public async Task Send_request_for_navigation_unit_test() { var _navigateRequestRepository = new Mock <INavigateRequestRepository>(); var _navigationRequestService = new Mock <INavigationRequestService>(); var _mvxNavigationService = new Mock <IMvxNavigationService>(); var _messageRepository = new Mock <IMessageRepository>(); var chatParematers = _fixture.Create <ChatParameters>(); var sut = new ChatViewModel( _navigateRequestRepository.Object, _navigationRequestService.Object, _messageRepository.Object, _mvxNavigationService.Object ); await sut.PrepareAsync(chatParematers); await sut.SendNavigationRequest(); _navigationRequestService.Verify(v => v.InitiatNavigationRequest(It.IsAny <NavigateRequest>())); // TODO: figure out the parameter meaning of following line, why null? _mvxNavigationService.Verify(v => v.Navigate <RequestViewModel, NavigateRequestParameters>(It.Is <NavigateRequestParameters>(c => c.Chat == chatParematers.Chat), null)); }