fix(agent): retire replaced tunnel sessions (#541)

go-gost/x/internal/util/sessionretire/sessionretire_test.go

@@ -0,0 +1,59 @@
+package sessionretire
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+type testSession struct {
+	mu      sync.Mutex
+	streams int
+	closed  bool
+}
+
+func (s *testSession) Close() error {
+	s.mu.Lock()
+	s.closed = true
+	s.mu.Unlock()
+	return nil
+}
+
+func (s *testSession) IsClosed() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.closed
+}
+
+func (s *testSession) NumStreams() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.streams
+}
+
+func TestWaitUntilIdlePreservesActiveStreams(t *testing.T) {
+	session := &testSession{streams: 1}
+	done := make(chan struct{})
+	go func() {
+		waitUntilIdle(session, 20*time.Millisecond, time.Millisecond)
+		close(done)
+	}()
+
+	time.Sleep(30 * time.Millisecond)
+	if session.IsClosed() {
+		t.Fatal("active session was closed")
+	}
+
+	session.mu.Lock()
+	session.streams = 0
+	session.mu.Unlock()
+
+	select {
+	case <-done:
+	case <-time.After(250 * time.Millisecond):
+		t.Fatal("idle session was not closed")
+	}
+	if !session.IsClosed() {
+		t.Fatal("retired session did not close after becoming idle")
+	}
+}