How to use MockMvc with mock of controller

Question

I have this contoller method:

@RequestMapping(value = "/addEvent", method = RequestMethod.POST)
    public String addEvent(Model model,
            @Valid @ModelAttribute("myEvent") Event event,
            BindingResult result, RedirectAttributes redirectAttributes,
            @RequestParam(required = true) Integer selectedEventTypeId,
            @RequestParam(required = true) Integer selectedEventStatusId) {

        if (result.getErrorCount() > 1 ){
            return "eventDetailsAdd";
        }
        eventService.addEvent(event, selectedEventTypeId, selectedEventStatusId);
        redirectAttributes.addAttribute("idEvent", event.getId());
        redirectAttributes.addAttribute("message", "added correctly at " + new Date() );
        return "redirect:eventDetails";
    }

Using mockMvc I want to mock result and check in both varians of if (result.getErrorCount() > 1 )

How I can make it?

Answer 1

With MockMvc, you cannot. MockMvc is a type of HTTP client. You generate your HTTP request with the MockMvcRequestBuilders, setup your headers, request parameters, body, and URL. MockMvc will mock sending the request integrating the full DispatcherServlet stack.

If you want to mock the BindingResult argument, I suggest you test your @Controller class independently.

// in @Test
MyController controller = new MyController(/* maybe other arguments */)
// generate your mocks and declare expectations
controller.addEvent(/* mocks go here */);
// verify your mocks