public void TestAllTracks() { var options = new DbContextOptionsBuilder <MusicSpotDbContext>().UseInMemoryDatabase("returnTrackNotNull").Options; var dbContext = new MusicSpotDbContext(options); var service = new TrackService(dbContext); var track = new Track { Name = "Joni", Duration = "4:44", AlbumId = 4 }; dbContext.Tracks.Add(track); dbContext.SaveChanges(); var result = service.AllTracks(4); Assert.That(result, Is.Not.Null); Assert.AreNotEqual("aaaaaa", result.Result.UserId); }