public async Task DeleteAuthorAsync_Test() { using (var context = new LibraryContext(Utilities.TestDbContextOptions())) using (ILibraryRepository repository = new LibraryRepository(context)) { // Arrange context.Authors.Add(new Author() { Id = new Guid("a1da1d8e-1988-4634-b538-a01709477b77"), FirstName = "Jens", LastName = "Lapidus", Genre = "Thriller", DateOfBirth = new DateTimeOffset(new DateTime(1974, 5, 24)), Books = new List <Book>() { new Book() { Id = new Guid("1325360c-8253-473a-a20f-55c269c20407"), Title = "Easy Money", Description = "Easy Money or Snabba cash is a novel from 2006 by Jens Lapidus." } } }); context.SaveChanges(); var author = await repository.GetAuthorAsync(Guid.Parse("a1da1d8e-1988-4634-b538-a01709477b77")); Assert.NotNull(author); // Act await repository.DeleteAuthorAsync(author); await repository.SaveChangesAsync(); // Assert var NonAuthor = await repository.GetAuthorAsync(Guid.Parse("a1da1d8e-1988-4634-b538-a01709477b77")); Assert.Null(NonAuthor); } }