public void RenameFiles() { MockFileSystem fileSystem = new MockFileSystem(new[] { @"Bullet For My Valentine - Cries in Vain.mp3", @"Anne-Marie - Ciao Adios.mp3" }); IActionStrategy fileNameAction = new FileNameAction(); foreach (string file in fileSystem.AllFiles) { AudioFile mp3File = new TestableMp3File(file, fileSystem); string artist = GetRandomString(); string title = GetRandomString(); mp3File.Artist = artist; mp3File.Title = title; fileNameAction.Process(mp3File); Assert.AreEqual(true, fileSystem.Exists($@"{artist} - {title}.mp3")); } }