How to write unit test for Kotlin delete by id method?-CodePudding

I have this method

  fun delete(id: Long) {
    NotFoundExceptionValidator(!dishOfTheDayEntityRepository.existsById(id), "dishOfTheDay not found")
    dishOfTheDayEntityRepository.deleteById(id)
}

NotFoundExceptionValidator this just checks if it's null then throws error

this is what I tried

    @ConcurrentExecution
internal class DishOfTheDayServiceTest {
    private val repo: DishOfTheDayEntityRepository = mockk()
    private val mapper: DishOfTheDayMapper = mockk()

    private val dishOfTheDayEntityService = DishOfTheDayService(repo, mapper)

    @Test
    fun `delete should work properly`() {
        //given
        val id: Long = 1;
        //when
        dishOfTheDayEntityService.delete(1)
        //then
        verify(exactly = 1) { repo.deleteById(1) }
    }
}

when i run it it throws this error

no answer found for: DishOfTheDayEntityRepository(#1).existsById(1) io.mockk.MockKException: no answer found for: DishOfTheDayEntityRepository(#1).existsById(1)

CodePudding user response：

You forgot to mock your mocks behaviour, i.e. you should explicitly specify what the existsById() and deleteById() methods return. For example for existsById() it should look like:

every { repo.existsById(id) } returns true

I suppose that the deleteById() method returns Unit so if you don't want to do it like above you can mock DishOfTheDayEntityRepository like:

private val repo: DishOfTheDayEntityRepository = mockk(relaxUnitFun = true)

Now you don't have to mock Unit returning methods of DishOfTheDayEntityRepository. You can find more about it here.