src/tools/tidy/src/alphabetical.rs

   1 //! Checks that a list of items is in alphabetical order
   2 //!
   3 //! To use, use the following annotation in the code:
   4 //! ```rust
   5 //! // tidy-alphabetical-start
   6 //! fn aaa() {}
   7 //! fn eee() {}
   8 //! fn z() {}
   9 //! // tidy-alphabetical-end
  10 //! ```
  11 //!
  12 //! The following lines are ignored:
  13 //! - Lines that are indented with more or less spaces than the first line
  14 //! - Lines starting with `//`, `#[`, `)`, `]`, `}` if the comment has the same indentation as
  15 //!   the first line
  16 //!
  17 //! If a line ends with an opening bracket, the line is ignored and the next line will have
  18 //! its extra indentation ignored.
  19
  20 use std::{fmt::Display, path::Path};
  21
  22 use crate::walk::{filter_dirs, walk};
  23
  24 fn indentation(line: &str) -> usize {
  25     line.find(|c| c != ' ').unwrap_or(0)
  26 }
  27
  28 fn is_close_bracket(c: char) -> bool {
  29     matches!(c, ')' | ']' | '}')
  30 }
  31
  32 const START_COMMENT: &str = "// tidy-alphabetical-start";
  33 const END_COMMENT: &str = "// tidy-alphabetical-end";
  34
  35 fn check_section<'a>(
  36     file: impl Display,
  37     lines: impl Iterator<Item = (usize, &'a str)>,
  38     bad: &mut bool,
  39 ) {
  40     let content_lines = lines.take_while(|(_, line)| !line.contains(END_COMMENT));
  41
  42     let mut prev_line = String::new();
  43     let mut first_indent = None;
  44     let mut in_split_line = None;
  45
  46     for (line_idx, line) in content_lines {
  47         if line.contains(START_COMMENT) {
  48             tidy_error!(
  49                 bad,
  50                 "{file}:{} found `// tidy-alphabetical-start` expecting `// tidy-alphabetical-end`",
  51                 line_idx
  52             )
  53         }
  54
  55         let indent = first_indent.unwrap_or_else(|| {
  56             let indent = indentation(line);
  57             first_indent = Some(indent);
  58             indent
  59         });
  60
  61         let line = if let Some(prev_split_line) = in_split_line {
  62             in_split_line = None;
  63             format!("{prev_split_line}{}", line.trim_start())
  64         } else {
  65             line.to_string()
  66         };
  67
  68         if indentation(&line) != indent {
  69             continue;
  70         }
  71
  72         let trimmed_line = line.trim_start_matches(' ');
  73
  74         if trimmed_line.starts_with("//")
  75             || trimmed_line.starts_with("#[")
  76             || trimmed_line.starts_with(is_close_bracket)
  77         {
  78             continue;
  79         }
  80
  81         if line.trim_end().ends_with('(') {
  82             in_split_line = Some(line);
  83             continue;
  84         }
  85
  86         let prev_line_trimmed_lowercase = prev_line.trim_start_matches(' ').to_lowercase();
  87
  88         if trimmed_line.to_lowercase() < prev_line_trimmed_lowercase {
  89             tidy_error!(bad, "{file}:{}: line not in alphabetical order", line_idx + 1,);
  90         }
  91
  92         prev_line = line;
  93     }
  94 }
  95
  96 pub fn check(path: &Path, bad: &mut bool) {
  97     walk(path, &mut filter_dirs, &mut |entry, contents| {
  98         let file = &entry.path().display();
  99
 100         let mut lines = contents.lines().enumerate().peekable();
 101         while let Some((_, line)) = lines.next() {
 102             if line.contains(START_COMMENT) {
 103                 check_section(file, &mut lines, bad);
 104                 if lines.peek().is_none() {
 105                     tidy_error!(
 106                         bad,
 107                         "{file}: reached end of file expecting `// tidy-alphabetical-end`"
 108                     )
 109                 }
 110             }
 111         }
 112     });
 113 }