              )
          )
-@@ -117,23 +68,18 @@
+@@ -117,23 +69,18 @@
              \n?
          )
          $
@@ -276,7 +276,7 @@ def __await__(): return (yield)
  ) -> A:
      return (
          yield from A(
-@@ -142,7 +88,4 @@
+@@ -142,7 +89,4 @@
              **kwargs,
          )
      )
@@ -290,6 +290,7 @@ def __await__(): return (yield)
 ## Ruff Output
 
 ```py
+#!/usr/bin/env python3
 import asyncio
 import sys
 from third_party import X, Y, Z

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__function_trailing_comma_py.snap

@@ -74,7 +74,7 @@ some_module.some_function(
 ```diff
 --- Black
 +++ Ruff
-@@ -1,114 +1,42 @@
+@@ -1,114 +1,46 @@
 -def f(
 -    a,
 -):
@@ -152,12 +152,12 @@ some_module.some_function(
 -    }
 -
 -
--# The type annotation shouldn't get a trailing comma since that would change its type.
--# Relevant bug report: https://github.com/psf/black/issues/2381.
 +def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> Set[
 +    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 +]:
 +    json = {"k": {"k2": {"k3": [1,]}}}
+ # The type annotation shouldn't get a trailing comma since that would change its type.
+ # Relevant bug report: https://github.com/psf/black/issues/2381.
  def some_function_with_a_really_long_name() -> (
      returning_a_deeply_nested_import_of_a_type_i_suppose
  ):
@@ -192,12 +192,12 @@ some_module.some_function(
      pass
 -
 -
--# Make sure inner one-element tuple won't explode
+ # Make sure inner one-element tuple won't explode
  some_module.some_function(
      argument1, (one_element_tuple,), argument4, argument5, argument6
  )
 -
--# Inner trailing comma causes outer to explode
+ # Inner trailing comma causes outer to explode
  some_module.some_function(
 -    argument1,
 -    (
@@ -233,6 +233,8 @@ def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> Set[
     "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 ]:
     json = {"k": {"k2": {"k3": [1,]}}}
+# The type annotation shouldn't get a trailing comma since that would change its type.
+# Relevant bug report: https://github.com/psf/black/issues/2381.
 def some_function_with_a_really_long_name() -> (
     returning_a_deeply_nested_import_of_a_type_i_suppose
 ):
@@ -250,9 +252,11 @@ def func() -> ((also_super_long_type_annotation_that_may_cause_an_AST_related_cr
     ))
 ):
     pass
+# Make sure inner one-element tuple won't explode
 some_module.some_function(
     argument1, (one_element_tuple,), argument4, argument5, argument6
 )
+# Inner trailing comma causes outer to explode
 some_module.some_function(
     argument1, (one, two,), argument4, argument5, argument6
 )

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__import_spacing_py.snap

@@ -62,11 +62,11 @@ __all__ = (
 ```diff
 --- Black
 +++ Ruff
-@@ -1,55 +1,30 @@
+@@ -1,55 +1,33 @@
  """The asyncio package, tracking PEP 3156."""
 -
--# flake8: noqa
+ # flake8: noqa
--
+ 
 -from logging import WARNING
  from logging import (
 +    WARNING
@@ -76,19 +76,16 @@ __all__ = (
  )
  import sys
 -
--# This relies on each of the submodules having an __all__ variable.
+ # This relies on each of the submodules having an __all__ variable.
  from .base_events import *
  from .coroutines import *
--from .events import *  # comment here
+ from .events import *  # comment here
 -
-+from .events import *
  from .futures import *
--from .locks import *  # comment here
+ from .locks import *  # comment here
-+from .locks import *
  from .protocols import *
 -
--from ..runners import *  # comment here
+ from ..runners import *  # comment here
-+from ..runners import *
  from ..queues import *
  from ..streams import *
 -
@@ -136,6 +133,8 @@ __all__ = (
 
 ```py
 """The asyncio package, tracking PEP 3156."""
+# flake8: noqa
+
 from logging import (
     WARNING
 )
@@ -143,13 +142,14 @@ from logging import (
     ERROR,
 )
 import sys
+# This relies on each of the submodules having an __all__ variable.
 from .base_events import *
 from .coroutines import *
-from .events import *
+from .events import *  # comment here
 from .futures import *
-from .locks import *
+from .locks import *  # comment here
 from .protocols import *
-from ..runners import *
+from ..runners import *  # comment here
 from ..queues import *
 from ..streams import *
 from some_library import (

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__one_element_subscript_py.snap

@@ -25,13 +25,12 @@ list_of_types = [tuple[int,],]
 ```diff
 --- Black
 +++ Ruff
-@@ -1,22 +1,6 @@
+@@ -2,21 +2,9 @@
--# We should not treat the trailing comma
+ # in a single-element subscript.
--# in a single-element subscript.
  a: tuple[int,]
  b = tuple[int,]
 -
--# The magic comma still applies to multi-element subscripts.
+ # The magic comma still applies to multi-element subscripts.
 -c: tuple[
 -    int,
 -    int,
@@ -41,15 +40,15 @@ list_of_types = [tuple[int,],]
 -    int,
 -]
 -
--# Magic commas still work as expected for non-subscripts.
++c: tuple[int, int,]
++d = tuple[int, int,]
+ # Magic commas still work as expected for non-subscripts.
 -small_list = [
 -    1,
 -]
 -list_of_types = [
 -    tuple[int,],
 -]
-+c: tuple[int, int,]
-+d = tuple[int, int,]
 +small_list = [1,]
 +list_of_types = [tuple[int,],]
 ```
@@ -57,10 +56,14 @@ list_of_types = [tuple[int,],]
 ## Ruff Output
 
 ```py
+# We should not treat the trailing comma
+# in a single-element subscript.
 a: tuple[int,]
 b = tuple[int,]
+# The magic comma still applies to multi-element subscripts.
 c: tuple[int, int,]
 d = tuple[int, int,]
+# Magic commas still work as expected for non-subscripts.
 small_list = [1,]
 list_of_types = [tuple[int,],]
 ```

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__power_op_spacing_py.snap

@@ -103,17 +103,16 @@ return np.divide(
  a = 5.0**~4.0
  b = 5.0 ** f()
  c = -(5.0**2.0)
-@@ -47,9 +40,6 @@
+@@ -47,8 +40,6 @@
  o = settings(max_examples=10**6.0)
  p = {(k, k**2): v**2.0 for k, v in pairs}
  q = [10.5**i for i in range(6)]
 -
 -
--# WE SHOULD DEFINITELY NOT EAT THESE COMMENTS (https://github.com/psf/black/issues/2873)
+ # WE SHOULD DEFINITELY NOT EAT THESE COMMENTS (https://github.com/psf/black/issues/2873)
  if hasattr(view, "sum_of_weights"):
      return np.divide(  # type: ignore[no-any-return]
-         view.variance,  # type: ignore[union-attr]
+@@ -57,7 +48,6 @@
-@@ -57,7 +47,6 @@
          out=np.full(view.sum_of_weights.shape, np.nan),  # type: ignore[union-attr]
          where=view.sum_of_weights**2 > view.sum_of_weights_squared,  # type: ignore[union-attr]
      )
@@ -168,6 +167,7 @@ n = count <= 10**5.0
 o = settings(max_examples=10**6.0)
 p = {(k, k**2): v**2.0 for k, v in pairs}
 q = [10.5**i for i in range(6)]
+# WE SHOULD DEFINITELY NOT EAT THESE COMMENTS (https://github.com/psf/black/issues/2873)
 if hasattr(view, "sum_of_weights"):
     return np.divide(  # type: ignore[no-any-return]
         view.variance,  # type: ignore[union-attr]

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__prefer_rhs_split_reformatted_py.snap

@@ -25,11 +25,10 @@ xxxxxxxxx_yyy_zzzzzzzz[xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxx
 ```diff
 --- Black
 +++ Ruff
-@@ -1,21 +1,5 @@
+@@ -2,20 +2,10 @@
--# Test cases separate from `prefer_rhs_split.py` that contains unformatted source.
+ 
--
+ # Left hand side fits in a single line but will still be exploded by the
--# Left hand side fits in a single line but will still be exploded by the
+ # magic trailing comma.
--# magic trailing comma.
 -(
 -    first_value,
 -    (
@@ -43,8 +42,8 @@ xxxxxxxxx_yyy_zzzzzzzz[xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxx
      arg2,
  )
 -
--# Make when when the left side of assignment plus the opening paren "... = (" is
+ # 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.
+ # exactly line length limit + 1, it won't be split like that.
 -xxxxxxxxx_yyy_zzzzzzzz[
 -    xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxxx=1)
 -] = 1
@@ -54,10 +53,16 @@ xxxxxxxxx_yyy_zzzzzzzz[xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxx
 ## Ruff Output
 
 ```py
+# Test cases separate from `prefer_rhs_split.py` that contains unformatted source.
+
+# Left hand side fits in a single line but will still be exploded by the
+# magic trailing comma.
 first_value, (m1, m2,), third_value = xxxxxx_yyyyyy_zzzzzz_wwwwww_uuuuuuu_vvvvvvvvvvv(
     arg1,
     arg2,
 )
+# 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.
 xxxxxxxxx_yyy_zzzzzzzz[xx.xxxxxx(x_yyy_zzzzzz.xxxxx[0]), x_yyy_zzzzzz.xxxxxx(xxxx=1)] = 1
 ```
 

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_await_parens_py.snap

@@ -94,16 +94,16 @@ async def main():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,93 +1,56 @@
+@@ -1,93 +1,64 @@
  import asyncio
 -
 -
--# Control example
+ # Control example
  async def main():
      await asyncio.sleep(1)
 -
 -
--# Remove brackets for short coroutine/task
+ # Remove brackets for short coroutine/task
  async def main():
 -    await asyncio.sleep(1)
 -
@@ -120,40 +120,31 @@ async def main():
 -    await asyncio.sleep(1)
 -
 -
--# Check comments
--async def main():
--    await asyncio.sleep(1)  # Hello
--
--
--async def main():
--    await asyncio.sleep(1)  # Hello
--
--
 +    await (asyncio.sleep(1)
 +    )
+ # Check comments
  async def main():
 -    await asyncio.sleep(1)  # Hello
 -
 -
--# Long lines
 +    await (  # Hello
 +        asyncio.sleep(1)
 +    )
  async def main():
--    await asyncio.gather(
+-    await asyncio.sleep(1)  # Hello
--        asyncio.sleep(1),
+-
--        asyncio.sleep(1),
+-
--        asyncio.sleep(1),
--        asyncio.sleep(1),
--        asyncio.sleep(1),
--        asyncio.sleep(1),
--        asyncio.sleep(1),
 +    await (
 +        asyncio.sleep(1)  # Hello
-     )
++    )
+ async def main():
+-    await asyncio.sleep(1)  # Hello
 -
 -
--# Same as above but with magic trailing comma in function
++    await (
++        asyncio.sleep(1)
++    )  # Hello
+ # Long lines
  async def main():
 -    await asyncio.gather(
 -        asyncio.sleep(1),
@@ -163,21 +154,29 @@ async def main():
 -        asyncio.sleep(1),
 -        asyncio.sleep(1),
 -        asyncio.sleep(1),
-+    await (
+-    )
-+        asyncio.sleep(1)
-     )
 -
 -
--# Cr@zY Br@ck3Tz
++    await asyncio.gather(asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1))
+ # Same as above but with magic trailing comma in function
+ async def main():
+-    await asyncio.gather(
+-        asyncio.sleep(1),
+-        asyncio.sleep(1),
+-        asyncio.sleep(1),
+-        asyncio.sleep(1),
+-        asyncio.sleep(1),
+-        asyncio.sleep(1),
+-        asyncio.sleep(1),
+-    )
+-
+-
++    await asyncio.gather(asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1),)
+ # Cr@zY Br@ck3Tz
  async def main():
 -    await black(1)
 -
 -
--# Keep brackets around non power operations and nested awaits
-+    await asyncio.gather(asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1))
-+async def main():
-+    await asyncio.gather(asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1),)
-+async def main():
 +    await (
 +        (((((((((((((
 +        (((        (((
@@ -191,6 +190,7 @@ async def main():
 +        )))        )))
 +        )))))))))))))
 +    )
+ # Keep brackets around non power operations and nested awaits
  async def main():
      await (set_of_tasks | other_set)
 -
@@ -199,7 +199,7 @@ async def main():
      await (await asyncio.sleep(1))
 -
 -
--# It's awaits all the way down...
+ # It's awaits all the way down...
  async def main():
      await (await x)
 -
@@ -226,8 +226,10 @@ async def main():
 
 ```py
 import asyncio
+# Control example
 async def main():
     await asyncio.sleep(1)
+# Remove brackets for short coroutine/task
 async def main():
     await (asyncio.sleep(1))
 async def main():
@@ -237,6 +239,7 @@ async def main():
 async def main():
     await (asyncio.sleep(1)
     )
+# Check comments
 async def main():
     await (  # Hello
         asyncio.sleep(1)
@@ -248,11 +251,14 @@ async def main():
 async def main():
     await (
         asyncio.sleep(1)
-    )
+    )  # Hello
+# Long lines
 async def main():
     await asyncio.gather(asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1))
+# Same as above but with magic trailing comma in function
 async def main():
     await asyncio.gather(asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1), asyncio.sleep(1),)
+# Cr@zY Br@ck3Tz
 async def main():
     await (
         (((((((((((((
@@ -267,10 +273,12 @@ async def main():
         )))        )))
         )))))))))))))
     )
+# Keep brackets around non power operations and nested awaits
 async def main():
     await (set_of_tasks | other_set)
 async def main():
     await (await asyncio.sleep(1))
+# It's awaits all the way down...
 async def main():
     await (await x)
 async def main():

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_except_parens_py.snap

@@ -48,8 +48,8 @@ except (some.really.really.really.looooooooooooooooooooooooooooooooong.module.ov
 ```diff
 --- Black
 +++ Ruff
-@@ -1,42 +1,24 @@
+@@ -1,42 +1,25 @@
--# These brackets are redundant, therefore remove.
+ # These brackets are redundant, therefore remove.
  try:
      a.something
 -except AttributeError as err:
@@ -100,6 +100,7 @@ except (some.really.really.really.looooooooooooooooooooooooooooooooong.module.ov
 ## Ruff Output
 
 ```py
+# These brackets are redundant, therefore remove.
 try:
     a.something
 except (AttributeError) as err:

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_for_brackets_py.snap

@@ -32,18 +32,18 @@ for (((((k, v))))) in d.items():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,27 +1,11 @@
+@@ -1,27 +1,15 @@
--# Only remove tuple brackets after `for`
+ # Only remove tuple brackets after `for`
 -for k, v in d.items():
 +for (k, v) in d.items():
      print(k, v)
 -
--# Don't touch tuple brackets after `in`
+ # Don't touch tuple brackets after `in`
  for module in (core, _unicodefun):
      if hasattr(module, "_verify_python3_env"):
          module._verify_python3_env = lambda: None
 -
--# Brackets remain for long for loop lines
+ # Brackets remain for long for loop lines
 -for (
 -    why_would_anyone_choose_to_name_a_loop_variable_with_a_name_this_long,
 -    i_dont_know_but_we_should_still_check_the_behaviour_if_they_do,
@@ -60,7 +60,7 @@ for (((((k, v))))) in d.items():
 +for (k, v) in dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items():
      print(k, v)
 -
--# Test deeply nested brackets
+ # Test deeply nested brackets
 -for k, v in d.items():
 +for (((((k, v))))) in d.items():
      print(k, v)
@@ -69,15 +69,19 @@ for (((((k, v))))) in d.items():
 ## Ruff Output
 
 ```py
+# Only remove tuple brackets after `for`
 for (k, v) in d.items():
     print(k, v)
+# Don't touch tuple brackets after `in`
 for module in (core, _unicodefun):
     if hasattr(module, "_verify_python3_env"):
         module._verify_python3_env = lambda: None
+# Brackets remain for long for loop lines
 for (why_would_anyone_choose_to_name_a_loop_variable_with_a_name_this_long, i_dont_know_but_we_should_still_check_the_behaviour_if_they_do) in d.items():
     print(k, v)
 for (k, v) in dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items():
     print(k, v)
+# Test deeply nested brackets
 for (((((k, v))))) in d.items():
     print(k, v)
 ```

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__return_annotation_brackets_py.snap

@@ -101,45 +101,33 @@ def foo() -> tuple[int, int, int,]:
 ```diff
 --- Black
 +++ Ruff
-@@ -1,120 +1,60 @@
+@@ -1,120 +1,70 @@
--# Control
+ # Control
--def double(a: int) -> int:
--    return 2 * a
--
--
--# Remove the brackets
--def double(a: int) -> int:
--    return 2 * a
--
--
--# Some newline variations
--def double(a: int) -> int:
--    return 2 * a
--
--
--def double(a: int) -> int:
--    return 2 * a
--
--
  def double(a: int) -> int:
 -    return 2 * a
 -
 -
--# Don't lose the comments
--def double(a: int) -> int:  # Hello
--    return 2 * a
--
--
--def double(a: int) -> int:  # Hello
--    return 2 * a
--
--
--# Really long annotations
--def foo() -> (
--    intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
 +    return 2*a
+ # Remove the brackets
+-def double(a: int) -> int:
+-    return 2 * a
+-
+-
 +def double(a: int) -> (int):
 +    return 2*a
+ # Some newline variations
+-def double(a: int) -> int:
+-    return 2 * a
+-
+-
+-def double(a: int) -> int:
+-    return 2 * a
+-
+-
+-def double(a: int) -> int:
+-    return 2 * a
+-
+-
 +def double(a: int) -> (
 +    int):
 +    return 2*a
@@ -150,17 +138,24 @@ def foo() -> tuple[int, int, int,]:
 +    int
 +):
 +    return 2*a
+ # Don't lose the comments
+-def double(a: int) -> int:  # Hello
+-    return 2 * a
+-
+-
+-def double(a: int) -> int:  # Hello
+-    return 2 * a
+-
+-
 +def double(a: int) -> ( # Hello
 +    int
- ):
++):
--    return 2
--
--
 +    return 2*a
 +def double(a: int) -> (
 +    int # Hello
 +):
 +    return 2*a
+ # Really long annotations
  def foo() -> (
      intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
  ):
@@ -169,10 +164,15 @@ def foo() -> tuple[int, int, int,]:
 -
 -def foo() -> (
 -    intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
--    | intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
 -):
 +def foo() -> intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds:
-+    return 2
+     return 2
+-
+-
+-def foo() -> (
+-    intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
+-    | intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
+-):
 +def foo() -> intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds | intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds:
      return 2
 -
@@ -198,7 +198,7 @@ def foo() -> tuple[int, int, int,]:
      return 2
 -
 -
--# Split args but no need to split return
+ # Split args but no need to split return
 -def foo(
 -    a: int,
 -    b: int,
@@ -208,8 +208,8 @@ def foo() -> tuple[int, int, int,]:
      return 2
 -
 -
--# Deeply nested brackets
+ # Deeply nested brackets
--# with *interesting* spacing
+ # with *interesting* spacing
 -def double(a: int) -> int:
 -    return 2 * a
 -
@@ -237,7 +237,7 @@ def foo() -> tuple[int, int, int,]:
      return 2
 -
 -
--# Return type with commas
+ # Return type with commas
 -def foo() -> tuple[int, int, int]:
 -    return 2
 -
@@ -253,7 +253,9 @@ def foo() -> tuple[int, int, int,]:
      return 2
 -
 -
--# Magic trailing comma example
++def foo() -> tuple[loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong, loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong, loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong]:
++    return 2
+ # Magic trailing comma example
 -def foo() -> (
 -    tuple[
 -        int,
@@ -261,8 +263,6 @@ def foo() -> tuple[int, int, int,]:
 -        int,
 -    ]
 -):
-+def foo() -> tuple[loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong, loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong, loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong]:
-+    return 2
 +def foo() -> tuple[int, int, int,]:
      return 2
 ```
@@ -270,10 +270,13 @@ def foo() -> tuple[int, int, int,]:
 ## Ruff Output
 
 ```py
+# Control
 def double(a: int) -> int:
     return 2*a
+# Remove the brackets
 def double(a: int) -> (int):
     return 2*a
+# Some newline variations
 def double(a: int) -> (
     int):
     return 2*a
@@ -284,6 +287,7 @@ def double(a: int) -> (
     int
 ):
     return 2*a
+# Don't lose the comments
 def double(a: int) -> ( # Hello
     int
 ):
@@ -292,6 +296,7 @@ def double(a: int) -> (
     int # Hello
 ):
     return 2*a
+# Really long annotations
 def foo() -> (
     intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds
 ):
@@ -304,8 +309,11 @@ def foo(a: int, b: int, c: int,) -> intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasd
     return 2
 def foo(a: int, b: int, c: int,) -> intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds | intsdfsafafafdfdsasdfsfsdfasdfafdsafdfdsfasdskdsdsfdsafdsafsdfdasfffsfdsfdsafafhdskfhdsfjdslkfdlfsdkjhsdfjkdshfkljds:
     return 2
+# Split args but no need to split return
 def foo(a: int, b: int, c: int,) -> int:
     return 2
+# Deeply nested brackets
+# with *interesting* spacing
 def double(a: int) -> (((((int))))):
     return 2*a
 def double(a: int) -> (
@@ -322,12 +330,14 @@ def foo() -> (
 )
 )):
     return 2
+# Return type with commas
 def foo() -> (
     tuple[int, int, int]
 ):
     return 2
 def foo() -> tuple[loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong, loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong, loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong]:
     return 2
+# Magic trailing comma example
 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

@@ -60,31 +60,31 @@ func(
 ```diff
 --- Black
 +++ Ruff
-@@ -1,25 +1,35 @@
+@@ -1,25 +1,40 @@
--# We should not remove the trailing comma in a single-element subscript.
+ # We should not remove the trailing comma in a single-element subscript.
  a: tuple[int,]
  b = tuple[int,]
 -
--# But commas in multiple element subscripts should be removed.
+ # But commas in multiple element subscripts should be removed.
 -c: tuple[int, int]
 -d = tuple[int, int]
 -
--# Remove commas for non-subscripts.
++c: tuple[int, int,]
++d = tuple[int, int,]
+ # Remove commas for non-subscripts.
 -small_list = [1]
 -list_of_types = [tuple[int,]]
 -small_set = {1}
 -set_of_types = {tuple[int,]}
 -
--# Except single element tuples
-+c: tuple[int, int,]
-+d = tuple[int, int,]
 +small_list = [1,]
 +list_of_types = [tuple[int,],]
 +small_set = {1,}
 +set_of_types = {tuple[int,],}
+ # Except single element tuples
  small_tuple = (1,)
 -
--# Trailing commas in multiple chained non-nested parens.
+ # Trailing commas in multiple chained non-nested parens.
 -zero(one).two(three).four(five)
 -
 -func1(arg1).func2(arg2).func3(arg3).func4(arg4).func5(arg5)
@@ -123,15 +123,20 @@ func(
 ## Ruff Output
 
 ```py
+# We should not remove the trailing comma in a single-element subscript.
 a: tuple[int,]
 b = tuple[int,]
+# But commas in multiple element subscripts should be removed.
 c: tuple[int, int,]
 d = tuple[int, int,]
+# Remove commas for non-subscripts.
 small_list = [1,]
 list_of_types = [tuple[int,],]
 small_set = {1,}
 set_of_types = {tuple[int,],}
+# Except single element tuples
 small_tuple = (1,)
+# Trailing commas in multiple chained non-nested parens.
 zero(
     one,
 ).two(

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__slices_py.snap

@@ -76,7 +76,7 @@ x[
 ```diff
 --- Black
 +++ Ruff
-@@ -17,19 +17,12 @@
+@@ -17,19 +17,14 @@
  slice[not so_simple : 1 < val <= 10]
  slice[(1 for i in range(42)) : x]
  slice[:: [i for i in range(42)]]
@@ -86,17 +86,17 @@ x[
      slice[await x : [i async for i in arange(42)] : 42]
 -
 -
--# These are from PEP-8:
+ # These are from PEP-8:
  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+offset : upper+offset]
+ # ham[lower+offset : upper+offset]
  ham[: upper_fn(x) : step_fn(x)], ham[:: step_fn(x)]
  ham[lower + offset : upper + offset]
 -
  slice[::, ::]
  slice[
      # A
-@@ -46,7 +39,6 @@
+@@ -46,7 +41,6 @@
      # C
      3
  ]
@@ -104,7 +104,7 @@ x[
  slice[
      # A
      1
-@@ -56,4 +48,8 @@
+@@ -56,4 +50,8 @@
      # C
      4
  ]
@@ -140,8 +140,10 @@ slice[(1 for i in range(42)) : x]
 slice[:: [i for i in range(42)]]
 async def f():
     slice[await x : [i async for i in arange(42)] : 42]
+# These are from PEP-8:
 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+offset : upper+offset]
 ham[: upper_fn(x) : step_fn(x)], ham[:: step_fn(x)]
 ham[lower + offset : upper + offset]
 slice[::, ::]

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__string_prefixes_py.snap

@@ -33,9 +33,9 @@ def docstring_multiline():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,19 +1,12 @@
+@@ -1,19 +1,14 @@
--#!/usr/bin/env python3
+ #!/usr/bin/env python3
--
+ 
  name = "Łukasz"
 -(f"hello {name}", f"hello {name}")
 -(b"", b"")
@@ -63,6 +63,8 @@ def docstring_multiline():
 ## Ruff Output
 
 ```py
+#!/usr/bin/env python3
+
 name = "Łukasz"
 (f"hello {name}", F"hello {name}")
 (b"", B"")

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__torture_py.snap

@@ -50,7 +50,7 @@ assert (
 -    ** 101234234242352525425252352352525234890264906820496920680926538059059209922523523525
 -)  #
 -
-+() << 0 ** 101234234242352525425252352352525234890264906820496920680926538059059209922523523525
++() << 0 ** 101234234242352525425252352352525234890264906820496920680926538059059209922523523525  #
  assert sort_by_dependency(
      {
 -        "1": {"2", "3"},
@@ -70,7 +70,7 @@ assert (
 -0 ^ 0  #
 -
 -
-+0^0
++0^0  #
  class A:
      def foo(self):
          for _ in range(10):
@@ -120,7 +120,7 @@ assert (
 
 ```py
 importA
-() << 0 ** 101234234242352525425252352352525234890264906820496920680926538059059209922523523525
+() << 0 ** 101234234242352525425252352352525234890264906820496920680926538059059209922523523525  #
 assert sort_by_dependency(
     {
         "1": {"2", "3"}, "2": {"2a", "2b"}, "3": {"3a", "3b"},
@@ -129,7 +129,7 @@ assert sort_by_dependency(
 ) == ["2a", "2b", "2", "3a", "3b", "3", "1"]
 importA
 0
-0^0
+0^0  #
 class A:
     def foo(self):
         for _ in range(10):

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
-@@ -1,31 +1,7 @@
+@@ -1,30 +1,8 @@
 -zero(
 -    one,
 -).two(
@@ -61,9 +61,9 @@ assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
 -    arg4,
 -).func5(arg5)
 -
--# Inner one-element tuple shouldn't explode
 +zero(one,).two(three,).four(five,)
 +func1(arg1).func2(arg2,).func3(arg3).func4(arg4,).func5(arg5)
+ # Inner one-element tuple shouldn't explode
  func1(arg1).func2(arg1, (one_tuple,)).func3(arg3)
 -
 -(
@@ -76,28 +76,26 @@ assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
 -) and func2(arg2)
 -
 -
--# Example from https://github.com/psf/black/issues/3229
 +(a, b, c, d,) = func1(arg1) and func2(arg2)
+ # Example from https://github.com/psf/black/issues/3229
  def refresh_token(self, device_family, refresh_token, api_key):
      return self.orchestration.refresh_token(
-         data={
+@@ -33,15 +11,12 @@
-@@ -33,16 +9,10 @@
          },
          api_key=api_key,
      )["extensions"]["sdk"]["token"]
 -
 -
--# Edge case where a bug in a working-in-progress version of
+ # Edge case where a bug in a working-in-progress version of
--# https://github.com/psf/black/pull/3370 causes an infinite recursion.
+ # https://github.com/psf/black/pull/3370 causes an infinite recursion.
  assert (
      long_module.long_class.long_func().another_func()
      == long_module.long_class.long_func()["some_key"].another_func(arg1)
  )
 -
--# Regression test for https://github.com/psf/black/issues/3414.
+ # Regression test for https://github.com/psf/black/issues/3414.
  assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
      xxxxxxxxx
- ).xxxxxxxxxxxxxxxxxx(), (
 ```
 
 ## Ruff Output
@@ -105,8 +103,10 @@ assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
 ```py
 zero(one,).two(three,).four(five,)
 func1(arg1).func2(arg2,).func3(arg3).func4(arg4,).func5(arg5)
+# Inner one-element tuple shouldn't explode
 func1(arg1).func2(arg1, (one_tuple,)).func3(arg3)
 (a, b, c, d,) = func1(arg1) and func2(arg2)
+# Example from https://github.com/psf/black/issues/3229
 def refresh_token(self, device_family, refresh_token, api_key):
     return self.orchestration.refresh_token(
         data={
@@ -114,10 +114,13 @@ def refresh_token(self, device_family, refresh_token, api_key):
         },
         api_key=api_key,
     )["extensions"]["sdk"]["token"]
+# Edge case where a bug in a working-in-progress version of
+# https://github.com/psf/black/pull/3370 causes an infinite recursion.
 assert (
     long_module.long_class.long_func().another_func()
     == long_module.long_class.long_func()["some_key"].another_func(arg1)
 )
+# Regression test for https://github.com/psf/black/issues/3414.
 assert xxxxxxxxx.xxxxxxxxx.xxxxxxxxx(
     xxxxxxxxx
 ).xxxxxxxxxxxxxxxxxx(), (

crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__tupleassign_py.snap

@@ -20,8 +20,8 @@ this_will_be_wrapped_in_parens, = struct.unpack(b"12345678901234567890")
 ```diff
 --- Black
 +++ Ruff
-@@ -1,12 +1,3 @@
+@@ -1,12 +1,5 @@
--# This is a standalone comment.
+ # This is a standalone comment.
 -(
 -    sdfjklsdfsjldkflkjsf,
 -    sdfjsdfjlksdljkfsdlkf,
@@ -29,10 +29,10 @@ this_will_be_wrapped_in_parens, = struct.unpack(b"12345678901234567890")
 -    sdsfsdfjskdflsfsdf,
 -) = (1, 2, 3)
 -
--# This is as well.
++sdfjklsdfsjldkflkjsf, sdfjsdfjlksdljkfsdlkf, sdfsdjfklsdfjlksdljkf, sdsfsdfjskdflsfsdf = 1, 2, 3
+ # This is as well.
 -(this_will_be_wrapped_in_parens,) = struct.unpack(b"12345678901234567890")
 -
-+sdfjklsdfsjldkflkjsf, sdfjsdfjlksdljkfsdlkf, sdfsdjfklsdfjlksdljkf, sdsfsdfjskdflsfsdf = 1, 2, 3
 +this_will_be_wrapped_in_parens, = struct.unpack(b"12345678901234567890")
  (a,) = call()
 ```
@@ -40,7 +40,9 @@ this_will_be_wrapped_in_parens, = struct.unpack(b"12345678901234567890")
 ## Ruff Output
 
 ```py
+# This is a standalone comment.
 sdfjklsdfsjldkflkjsf, sdfjsdfjlksdljkfsdlkf, sdfsdjfklsdfjlksdljkf, sdsfsdfjskdflsfsdf = 1, 2, 3
+# This is as well.
 this_will_be_wrapped_in_parens, = struct.unpack(b"12345678901234567890")
 (a,) = call()
 ```

crates/ruff_python_formatter/src/trivia.rs

@@ -68,9 +68,33 @@ pub(crate) fn lines_before(code: &str, offset: TextSize) -> u32 {
     newlines
 }
 
+/// Counts the empty lines between `offset` and the first non-whitespace character.
+pub(crate) fn lines_after(code: &str, offset: TextSize) -> u32 {
+    let rest = &code[usize::from(offset)..];
+    let mut newlines = 0;
+
+    for (index, c) in rest.char_indices() {
+        match c {
+            '\n' => {
+                newlines += 1;
+            }
+            '\r' if rest.as_bytes().get(index + 1).copied() == Some(b'\n') => {
+                continue;
+            }
+            '\r' => {
+                newlines += 1;
+            }
+            c if is_python_whitespace(c) => continue,
+            _ => break,
+        }
+    }
+
+    newlines
+}
+
 #[cfg(test)]
 mod tests {
-    use crate::trivia::lines_before;
+    use crate::trivia::{lines_after, lines_before};
     use ruff_text_size::TextSize;
 
     #[test]
@@ -113,4 +137,37 @@ mod tests {
             1
         );
     }
+
+    #[test]
+    fn lines_after_empty_string() {
+        assert_eq!(lines_after("", TextSize::new(0)), 0);
+    }
+
+    #[test]
+    fn lines_after_in_the_middle_of_a_line() {
+        assert_eq!(lines_after("a = 20", TextSize::new(4)), 0);
+    }
+
+    #[test]
+    fn lines_after_before_a_new_line() {
+        assert_eq!(lines_after("a = 20\nb = 10", TextSize::new(6)), 1);
+    }
+
+    #[test]
+    fn lines_after_multiple_newlines() {
+        assert_eq!(lines_after("a = 20\n\r\nb = 10", TextSize::new(6)), 2);
+    }
+
+    #[test]
+    fn lines_after_before_comment_offset() {
+        assert_eq!(lines_after("a = 20 # a comment\n", TextSize::new(7)), 0);
+    }
+
+    #[test]
+    fn lines_after_with_comment_only_line() {
+        assert_eq!(
+            lines_after("a = 20\n# some comment\nb = 10", TextSize::new(6)),
+            1
+        );
+    }
 }