How add assertion on Completablefuture<boolean> Junit Mockito

Question

I have a Service called asynEvaluaEstadoSiniestro that return true or false, and some repositories that are mocked in my test.

@Service
@Slf4j
public class AsynEvaluaEstadoSiniestroImpl implements AsynEvaluaEstadoSiniestro {

  @Async("myExecutor")
  public CompletableFuture<Boolean> getEvaluacionEstadoSiniestro(DocumentRequest request) throws BusinessException {
  //do some persistances operations in repositories and return fooResult as true or false;|

  return CompletableFuture.completedFuture(fooResult);
  }
}

@InjectMocks
AsynEvaluaEstadoSiniestroImpl asynEvaluaEstadoSiniestro;

@Test
@DisplayName("Async process (1)")
void insertarSolicitudTest() throws BusinessException {
   //some when repositories functions needed for testing

CompletableFuture<Boolean> cf = asynEvaluaEstadoSiniestro.getEvaluacionEstadoSiniestro(documentRequest());
        cf.isDone();
}

when i execute sonaqube coverity it say:
Add at least one assertion to this test case.

How can i add a assertion to this test???

i hope to add a assertion to this test.

Answer 1

Every decent test case has these steps:

1. [Given] - Create input (e.g. a DocumentRequest instance)
2. [When] - Make some modification(s) (e.g the service call)
3. [Then] - Check correctness of the result obtained (assertions)

Unit testing asynchronous methods is not so hard what is seems. Fortunately there are a lot of good library to help. One of popular library is Awaitility

If you use Maven as build tool, just add this dependency to pom.xml

<dependency>
    <groupId>org.awaitility</groupId>
    <artifactId>awaitility</artifactId>
    <version>4.2.0</version>
    <scope>test</scope>
</dependency>

For demonstration I made a sample service:

public class FutureService {
    private final Executor executor = CompletableFuture.delayedExecutor(5L, TimeUnit.SECONDS);

    public CompletableFuture<Boolean> negate(boolean input) {
        return CompletableFuture.supplyAsync(() -> !input, executor);
    }
}

The negate method returns CompletableFuture<Boolean> which waits for 5 seconds before completition. It is just for the demonstration.

The test for this service is something like this.

class FutureTest {

    private final FutureService futureService = new FutureService();

    @Test
    void futureTest() throws ExecutionException, InterruptedException {
        // given (call service)
        CompletableFuture<Boolean> future = futureService.negate(true);
        // when (wait until the CompletableFuture will be done but at most 10 seconds
        Awaitility.await().atMost(Duration.ofSeconds(10L)).until(future::isDone);
        // then (in this case the returned boolean value should be false)
        Assertions.assertFalse(future.get());
    }
}