linecheck 1.0.0

A fast, configurable tool that warns or errors when files exceed a set line count
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

//! Low-level line counting and inline-ignore detection.
use anyhow::{Context, Result};
use std::fs;
use std::path::Path;

// Escape ':' as \x3a so this file does not contain the marker as a raw literal
// and accidentally ignore itself when linecheck scans its own source tree.
const IGNORE_MARKER: &[u8] = b"linecheck\x3aignore";

/// Read `path` and return `(line_count, is_ignored)`.
///
/// `is_ignored` is `true` when the file contains the ignore marker anywhere.
pub fn file_info(path: &Path) -> Result<(usize, bool)> {
    let data = fs::read(path).with_context(|| format!("reading {}", path.display()))?;
    let ignored = data
        .windows(IGNORE_MARKER.len())
        .any(|w| w == IGNORE_MARKER);
    Ok((count_newlines(&data), ignored))
}

/// Count logical lines in raw file bytes.
///
/// A file with no trailing newline has its last line counted anyway, so
/// `"hello\nworld"` returns 2 just like `"hello\nworld\n"`.
pub fn count_newlines(data: &[u8]) -> usize {
    if data.is_empty() {
        return 0;
    }
    let newlines = data.iter().filter(|&&b| b == b'\n').count();
    if data.last() != Some(&b'\n') {
        newlines + 1
    } else {
        newlines
    }
}

#[cfg(test)]
#[path = "lines_tests.rs"]
mod tests;