public async Task Delete_NoSuchRegistration_ReturnsBadRequest()
        {
            // Arrange 
            var user = DummyData.UserFaker.Generate();
            var registrationId = Guid.NewGuid();

            _sut.ControllerContext = FakeControllerContext.For(user);

            _userRepository.GetBy(user.Email).Returns(user);
            _registrationRepository.GetBy(Arg.Any<Guid>(), user.Email).ReturnsNull();

            var appUser = FakeAppUser.For(user).WithClaims("admin");
            _um.FindByNameAsync(user.Email).Returns(Task.FromResult(appUser));


            // Act 
            var numberOfRegistrations = user.Registrations.Count;
            var result = await _sut.DeleteAsync(registrationId);

            // Assert 
            result.Should().BeOfType<BadRequestResult>();

            user.Registrations.Count.Should().Be(numberOfRegistrations);
            _userRepository.Received().GetBy(user.Email);
            _registrationRepository.Received().GetBy(registrationId, user.Email);
            _registrationRepository.DidNotReceive().Delete(Arg.Any<Registration>(), user.Email);
        }
        public void SearchWalk_WalkerNotFound_ReturnsNotFound()
        {
            // Arrange
            var walker = DummyData.UserFaker.Generate();

            _userRepository.GetBy(walker.Email).ReturnsNull(); //!

            // Act
            var result = _sut.SearchWalk(walker.Email);

            // Assert
            result.Should().BeOfType <NotFoundObjectResult>();

            _userRepository.Received().GetBy(walker.Email);
            _registrationRepository.DidNotReceive().GetLast(walker.Email);
            _walkRepository.DidNotReceiveWithAnyArgs().GetByUserAndRoute(default, default);