NullPointerException here: This method call was *not* stubbed correctly

Question
1

I am testing the getDbStatus method using Mockito in Scala. But I see the following error. Can anyone help me with this?

Error

You have a NullPointerException here:
-> at com.knoldus.services.info.InfoServiceSpec$anon$2.<init>(InfoServiceSpec.scala:50)
because this method call was *not* stubbed correctly:
-> at scala.Option.orElse(Option.scala:447)
daoInstantiator.userDao();

org.mockito.exceptions.verification.SmartNullPointerException: 
You have a NullPointerException here:
-> at com.knoldus.services.info.InfoServiceSpec$anon$2.<init>(InfoServiceSpec.scala:50)
because this method call was *not* stubbed correctly:
-> at scala.Option.orElse(Option.scala:447)
daoInstantiator.userDao();

InfoServiceSpec.scala

class InfoServiceSpec extends BaseSpec {

  trait Setup {
    val daoInstantiator: DaoInstantiator = mock[DaoInstantiator]
    val service = new InfoService(conf,daoInstantiator)(ec, logger)
  }

  "InfoService#getDbStatus" should {

    "get DbStatus" in new Setup {
      when(daoInstantiator.userDao.count(any[Filter])(any[concurrent.ExecutionContext])).thenReturn(Future(1))

      whenReady(service.getDbStatus){ result =>
        assert(result == "active")
      }
    }

  }
}

InfoService.scala

class InfoService(config: Config, daoInstantiator: DaoInstantiator)(implicit
  val ec: ExecutionContext,
  val logger: LoggingAdapter
) {

  def getDbStatus: Future[String] = {
    var response = Future("inActive")
    val users = daoInstantiator.userDao.count(CheckActiveUsers(true))
    users.map { _ =>
      response = Future.successful("active")
    }
    Thread.sleep(1000)
    response
  }
}

DaoInstantiator.scala

class DaoInstantiator(database: MongoDatabase) {    
  lazy val userDao = new UserDao(database)    
}
2

Hi,

you’ve mocked the DaoInstantiator, but not provided a stub for the “userDao”

you probably wanted to do something like

val mockUserDao = mock[UserDao]
when(instantiator.userDao).thenReturn(mockUserDao)
when(mockUserDao.count ...).thenReturn(...)
1 Like
3

Thanks, It solved the problem