Why does method get executed after mocking it?

Question

I have the following test

public class MyclassTest extends JUnitSuite {

  KubernetesClient kubeClient;

  @SuppressWarnings("static-access")
  @BeforeClass
  public static void setup() {
    system = ActorSystem.create();
    KubeDeployment mockKubeDeployment = Mockito.mock(KubeDeployment.class);
    KubeNamespace mockKubeNamespace = Mockito.mock(KubeNamespace.class);
    Deployment deployment = Mockito.mock(Deployment.class);
    Namespace namespace = Mockito.mock(Namespace.class);
    KubernetesClient kubeClient = Mockito.mock(KubernetesClient.class);
    Service serviceTodeploy = new Service("group","artifact","version");
    DeployEnvironment deployEnvironment = new DeployEnvironment();
    deployEnvironment.setName("K8sDeploymentCreatorTest");

    when(mockKubeNamespace.createNamespace(kubeClient, serviceTodeploy)).thenReturn(namespace);
    when(mockKubeDeployment.createDeployment(serviceTodeploy, kubeClient, namespace)).thenReturn(deployment);

  }

And here is the real method

public class KubeNamespace {
  /**
   * Creates a kubernetes namespace
   * 
   * @param kubeClient
   * @param namespaceName
   * @param labelValue
   * @return
   */
  public static Namespace createNamespace(KubernetesClient kubeClient, Service serviceToDeploy) {
    String namespaceName = serviceToDeploy.getDeployEnvironment().getName();
    Namespace namespace = kubeClient.namespaces().createNew().withNewMetadata().withName(namespaceName)
        .addToLabels(namespaceName, serviceToDeploy.getServiceCoordinates().toString()).endMetadata().done();

    return namespace;
  }

This throws an NPE at the first when statement. Upon debugging it looks like it throws an error somewhere inside the 'createNamespace' method. None of the arguments sent to the method are null some are real instances while some are mocked objects. The question is why is the method getting executed if its mocked?

After some more debugging it looks like it is not that the method is gettng executed because I tried adding another method that just returns a string and made the same when rule

 when(mockKubeNamespace.someStupidMEthod(kubeClient, serviceTodeploy)).thenReturn("namespace");

And the actual method

public static String someStupidMEthod(KubernetesClient kubeClient, Service serviceToDeploy) {
    String namespaceName = serviceToDeploy.getDeployEnvironment().getName();
    return namespaceName;

  }

This is still returning a null, something tells me its the way the class is mocked and the static access to these methods. BUt I dont understand it correctly

After the following comments I changed the static methids to instance methods and am making the calls like this

when(new KubeNamespace().createNamespace(kubeClient, serviceTodeploy)).thenReturn(namespace);

Still get the NPE at the same line

Here is the final code

public class K8sDeploymentCreatorTest extends JUnitSuite {

  static ActorSystem system;


  @Before
  public  void setup() {
    system = ActorSystem.create();
    KubeDeployment mockKubeDeployment = mock(KubeDeployment.class);
    KubeNamespace mockKubeNamespace = mock(KubeNamespace.class);
    Deployment deployment = Mockito.mock(Deployment.class);
    Namespace namespace = Mockito.mock(Namespace.class);
    KubernetesClient kubeClient = Mockito.mock(KubernetesClient.class);
    Service serviceTodeploy = new Service("group","artifact","version");
    DeployEnvironment deployEnvironment = new DeployEnvironment();
    deployEnvironment.setName("K8sDeploymentCreatorTest");
    serviceTodeploy.setDeployEnvironment(deployEnvironment);
    when(mockKubeNamespace.createNamespace(kubeClient, serviceTodeploy)).thenReturn(namespace);
    when(mockKubeDeployment.createDeployment(serviceTodeploy, kubeClient, namespace)).thenReturn(deployment);

  }


  @AfterClass
  public static void teardown() {
    TestKit.shutdownActorSystem(system);
    system = null;
  }

  @Test
  public void testK8sDeployment() {

    new TestKit(system) {
      {
        final Props props = Props.create(K8sDeploymentCreator.class);
        final ActorRef underTest = system.actorOf(props);
        KubernetesClient kubeClient = Mockito.mock(KubernetesClient.class);
        DeployEnvironment deployEnvironment = new DeployEnvironment();
        deployEnvironment.setName("K8sDeploymentCreatorTest");
        Service serviceTodeploy = new Service("group","artifact","version");
        serviceTodeploy.setDeployEnvironment(deployEnvironment);
        createK8sDeployment msg = new createK8sDeployment(serviceTodeploy, kubeClient);
        underTest.tell(msg, getRef());
        expectMsg(K8sDeploymentComplete.class);
      }
    };
  }

}


public class K8sDeploymentCreator extends AbstractActor {
  private final LoggingAdapter log = Logging.getLogger(getContext().getSystem(), this);


  @Override
  public Receive createReceive() {
    return receiveBuilder().match(createK8sDeployment.class, msg -> {

      KubeNamespace kubenamespace = new KubeNamespace();
      KubeDeployment kubeDeployment = new KubeDeployment();
      Namespace namespace = kubenamespace.createNamespace(msg.kubeClient, msg.service);
      Deployment deployment = kubeDeployment.createDeployment(msg.service, msg.kubeClient, namespace);
      log.info("sending complete depl msg");

      getSender().tell(new K8sDeploymentComplete(deployment), getSelf());
    })
        .matchAny(o -> log.info("received unknown message")).build();
  }

You have static methods, which [Mockito can't mock](https://stackoverflow.com/questions/21105403/mocking-static-methods-with-mockito). You need something else here, like `PowerMockito` suggested under the same link. — M. Prokhorov, Mar 26 '18 at 13:41
Are these actually a problem though? Do you need to mock namespace and deployments? — M. Prokhorov, Mar 26 '18 at 13:42
you mean the return types? or the type containing the static method? — user_mda, Mar 26 '18 at 13:45
I changed the static methods to be instance methods and removed the mock calls but stil get the same npe — user_mda, Mar 26 '18 at 13:50
Dont use static methods, use singleton factory insteed - you will be able to mock instance of such factory no problem. — Antoniossss, Mar 26 '18 at 14:00

score 1 · Accepted Answer · edited Mar 27 '18 at 12:28

1

This is not right way

when(new KubeNamespace().createNamespace

Because here you are creating new object which not mocked. After making method not static, use mocked object you created earlier ( KubeNamespace mockKubeNamespace = Mockito.mock(KubeNamespace.class); )

Basically your old 'when' statement should work after making createNamespace method non-static.

when(mockKubeNamespace.createNamespace(kubeClient, serviceTodeploy)).thenReturn(namespace);

edited Mar 27 '18 at 12:28

Dherik

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answered Mar 26 '18 at 14:22

ddinde

96
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9

That was it! Thanks – user_mda Mar 26 '18 at 14:45
But the method in the actual class is still getting executed – user_mda Mar 26 '18 at 17:01
Can you paste your new code again and tell which method is getting executed even if its mocked – ddinde Mar 26 '18 at 18:55
can you share stacktrace of NPE ? – ddinde Mar 27 '18 at 19:52

Why does method get executed after mocking it?

1 Answers1