From 05eb06f333ab5a4705d14121c4fe61ff15bf6cc8 Mon Sep 17 00:00:00 2001
From: MHSanaei <ho3ein.sanaei@gmail.com>
Date: Sat, 3 Oct 2026 13:43:06 +0200
Subject: [PATCH] fix(tuic): wait for both traffic counters in the relay E2E
 tests

The race job failed on TestServerUDPDatagramE2E with Up:0 Down:1300.
BytesUp is added on the sending goroutine after the relay Send returns,
while BytesDown is added on the response goroutine, so the mock echo can
be counted and delivered before the upload is. The test drained the
counters once right after the reply and assumed both were present.

Production is unaffected: deltas left for the next collection window are
still summed. The TCP E2E test made the same assumption, so both now
accumulate drained deltas until up and down reach the payload size.
---
 internal/tuic/server_test.go | 38 ++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/internal/tuic/server_test.go b/internal/tuic/server_test.go
index 5d7f7316a..baf505d79 100644
--- a/internal/tuic/server_test.go
+++ b/internal/tuic/server_test.go
@@ -196,12 +196,30 @@ func testServerTCPConnectE2E(t *testing.T, controller string) {
 		t.Fatalf("expected active email alice@example.com, got %v", activeEmails)
 	}
 
-	deltas := server.CollectClientTraffic()
-	if len(deltas) == 0 {
-		t.Fatalf("expected traffic deltas, got none")
-	}
-	if deltas[0].Email != "alice@example.com" || deltas[0].Up < int64(len(testMsg)) || deltas[0].Down < int64(len(testMsg)) {
-		t.Fatalf("unexpected traffic deltas: %+v", deltas[0])
+	waitForClientTraffic(t, server, "alice@example.com", int64(len(testMsg)))
+}
+
+// waitForClientTraffic accumulates drained deltas because the up and down counters are
+// bumped on different relay goroutines, so the echo can arrive before the upload is counted.
+func waitForClientTraffic(t *testing.T, server *Server, email string, minBytes int64) {
+	t.Helper()
+	var up, down int64
+	deadline := time.Now().Add(4 * time.Second)
+	for {
+		for _, delta := range server.CollectClientTraffic() {
+			if delta.Email != email {
+				t.Fatalf("unexpected traffic delta for %q: %+v", delta.Email, delta)
+			}
+			up += delta.Up
+			down += delta.Down
+		}
+		if up >= minBytes && down >= minBytes {
+			return
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("traffic for %s = up %d, down %d; want both >= %d", email, up, down, minBytes)
+		}
+		time.Sleep(5 * time.Millisecond)
 	}
 }
 
@@ -356,13 +374,7 @@ func testServerUDPDatagramE2E(t *testing.T, controller string) {
 	}
 
 	// 4. Verify traffic
-	deltas := server.CollectClientTraffic()
-	if len(deltas) == 0 {
-		t.Fatalf("expected traffic deltas, got none")
-	}
-	if deltas[0].Email != "bob@example.com" || deltas[0].Up < int64(len(udpMsg)) || deltas[0].Down < int64(len(udpMsg)) {
-		t.Fatalf("unexpected traffic deltas: %+v", deltas[0])
-	}
+	waitForClientTraffic(t, server, "bob@example.com", int64(len(udpMsg)))
 }
 
 func TestServerUDPStreamE2E(t *testing.T) {