linecheck 1.1.0

A fast, configurable tool that warns or errors when files exceed a set line count
Documentation 
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//! 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()))?;
    Ok(content_info(&data))
}

/// Compute `(line_count, is_ignored)` directly from in-memory bytes (used by
/// WASM bindings). Binary content is treated as ignored — its raw newline
/// bytes aren't meaningful lines.
#[must_use]
pub fn content_info(data: &[u8]) -> (usize, bool) {
    let ignored = content_inspector::inspect(data).is_binary()
        || data
            .windows(IGNORE_MARKER.len())
            .any(|w| w == IGNORE_MARKER);
    (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"`.
#[must_use]
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;