Function comment_width

xtask/src/main.rs:187–209

(explicit: Option<usize>, rustfmt_config: &Path)

}

fn comment_width(explicit: Option<usize>, rustfmt_config: &Path) -> Result<usize> {
    if let Some(width) = explicit {
        return validate_width(width);
    }

    let source = match fs_err::read_to_string(rustfmt_config) {
        Ok(source) => source,
        Err(err) if err.kind() == ErrorKind::NotFound => return Ok(100),
        Err(err) => {
            return Err(err).with_context(|| format!("reading {}", rustfmt_config.display()));
        },
    };

    let config = toml::from_str::<toml::Value>(&source)
        .context("parsing rustfmt config for comment_width")?;
    let width = config
        .get("comment_width")
        .and_then(toml::Value::as_integer)
        .and_then(|width| usize::try_from(width).ok())
        .unwrap_or(100);

    validate_width(width)
}

fn validate_width(width: usize) -> Result<usize> {
    ensure!(width >= 20, "comment width must be at least 20 columns");