public void DbWorkerCreateRecord() { //reset setting if (File.Exists("Record.txt")) { File.Delete("Record.txt"); } //internal is visible because [assembly:InternalsVisibleTo("UnitTestProject1")] in AssemblyInfo.cs IOracle connectorOracle = new Oracle("", new Logger2()); connectorOracle.CreateNewRecord(); Assert.IsTrue(File.Exists("Record.txt")); //C:\Users\valdaufj\source\repos\ArmasterCZ\2020.05.21_DependenciInjection\UnitTestProject1\bin\Debug }