Mockito doAnswer & thenReturn in one method

Question

I have a situation where my method is returning some object, and method is containing some arguments and I have condition on the basis of returned response and one of the argument.

Map<String,List<Object>> testMap = new HashMap<>(); 
Object obj = new Object(); 

Set<String> test = myService.getModelSearchStrings(testMap, obj);
if(CollectionUtils.isNotEmpty(test){

}

if(MapUtils.isNotEmpty(testMap){

}

Test:

Set<String> result = new HashSet<>();
result.add("123");

Mockito.when(mockedMtnService.getModelSearchStrings(Mockito.anyMap(), Mockito.anyObject())).thenReturn(result);

I want to return Dummy response i.e. result HashSet and want to update argument value(Map).

Answer 1

I can only assume that you are looking for thenAnswer & Answer. With thenAnswer you can modify the arguments of the mocked method and also return a result from that method.

E.g:

Set<String> result = new HashSet<>();
result.add("123");

Mockito.when(mockedMtnService.getModelSearchStrings(Mockito.anyMap(), Mockito.anyObject())).thenAnswer(new Answer<Set>() {
    @Override
    public String answer(InvocationOnMock invocation) throws Throwable {
        Map<String,List<Object>> mapArg = (Map<String,List<Object>>)invocation.getArguments()[0];
        // do something with mapArg....
        return result;
    }
});

Or with Java 8 lambda:

Mockito.when(mockedMtnService.getModelSearchStrings(Mockito.anyMap(), Mockito.anyObject())).thenAnswer(invocation -> {
    Map<String,List<Object>> mapArg = (Map<String,List<Object>>)invocation.getArguments()[0];
    // do something with mapArg....
    return result;
});