public void AllShouldReturnCollectionOfGenres() { var options = new DbContextOptionsBuilder <BookStoreDbContext>() .UseInMemoryDatabase(Guid.NewGuid().ToString()) .Options; // var dbContext = new BookStoreDbContext(options); var genreServices = new GenreService(dbContext); var history = new Genre { Name = "History" }; dbContext.Genres.Add(history); var music = new Genre { Name = "Music" }; dbContext.Genres.Add(music); dbContext.SaveChanges(); var genreCollection = genreServices.All().ToList(); Assert.True(genreCollection.Count == 2); Assert.True(genreCollection[0].Name == "History"); Assert.True(genreCollection[1].Name == "Music"); }