test: improve test_txt_public_stun_server with timeout and retry mechanism (#2014)

easytier/src/common/stun.rs

@@ -1342,6 +1342,7 @@ mod tests {
         common::scoped_task::ScopedTask,
         tunnel::{udp::UdpTunnelListener, TunnelListener},
     };
+    use tokio::time::{sleep, timeout};
 
     use super::*;
 
@@ -1399,18 +1400,20 @@ mod tests {
     async fn test_txt_public_stun_server() {
         let stun_servers = vec!["txt:stun.easytier.cn".to_string()];
         let detector = UdpNatTypeDetector::new(stun_servers, 1);
-        for _ in 0..5 {
+        timeout(Duration::from_secs(30), async {
+            loop {
                 let ret = detector.detect_nat_type(0).await;
                 println!("{:#?}, {:?}", ret, ret.as_ref().map(|x| x.nat_type()));
                 if let Ok(resp) = ret {
-                assert!(!resp.stun_resps.is_empty());
+                    if !resp.stun_resps.is_empty() {
                         return;
                     }
                 }
-        debug_assert!(
+                sleep(Duration::from_secs(1)).await;
-            false,
+            }
-            "should not reach here, stun server should be available"
+        })
-        );
+        .await
+        .expect("stun server should be available");
     }
 
     #[tokio::test]