dioxus/packages/core/tests/test_logging.rs

pub fn set_up_logging(enabled: bool) {
    use fern::colors::{Color, ColoredLevelConfig};
    use log::debug;

    if !enabled {
        return;
    }

    // configure colors for the whole line
    let colors_line = ColoredLevelConfig::new()
        .error(Color::Red)
        .warn(Color::Yellow)
        // we actually don't need to specify the color for debug and info, they are white by default
        .info(Color::White)
        .debug(Color::White)
        // depending on the terminals color scheme, this is the same as the background color
        .trace(Color::BrightBlack);

    // configure colors for the name of the level.
    // since almost all of them are the same as the color for the whole line, we
    // just clone `colors_line` and overwrite our changes
    let colors_level = colors_line.clone().info(Color::Green);
    // here we set up our fern Dispatch

    // when running tests in batch, the logger is re-used, so ignore the logger error
    let _ = fern::Dispatch::new()
        .format(move |out, message, record| {
            out.finish(format_args!(
                "{color_line}[{level}{color_line}] {message}\x1B[0m",
                color_line = format_args!(
                    "\x1B[{}m",
                    colors_line.get_color(&record.level()).to_fg_str()
                ),
                level = colors_level.color(record.level()),
                message = message,
            ));
        })
        // set the default log level. to filter out verbose log messages from dependencies, set
        // this to Warn and overwrite the log level for your crate.
        .level(log::LevelFilter::Debug)
        // .level(log::LevelFilter::Warn)
        // change log levels for individual modules. Note: This looks for the record's target
        // field which defaults to the module path but can be overwritten with the `target`
        // parameter:
        // `info!(target="special_target", "This log message is about special_target");`
        // .level_for("dioxus", log::LevelFilter::Debug)
        // .level_for("dioxus", log::LevelFilter::Info)
        // .level_for("pretty_colored", log::LevelFilter::Trace)
        // output to stdout
        .chain(std::io::stdout())
        .apply();
}