1 // Formatting and tools for comments.
3 use std::{self, borrow::Cow, iter};
5 use itertools::{multipeek, MultiPeek};
8 use crate::config::Config;
9 use crate::rewrite::RewriteContext;
10 use crate::shape::{Indent, Shape};
11 use crate::string::{rewrite_string, StringFormat};
13 count_newlines, first_line_width, last_line_width, trim_left_preserve_layout,
14 trimmed_last_line_width, unicode_str_width,
16 use crate::{ErrorKind, FormattingError};
18 fn is_custom_comment(comment: &str) -> bool {
19 if !comment.starts_with("//") {
21 } else if let Some(c) = comment.chars().nth(2) {
22 !c.is_alphanumeric() && !c.is_whitespace()
28 #[derive(Copy, Clone, PartialEq, Eq)]
29 pub(crate) enum CommentStyle<'a> {
39 fn custom_opener(s: &str) -> &str {
40 s.lines().next().map_or("", |first_line| {
43 .map_or(first_line, |space_index| &first_line[0..=space_index])
47 impl<'a> CommentStyle<'a> {
48 /// Returns `true` if the commenting style covers a line only.
49 pub(crate) fn is_line_comment(&self) -> bool {
51 CommentStyle::DoubleSlash
52 | CommentStyle::TripleSlash
54 | CommentStyle::Custom(_) => true,
59 /// Returns `true` if the commenting style can span over multiple lines.
60 pub(crate) fn is_block_comment(&self) -> bool {
62 CommentStyle::SingleBullet | CommentStyle::DoubleBullet | CommentStyle::Exclamation => {
69 /// Returns `true` if the commenting style is for documentation.
70 pub(crate) fn is_doc_comment(&self) -> bool {
71 matches!(*self, CommentStyle::TripleSlash | CommentStyle::Doc)
74 pub(crate) fn opener(&self) -> &'a str {
76 CommentStyle::DoubleSlash => "// ",
77 CommentStyle::TripleSlash => "/// ",
78 CommentStyle::Doc => "//! ",
79 CommentStyle::SingleBullet => "/* ",
80 CommentStyle::DoubleBullet => "/** ",
81 CommentStyle::Exclamation => "/*! ",
82 CommentStyle::Custom(opener) => opener,
86 pub(crate) fn closer(&self) -> &'a str {
88 CommentStyle::DoubleSlash
89 | CommentStyle::TripleSlash
90 | CommentStyle::Custom(..)
91 | CommentStyle::Doc => "",
92 CommentStyle::SingleBullet | CommentStyle::DoubleBullet | CommentStyle::Exclamation => {
98 pub(crate) fn line_start(&self) -> &'a str {
100 CommentStyle::DoubleSlash => "// ",
101 CommentStyle::TripleSlash => "/// ",
102 CommentStyle::Doc => "//! ",
103 CommentStyle::SingleBullet | CommentStyle::DoubleBullet | CommentStyle::Exclamation => {
106 CommentStyle::Custom(opener) => opener,
110 pub(crate) fn to_str_tuplet(&self) -> (&'a str, &'a str, &'a str) {
111 (self.opener(), self.closer(), self.line_start())
115 pub(crate) fn comment_style(orig: &str, normalize_comments: bool) -> CommentStyle<'_> {
116 if !normalize_comments {
117 if orig.starts_with("/**") && !orig.starts_with("/**/") {
118 CommentStyle::DoubleBullet
119 } else if orig.starts_with("/*!") {
120 CommentStyle::Exclamation
121 } else if orig.starts_with("/*") {
122 CommentStyle::SingleBullet
123 } else if orig.starts_with("///") && orig.chars().nth(3).map_or(true, |c| c != '/') {
124 CommentStyle::TripleSlash
125 } else if orig.starts_with("//!") {
127 } else if is_custom_comment(orig) {
128 CommentStyle::Custom(custom_opener(orig))
130 CommentStyle::DoubleSlash
132 } else if (orig.starts_with("///") && orig.chars().nth(3).map_or(true, |c| c != '/'))
133 || (orig.starts_with("/**") && !orig.starts_with("/**/"))
135 CommentStyle::TripleSlash
136 } else if orig.starts_with("//!") || orig.starts_with("/*!") {
138 } else if is_custom_comment(orig) {
139 CommentStyle::Custom(custom_opener(orig))
141 CommentStyle::DoubleSlash
145 /// Returns true if the last line of the passed string finishes with a block-comment.
146 pub(crate) fn is_last_comment_block(s: &str) -> bool {
147 s.trim_end().ends_with("*/")
150 /// Combine `prev_str` and `next_str` into a single `String`. `span` may contain
151 /// comments between two strings. If there are such comments, then that will be
152 /// recovered. If `allow_extend` is true and there is no comment between the two
153 /// strings, then they will be put on a single line as long as doing so does not
154 /// exceed max width.
155 pub(crate) fn combine_strs_with_missing_comments(
156 context: &RewriteContext<'_>,
162 ) -> Option<String> {
164 "combine_strs_with_missing_comments `{}` `{}` {:?} {:?}",
172 String::with_capacity(prev_str.len() + next_str.len() + shape.indent.width() + 128);
173 result.push_str(prev_str);
174 let mut allow_one_line = !prev_str.contains('\n') && !next_str.contains('\n');
176 if prev_str.is_empty() || next_str.is_empty() || trimmed_last_line_width(prev_str) == 0 {
181 let mut one_line_width =
182 last_line_width(prev_str) + first_line_width(next_str) + first_sep.len();
184 let config = context.config;
185 let indent = shape.indent;
186 let missing_comment = rewrite_missing_comment(span, shape, context)?;
188 if missing_comment.is_empty() {
189 if allow_extend && one_line_width <= shape.width {
190 result.push_str(first_sep);
191 } else if !prev_str.is_empty() {
192 result.push_str(&indent.to_string_with_newline(config))
194 result.push_str(next_str);
198 // We have a missing comment between the first expression and the second expression.
200 // Peek the the original source code and find out whether there is a newline between the first
201 // expression and the second expression or the missing comment. We will preserve the original
202 // layout whenever possible.
203 let original_snippet = context.snippet(span);
204 let prefer_same_line = if let Some(pos) = original_snippet.find('/') {
205 !original_snippet[..pos].contains('\n')
207 !original_snippet.contains('\n')
210 one_line_width -= first_sep.len();
211 let first_sep = if prev_str.is_empty() || missing_comment.is_empty() {
214 let one_line_width = last_line_width(prev_str) + first_line_width(&missing_comment) + 1;
215 if prefer_same_line && one_line_width <= shape.width {
218 indent.to_string_with_newline(config)
221 result.push_str(&first_sep);
222 result.push_str(&missing_comment);
224 let second_sep = if missing_comment.is_empty() || next_str.is_empty() {
226 } else if missing_comment.starts_with("//") {
227 indent.to_string_with_newline(config)
229 one_line_width += missing_comment.len() + first_sep.len() + 1;
230 allow_one_line &= !missing_comment.starts_with("//") && !missing_comment.contains('\n');
231 if prefer_same_line && allow_one_line && one_line_width <= shape.width {
234 indent.to_string_with_newline(config)
237 result.push_str(&second_sep);
238 result.push_str(next_str);
243 pub(crate) fn rewrite_doc_comment(orig: &str, shape: Shape, config: &Config) -> Option<String> {
244 identify_comment(orig, false, shape, config, true)
247 pub(crate) fn rewrite_comment(
252 ) -> Option<String> {
253 identify_comment(orig, block_style, shape, config, false)
261 is_doc_comment: bool,
262 ) -> Option<String> {
263 let style = comment_style(orig, false);
265 // Computes the byte length of line taking into account a newline if the line is part of a
267 fn compute_len(orig: &str, line: &str) -> usize {
268 if orig.len() > line.len() {
269 if orig.as_bytes()[line.len()] == b'\r' {
279 // Get the first group of line comments having the same commenting style.
281 // Returns a tuple with:
282 // - a boolean indicating if there is a blank line
283 // - a number indicating the size of the first group of comments
284 fn consume_same_line_comments(
285 style: CommentStyle<'_>,
289 let mut first_group_ending = 0;
292 for line in orig.lines() {
293 let trimmed_line = line.trim_start();
294 if trimmed_line.is_empty() {
297 } else if trimmed_line.starts_with(line_start)
298 || comment_style(trimmed_line, false) == style
300 first_group_ending += compute_len(&orig[first_group_ending..], line);
305 (hbl, first_group_ending)
308 let (has_bare_lines, first_group_ending) = match style {
309 CommentStyle::DoubleSlash | CommentStyle::TripleSlash | CommentStyle::Doc => {
310 let line_start = style.line_start().trim_start();
311 consume_same_line_comments(style, orig, line_start)
313 CommentStyle::Custom(opener) => {
314 let trimmed_opener = opener.trim_end();
315 consume_same_line_comments(style, orig, trimmed_opener)
317 // for a block comment, search for the closing symbol
318 CommentStyle::DoubleBullet | CommentStyle::SingleBullet | CommentStyle::Exclamation => {
319 let closer = style.closer().trim_start();
320 let mut count = orig.matches(closer).count();
321 let mut closing_symbol_offset = 0;
323 let mut first = true;
324 for line in orig.lines() {
325 closing_symbol_offset += compute_len(&orig[closing_symbol_offset..], line);
326 let mut trimmed_line = line.trim_start();
327 if !trimmed_line.starts_with('*')
328 && !trimmed_line.starts_with("//")
329 && !trimmed_line.starts_with("/*")
334 // Remove opener from consideration when searching for closer
336 let opener = style.opener().trim_end();
337 trimmed_line = &trimmed_line[opener.len()..];
340 if trimmed_line.ends_with(closer) {
347 (hbl, closing_symbol_offset)
351 let (first_group, rest) = orig.split_at(first_group_ending);
352 let rewritten_first_group =
353 if !config.normalize_comments() && has_bare_lines && style.is_block_comment() {
354 trim_left_preserve_layout(first_group, shape.indent, config)?
355 } else if !config.normalize_comments()
356 && !config.wrap_comments()
357 && !config.format_code_in_doc_comments()
359 light_rewrite_comment(first_group, shape.indent, config, is_doc_comment)
361 rewrite_comment_inner(
367 is_doc_comment || style.is_doc_comment(),
371 Some(rewritten_first_group)
383 rewritten_first_group,
384 // insert back the blank line
385 if has_bare_lines && style.is_line_comment() {
390 shape.indent.to_string(config),
397 /// Enum indicating if the code block contains rust based on attributes
398 enum CodeBlockAttribute {
403 impl CodeBlockAttribute {
404 /// Parse comma separated attributes list. Return rust only if all
405 /// attributes are valid rust attributes
406 /// See <https://doc.rust-lang.org/rustdoc/print.html#attributes>
407 fn new(attributes: &str) -> CodeBlockAttribute {
408 for attribute in attributes.split(',') {
409 match attribute.trim() {
410 "" | "rust" | "should_panic" | "no_run" | "edition2015" | "edition2018"
411 | "edition2021" => (),
412 "ignore" | "compile_fail" | "text" => return CodeBlockAttribute::NotRust,
413 _ => return CodeBlockAttribute::NotRust,
416 CodeBlockAttribute::Rust
420 /// Block that is formatted as an item.
422 /// An item starts with either a star `*` or a dash `-`. Different level of indentation are
423 /// handled by shrinking the shape accordingly.
424 struct ItemizedBlock {
425 /// the lines that are identified as part of an itemized block
427 /// the number of whitespaces up to the item sigil
429 /// the string that marks the start of an item
431 /// sequence of whitespaces to prefix new lines that are part of the item
436 /// Returns `true` if the line is formatted as an item
437 fn is_itemized_line(line: &str) -> bool {
438 let trimmed = line.trim_start();
439 trimmed.starts_with("* ") || trimmed.starts_with("- ")
442 /// Creates a new ItemizedBlock described with the given line.
443 /// The `is_itemized_line` needs to be called first.
444 fn new(line: &str) -> ItemizedBlock {
445 let space_to_sigil = line.chars().take_while(|c| c.is_whitespace()).count();
446 let indent = space_to_sigil + 2;
448 lines: vec![line[indent..].to_string()],
450 opener: line[..indent].to_string(),
451 line_start: " ".repeat(indent),
455 /// Returns a `StringFormat` used for formatting the content of an item.
456 fn create_string_format<'a>(&'a self, fmt: &'a StringFormat<'_>) -> StringFormat<'a> {
462 shape: Shape::legacy(fmt.shape.width.saturating_sub(self.indent), Indent::empty()),
468 /// Returns `true` if the line is part of the current itemized block.
469 /// If it is, then it is added to the internal lines list.
470 fn add_line(&mut self, line: &str) -> bool {
471 if !ItemizedBlock::is_itemized_line(line)
472 && self.indent <= line.chars().take_while(|c| c.is_whitespace()).count()
474 self.lines.push(line.to_string());
480 /// Returns the block as a string, with each line trimmed at the start.
481 fn trimmed_block_as_string(&self) -> String {
484 .map(|line| format!("{} ", line.trim_start()))
488 /// Returns the block as a string under its original form.
489 fn original_block_as_string(&self) -> String {
490 self.lines.join("\n")
494 struct CommentRewrite<'a> {
496 code_block_buffer: String,
497 is_prev_line_multi_line: bool,
498 code_block_attr: Option<CodeBlockAttribute>,
499 item_block: Option<ItemizedBlock>,
500 comment_line_separator: String,
504 fmt: StringFormat<'a>,
511 impl<'a> CommentRewrite<'a> {
517 ) -> CommentRewrite<'a> {
518 let (opener, closer, line_start) = if block_style {
519 CommentStyle::SingleBullet.to_str_tuplet()
521 comment_style(orig, config.normalize_comments()).to_str_tuplet()
524 let max_width = shape
526 .checked_sub(closer.len() + opener.len())
528 let indent_str = shape.indent.to_string_with_newline(config).to_string();
530 let mut cr = CommentRewrite {
531 result: String::with_capacity(orig.len() * 2),
532 code_block_buffer: String::with_capacity(128),
533 is_prev_line_multi_line: false,
534 code_block_attr: None,
536 comment_line_separator: format!("{}{}", indent_str, line_start),
539 fmt_indent: shape.indent,
546 shape: Shape::legacy(max_width, shape.indent),
551 opener: opener.to_owned(),
552 closer: closer.to_owned(),
553 line_start: line_start.to_owned(),
555 cr.result.push_str(opener);
559 fn join_block(s: &str, sep: &str) -> String {
560 let mut result = String::with_capacity(s.len() + 128);
561 let mut iter = s.lines().peekable();
562 while let Some(line) = iter.next() {
563 result.push_str(line);
564 result.push_str(match iter.peek() {
565 Some(next_line) if next_line.is_empty() => sep.trim_end(),
573 fn finish(mut self) -> String {
574 if !self.code_block_buffer.is_empty() {
575 // There is a code block that is not properly enclosed by backticks.
576 // We will leave them untouched.
577 self.result.push_str(&self.comment_line_separator);
578 self.result.push_str(&Self::join_block(
579 &trim_custom_comment_prefix(&self.code_block_buffer),
580 &self.comment_line_separator,
584 if let Some(ref ib) = self.item_block {
585 // the last few lines are part of an itemized block
586 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
587 let item_fmt = ib.create_string_format(&self.fmt);
588 self.result.push_str(&self.comment_line_separator);
589 self.result.push_str(&ib.opener);
590 match rewrite_string(
591 &ib.trimmed_block_as_string(),
593 self.max_width.saturating_sub(ib.indent),
595 Some(s) => self.result.push_str(&Self::join_block(
597 &format!("{}{}", self.comment_line_separator, ib.line_start),
599 None => self.result.push_str(&Self::join_block(
600 &ib.original_block_as_string(),
601 &self.comment_line_separator,
606 self.result.push_str(&self.closer);
607 if self.result.ends_with(&self.opener) && self.opener.ends_with(' ') {
620 has_leading_whitespace: bool,
622 let is_last = i == count_newlines(orig);
624 if let Some(ref mut ib) = self.item_block {
625 if ib.add_line(line) {
628 self.is_prev_line_multi_line = false;
629 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
630 let item_fmt = ib.create_string_format(&self.fmt);
631 self.result.push_str(&self.comment_line_separator);
632 self.result.push_str(&ib.opener);
633 match rewrite_string(
634 &ib.trimmed_block_as_string(),
636 self.max_width.saturating_sub(ib.indent),
638 Some(s) => self.result.push_str(&Self::join_block(
640 &format!("{}{}", self.comment_line_separator, ib.line_start),
642 None => self.result.push_str(&Self::join_block(
643 &ib.original_block_as_string(),
644 &self.comment_line_separator,
647 } else if self.code_block_attr.is_some() {
648 if line.starts_with("```") {
649 let code_block = match self.code_block_attr.as_ref().unwrap() {
650 CodeBlockAttribute::Rust
651 if self.fmt.config.format_code_in_doc_comments()
652 && !self.code_block_buffer.is_empty() =>
654 let mut config = self.fmt.config.clone();
655 config.set().wrap_comments(false);
657 crate::format_code_block(&self.code_block_buffer, &config, false)
659 trim_custom_comment_prefix(&s.snippet)
661 trim_custom_comment_prefix(&self.code_block_buffer)
664 _ => trim_custom_comment_prefix(&self.code_block_buffer),
666 if !code_block.is_empty() {
667 self.result.push_str(&self.comment_line_separator);
669 .push_str(&Self::join_block(&code_block, &self.comment_line_separator));
671 self.code_block_buffer.clear();
672 self.result.push_str(&self.comment_line_separator);
673 self.result.push_str(line);
674 self.code_block_attr = None;
676 self.code_block_buffer
677 .push_str(&hide_sharp_behind_comment(line));
678 self.code_block_buffer.push('\n');
683 self.code_block_attr = None;
684 self.item_block = None;
685 if let Some(stripped) = line.strip_prefix("```") {
686 self.code_block_attr = Some(CodeBlockAttribute::new(stripped))
687 } else if self.fmt.config.wrap_comments() && ItemizedBlock::is_itemized_line(line) {
688 let ib = ItemizedBlock::new(line);
689 self.item_block = Some(ib);
693 if self.result == self.opener {
694 let force_leading_whitespace = &self.opener == "/* " && count_newlines(orig) == 0;
695 if !has_leading_whitespace && !force_leading_whitespace && self.result.ends_with(' ') {
701 } else if self.is_prev_line_multi_line && !line.is_empty() {
702 self.result.push(' ')
703 } else if is_last && line.is_empty() {
704 // trailing blank lines are unwanted
705 if !self.closer.is_empty() {
706 self.result.push_str(&self.indent_str);
710 self.result.push_str(&self.comment_line_separator);
711 if !has_leading_whitespace && self.result.ends_with(' ') {
716 if self.fmt.config.wrap_comments()
717 && unicode_str_width(line) > self.fmt.shape.width
720 match rewrite_string(line, &self.fmt, self.max_width) {
722 self.is_prev_line_multi_line = s.contains('\n');
723 self.result.push_str(s);
725 None if self.is_prev_line_multi_line => {
726 // We failed to put the current `line` next to the previous `line`.
727 // Remove the trailing space, then start rewrite on the next line.
729 self.result.push_str(&self.comment_line_separator);
730 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
731 match rewrite_string(line, &self.fmt, self.max_width) {
733 self.is_prev_line_multi_line = s.contains('\n');
734 self.result.push_str(s);
737 self.is_prev_line_multi_line = false;
738 self.result.push_str(line);
743 self.is_prev_line_multi_line = false;
744 self.result.push_str(line);
748 self.fmt.shape = if self.is_prev_line_multi_line {
750 let offset = 1 + last_line_width(&self.result) - self.line_start.len();
752 width: self.max_width.saturating_sub(offset),
753 indent: self.fmt_indent,
754 offset: self.fmt.shape.offset + offset,
757 Shape::legacy(self.max_width, self.fmt_indent)
760 if line.is_empty() && self.result.ends_with(' ') && !is_last {
761 // Remove space if this is an empty comment or a doc comment.
764 self.result.push_str(line);
765 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
766 self.is_prev_line_multi_line = false;
773 fn rewrite_comment_inner(
776 style: CommentStyle<'_>,
779 is_doc_comment: bool,
780 ) -> Option<String> {
781 let mut rewriter = CommentRewrite::new(orig, block_style, shape, config);
783 let line_breaks = count_newlines(orig.trim_end());
787 .map(|(i, mut line)| {
788 line = trim_end_unless_two_whitespaces(line.trim_start(), is_doc_comment);
790 if i == line_breaks && line.ends_with("*/") && !line.starts_with("//") {
791 line = line[..(line.len() - 2)].trim_end();
796 .map(|s| left_trim_comment_line(s, &style))
797 .map(|(line, has_leading_whitespace)| {
798 if orig.starts_with("/*") && line_breaks == 0 {
801 has_leading_whitespace || config.normalize_comments(),
804 (line, has_leading_whitespace || config.normalize_comments())
808 for (i, (line, has_leading_whitespace)) in lines.enumerate() {
809 if rewriter.handle_line(orig, i, line, has_leading_whitespace) {
814 Some(rewriter.finish())
817 const RUSTFMT_CUSTOM_COMMENT_PREFIX: &str = "//#### ";
819 fn hide_sharp_behind_comment(s: &str) -> Cow<'_, str> {
820 let s_trimmed = s.trim();
821 if s_trimmed.starts_with("# ") || s_trimmed == "#" {
822 Cow::from(format!("{}{}", RUSTFMT_CUSTOM_COMMENT_PREFIX, s))
828 fn trim_custom_comment_prefix(s: &str) -> String {
831 let left_trimmed = line.trim_start();
832 if left_trimmed.starts_with(RUSTFMT_CUSTOM_COMMENT_PREFIX) {
833 left_trimmed.trim_start_matches(RUSTFMT_CUSTOM_COMMENT_PREFIX)
842 /// Returns `true` if the given string MAY include URLs or alike.
843 fn has_url(s: &str) -> bool {
844 // This function may return false positive, but should get its job done in most cases.
845 s.contains("https://") || s.contains("http://") || s.contains("ftp://") || s.contains("file://")
848 /// Given the span, rewrite the missing comment inside it if available.
849 /// Note that the given span must only include comments (or leading/trailing whitespaces).
850 pub(crate) fn rewrite_missing_comment(
853 context: &RewriteContext<'_>,
854 ) -> Option<String> {
855 let missing_snippet = context.snippet(span);
856 let trimmed_snippet = missing_snippet.trim();
857 // check the span starts with a comment
858 let pos = trimmed_snippet.find('/');
859 if !trimmed_snippet.is_empty() && pos.is_some() {
860 rewrite_comment(trimmed_snippet, false, shape, context.config)
866 /// Recover the missing comments in the specified span, if available.
867 /// The layout of the comments will be preserved as long as it does not break the code
868 /// and its total width does not exceed the max width.
869 pub(crate) fn recover_missing_comment_in_span(
872 context: &RewriteContext<'_>,
874 ) -> Option<String> {
875 let missing_comment = rewrite_missing_comment(span, shape, context)?;
876 if missing_comment.is_empty() {
879 let missing_snippet = context.snippet(span);
880 let pos = missing_snippet.find('/')?;
882 let total_width = missing_comment.len() + used_width + 1;
883 let force_new_line_before_comment =
884 missing_snippet[..pos].contains('\n') || total_width > context.config.max_width();
885 let sep = if force_new_line_before_comment {
886 shape.indent.to_string_with_newline(context.config)
890 Some(format!("{}{}", sep, missing_comment))
894 /// Trim trailing whitespaces unless they consist of two or more whitespaces.
895 fn trim_end_unless_two_whitespaces(s: &str, is_doc_comment: bool) -> &str {
896 if is_doc_comment && s.ends_with(" ") {
903 /// Trims whitespace and aligns to indent, but otherwise does not change comments.
904 fn light_rewrite_comment(
908 is_doc_comment: bool,
910 let lines: Vec<&str> = orig
913 // This is basically just l.trim(), but in the case that a line starts
914 // with `*` we want to leave one space before it, so it aligns with the
916 let first_non_whitespace = l.find(|c| !char::is_whitespace(c));
917 let left_trimmed = if let Some(fnw) = first_non_whitespace {
918 if l.as_bytes()[fnw] == b'*' && fnw > 0 {
926 // Preserve markdown's double-space line break syntax in doc comment.
927 trim_end_unless_two_whitespaces(left_trimmed, is_doc_comment)
930 lines.join(&format!("\n{}", offset.to_string(config)))
933 /// Trims comment characters and possibly a single space from the left of a string.
934 /// Does not trim all whitespace. If a single space is trimmed from the left of the string,
935 /// this function returns true.
936 fn left_trim_comment_line<'a>(line: &'a str, style: &CommentStyle<'_>) -> (&'a str, bool) {
937 if line.starts_with("//! ")
938 || line.starts_with("/// ")
939 || line.starts_with("/*! ")
940 || line.starts_with("/** ")
943 } else if let CommentStyle::Custom(opener) = *style {
944 if let Some(stripped) = line.strip_prefix(opener) {
947 (&line[opener.trim_end().len()..], false)
949 } else if line.starts_with("/* ")
950 || line.starts_with("// ")
951 || line.starts_with("//!")
952 || line.starts_with("///")
953 || line.starts_with("** ")
954 || line.starts_with("/*!")
955 || (line.starts_with("/**") && !line.starts_with("/**/"))
957 (&line[3..], line.chars().nth(2).unwrap() == ' ')
958 } else if line.starts_with("/*")
959 || line.starts_with("* ")
960 || line.starts_with("//")
961 || line.starts_with("**")
963 (&line[2..], line.chars().nth(1).unwrap() == ' ')
964 } else if let Some(stripped) = line.strip_prefix('*') {
967 (line, line.starts_with(' '))
971 pub(crate) trait FindUncommented {
972 fn find_uncommented(&self, pat: &str) -> Option<usize>;
973 fn find_last_uncommented(&self, pat: &str) -> Option<usize>;
976 impl FindUncommented for str {
977 fn find_uncommented(&self, pat: &str) -> Option<usize> {
978 let mut needle_iter = pat.chars();
979 for (kind, (i, b)) in CharClasses::new(self.char_indices()) {
980 match needle_iter.next() {
982 return Some(i - pat.len());
984 Some(c) => match kind {
985 FullCodeCharKind::Normal | FullCodeCharKind::InString if b == c => {}
987 needle_iter = pat.chars();
993 // Handle case where the pattern is a suffix of the search string
994 match needle_iter.next() {
996 None => Some(self.len() - pat.len()),
1000 fn find_last_uncommented(&self, pat: &str) -> Option<usize> {
1001 if let Some(left) = self.find_uncommented(pat) {
1002 let mut result = left;
1003 // add 1 to use find_last_uncommented for &str after pat
1004 while let Some(next) = self[(result + 1)..].find_last_uncommented(pat) {
1014 // Returns the first byte position after the first comment. The given string
1015 // is expected to be prefixed by a comment, including delimiters.
1016 // Good: `/* /* inner */ outer */ code();`
1017 // Bad: `code(); // hello\n world!`
1018 pub(crate) fn find_comment_end(s: &str) -> Option<usize> {
1019 let mut iter = CharClasses::new(s.char_indices());
1020 for (kind, (i, _c)) in &mut iter {
1021 if kind == FullCodeCharKind::Normal || kind == FullCodeCharKind::InString {
1026 // Handle case where the comment ends at the end of `s`.
1027 if iter.status == CharClassesStatus::Normal {
1034 /// Returns `true` if text contains any comment.
1035 pub(crate) fn contains_comment(text: &str) -> bool {
1036 CharClasses::new(text.chars()).any(|(kind, _)| kind.is_comment())
1039 pub(crate) struct CharClasses<T>
1045 status: CharClassesStatus,
1048 pub(crate) trait RichChar {
1049 fn get_char(&self) -> char;
1052 impl RichChar for char {
1053 fn get_char(&self) -> char {
1058 impl RichChar for (usize, char) {
1059 fn get_char(&self) -> char {
1064 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1065 enum CharClassesStatus {
1067 /// Character is within a string
1070 /// Character is within a raw string
1072 RawStringPrefix(u32),
1073 RawStringSuffix(u32),
1076 /// Character inside a block comment, with the integer indicating the nesting deepness of the
1079 /// Character inside a block-commented string, with the integer indicating the nesting deepness
1081 StringInBlockComment(u32),
1082 /// Status when the '/' has been consumed, but not yet the '*', deepness is
1083 /// the new deepness (after the comment opening).
1084 BlockCommentOpening(u32),
1085 /// Status when the '*' has been consumed, but not yet the '/', deepness is
1086 /// the new deepness (after the comment closing).
1087 BlockCommentClosing(u32),
1088 /// Character is within a line comment
1092 /// Distinguish between functional part of code and comments
1093 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1094 pub(crate) enum CodeCharKind {
1099 /// Distinguish between functional part of code and comments,
1100 /// describing opening and closing of comments for ease when chunking
1101 /// code from tagged characters
1102 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1103 pub(crate) enum FullCodeCharKind {
1105 /// The first character of a comment, there is only one for a comment (always '/')
1107 /// Any character inside a comment including the second character of comment
1108 /// marks ("//", "/*")
1110 /// Last character of a comment, '\n' for a line comment, '/' for a block comment.
1112 /// Start of a mutlitine string inside a comment
1113 StartStringCommented,
1114 /// End of a mutlitine string inside a comment
1116 /// Inside a commented string
1118 /// Start of a mutlitine string
1120 /// End of a mutlitine string
1122 /// Inside a string.
1126 impl FullCodeCharKind {
1127 pub(crate) fn is_comment(self) -> bool {
1129 FullCodeCharKind::StartComment
1130 | FullCodeCharKind::InComment
1131 | FullCodeCharKind::EndComment
1132 | FullCodeCharKind::StartStringCommented
1133 | FullCodeCharKind::InStringCommented
1134 | FullCodeCharKind::EndStringCommented => true,
1139 /// Returns true if the character is inside a comment
1140 pub(crate) fn inside_comment(self) -> bool {
1142 FullCodeCharKind::InComment
1143 | FullCodeCharKind::StartStringCommented
1144 | FullCodeCharKind::InStringCommented
1145 | FullCodeCharKind::EndStringCommented => true,
1150 pub(crate) fn is_string(self) -> bool {
1151 self == FullCodeCharKind::InString || self == FullCodeCharKind::StartString
1154 /// Returns true if the character is within a commented string
1155 pub(crate) fn is_commented_string(self) -> bool {
1156 self == FullCodeCharKind::InStringCommented
1157 || self == FullCodeCharKind::StartStringCommented
1160 fn to_codecharkind(self) -> CodeCharKind {
1161 if self.is_comment() {
1162 CodeCharKind::Comment
1164 CodeCharKind::Normal
1169 impl<T> CharClasses<T>
1174 pub(crate) fn new(base: T) -> CharClasses<T> {
1176 base: multipeek(base),
1177 status: CharClassesStatus::Normal,
1182 fn is_raw_string_suffix<T>(iter: &mut MultiPeek<T>, count: u32) -> bool
1189 Some(c) if c.get_char() == '#' => continue,
1196 impl<T> Iterator for CharClasses<T>
1201 type Item = (FullCodeCharKind, T::Item);
1203 fn next(&mut self) -> Option<(FullCodeCharKind, T::Item)> {
1204 let item = self.base.next()?;
1205 let chr = item.get_char();
1206 let mut char_kind = FullCodeCharKind::Normal;
1207 self.status = match self.status {
1208 CharClassesStatus::LitRawString(sharps) => {
1209 char_kind = FullCodeCharKind::InString;
1213 char_kind = FullCodeCharKind::Normal;
1214 CharClassesStatus::Normal
1215 } else if is_raw_string_suffix(&mut self.base, sharps) {
1216 CharClassesStatus::RawStringSuffix(sharps)
1218 CharClassesStatus::LitRawString(sharps)
1221 _ => CharClassesStatus::LitRawString(sharps),
1224 CharClassesStatus::RawStringPrefix(sharps) => {
1225 char_kind = FullCodeCharKind::InString;
1227 '#' => CharClassesStatus::RawStringPrefix(sharps + 1),
1228 '"' => CharClassesStatus::LitRawString(sharps),
1229 _ => CharClassesStatus::Normal, // Unreachable.
1232 CharClassesStatus::RawStringSuffix(sharps) => {
1236 CharClassesStatus::Normal
1238 char_kind = FullCodeCharKind::InString;
1239 CharClassesStatus::RawStringSuffix(sharps - 1)
1242 _ => CharClassesStatus::Normal, // Unreachable
1245 CharClassesStatus::LitString => {
1246 char_kind = FullCodeCharKind::InString;
1248 '"' => CharClassesStatus::Normal,
1249 '\\' => CharClassesStatus::LitStringEscape,
1250 _ => CharClassesStatus::LitString,
1253 CharClassesStatus::LitStringEscape => {
1254 char_kind = FullCodeCharKind::InString;
1255 CharClassesStatus::LitString
1257 CharClassesStatus::LitChar => match chr {
1258 '\\' => CharClassesStatus::LitCharEscape,
1259 '\'' => CharClassesStatus::Normal,
1260 _ => CharClassesStatus::LitChar,
1262 CharClassesStatus::LitCharEscape => CharClassesStatus::LitChar,
1263 CharClassesStatus::Normal => match chr {
1264 'r' => match self.base.peek().map(RichChar::get_char) {
1265 Some('#') | Some('"') => {
1266 char_kind = FullCodeCharKind::InString;
1267 CharClassesStatus::RawStringPrefix(0)
1269 _ => CharClassesStatus::Normal,
1272 char_kind = FullCodeCharKind::InString;
1273 CharClassesStatus::LitString
1276 // HACK: Work around mut borrow.
1277 match self.base.peek() {
1278 Some(next) if next.get_char() == '\\' => {
1279 self.status = CharClassesStatus::LitChar;
1280 return Some((char_kind, item));
1285 match self.base.peek() {
1286 Some(next) if next.get_char() == '\'' => CharClassesStatus::LitChar,
1287 _ => CharClassesStatus::Normal,
1290 '/' => match self.base.peek() {
1291 Some(next) if next.get_char() == '*' => {
1292 self.status = CharClassesStatus::BlockCommentOpening(1);
1293 return Some((FullCodeCharKind::StartComment, item));
1295 Some(next) if next.get_char() == '/' => {
1296 self.status = CharClassesStatus::LineComment;
1297 return Some((FullCodeCharKind::StartComment, item));
1299 _ => CharClassesStatus::Normal,
1301 _ => CharClassesStatus::Normal,
1303 CharClassesStatus::StringInBlockComment(deepness) => {
1304 char_kind = FullCodeCharKind::InStringCommented;
1306 CharClassesStatus::BlockComment(deepness)
1307 } else if chr == '*' && self.base.peek().map(RichChar::get_char) == Some('/') {
1308 char_kind = FullCodeCharKind::InComment;
1309 CharClassesStatus::BlockCommentClosing(deepness - 1)
1311 CharClassesStatus::StringInBlockComment(deepness)
1314 CharClassesStatus::BlockComment(deepness) => {
1315 assert_ne!(deepness, 0);
1316 char_kind = FullCodeCharKind::InComment;
1317 match self.base.peek() {
1318 Some(next) if next.get_char() == '/' && chr == '*' => {
1319 CharClassesStatus::BlockCommentClosing(deepness - 1)
1321 Some(next) if next.get_char() == '*' && chr == '/' => {
1322 CharClassesStatus::BlockCommentOpening(deepness + 1)
1324 _ if chr == '"' => CharClassesStatus::StringInBlockComment(deepness),
1328 CharClassesStatus::BlockCommentOpening(deepness) => {
1329 assert_eq!(chr, '*');
1330 self.status = CharClassesStatus::BlockComment(deepness);
1331 return Some((FullCodeCharKind::InComment, item));
1333 CharClassesStatus::BlockCommentClosing(deepness) => {
1334 assert_eq!(chr, '/');
1336 self.status = CharClassesStatus::Normal;
1337 return Some((FullCodeCharKind::EndComment, item));
1339 self.status = CharClassesStatus::BlockComment(deepness);
1340 return Some((FullCodeCharKind::InComment, item));
1343 CharClassesStatus::LineComment => match chr {
1345 self.status = CharClassesStatus::Normal;
1346 return Some((FullCodeCharKind::EndComment, item));
1349 self.status = CharClassesStatus::LineComment;
1350 return Some((FullCodeCharKind::InComment, item));
1354 Some((char_kind, item))
1358 /// An iterator over the lines of a string, paired with the char kind at the
1359 /// end of the line.
1360 pub(crate) struct LineClasses<'a> {
1361 base: iter::Peekable<CharClasses<std::str::Chars<'a>>>,
1362 kind: FullCodeCharKind,
1365 impl<'a> LineClasses<'a> {
1366 pub(crate) fn new(s: &'a str) -> Self {
1368 base: CharClasses::new(s.chars()).peekable(),
1369 kind: FullCodeCharKind::Normal,
1374 impl<'a> Iterator for LineClasses<'a> {
1375 type Item = (FullCodeCharKind, String);
1377 fn next(&mut self) -> Option<Self::Item> {
1380 let mut line = String::new();
1382 let start_kind = match self.base.peek() {
1383 Some((kind, _)) => *kind,
1384 None => unreachable!(),
1387 for (kind, c) in self.base.by_ref() {
1388 // needed to set the kind of the ending character on the last line
1391 self.kind = match (start_kind, kind) {
1392 (FullCodeCharKind::Normal, FullCodeCharKind::InString) => {
1393 FullCodeCharKind::StartString
1395 (FullCodeCharKind::InString, FullCodeCharKind::Normal) => {
1396 FullCodeCharKind::EndString
1398 (FullCodeCharKind::InComment, FullCodeCharKind::InStringCommented) => {
1399 FullCodeCharKind::StartStringCommented
1401 (FullCodeCharKind::InStringCommented, FullCodeCharKind::InComment) => {
1402 FullCodeCharKind::EndStringCommented
1411 // Workaround for CRLF newline.
1412 if line.ends_with('\r') {
1416 Some((self.kind, line))
1420 /// Iterator over functional and commented parts of a string. Any part of a string is either
1421 /// functional code, either *one* block comment, either *one* line comment. Whitespace between
1422 /// comments is functional code. Line comments contain their ending newlines.
1423 struct UngroupedCommentCodeSlices<'a> {
1425 iter: iter::Peekable<CharClasses<std::str::CharIndices<'a>>>,
1428 impl<'a> UngroupedCommentCodeSlices<'a> {
1429 fn new(code: &'a str) -> UngroupedCommentCodeSlices<'a> {
1430 UngroupedCommentCodeSlices {
1432 iter: CharClasses::new(code.char_indices()).peekable(),
1437 impl<'a> Iterator for UngroupedCommentCodeSlices<'a> {
1438 type Item = (CodeCharKind, usize, &'a str);
1440 fn next(&mut self) -> Option<Self::Item> {
1441 let (kind, (start_idx, _)) = self.iter.next()?;
1443 FullCodeCharKind::Normal | FullCodeCharKind::InString => {
1444 // Consume all the Normal code
1445 while let Some(&(char_kind, _)) = self.iter.peek() {
1446 if char_kind.is_comment() {
1449 let _ = self.iter.next();
1452 FullCodeCharKind::StartComment => {
1453 // Consume the whole comment
1455 match self.iter.next() {
1456 Some((kind, ..)) if kind.inside_comment() => continue,
1463 let slice = match self.iter.peek() {
1464 Some(&(_, (end_idx, _))) => &self.slice[start_idx..end_idx],
1465 None => &self.slice[start_idx..],
1468 if kind.is_comment() {
1469 CodeCharKind::Comment
1471 CodeCharKind::Normal
1479 /// Iterator over an alternating sequence of functional and commented parts of
1480 /// a string. The first item is always a, possibly zero length, subslice of
1481 /// functional text. Line style comments contain their ending newlines.
1482 pub(crate) struct CommentCodeSlices<'a> {
1484 last_slice_kind: CodeCharKind,
1485 last_slice_end: usize,
1488 impl<'a> CommentCodeSlices<'a> {
1489 pub(crate) fn new(slice: &'a str) -> CommentCodeSlices<'a> {
1492 last_slice_kind: CodeCharKind::Comment,
1498 impl<'a> Iterator for CommentCodeSlices<'a> {
1499 type Item = (CodeCharKind, usize, &'a str);
1501 fn next(&mut self) -> Option<Self::Item> {
1502 if self.last_slice_end == self.slice.len() {
1506 let mut sub_slice_end = self.last_slice_end;
1507 let mut first_whitespace = None;
1508 let subslice = &self.slice[self.last_slice_end..];
1509 let mut iter = CharClasses::new(subslice.char_indices());
1511 for (kind, (i, c)) in &mut iter {
1512 let is_comment_connector = self.last_slice_kind == CodeCharKind::Normal
1513 && &subslice[..2] == "//"
1514 && [' ', '\t'].contains(&c);
1516 if is_comment_connector && first_whitespace.is_none() {
1517 first_whitespace = Some(i);
1520 if kind.to_codecharkind() == self.last_slice_kind && !is_comment_connector {
1521 let last_index = match first_whitespace {
1525 sub_slice_end = self.last_slice_end + last_index;
1529 if !is_comment_connector {
1530 first_whitespace = None;
1534 if let (None, true) = (iter.next(), sub_slice_end == self.last_slice_end) {
1535 // This was the last subslice.
1536 sub_slice_end = match first_whitespace {
1537 Some(i) => self.last_slice_end + i,
1538 None => self.slice.len(),
1542 let kind = match self.last_slice_kind {
1543 CodeCharKind::Comment => CodeCharKind::Normal,
1544 CodeCharKind::Normal => CodeCharKind::Comment,
1548 self.last_slice_end,
1549 &self.slice[self.last_slice_end..sub_slice_end],
1551 self.last_slice_end = sub_slice_end;
1552 self.last_slice_kind = kind;
1558 /// Checks is `new` didn't miss any comment from `span`, if it removed any, return previous text
1559 /// (if it fits in the width/offset, else return `None`), else return `new`
1560 pub(crate) fn recover_comment_removed(
1563 context: &RewriteContext<'_>,
1564 ) -> Option<String> {
1565 let snippet = context.snippet(span);
1566 if snippet != new && changed_comment_content(snippet, &new) {
1567 // We missed some comments. Warn and keep the original text.
1568 if context.config.error_on_unformatted() {
1569 context.report.append(
1570 context.parse_sess.span_to_filename(span),
1571 vec![FormattingError::from_span(
1574 ErrorKind::LostComment,
1578 Some(snippet.to_owned())
1584 pub(crate) fn filter_normal_code(code: &str) -> String {
1585 let mut buffer = String::with_capacity(code.len());
1586 LineClasses::new(code).for_each(|(kind, line)| match kind {
1587 FullCodeCharKind::Normal
1588 | FullCodeCharKind::StartString
1589 | FullCodeCharKind::InString
1590 | FullCodeCharKind::EndString => {
1591 buffer.push_str(&line);
1596 if !code.ends_with('\n') && buffer.ends_with('\n') {
1602 /// Returns `true` if the two strings of code have the same payload of comments.
1603 /// The payload of comments is everything in the string except:
1604 /// - actual code (not comments),
1605 /// - comment start/end marks,
1607 /// - '*' at the beginning of lines in block comments.
1608 fn changed_comment_content(orig: &str, new: &str) -> bool {
1609 // Cannot write this as a fn since we cannot return types containing closures.
1610 let code_comment_content = |code| {
1611 let slices = UngroupedCommentCodeSlices::new(code);
1613 .filter(|&(ref kind, _, _)| *kind == CodeCharKind::Comment)
1614 .flat_map(|(_, _, s)| CommentReducer::new(s))
1616 let res = code_comment_content(orig).ne(code_comment_content(new));
1618 "comment::changed_comment_content: {}\norig: '{}'\nnew: '{}'\nraw_old: {}\nraw_new: {}",
1622 code_comment_content(orig).collect::<String>(),
1623 code_comment_content(new).collect::<String>()
1628 /// Iterator over the 'payload' characters of a comment.
1629 /// It skips whitespace, comment start/end marks, and '*' at the beginning of lines.
1630 /// The comment must be one comment, ie not more than one start mark (no multiple line comments,
1632 struct CommentReducer<'a> {
1634 at_start_line: bool,
1635 iter: std::str::Chars<'a>,
1638 impl<'a> CommentReducer<'a> {
1639 fn new(comment: &'a str) -> CommentReducer<'a> {
1640 let is_block = comment.starts_with("/*");
1641 let comment = remove_comment_header(comment);
1644 // There are no supplementary '*' on the first line.
1645 at_start_line: false,
1646 iter: comment.chars(),
1651 impl<'a> Iterator for CommentReducer<'a> {
1654 fn next(&mut self) -> Option<Self::Item> {
1656 let mut c = self.iter.next()?;
1657 if self.is_block && self.at_start_line {
1658 while c.is_whitespace() {
1659 c = self.iter.next()?;
1661 // Ignore leading '*'.
1663 c = self.iter.next()?;
1665 } else if c == '\n' {
1666 self.at_start_line = true;
1668 if !c.is_whitespace() {
1675 fn remove_comment_header(comment: &str) -> &str {
1676 if comment.starts_with("///") || comment.starts_with("//!") {
1678 } else if let Some(stripped) = comment.strip_prefix("//") {
1680 } else if (comment.starts_with("/**") && !comment.starts_with("/**/"))
1681 || comment.starts_with("/*!")
1683 &comment[3..comment.len() - 2]
1686 comment.starts_with("/*"),
1687 "string '{}' is not a comment",
1690 &comment[2..comment.len() - 2]
1697 use crate::shape::{Indent, Shape};
1701 let mut iter = CharClasses::new("//\n\n".chars());
1703 assert_eq!((FullCodeCharKind::StartComment, '/'), iter.next().unwrap());
1704 assert_eq!((FullCodeCharKind::InComment, '/'), iter.next().unwrap());
1705 assert_eq!((FullCodeCharKind::EndComment, '\n'), iter.next().unwrap());
1706 assert_eq!((FullCodeCharKind::Normal, '\n'), iter.next().unwrap());
1707 assert_eq!(None, iter.next());
1711 fn comment_code_slices() {
1712 let input = "code(); /* test */ 1 + 1";
1713 let mut iter = CommentCodeSlices::new(input);
1715 assert_eq!((CodeCharKind::Normal, 0, "code(); "), iter.next().unwrap());
1717 (CodeCharKind::Comment, 8, "/* test */"),
1718 iter.next().unwrap()
1720 assert_eq!((CodeCharKind::Normal, 18, " 1 + 1"), iter.next().unwrap());
1721 assert_eq!(None, iter.next());
1725 fn comment_code_slices_two() {
1726 let input = "// comment\n test();";
1727 let mut iter = CommentCodeSlices::new(input);
1729 assert_eq!((CodeCharKind::Normal, 0, ""), iter.next().unwrap());
1731 (CodeCharKind::Comment, 0, "// comment\n"),
1732 iter.next().unwrap()
1735 (CodeCharKind::Normal, 11, " test();"),
1736 iter.next().unwrap()
1738 assert_eq!(None, iter.next());
1742 fn comment_code_slices_three() {
1743 let input = "1 // comment\n // comment2\n\n";
1744 let mut iter = CommentCodeSlices::new(input);
1746 assert_eq!((CodeCharKind::Normal, 0, "1 "), iter.next().unwrap());
1748 (CodeCharKind::Comment, 2, "// comment\n // comment2\n"),
1749 iter.next().unwrap()
1751 assert_eq!((CodeCharKind::Normal, 29, "\n"), iter.next().unwrap());
1752 assert_eq!(None, iter.next());
1757 fn format_doc_comments() {
1758 let mut wrap_normalize_config: crate::config::Config = Default::default();
1759 wrap_normalize_config.set().wrap_comments(true);
1760 wrap_normalize_config.set().normalize_comments(true);
1762 let mut wrap_config: crate::config::Config = Default::default();
1763 wrap_config.set().wrap_comments(true);
1765 let comment = rewrite_comment(" //test",
1767 Shape::legacy(100, Indent::new(0, 100)),
1768 &wrap_normalize_config).unwrap();
1769 assert_eq!("/* test */", comment);
1771 let comment = rewrite_comment("// comment on a",
1773 Shape::legacy(10, Indent::empty()),
1774 &wrap_normalize_config).unwrap();
1775 assert_eq!("// comment\n// on a", comment);
1777 let comment = rewrite_comment("// A multi line comment\n // between args.",
1779 Shape::legacy(60, Indent::new(0, 12)),
1780 &wrap_normalize_config).unwrap();
1781 assert_eq!("// A multi line comment\n // between args.", comment);
1783 let input = "// comment";
1786 let comment = rewrite_comment(input,
1788 Shape::legacy(9, Indent::new(0, 69)),
1789 &wrap_normalize_config).unwrap();
1790 assert_eq!(expected, comment);
1792 let comment = rewrite_comment("/* trimmed */",
1794 Shape::legacy(100, Indent::new(0, 100)),
1795 &wrap_normalize_config).unwrap();
1796 assert_eq!("/* trimmed */", comment);
1798 // Check that different comment style are properly recognised.
1799 let comment = rewrite_comment(r#"/// test1
1805 Shape::legacy(100, Indent::new(0, 0)),
1806 &wrap_normalize_config).unwrap();
1807 assert_eq!("/// test1\n/// test2\n// test3", comment);
1809 // Check that the blank line marks the end of a commented paragraph.
1810 let comment = rewrite_comment(r#"// test1
1814 Shape::legacy(100, Indent::new(0, 0)),
1815 &wrap_normalize_config).unwrap();
1816 assert_eq!("// test1\n\n// test2", comment);
1818 // Check that the blank line marks the end of a custom-commented paragraph.
1819 let comment = rewrite_comment(r#"//@ test1
1823 Shape::legacy(100, Indent::new(0, 0)),
1824 &wrap_normalize_config).unwrap();
1825 assert_eq!("//@ test1\n\n//@ test2", comment);
1827 // Check that bare lines are just indented but otherwise left unchanged.
1828 let comment = rewrite_comment(r#"// test1
1835 Shape::legacy(100, Indent::new(0, 0)),
1836 &wrap_config).unwrap();
1837 assert_eq!("// test1\n/*\n a bare line!\n\n another bare line!\n*/", comment);
1840 // This is probably intended to be a non-test fn, but it is not used.
1841 // We should keep this around unless it helps us test stuff to remove it.
1842 fn uncommented(text: &str) -> String {
1843 CharClasses::new(text.chars())
1844 .filter_map(|(s, c)| match s {
1845 FullCodeCharKind::Normal | FullCodeCharKind::InString => Some(c),
1852 fn test_uncommented() {
1853 assert_eq!(&uncommented("abc/*...*/"), "abc");
1855 &uncommented("// .... /* \n../* /* *** / */ */a/* // */c\n"),
1858 assert_eq!(&uncommented("abc \" /* */\" qsdf"), "abc \" /* */\" qsdf");
1862 fn test_contains_comment() {
1863 assert_eq!(contains_comment("abc"), false);
1864 assert_eq!(contains_comment("abc // qsdf"), true);
1865 assert_eq!(contains_comment("abc /* kqsdf"), true);
1866 assert_eq!(contains_comment("abc \" /* */\" qsdf"), false);
1870 fn test_find_uncommented() {
1871 fn check(haystack: &str, needle: &str, expected: Option<usize>) {
1872 assert_eq!(expected, haystack.find_uncommented(needle));
1875 check("/*/ */test", "test", Some(6));
1876 check("//test\ntest", "test", Some(7));
1877 check("/* comment only */", "whatever", None);
1879 "/* comment */ some text /* more commentary */ result",
1883 check("sup // sup", "p", Some(2));
1884 check("sup", "x", None);
1885 check(r#"π? /**/ π is nice!"#, r#"π is nice"#, Some(9));
1886 check("/*sup yo? \n sup*/ sup", "p", Some(20));
1887 check("hel/*lohello*/lo", "hello", None);
1888 check("acb", "ab", None);
1889 check(",/*A*/ ", ",", Some(0));
1890 check("abc", "abc", Some(0));
1891 check("/* abc */", "abc", None);
1892 check("/**/abc/* */", "abc", Some(4));
1893 check("\"/* abc */\"", "abc", Some(4));
1894 check("\"/* abc", "abc", Some(4));
1898 fn test_filter_normal_code() {
1901 println!("hello, world");
1904 assert_eq!(s, filter_normal_code(s));
1905 let s_with_comment = r#"
1908 println!("hello, world");
1911 assert_eq!(s, filter_normal_code(s_with_comment));