test(channel): harden Lark WS heartbeat activity handling

src/channels/lark.rs

@@ -127,6 +127,12 @@ struct LarkMessage {
 /// If no binary frame (pong or event) is received within this window, reconnect.
 const WS_HEARTBEAT_TIMEOUT: Duration = Duration::from_secs(300);
 
+/// Returns true when the WebSocket frame indicates live traffic that should
+/// refresh the heartbeat watchdog.
+fn should_refresh_last_recv(msg: &WsMsg) -> bool {
+    matches!(msg, WsMsg::Binary(_) | WsMsg::Ping(_) | WsMsg::Pong(_))
+}
+
 /// Lark/Feishu channel.
 ///
 /// Supports two receive modes (configured via `receive_mode` in config):
@@ -321,12 +327,20 @@ impl LarkChannel {
 
                 msg = read.next() => {
                     let raw = match msg {
-                        Some(Ok(WsMsg::Binary(b))) => { last_recv = Instant::now(); b }
-                        Some(Ok(WsMsg::Ping(d))) => { last_recv = Instant::now(); let _ = write.send(WsMsg::Pong(d)).await; continue; }
-                        Some(Ok(WsMsg::Pong(_))) => { last_recv = Instant::now(); continue; }
-                        Some(Ok(WsMsg::Close(_))) | None => { tracing::info!("Lark: WS closed — reconnecting"); break; }
+                        Some(Ok(ws_msg)) => {
+                            if should_refresh_last_recv(&ws_msg) {
+                                last_recv = Instant::now();
+                            }
+                            match ws_msg {
+                                WsMsg::Binary(b) => b,
+                                WsMsg::Ping(d) => { let _ = write.send(WsMsg::Pong(d)).await; continue; }
+                                WsMsg::Pong(_) => continue,
+                                WsMsg::Close(_) => { tracing::info!("Lark: WS closed — reconnecting"); break; }
+                                _ => continue,
+                            }
+                        }
+                        None => { tracing::info!("Lark: WS closed — reconnecting"); break; }
                         Some(Err(e)) => { tracing::error!("Lark: WS read error: {e}"); break; }
-                        _ => continue,
                     };
 
                     let frame = match PbFrame::decode(&raw[..]) {
@@ -899,6 +913,19 @@ mod tests {
         assert_eq!(ch.name(), "lark");
     }
 
+    #[test]
+    fn lark_ws_activity_refreshes_heartbeat_watchdog() {
+        assert!(should_refresh_last_recv(&WsMsg::Binary(vec![1, 2, 3])));
+        assert!(should_refresh_last_recv(&WsMsg::Ping(vec![9, 9])));
+        assert!(should_refresh_last_recv(&WsMsg::Pong(vec![8, 8])));
+    }
+
+    #[test]
+    fn lark_ws_non_activity_frames_do_not_refresh_heartbeat_watchdog() {
+        assert!(!should_refresh_last_recv(&WsMsg::Text("hello".into())));
+        assert!(!should_refresh_last_recv(&WsMsg::Close(None)));
+    }
+
     #[test]
     fn lark_user_allowed_exact() {
         let ch = make_channel();