as-rust/global/tests/appender_test.rs

use tracing::{info};
use tracing_subscriber::{fmt};
use tracing_subscriber::prelude::*;
use std::io;

#[tokio::test]
async fn appender_test() {
    let file_appender = tracing_appender::rolling::daily("./logs", "tracing.log");
    let (non_blocking, _) = tracing_appender::non_blocking(file_appender);

    let fmt_layer = fmt::layer()
        .with_target(false)
        .with_level(true)
        .with_writer(io::stdout);

    let file_layer = fmt::layer()
        .with_target(true)
        .with_ansi(false)
        .with_level(true)
        .with_writer(non_blocking.clone());

    let subscriber = tracing_subscriber::Registry::default()
        .with(fmt_layer)
        .with(file_layer)
        .with(tracing_subscriber::EnvFilter::new("info"));

    let _ = tracing::subscriber::set_global_default(subscriber);
    let number = 42;
    info!(answer = number, "the answer to life, the universe, and everything");

    // 使 main 函数“等待”一段时间，增大日志被正确写入的机会
    tokio::time::sleep(std::time::Duration::from_secs(10)).await;
}