How to mock a value to test a conditional in another method with JUnit/Mockito?

Question

I am new to JUnit and Mockito, and am struggling trying to mock a value coming back from a boolean method to hit inside a conditional.

I have tried the answer from this post, but doesn't seem to work for this. I’ve tried using spy, thenCallRealMethod, can’t figure it out.

I have tested for when the value is true, but I cannot seem to get inside the else part for the test.

Here an example of what I've done:

ServiceImpl.java has a method register() that calls a boolean method shouldRegister(). The shouldRegister() method simply checks another service to see if a boolean value is true or false, and then returns that.

If true, it builds a JsonNode payload to send, else, if false, it removes one field from the payload.

// ServiceImpl.java:

// in the record() method: 

if (body.has("fieldtoBeRemoved")) {
   if (shouldRegister()) {
      ((ObjectNode) body).set("fieldtoBeRemoved");
    } else {
       // this is the line I am trying to test
       ((ObjectNode) body).remove("fieldtoBeRemoved");
       }
   }

// method being called above in the conditional
protected boolean shouldRegister() {
        Optional<String> flag = configService.getString("booleanValue");
        String stringFlag = flag.orElse("false");
        return BooleanUtils.toBoolean(stringFlag);
    }


// In the test

@InjectMocks
private ServiceImpl serviceImpl;

@Test
public void testingForFalse() {
     serviceImpl = new ServiceImpl();

     // what I am struggling with, trying to make the value false,
     // so that it hits the else in the record() method in ServiceImpl
    // and removes fieldtoBeRemoved from the payload
    when(serviceImpl.shouldRegister()).thenCallRealMethod();
   doReturn(false).when(spy(serviceImpl)).shouldRegister();

    assertThat(fieldtoBeRemoved, is(""));

}

When I run this, it fails because the value of fieldtoBeRemoved is not empty, it has the value from the field in the payload, which it should not have. I’m guessing the value is still coming back as true because I’m not mocking it correctly/setting it to be false for this test case. I’ve also tried mocking the call to the record() method. Any help appreciated!

score 0 · Accepted Answer · answered Jun 26 '19 at 06:35

0

You can do something like this if the source and test are in the same package and the shouldRegister at least package-private

@Test
public void testingForFalse() {
    serviceImpl = new ServiceImpl() {
        @Override
        public boolean shouldRegister() {
            return false;
        }
    }

    // rest of the test
}

In this case you don't need any mocking for this method.

answered Jun 26 '19 at 06:35

Rashin

726
6
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Sadly they are not in the same package :( – vtboyarc Jun 26 '19 at 12:10
if the `shouldRegister` method is public then it should still work. – Rashin Jun 26 '19 at 12:12
Darn, it compiles and does run, however same thing, failed because the value of the field is not being removed still. – vtboyarc Jun 26 '19 at 12:57
Can you post the whole test method and the method that you want to test as well? – Rashin Jun 26 '19 at 13:26

How to mock a value to test a conditional in another method with JUnit/Mockito?

1 Answers1