Handling orElseThrow

Question

My method looks like this

public EP updateEP(long id, EP eP) {
        EE eE = eRepo.findById(id).orElseThrow(EntityNotFoundException::new);
        //some code
    }

and my test method looks like this

    @Test
    public void testUpdateEWhenEExists() {
        long id = 1l;
        EE eE = new EE();
        eE.setPosId(1l);
        eE.setPosName("pos");
        EPE ePE = new EPE();
        ePE.setEId(id);
     when(eRepo.findById(id).orElseThrow(EntityNotFoundException::new)).thenReturn(eE);
        //some code
    }

And it always throw EntityNotFoundException.I want to be returned to me eE instead of EntityNotFoundException

EDIT

    @Test
    public void testUpdateEPWhenEExists() {
        long id = 1l;
        EE eE = new E();
        eE.setPositionId(1l);
        eE.setPosName("pos");
        EPE ePE = new EPE();
        ePE.setEId(id);

        when(eRepo.findById(id)).thenReturn(Optional.of(eE));
    
    }

In this case error is

org.mockito.exceptions.misusing.WrongTypeOfReturnValue: 
EPE cannot be returned by findById()
findById() should return Optional

`when(eRepo.findById(id)).thenReturn(eE)` should do the trick — Federico klez Culloca, Mar 31 '22 at 13:08
Then i have to lie down in ```thenReturn``` ```Optional.of(eE)``` and it doesn`t help me. — Uga Rimad, Mar 31 '22 at 13:11
What do you mean you have to lie down? EDIT: nevermind, I see what you mean, then just return an `Option.of(eE)` — Federico klez Culloca, Mar 31 '22 at 13:14
Yeah, I understood just after I posted my comment, see the edited version. — Federico klez Culloca, Mar 31 '22 at 13:17
Could you see my comment on the answer below, I tried the same advice) — Uga Rimad, Mar 31 '22 at 13:20
How are `eRepo` in the first snippet and `eRepository` in the test declared, respectively? (i.e., what type are they) — Federico klez Culloca, Mar 31 '22 at 13:29

score 2 · Accepted Answer · answered Mar 31 '22 at 13:14

2

From the code sample you've provided it seems that eRepo.findById(id) returns an Optional.

eRepo.findById(id).orElseThrow(...)

receives that Optional and basically checks, if the Optional is empty. If not, it returns the instance of EE, otherwise it throws the specified exception.

In your test there is no need to call

orElseThrow(EntityNotFoundException::new)

because you're explicitly mocking the behaviour of findById. Just do it like that:

when(eRepo.findById(id)).thenReturn(Optional.of(eE));

answered Mar 31 '22 at 13:14

grange

582
5
17

I did as you said and this is the result ```org.mockito.exceptions.misusing.WrongTypeOfReturnValue: EPE cannot be returned by findById() findById() should return Optional``` – Uga Rimad Mar 31 '22 at 13:18
please provide code snippets from your repository and your test. It seems that you try to return Optional.of(ePE) instead of Optional.of(eE); – grange Mar 31 '22 at 13:22
I need the full classes in an example because I can't see what you're trying to do exactly. And please don't modify the original question, because all comments and answers won't match the question after that. Just add a new answer with your changed code samples. – grange Mar 31 '22 at 13:33

score 1 · Answer 2 · answered Apr 12 '22 at 20:15

I am posting this to help anyone find this quicker. I needed to assert the message and condition for the exception in a .orElseThrow() from an JPA repository. The normal case is obvious to return Optional.of(someDataYouAlreadyMockedUp), but to get the exception , the repository stream must get a null (Empty) so use Optional.empty() ...

In my code I have

    License license = licenseRepository.findById(licenseId).orElseThrow(() ->
        new BadRequest("License " + licenseId + " not found."));

To test and assert the value in the Test I mock it like this:

when(licenseRepository.findById(1L)).thenReturn(Optional.empty());

And then call and assert like this:

 try {
      SomeDto result = someService.getSomeStuffByLicenseId(1L);
      fail("should have already thrown exception here!");
 }catch (BadRequest br) {
      assertEquals("License 1 not found", br.getMessage());
 }

Handling orElseThrow

2 Answers2