From a8e2b82e383dc13023b3c5aab13a40a4d582ddcb Mon Sep 17 00:00:00 2001
From: Lijun Wang <83639177+lijunwangs@users.noreply.github.com>
Date: Fri, 19 May 2023 08:24:52 -0700
Subject: [PATCH] Expect errors when opening 2nd stream due to connection limit
 (#31706)

---
 streamer/src/nonblocking/quic.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/streamer/src/nonblocking/quic.rs b/streamer/src/nonblocking/quic.rs
index 1383ec617..18c8a31b5 100644
--- a/streamer/src/nonblocking/quic.rs
+++ b/streamer/src/nonblocking/quic.rs
@@ -1232,7 +1232,16 @@ pub mod test {
         let conn1 = make_client_endpoint(&server_address, None).await;
         let conn2 = make_client_endpoint(&server_address, None).await;
         let mut s1 = conn1.open_uni().await.unwrap();
-        let mut s2 = conn2.open_uni().await.unwrap();
+        let s2 = conn2.open_uni().await;
+        if s2.is_err() {
+            // It has been noticed if there is already connection open against the server, this open_uni can fail
+            // with ApplicationClosed(ApplicationClose) error due to CONNECTION_CLOSE_CODE_TOO_MANY before writing to
+            // the stream -- expect it.
+            let s2 = s2.err().unwrap();
+            assert!(matches!(s2, quinn::ConnectionError::ApplicationClosed(_)));
+            return;
+        }
+        let mut s2 = s2.unwrap();
         s1.write_all(&[0u8]).await.unwrap();
         s1.finish().await.unwrap();
         // Send enough data to create more than 1 chunks.