fixed test to properly wait for goroutine completion

dataext/pubsub_test.go

@@ -129,15 +129,17 @@ func TestPubSub_SubscribeByIter(t *testing.T) {
 
 	// Channel to communicate when message is received
 	done := make(chan bool)
+	goroutineDone := make(chan struct{})
 	received := false
 
 	// Start a goroutine to use the iterator
 	go func() {
+		defer close(goroutineDone)
 		for msg := range iterSeq {
 			if msg == "hello" {
 				received = true
 				done <- true
-				return // Stop iteration
+				return // Stop iteration — triggers Unsubscribe via yield returning false
 			}
 		}
 	}()
@@ -158,6 +160,14 @@ func TestPubSub_SubscribeByIter(t *testing.T) {
 		t.Fatal("Timed out waiting for message")
 	}
 
+	// Wait for the goroutine to fully exit so Unsubscribe (triggered by the
+	// iterator cleanup when yield returns false) has completed.
+	select {
+	case <-goroutineDone:
+	case <-time.After(time.Second):
+		t.Fatal("Timed out waiting for goroutine to finish")
+	}
+
 	subCount := ps.SubscriberCount("test-ns")
 	if subCount != 0 {
 		t.Fatalf("Expected 0 receivers, got %d", subCount)