public void TestDoesNotSeeInvalidFiles()
        {
            var monitor = new DirectoryMonitor(DirectoryName);

            monitor.MarkFileNameAsInvalid(TestFileName1);
            var fileNames = monitor.GetUnprocessedFileNames().OrderBy(s => s).ToList();

            Assert.AreEqual <int>(fileNames.Count, 1);
            Assert.AreEqual <string>(fileNames[0], TestFileName2);
        }
        public void SeesOnlyNewFiles()
        {
            var monitor = new DirectoryMonitor(DirectoryName);

            monitor.MarkFileNameAsProcessed(TestFileName1);
            monitor.MarkFileNameAsInvalid(TestFileName2);
            var fileNames = monitor.GetUnprocessedFileNames().OrderBy(s => s).ToList();

            Assert.AreEqual <int>(fileNames.Count, 0);

            var fs3 = File.Create(TestFileName3);

            fs3.Close();

            fileNames = monitor.GetUnprocessedFileNames().OrderBy(s => s).ToList();
            Assert.AreEqual <int>(fileNames.Count, 1);
            Assert.AreEqual <string>(fileNames[0], TestFileName3);
        }