Created test for QueryEndpoint.Singe/SingleOrDefault

Author: alex-kulakov

Orm/Xtensive.Orm.Tests.Framework/QueryExecutionDetector.cs

@@ -0,0 +1,33 @@
+// Copyright (C) 2026 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+using System;
+using Xtensive.Core;
+
+namespace Xtensive.Orm.Tests
+{
+  public sealed class QueryExecutionDetector
+  {
+    private int dbCommandCounter = 0;
+    private int queryCounter = 0;
+
+    public bool DbCommandsDetected => dbCommandCounter > 0;
+    public bool QueriesDetected => queryCounter > 0;
+
+    public IDisposable Attach(Session session)
+    {
+      session.Events.DbCommandExecuted += Events_DbCommandExecuted;
+
+      return new Disposable((b) => { session.Events.DbCommandExecuted -= Events_DbCommandExecuted; });
+    }
+
+    public void Reset()
+    {
+      dbCommandCounter = 0;
+      queryCounter = 0;
+    }
+
+    private void Events_DbCommandExecuted(object sender, DbCommandEventArgs e) => dbCommandCounter++;
+  }
+}