MockMvc fails because of method invocation inside the controller method - mockito

Question

I try to mock a controller which contains a util method inside even though I mock the util method, the mvcMock ignore the result from the when(...) and call the method again with empty parameters which lead to nullpointerexception
How I can ship the call of
when(utilMock.getOperatorsAdNameWrapper(userName, adNames)).thenReturn(roleSet);
with the mockMvc.perform?
#GetMapping(value = {"/wellbore"})
public String wellboreForm(Model model, #RequestParam("mode") String mode, HttpServletRequest request) {
Set<String> operators = new LinkedHashSet<>();
String userName = (String) request.getSession().getAttribute("userName");
Set<String> operatorsSet = (HashSet<String>) request.getSession().getAttribute("userRoles");
Set<String> operatorsAdName = util.getOperatorsAdNameWrapper(userName, operatorsSet);
operatorsAdName.forEach(adName -> {
Query query = new Query()
.setClassname(Wellbore.CLASS)
.eq(Wellbore.operatorsGroup, adName);
operators.addAll(getWellboresNameList(query));
});
model.addAttribute("wellboreDataList", operators);
model.addAttribute("wellboreData", new WellboreForm());
return "ui/selectWellbore";
}
public static Set<String> getOperatorsAdName(String userName, Set<String> operatorsAdName) {
operatorsAdName.removeIf(x -> x.equals(userName)
|| x.equals("SCOUT")
|| x.equals("GTO")
|| x.equals("KADME")
|| x.equals("offline_access")
|| x.equals("uma_authorization"));
return operatorsAdName;
}
public Set<String> getOperatorsAdNameWrapper(String userName, Set<String> operatorsAdName) {
return getOperatorsAdName(userName,operatorsAdName);
}
#Mock
private Util utilMock;
#Test
#DisplayName("GET /wellbore - Select Wellbore")
void testMockMvc() throws Exception {
HttpServletRequest req = Mockito.mock(HttpServletRequest.class);
when(req.getAttribute("userName")).thenReturn("abcd");
String userName = (String) req.getAttribute("userName");
//Here I get the correct result Result
when(utilMock.getOperatorsAdNameWrapper(userName, adNames)).thenReturn(roleSet);
//another call made here with empy parameters to utilMock.getOperatorsAdNameWrapper("", null)
mockMvc.perform(get("/wellbore").param("mode","selectWellbore")
.sessionAttr("wellboreDataList", new LinkedHashSet<>())
.sessionAttr("wellboreData", new WellboreForm())
)
.andExpect(status().isOk())
.andExpect(view().name("ui/selectWellbore"))
.andExpect(model().attribute("wellboreDataList", hasSize(2)));
}

Answer 1

1) In the Controller move the line:
util.getOperatorsAdNameWrapper(userName, operatorsSet);
into a package level method:
Set<String> getOperatorsAdNameWrapper(userName, operatorsSet){
return util.getOperatorsAdNameWrapper(userName, operatorsSet);
}
2) In your test use SpyBean:
#SpyBean
private Controller controllerSpy;
#Test
#DisplayName("GET /wellbore - Select Wellbore")
void testMockMvc() throws Exception {
doReturn(roleSet).when(controllerSpy).getOperatorsAdNameWrapper(userName, adNames);
The general gist is that you cannot mock a static call with vanilla Mockito. You have to refactor a bit first.

Answer 2

The Problem was with the Util class
since I am using mockmvc as unit testing, not as integration test by standaloneSetup
mockMvc = MockMvcBuilders
//To avoid loading springContext
.standaloneSetup(controller)
.setViewResolvers(viewResolver())
.build();
so the Util class not loaded to the context to solve this you have to option
Move the wrapper method in the util class to the service class and from there you can wrapper the static method in the Util class
Add the util class to the controller constructor