public void TestGetByEmailNull() { Administrator administrator = new Administrator() { Id = 1, Email = "*****@*****.**", Password = "******" }; List <Administrator> administrators = new List <Administrator>() { administrator, new Administrator() { Id = 2, Email = "*****@*****.**", Password = "******" }, }; administrators.ForEach(s => _context.Add(s)); _context.SaveChanges(); var repository = new AdministratorRepository(_context); var result = repository.GetByEmail("*****@*****.**"); Assert.IsNull(result); }