mirror of
https://github.com/astral-sh/ruff.git
synced 2025-07-23 04:55:21 +00:00
bc63cc9b3c
## Summary This fixes two problems discovered when trying to format the cpython repo with `cargo run --bin ruff_dev -- check-formatter-stability projects/cpython`: The first is to ignore try/except trailing comments for now since they lead to unstable formatting on the dummy. The second is to avoid dropping trailing if comments through placement: This changes the placement to keep a comment trailing an if-elif or if-elif-else to keep the comment a trailing comment on the entire if. Previously the last comment would have been lost. ```python if "first if": pass elif "first elif": pass ``` The last remaining problem in cpython so far is function signature argument separator comment placement which is its own PR on top of this. ## Test Plan I added test fixtures of minimized examples with links back to the original cpython location
1243 lines
43 KiB
Rust
1243 lines
43 KiB
Rust
use crate::comments::visitor::{CommentPlacement, DecoratedComment};
|
|
use crate::comments::CommentLinePosition;
|
|
use crate::expression::expr_slice::{assign_comment_in_slice, ExprSliceCommentSection};
|
|
use crate::trivia::{first_non_trivia_token_rev, SimpleTokenizer, Token, TokenKind};
|
|
use ruff_python_ast::node::{AnyNodeRef, AstNode};
|
|
use ruff_python_ast::source_code::Locator;
|
|
use ruff_python_ast::whitespace;
|
|
use ruff_python_whitespace::{PythonWhitespace, UniversalNewlines};
|
|
use ruff_text_size::{TextRange, TextSize};
|
|
use rustpython_parser::ast::{Expr, ExprSlice, Ranged};
|
|
use std::cmp::Ordering;
|
|
|
|
/// Implements the custom comment placement logic.
|
|
pub(super) fn place_comment<'a>(
|
|
mut comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
static HANDLERS: &[for<'a> fn(DecoratedComment<'a>, &Locator) -> CommentPlacement<'a>] = &[
|
|
handle_in_between_except_handlers_or_except_handler_and_else_or_finally_comment,
|
|
handle_match_comment,
|
|
handle_in_between_bodies_own_line_comment,
|
|
handle_in_between_bodies_end_of_line_comment,
|
|
handle_trailing_body_comment,
|
|
handle_trailing_end_of_line_body_comment,
|
|
handle_trailing_end_of_line_condition_comment,
|
|
handle_module_level_own_line_comment_before_class_or_function_comment,
|
|
handle_positional_only_arguments_separator_comment,
|
|
handle_trailing_binary_expression_left_or_operator_comment,
|
|
handle_leading_function_with_decorators_comment,
|
|
handle_dict_unpacking_comment,
|
|
handle_slice_comments,
|
|
];
|
|
for handler in HANDLERS {
|
|
comment = match handler(comment, locator) {
|
|
CommentPlacement::Default(comment) => comment,
|
|
placement => return placement,
|
|
};
|
|
}
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
|
|
/// Handles leading comments in front of a match case or a trailing comment of the `match` statement.
|
|
/// ```python
|
|
/// match pt:
|
|
/// # Leading `case(x, y)` comment
|
|
/// case (x, y):
|
|
/// return Point3d(x, y, 0)
|
|
/// # Leading `case (x, y, z)` comment
|
|
/// case _:
|
|
/// ```
|
|
fn handle_match_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
// Must be an own line comment after the last statement in a match case
|
|
if comment.line_position().is_end_of_line() || comment.following_node().is_some() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// Get the enclosing match case
|
|
let Some(match_case) = comment.enclosing_node().match_case() else {
|
|
return CommentPlacement::Default(comment)
|
|
};
|
|
|
|
// And its parent match statement.
|
|
let Some(match_stmt) = comment
|
|
.enclosing_parent()
|
|
.and_then(AnyNodeRef::stmt_match) else {
|
|
return CommentPlacement::Default(comment)
|
|
};
|
|
|
|
// Get the next sibling (sibling traversal would be really nice)
|
|
let current_case_index = match_stmt
|
|
.cases
|
|
.iter()
|
|
.position(|case| case == match_case)
|
|
.expect("Expected case to belong to parent match statement.");
|
|
|
|
let next_case = match_stmt.cases.get(current_case_index + 1);
|
|
|
|
let comment_indentation =
|
|
whitespace::indentation_at_offset(locator, comment.slice().range().start())
|
|
.map(str::len)
|
|
.unwrap_or_default();
|
|
let match_case_indentation = whitespace::indentation(locator, match_case).unwrap().len();
|
|
|
|
if let Some(next_case) = next_case {
|
|
// The comment's indentation is less or equal to the `case` indention and there's a following
|
|
// `case` arm.
|
|
// ```python
|
|
// match pt:
|
|
// case (x, y):
|
|
// return Point3d(x, y, 0)
|
|
// # Leading `case (x, y, z)` comment
|
|
// case _:
|
|
// pass
|
|
// ```
|
|
// Attach the `comment` as leading comment to the next case.
|
|
if comment_indentation <= match_case_indentation {
|
|
CommentPlacement::leading(next_case.into(), comment)
|
|
} else {
|
|
// Otherwise, delegate to `handle_trailing_body_comment`
|
|
// ```python
|
|
// match pt:
|
|
// case (x, y):
|
|
// return Point3d(x, y, 0)
|
|
// # Trailing case body comment
|
|
// case _:
|
|
// pass
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
} else {
|
|
// Comment after the last statement in a match case...
|
|
let match_stmt_indentation =
|
|
whitespace::indentation(locator, match_stmt).map_or(usize::MAX, str::len);
|
|
|
|
if comment_indentation <= match_case_indentation
|
|
&& comment_indentation > match_stmt_indentation
|
|
{
|
|
// The comment's indent matches the `case` indent (or is larger than the `match`'s indent).
|
|
// ```python
|
|
// match pt:
|
|
// case (x, y):
|
|
// return Point3d(x, y, 0)
|
|
// case _:
|
|
// pass
|
|
// # Trailing match comment
|
|
// ```
|
|
// This is a trailing comment of the last case.
|
|
CommentPlacement::trailing(match_case.into(), comment)
|
|
} else {
|
|
// Delegate to `handle_trailing_body_comment` because it's either a trailing indent
|
|
// for the last statement in the `case` body or a comment for the parent of the `match`
|
|
//
|
|
// ```python
|
|
// match pt:
|
|
// case (x, y):
|
|
// return Point3d(x, y, 0)
|
|
// case _:
|
|
// pass
|
|
// # trailing case comment
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Handles comments between except handlers and between the last except handler and any following `else` or `finally` block.
|
|
fn handle_in_between_except_handlers_or_except_handler_and_else_or_finally_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
if comment.line_position().is_end_of_line() || comment.following_node().is_none() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
if let Some(AnyNodeRef::ExceptHandlerExceptHandler(except_handler)) = comment.preceding_node() {
|
|
// it now depends on the indentation level of the comment if it is a leading comment for e.g.
|
|
// the following `elif` or indeed a trailing comment of the previous body's last statement.
|
|
let comment_indentation =
|
|
whitespace::indentation_at_offset(locator, comment.slice().range().start())
|
|
.map(str::len)
|
|
.unwrap_or_default();
|
|
|
|
if let Some(except_indentation) =
|
|
whitespace::indentation(locator, except_handler).map(str::len)
|
|
{
|
|
return if comment_indentation <= except_indentation {
|
|
// It has equal, or less indent than the `except` handler. It must be a comment
|
|
// of the following `finally` or `else` block
|
|
//
|
|
// ```python
|
|
// try:
|
|
// pass
|
|
// except Exception:
|
|
// print("noop")
|
|
// # leading
|
|
// finally:
|
|
// pass
|
|
// ```
|
|
// Attach it to the `try` statement.
|
|
CommentPlacement::dangling(comment.enclosing_node(), comment)
|
|
} else {
|
|
// Delegate to `handle_trailing_body_comment`
|
|
CommentPlacement::Default(comment)
|
|
};
|
|
}
|
|
}
|
|
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
|
|
/// Handles own line comments between the last statement and the first statement of two bodies.
|
|
///
|
|
/// ```python
|
|
/// if x == y:
|
|
/// pass
|
|
/// # This should be a trailing comment of `pass` and not a leading comment of the `print`
|
|
/// # in the `else` branch
|
|
/// else:
|
|
/// print("I have no comments")
|
|
/// ```
|
|
fn handle_in_between_bodies_own_line_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
if !comment.line_position().is_own_line() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// The comment must be between two statements...
|
|
if let (Some(preceding), Some(following)) = (comment.preceding_node(), comment.following_node())
|
|
{
|
|
// ...and the following statement must be the first statement in an alternate body of the parent...
|
|
if !is_first_statement_in_enclosing_alternate_body(following, comment.enclosing_node()) {
|
|
// ```python
|
|
// if test:
|
|
// a
|
|
// # comment
|
|
// b
|
|
// ```
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// If there's any non-trivia token between the preceding node and the comment, than it means that
|
|
// we're past the case of the alternate branch, defer to the default rules
|
|
// ```python
|
|
// if a:
|
|
// pass
|
|
// else:
|
|
// # leading comment
|
|
// def inline_after_else(): ...
|
|
// ```
|
|
if SimpleTokenizer::new(
|
|
locator.contents(),
|
|
TextRange::new(preceding.end(), comment.slice().start()),
|
|
)
|
|
.skip_trivia()
|
|
.next()
|
|
.is_some()
|
|
{
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// it now depends on the indentation level of the comment if it is a leading comment for e.g.
|
|
// the following `elif` or indeed a trailing comment of the previous body's last statement.
|
|
let comment_indentation =
|
|
whitespace::indentation_at_offset(locator, comment.slice().range().start())
|
|
.map(str::len)
|
|
.unwrap_or_default();
|
|
|
|
if let Some(preceding_indentation) =
|
|
whitespace::indentation(locator, &preceding).map(str::len)
|
|
{
|
|
return if comment_indentation >= preceding_indentation {
|
|
// `# comment` has the same or a larger indent than the `pass` statement.
|
|
// It likely is a trailing comment of the `pass` statement.
|
|
// ```python
|
|
// if x == y:
|
|
// pass
|
|
// # comment
|
|
// else:
|
|
// print("noop")
|
|
// ```
|
|
CommentPlacement::trailing(preceding, comment)
|
|
} else {
|
|
// Otherwise it has less indent than the previous statement. Meaning that it is a leading comment
|
|
// of the following block.
|
|
//
|
|
// ```python
|
|
// if x == y:
|
|
// pass
|
|
// # I'm a leading comment of the `elif` statement.
|
|
// elif:
|
|
// print("nooop")
|
|
// ```
|
|
if following.is_stmt_if() || following.is_except_handler() {
|
|
// The `elif` or except handlers have their own body to which we can attach the leading comment
|
|
CommentPlacement::leading(following, comment)
|
|
} else {
|
|
// There are no bodies for the "else" branch and other bodies that are represented as a `Vec<Stmt>`.
|
|
// This means, there's no good place to attach the comments to.
|
|
// That's why we make these dangling comments and format them manually
|
|
// in the enclosing node's formatting logic. For `try`, it's the formatters responsibility
|
|
// to correctly identify the comments for the `finally` and `orelse` block by looking
|
|
// at the comment's range.
|
|
//
|
|
// ```python
|
|
// if x == y:
|
|
// pass
|
|
// # I'm a leading comment of the `else` branch but there's no `else` node.
|
|
// else:
|
|
// print("nooop")
|
|
// ```
|
|
CommentPlacement::dangling(comment.enclosing_node(), comment)
|
|
}
|
|
};
|
|
}
|
|
}
|
|
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
|
|
/// Handles end of line comments comments between the last statement and the first statement of two bodies.
|
|
///
|
|
/// ```python
|
|
/// if x == y:
|
|
/// pass # trailing comment of pass
|
|
/// else: # trailing comment of `else`
|
|
/// print("I have no comments")
|
|
/// ```
|
|
fn handle_in_between_bodies_end_of_line_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
if !comment.line_position().is_end_of_line() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// The comment must be between two statements...
|
|
if let (Some(preceding), Some(following)) = (comment.preceding_node(), comment.following_node())
|
|
{
|
|
// ...and the following statement must be the first statement in an alternate body of the parent...
|
|
if !is_first_statement_in_enclosing_alternate_body(following, comment.enclosing_node()) {
|
|
// ```python
|
|
// if test:
|
|
// a
|
|
// # comment
|
|
// b
|
|
// ```
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
if !locator.contains_line_break(TextRange::new(preceding.end(), comment.slice().start())) {
|
|
// Trailing comment of the preceding statement
|
|
// ```python
|
|
// while test:
|
|
// a # comment
|
|
// else:
|
|
// b
|
|
// ```
|
|
if preceding.is_node_with_body() {
|
|
// We can't set this as a trailing comment of the function declaration because it
|
|
// will then move behind the function block instead of sticking with the pass
|
|
// ```python
|
|
// if True:
|
|
// def f():
|
|
// pass # a
|
|
// else:
|
|
// pass
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
} else {
|
|
CommentPlacement::trailing(preceding, comment)
|
|
}
|
|
} else if following.is_stmt_if() || following.is_except_handler() {
|
|
// The `elif` or except handlers have their own body to which we can attach the trailing comment
|
|
// ```python
|
|
// if test:
|
|
// a
|
|
// elif c: # comment
|
|
// b
|
|
// ```
|
|
CommentPlacement::trailing(following, comment)
|
|
} else {
|
|
// There are no bodies for the "else" branch and other bodies that are represented as a `Vec<Stmt>`.
|
|
// This means, there's no good place to attach the comments to.
|
|
// Make this a dangling comments and manually format the comment in
|
|
// in the enclosing node's formatting logic. For `try`, it's the formatters responsibility
|
|
// to correctly identify the comments for the `finally` and `orelse` block by looking
|
|
// at the comment's range.
|
|
//
|
|
// ```python
|
|
// while x == y:
|
|
// pass
|
|
// else: # trailing
|
|
// print("nooop")
|
|
// ```
|
|
CommentPlacement::dangling(comment.enclosing_node(), comment)
|
|
}
|
|
} else {
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
}
|
|
|
|
/// Handles trailing comments at the end of a body block (or any other block that is indented).
|
|
/// ```python
|
|
/// def test():
|
|
/// pass
|
|
/// # This is a trailing comment that belongs to the function `test`
|
|
/// # and not to the next statement.
|
|
///
|
|
/// print("I have no comments")
|
|
/// ```
|
|
fn handle_trailing_body_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
if comment.line_position().is_end_of_line() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// Only do something if the preceding node has a body (has indented statements).
|
|
let Some(preceding_node) = comment.preceding_node() else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
let Some(last_child) = last_child_in_body(preceding_node) else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
let Some(comment_indentation) = whitespace::indentation_at_offset(locator, comment.slice().range().start()) else {
|
|
// The comment can't be a comment for the previous block if it isn't indented..
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
// We only care about the length because indentations with mixed spaces and tabs are only valid if
|
|
// the indent-level doesn't depend on the tab width (the indent level must be the same if the tab width is 1 or 8).
|
|
let comment_indentation_len = comment_indentation.len();
|
|
|
|
// Keep the comment on the entire statement in case it's a trailing comment
|
|
// ```python
|
|
// if "first if":
|
|
// pass
|
|
// elif "first elif":
|
|
// pass
|
|
// # Trailing if comment
|
|
// ```
|
|
// Here we keep the comment a trailing comment of the `if`
|
|
let Some(preceding_node_indentation) = whitespace::indentation_at_offset(locator, preceding_node.start()) else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
if comment_indentation_len == preceding_node_indentation.len() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
let mut current_child = last_child;
|
|
let mut parent_body = Some(preceding_node);
|
|
let mut grand_parent_body = None;
|
|
|
|
loop {
|
|
let child_indentation =
|
|
whitespace::indentation(locator, ¤t_child).map_or(usize::MAX, str::len);
|
|
|
|
match comment_indentation_len.cmp(&child_indentation) {
|
|
Ordering::Less => {
|
|
break if let Some(parent_block) = grand_parent_body {
|
|
// Comment belongs to the parent block.
|
|
// ```python
|
|
// if test:
|
|
// if other:
|
|
// pass
|
|
// # comment
|
|
// ```
|
|
CommentPlacement::trailing(parent_block, comment)
|
|
} else {
|
|
// The comment does not belong to this block.
|
|
// ```python
|
|
// if test:
|
|
// pass
|
|
// # comment
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
};
|
|
}
|
|
Ordering::Equal => {
|
|
// The comment belongs to this block.
|
|
// ```python
|
|
// if test:
|
|
// pass
|
|
// # comment
|
|
// ```
|
|
break CommentPlacement::trailing(current_child, comment);
|
|
}
|
|
Ordering::Greater => {
|
|
if let Some(nested_child) = last_child_in_body(current_child) {
|
|
// The comment belongs to the inner block.
|
|
// ```python
|
|
// def a():
|
|
// if test:
|
|
// pass
|
|
// # comment
|
|
// ```
|
|
// Comment belongs to the `if`'s inner body
|
|
grand_parent_body = parent_body;
|
|
parent_body = Some(current_child);
|
|
current_child = nested_child;
|
|
} else {
|
|
// The comment belongs to this block.
|
|
// ```python
|
|
// if test:
|
|
// pass
|
|
// # comment
|
|
// ```
|
|
break CommentPlacement::trailing(current_child, comment);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Handles end of line comments of the last statement in an indented body:
|
|
///
|
|
/// ```python
|
|
/// while True:
|
|
/// if something.changed:
|
|
/// do.stuff() # trailing comment
|
|
/// ```
|
|
fn handle_trailing_end_of_line_body_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
_locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
// Must be an end of line comment
|
|
if comment.line_position().is_own_line() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// Must be *after* a statement
|
|
let Some(preceding) = comment.preceding_node() else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
// Recursively get the last child of statements with a body.
|
|
let last_children = std::iter::successors(last_child_in_body(preceding), |parent| {
|
|
last_child_in_body(*parent)
|
|
});
|
|
|
|
if let Some(last_child) = last_children.last() {
|
|
CommentPlacement::trailing(last_child, comment)
|
|
} else {
|
|
// End of line comment of a statement that has no body. This is not what we're looking for.
|
|
// ```python
|
|
// a # trailing comment
|
|
// b
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
}
|
|
|
|
/// Handles end of line comments after the `:` of a condition
|
|
///
|
|
/// ```python
|
|
/// while True: # comment
|
|
/// pass
|
|
/// ```
|
|
///
|
|
/// It attaches the comment as dangling comment to the enclosing `while` statement.
|
|
fn handle_trailing_end_of_line_condition_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
use ruff_python_ast::prelude::*;
|
|
|
|
// Must be an end of line comment
|
|
if comment.line_position().is_own_line() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// Must be between the condition expression and the first body element
|
|
let (Some(preceding), Some(following)) = (comment.preceding_node(), comment.following_node()) else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
let expression_before_colon = match comment.enclosing_node() {
|
|
AnyNodeRef::StmtIf(StmtIf { test: expr, .. })
|
|
| AnyNodeRef::StmtWhile(StmtWhile { test: expr, .. })
|
|
| AnyNodeRef::StmtFor(StmtFor { iter: expr, .. })
|
|
| AnyNodeRef::StmtAsyncFor(StmtAsyncFor { iter: expr, .. }) => {
|
|
Some(AnyNodeRef::from(expr.as_ref()))
|
|
}
|
|
|
|
AnyNodeRef::StmtWith(StmtWith { items, .. })
|
|
| AnyNodeRef::StmtAsyncWith(StmtAsyncWith { items, .. }) => {
|
|
items.last().map(AnyNodeRef::from)
|
|
}
|
|
AnyNodeRef::StmtFunctionDef(StmtFunctionDef { returns, args, .. })
|
|
| AnyNodeRef::StmtAsyncFunctionDef(StmtAsyncFunctionDef { returns, args, .. }) => returns
|
|
.as_deref()
|
|
.map(AnyNodeRef::from)
|
|
.or_else(|| Some(AnyNodeRef::from(args.as_ref()))),
|
|
_ => None,
|
|
};
|
|
|
|
let Some(last_before_colon) = expression_before_colon else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
// If the preceding is the node before the `colon`
|
|
// `while true:` The node before the `colon` is the `true` constant.
|
|
if preceding.ptr_eq(last_before_colon) {
|
|
let tokens = SimpleTokenizer::new(
|
|
locator.contents(),
|
|
TextRange::new(preceding.end(), following.start()),
|
|
)
|
|
.skip_trivia();
|
|
|
|
for token in tokens {
|
|
match token.kind() {
|
|
TokenKind::Colon => {
|
|
if comment.slice().start() > token.start() {
|
|
// Comment comes after the colon
|
|
// ```python
|
|
// while a: # comment
|
|
// ...
|
|
// ```
|
|
return CommentPlacement::dangling(comment.enclosing_node(), comment);
|
|
}
|
|
|
|
// Comment comes before the colon
|
|
// ```python
|
|
// while (
|
|
// a # comment
|
|
// ):
|
|
// ...
|
|
// ```
|
|
break;
|
|
}
|
|
TokenKind::RParen => {
|
|
// Skip over any closing parentheses
|
|
}
|
|
_ => {
|
|
unreachable!("Only ')' or ':' should follow the condition")
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
|
|
/// Attaches comments for the positional-only arguments separator `/` as trailing comments to the
|
|
/// enclosing [`Arguments`] node.
|
|
///
|
|
/// ```python
|
|
/// def test(
|
|
/// a,
|
|
/// # Positional arguments only after here
|
|
/// /, # trailing positional argument comment.
|
|
/// b,
|
|
/// ): pass
|
|
/// ```
|
|
fn handle_positional_only_arguments_separator_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
let AnyNodeRef::Arguments(arguments) = comment.enclosing_node() else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
// Using the `/` without any leading arguments is a syntax error.
|
|
let Some(last_argument_or_default) = comment.preceding_node() else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
let is_last_positional_argument =
|
|
are_same_optional(last_argument_or_default, arguments.posonlyargs.last());
|
|
|
|
if !is_last_positional_argument {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
let trivia_end = comment
|
|
.following_node()
|
|
.map_or(arguments.end(), |following| following.start());
|
|
let trivia_range = TextRange::new(last_argument_or_default.end(), trivia_end);
|
|
|
|
if let Some(slash_offset) = find_pos_only_slash_offset(trivia_range, locator) {
|
|
let comment_start = comment.slice().range().start();
|
|
let is_slash_comment = match comment.line_position() {
|
|
CommentLinePosition::EndOfLine => {
|
|
let preceding_end_line = locator.line_end(last_argument_or_default.end());
|
|
let slash_comments_start = preceding_end_line.min(slash_offset);
|
|
|
|
comment_start >= slash_comments_start
|
|
&& locator.line_end(slash_offset) > comment_start
|
|
}
|
|
CommentLinePosition::OwnLine => comment_start < slash_offset,
|
|
};
|
|
|
|
if is_slash_comment {
|
|
CommentPlacement::dangling(comment.enclosing_node(), comment)
|
|
} else {
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
} else {
|
|
// Should not happen, but let's go with it
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
}
|
|
|
|
/// Handles comments between the left side and the operator of a binary expression (trailing comments of the left),
|
|
/// and trailing end-of-line comments that are on the same line as the operator.
|
|
///
|
|
/// ```python
|
|
/// a = (
|
|
/// 5 # trailing left comment
|
|
/// + # trailing operator comment
|
|
/// # leading right comment
|
|
/// 3
|
|
/// )
|
|
/// ```
|
|
fn handle_trailing_binary_expression_left_or_operator_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
let Some(binary_expression) = comment.enclosing_node().expr_bin_op() else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
// Only if there's a preceding node (in which case, the preceding node is `left`).
|
|
if comment.preceding_node().is_none() || comment.following_node().is_none() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
let between_operands_range = TextRange::new(
|
|
binary_expression.left.end(),
|
|
binary_expression.right.start(),
|
|
);
|
|
|
|
let mut tokens = SimpleTokenizer::new(locator.contents(), between_operands_range).skip_trivia();
|
|
let operator_offset = if let Some(non_r_paren) = tokens.find(|t| t.kind() != TokenKind::RParen)
|
|
{
|
|
non_r_paren.start()
|
|
} else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
let comment_range = comment.slice().range();
|
|
|
|
if comment_range.end() < operator_offset {
|
|
// ```python
|
|
// a = (
|
|
// 5
|
|
// # comment
|
|
// +
|
|
// 3
|
|
// )
|
|
// ```
|
|
CommentPlacement::trailing(AnyNodeRef::from(binary_expression.left.as_ref()), comment)
|
|
} else if comment.line_position().is_end_of_line() {
|
|
// Is the operator on its own line.
|
|
if locator.contains_line_break(TextRange::new(
|
|
binary_expression.left.end(),
|
|
operator_offset,
|
|
)) && locator.contains_line_break(TextRange::new(
|
|
operator_offset,
|
|
binary_expression.right.start(),
|
|
)) {
|
|
// ```python
|
|
// a = (
|
|
// 5
|
|
// + # comment
|
|
// 3
|
|
// )
|
|
// ```
|
|
CommentPlacement::dangling(binary_expression.into(), comment)
|
|
} else {
|
|
// ```python
|
|
// a = (
|
|
// 5
|
|
// +
|
|
// 3 # comment
|
|
// )
|
|
// ```
|
|
// OR
|
|
// ```python
|
|
// a = (
|
|
// 5 # comment
|
|
// +
|
|
// 3
|
|
// )
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
} else {
|
|
// ```python
|
|
// a = (
|
|
// 5
|
|
// +
|
|
// # comment
|
|
// 3
|
|
// )
|
|
// ```
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
}
|
|
|
|
/// Handles own line comments on the module level before a class or function statement.
|
|
/// A comment only becomes the leading comment of a class or function if it isn't separated by an empty
|
|
/// line from the class. Comments that are separated by at least one empty line from the header of the
|
|
/// class are considered trailing comments of the previous statement.
|
|
///
|
|
/// This handling is necessary because Ruff inserts two empty lines before each class or function.
|
|
/// Let's take this example:
|
|
///
|
|
/// ```python
|
|
/// some = statement
|
|
/// # This should be stick to the statement above
|
|
///
|
|
///
|
|
/// # This should be split from the above by two lines
|
|
/// class MyClassWithComplexLeadingComments:
|
|
/// pass
|
|
/// ```
|
|
///
|
|
/// By default, the `# This should be stick to the statement above` would become a leading comment
|
|
/// of the `class` AND the `Suite` formatting separates the comment by two empty lines from the
|
|
/// previous statement, so that the result becomes:
|
|
///
|
|
/// ```python
|
|
/// some = statement
|
|
///
|
|
///
|
|
/// # This should be stick to the statement above
|
|
///
|
|
///
|
|
/// # This should be split from the above by two lines
|
|
/// class MyClassWithComplexLeadingComments:
|
|
/// pass
|
|
/// ```
|
|
///
|
|
/// Which is not what we want. The work around is to make the `# This should be stick to the statement above`
|
|
/// a trailing comment of the previous statement.
|
|
fn handle_module_level_own_line_comment_before_class_or_function_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
// Only applies for own line comments on the module level...
|
|
if !comment.line_position().is_own_line() || !comment.enclosing_node().is_module() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// ... for comments with a preceding and following node,
|
|
let (Some(preceding), Some(following)) = (comment.preceding_node(), comment.following_node()) else {
|
|
return CommentPlacement::Default(comment)
|
|
};
|
|
|
|
// ... where the following is a function or class statement.
|
|
if !matches!(
|
|
following,
|
|
AnyNodeRef::StmtAsyncFunctionDef(_)
|
|
| AnyNodeRef::StmtFunctionDef(_)
|
|
| AnyNodeRef::StmtClassDef(_)
|
|
) {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
|
|
// Make the comment a leading comment if there's no empty line between the comment and the function / class header
|
|
if max_empty_lines(locator.slice(TextRange::new(comment.slice().end(), following.start()))) == 0
|
|
{
|
|
CommentPlacement::leading(following, comment)
|
|
} else {
|
|
// Otherwise attach the comment as trailing comment to the previous statement
|
|
CommentPlacement::trailing(preceding, comment)
|
|
}
|
|
}
|
|
|
|
/// Handles the attaching comments left or right of the colon in a slice as trailing comment of the
|
|
/// preceding node or leading comment of the following node respectively.
|
|
/// ```python
|
|
/// a = "input"[
|
|
/// 1 # c
|
|
/// # d
|
|
/// :2
|
|
/// ]
|
|
/// ```
|
|
fn handle_slice_comments<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
let expr_slice = match comment.enclosing_node() {
|
|
AnyNodeRef::ExprSlice(expr_slice) => expr_slice,
|
|
AnyNodeRef::ExprSubscript(expr_subscript) => {
|
|
if expr_subscript.value.end() < expr_subscript.slice.start() {
|
|
if let Expr::Slice(expr_slice) = expr_subscript.slice.as_ref() {
|
|
expr_slice
|
|
} else {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
} else {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
}
|
|
_ => return CommentPlacement::Default(comment),
|
|
};
|
|
|
|
let ExprSlice {
|
|
range: _,
|
|
lower,
|
|
upper,
|
|
step,
|
|
} = expr_slice;
|
|
|
|
// Check for `foo[ # comment`, but only if they are on the same line
|
|
let after_lbracket = matches!(
|
|
first_non_trivia_token_rev(comment.slice().start(), locator.contents()),
|
|
Some(Token {
|
|
kind: TokenKind::LBracket,
|
|
..
|
|
})
|
|
);
|
|
if comment.line_position().is_end_of_line() && after_lbracket {
|
|
// Keep comments after the opening bracket there by formatting them outside the
|
|
// soft block indent
|
|
// ```python
|
|
// "a"[ # comment
|
|
// 1:
|
|
// ]
|
|
// ```
|
|
debug_assert!(
|
|
matches!(comment.enclosing_node(), AnyNodeRef::ExprSubscript(_)),
|
|
"{:?}",
|
|
comment.enclosing_node()
|
|
);
|
|
return CommentPlacement::dangling(comment.enclosing_node(), comment);
|
|
}
|
|
|
|
let assignment =
|
|
assign_comment_in_slice(comment.slice().range(), locator.contents(), expr_slice);
|
|
let node = match assignment {
|
|
ExprSliceCommentSection::Lower => lower,
|
|
ExprSliceCommentSection::Upper => upper,
|
|
ExprSliceCommentSection::Step => step,
|
|
};
|
|
|
|
if let Some(node) = node {
|
|
if comment.slice().start() < node.start() {
|
|
CommentPlacement::leading(node.as_ref().into(), comment)
|
|
} else {
|
|
// If a trailing comment is an end of line comment that's fine because we have a node
|
|
// ahead of it
|
|
CommentPlacement::trailing(node.as_ref().into(), comment)
|
|
}
|
|
} else {
|
|
CommentPlacement::dangling(expr_slice.as_any_node_ref(), comment)
|
|
}
|
|
}
|
|
|
|
/// Finds the offset of the `/` that separates the positional only and arguments from the other arguments.
|
|
/// Returns `None` if the positional only separator `/` isn't present in the specified range.
|
|
fn find_pos_only_slash_offset(
|
|
between_arguments_range: TextRange,
|
|
locator: &Locator,
|
|
) -> Option<TextSize> {
|
|
let mut tokens =
|
|
SimpleTokenizer::new(locator.contents(), between_arguments_range).skip_trivia();
|
|
|
|
if let Some(comma) = tokens.next() {
|
|
debug_assert_eq!(comma.kind(), TokenKind::Comma);
|
|
|
|
if let Some(maybe_slash) = tokens.next() {
|
|
if maybe_slash.kind() == TokenKind::Slash {
|
|
return Some(maybe_slash.start());
|
|
}
|
|
|
|
debug_assert_eq!(
|
|
maybe_slash.kind(),
|
|
TokenKind::RParen,
|
|
"{:?}",
|
|
maybe_slash.kind()
|
|
);
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
/// Handles own line comments between the last function decorator and the *header* of the function.
|
|
/// It attaches these comments as dangling comments to the function instead of making them
|
|
/// leading argument comments.
|
|
///
|
|
/// ```python
|
|
/// @decorator
|
|
/// # leading function comment
|
|
/// def test():
|
|
/// ...
|
|
/// ```
|
|
fn handle_leading_function_with_decorators_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
_locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
let is_preceding_decorator = comment
|
|
.preceding_node()
|
|
.map_or(false, |node| node.is_decorator());
|
|
|
|
let is_following_arguments = comment
|
|
.following_node()
|
|
.map_or(false, |node| node.is_arguments());
|
|
|
|
if comment.line_position().is_own_line() && is_preceding_decorator && is_following_arguments {
|
|
CommentPlacement::dangling(comment.enclosing_node(), comment)
|
|
} else {
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
}
|
|
|
|
/// Handles comments between `**` and the variable name in dict unpacking
|
|
/// It attaches these to the appropriate value node
|
|
///
|
|
/// ```python
|
|
/// {
|
|
/// ** # comment between `**` and the variable name
|
|
/// value
|
|
/// ...
|
|
/// }
|
|
/// ```
|
|
fn handle_dict_unpacking_comment<'a>(
|
|
comment: DecoratedComment<'a>,
|
|
locator: &Locator,
|
|
) -> CommentPlacement<'a> {
|
|
match comment.enclosing_node() {
|
|
// TODO: can maybe also add AnyNodeRef::Arguments here, but tricky to test due to
|
|
// https://github.com/astral-sh/ruff/issues/5176
|
|
AnyNodeRef::ExprDict(_) => {}
|
|
_ => {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
};
|
|
|
|
// no node after our comment so we can't be between `**` and the name (node)
|
|
let Some(following) = comment.following_node() else {
|
|
return CommentPlacement::Default(comment);
|
|
};
|
|
|
|
// we look at tokens between the previous node (or the start of the dict)
|
|
// and the comment
|
|
let preceding_end = match comment.preceding_node() {
|
|
Some(preceding) => preceding.end(),
|
|
None => comment.enclosing_node().start(),
|
|
};
|
|
if preceding_end > comment.slice().start() {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
let mut tokens = SimpleTokenizer::new(
|
|
locator.contents(),
|
|
TextRange::new(preceding_end, comment.slice().start()),
|
|
)
|
|
.skip_trivia();
|
|
|
|
// we start from the preceding node but we skip its token
|
|
if let Some(first) = tokens.next() {
|
|
debug_assert!(matches!(
|
|
first,
|
|
Token {
|
|
kind: TokenKind::LBrace | TokenKind::Comma | TokenKind::Colon,
|
|
..
|
|
}
|
|
));
|
|
}
|
|
|
|
// if the remaining tokens from the previous node is exactly `**`,
|
|
// re-assign the comment to the one that follows the stars
|
|
let mut count = 0;
|
|
for token in tokens {
|
|
if token.kind != TokenKind::Star {
|
|
return CommentPlacement::Default(comment);
|
|
}
|
|
count += 1;
|
|
}
|
|
if count == 2 {
|
|
return CommentPlacement::trailing(following, comment);
|
|
}
|
|
|
|
CommentPlacement::Default(comment)
|
|
}
|
|
|
|
/// Returns `true` if `right` is `Some` and `left` and `right` are referentially equal.
|
|
fn are_same_optional<'a, T>(left: AnyNodeRef, right: Option<T>) -> bool
|
|
where
|
|
T: Into<AnyNodeRef<'a>>,
|
|
{
|
|
right.map_or(false, |right| left.ptr_eq(right.into()))
|
|
}
|
|
|
|
fn last_child_in_body(node: AnyNodeRef) -> Option<AnyNodeRef> {
|
|
use ruff_python_ast::prelude::*;
|
|
|
|
let body = match node {
|
|
AnyNodeRef::StmtFunctionDef(StmtFunctionDef { body, .. })
|
|
| AnyNodeRef::StmtAsyncFunctionDef(StmtAsyncFunctionDef { body, .. })
|
|
| AnyNodeRef::StmtClassDef(StmtClassDef { body, .. })
|
|
| AnyNodeRef::StmtWith(StmtWith { body, .. })
|
|
| AnyNodeRef::StmtAsyncWith(StmtAsyncWith { body, .. })
|
|
| AnyNodeRef::MatchCase(MatchCase { body, .. })
|
|
| AnyNodeRef::ExceptHandlerExceptHandler(ExceptHandlerExceptHandler { body, .. }) => body,
|
|
|
|
AnyNodeRef::StmtIf(StmtIf { body, orelse, .. })
|
|
| AnyNodeRef::StmtFor(StmtFor { body, orelse, .. })
|
|
| AnyNodeRef::StmtAsyncFor(StmtAsyncFor { body, orelse, .. })
|
|
| AnyNodeRef::StmtWhile(StmtWhile { body, orelse, .. }) => {
|
|
if orelse.is_empty() {
|
|
body
|
|
} else {
|
|
orelse
|
|
}
|
|
}
|
|
|
|
AnyNodeRef::StmtMatch(StmtMatch { cases, .. }) => {
|
|
return cases.last().map(AnyNodeRef::from)
|
|
}
|
|
|
|
AnyNodeRef::StmtTry(StmtTry {
|
|
body,
|
|
handlers,
|
|
orelse,
|
|
finalbody,
|
|
..
|
|
})
|
|
| AnyNodeRef::StmtTryStar(StmtTryStar {
|
|
body,
|
|
handlers,
|
|
orelse,
|
|
finalbody,
|
|
..
|
|
}) => {
|
|
if finalbody.is_empty() {
|
|
if orelse.is_empty() {
|
|
if handlers.is_empty() {
|
|
body
|
|
} else {
|
|
return handlers.last().map(AnyNodeRef::from);
|
|
}
|
|
} else {
|
|
orelse
|
|
}
|
|
} else {
|
|
finalbody
|
|
}
|
|
}
|
|
|
|
// Not a node that contains an indented child node.
|
|
_ => return None,
|
|
};
|
|
|
|
body.last().map(AnyNodeRef::from)
|
|
}
|
|
|
|
/// Returns `true` if `following` is the first statement in an alternate `body` (e.g. the else of an if statement) of the `enclosing` node.
|
|
fn is_first_statement_in_enclosing_alternate_body(
|
|
following: AnyNodeRef,
|
|
enclosing: AnyNodeRef,
|
|
) -> bool {
|
|
use ruff_python_ast::prelude::*;
|
|
|
|
match enclosing {
|
|
AnyNodeRef::StmtIf(StmtIf { orelse, .. })
|
|
| AnyNodeRef::StmtFor(StmtFor { orelse, .. })
|
|
| AnyNodeRef::StmtAsyncFor(StmtAsyncFor { orelse, .. })
|
|
| AnyNodeRef::StmtWhile(StmtWhile { orelse, .. }) => {
|
|
are_same_optional(following, orelse.first())
|
|
}
|
|
|
|
AnyNodeRef::StmtTry(StmtTry {
|
|
handlers,
|
|
orelse,
|
|
finalbody,
|
|
..
|
|
})
|
|
| AnyNodeRef::StmtTryStar(StmtTryStar {
|
|
handlers,
|
|
orelse,
|
|
finalbody,
|
|
..
|
|
}) => {
|
|
are_same_optional(following, handlers.first())
|
|
// Comments between the handlers and the `else`, or comments between the `handlers` and the `finally`
|
|
// are already handled by `handle_in_between_except_handlers_or_except_handler_and_else_or_finally_comment`
|
|
|| handlers.is_empty() && are_same_optional(following, orelse.first())
|
|
|| (handlers.is_empty() || !orelse.is_empty())
|
|
&& are_same_optional(following, finalbody.first())
|
|
}
|
|
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
/// Counts the number of newlines in `contents`.
|
|
fn max_empty_lines(contents: &str) -> usize {
|
|
let mut empty_lines = 0;
|
|
let mut max_empty_lines = 0;
|
|
|
|
for line in contents.universal_newlines().skip(1) {
|
|
if line.trim_whitespace().is_empty() {
|
|
empty_lines += 1;
|
|
} else {
|
|
max_empty_lines = max_empty_lines.max(empty_lines);
|
|
empty_lines = 0;
|
|
}
|
|
}
|
|
|
|
max_empty_lines
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use crate::comments::placement::max_empty_lines;
|
|
|
|
#[test]
|
|
fn count_empty_lines_in_trivia() {
|
|
assert_eq!(max_empty_lines(""), 0);
|
|
assert_eq!(max_empty_lines("# trailing comment\n # other comment\n"), 0);
|
|
assert_eq!(
|
|
max_empty_lines("# trailing comment\n# own line comment\n"),
|
|
0
|
|
);
|
|
assert_eq!(
|
|
max_empty_lines("# trailing comment\n\n# own line comment\n"),
|
|
1
|
|
);
|
|
|
|
assert_eq!(
|
|
max_empty_lines(
|
|
"# trailing comment\n\n# own line comment\n\n# an other own line comment"
|
|
),
|
|
1
|
|
);
|
|
|
|
assert_eq!(
|
|
max_empty_lines(
|
|
"# trailing comment\n\n# own line comment\n\n# an other own line comment\n# block"
|
|
),
|
|
1
|
|
);
|
|
|
|
assert_eq!(
|
|
max_empty_lines(
|
|
"# trailing comment\n\n# own line comment\n\n\n# an other own line comment\n# block"
|
|
),
|
|
2
|
|
);
|
|
|
|
assert_eq!(
|
|
max_empty_lines(
|
|
r#"# This multiline comments section
|
|
# should be split from the statement
|
|
# above by two lines.
|
|
"#
|
|
),
|
|
0
|
|
);
|
|
}
|
|
}
|