public void CheckValidExtension() { var dir = "Data"; var files = Directory.EnumerateFiles(dir); ImageChecker imageChecker = new ImageChecker(); StreamUtil utils = new StreamUtil(); foreach (var file in files) { string fileName = file.Substring(dir.Length + 1); using var stream = new FileStream(file, FileMode.Open, FileAccess.Read); FileInformation fileInformation = new FileInformation() { data = utils.FileStreamToBytes(stream), fileName = fileName }; //assert imageChecker.CheckForExtension(fileInformation); } }