public async void GetOwnerApplicationUserShouldReturnCorrectUser() { var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(Guid.NewGuid().ToString()); var userRepository = new EfDeletableEntityRepository <ApplicationUser>(new ApplicationDbContext(options.Options)); var dogsitterRepository = new EfDeletableEntityRepository <Dogsitter>(new ApplicationDbContext(options.Options)); var ownerRepository = new EfDeletableEntityRepository <Owner>(new ApplicationDbContext(options.Options)); var ownersService = new OwnersService(userRepository, ownerRepository, dogsitterRepository); var user = new ApplicationUser(); var owner = new Owner { User = user, UserId = user.Id, }; user.Owner = owner; await userRepository.AddAsync(user); await userRepository.SaveChangesAsync(); var appUser = ownersService.GetOwnerApplicationUser(owner.Id); Assert.Equal(user.Id, appUser.Id); }