Mocking a method within a class using Mockito spy

Question

class Temp() {

public boolean methodA(String param) {

     try {

         if(methodB(param))
               return true;

         return false;
     } catch (Exception e) {
           e.printStackTrace();
     }
}
}

The test class

@Test
public void testMethodA() {

Temp temp = new Temp();
Temp spyTemp = Mockito.spy(temp);

Mockito.doReturn(true).when(spyTemp).methodB(Mockito.any()); 
boolean status = temp.methodA("XYZ");

Assert.assertEquals(true, status);
}

When calling the real class temp to methodA should return the mocked method B value. Thus returning true. Why is this incorrect. I encounter the same problem. I want to run the test on the real class and not for mock object as suggested by the answer. I want to run the class methodA and expect the mocked object spyTemp methodB value when it is called

Please post a [mcve]. It's `methodB(param)` in the linked question not `methodB()` — , Oct 12 '17 at 13:03
I don't get why you have to re-ask the linked question. The answer there already answers your question here. — Tom, Oct 12 '17 at 13:14
so now i need to know if methodB is public or not. if it´s private you need to handle it like it´s code is written into methodA and if it´s public you could mock it. — LenglBoy, Oct 12 '17 at 13:15

LenglBoy · Accepted Answer · 2017-10-12T13:24:59.623

Here is the Problem: methodA() you´re callint is from temp and you´ve defined a returning value from tempSPY.

So you need to call tempSpy.methodA() and then it´s returning the value of methodB() you´ve defined.

Here the solution if methodB() is public - spy temp/cut and call it this way:

// temp = cut
@Test
public void testMethodA_valid() {
    // given
    Temp spyTemp = Mockito.spy(temp);
    boolean expected = true;
    Mockito.doReturn(expected).when(spyTemp).methodB(Mockito.any(String.class)); 

    // when
    boolean actual = spyTemp.methodA("XYZ");

    // then (faster readable)       
    Mockito.verify(spyTemp, times(1)).methodB(any(String.class))
    Mockito.verifyNoMoreInteraction(<ALL YOUR MOCKS HERE>);
    Assert.assertEquals(expected, is(equalTo(actual)));
}

If methodB() is private you can´t define what it should return. Then is´t just this and if error occures then methodB() got wrong behaviour:

@Test
public void testMethodA_valid() {
    // given
    boolean expected = true;

    // when
    boolean actual = temp.methodA("XYZ");

    // then (faster readable)       
    Assert.assertEquals(expected, is(equalTo(actual)));
}

But what if I want to run the class methodA and expect the mocked object spyTemp methodB value when it is called — learningUser, Oct 12 '17 at 13:07
no sense there. so sou´re goint to tell you testclass/method what it should return an then assert it. you willl pass it every time and you can´t check any wrong behaviour. — LenglBoy, Oct 12 '17 at 13:12
and don´t use hardcoded values. just set `expectedValue = true` and assert it with `actualValue` from method call — LenglBoy, Oct 12 '17 at 13:13

Mocking a method within a class using Mockito spy

1 Answers1