Cannot access MyApplication members from Mockito - android

This is my code:
#Mock
MyApplication application;
#Before
public void setup() {
application = Mockito.mock(MyApplication .class);
}
#Test
public void createProducts() {
application.ormLiteDatabaseHelper.getProductDao().create(new Product());
}
I get a NullPointerException at this line. My Application class inits the OrmLiteDatabaseHelper in its onCreate, how do I access the ormLiteDatabaseHelper from the mocked version of MyApplication?

application is a "mock" object. It only pretents to be a "MyApplication". Thus the only thing it can return for the method ormLiteDatabaseHelper is null and thus calling getProductDao on that will fail with a NullPointerException.
If you want it to return anything, then you need to tell your mock that, for example by...
OrmLiteDatabaseHelper ormLiteDatabaseHelper = ..something...;
Mockito.when( application.ormLiteDatabaseHelper ).thenReturn ( ormLiteDatabaseHelper);
Only then will your mock know to return something else than null. Of course, there are other ways, but for starters... Perhaps you also need partial mocking, which would be explained here, but without further info, it's hard to say.
Also, if you write #Mock, then you should either use the correct #RunWith annotation or call MockitoAnnotations.initMocks(this); instead of creating the mock manually via Mockito.mock. If you want to use the later, you don't need the #Mock annotation.

Related

How to test void method with Mockito's doAnswer

I am new to Mockito and trying to understand how to use doAnswer in order to test a void method.
Here's my class with the onDestroy method to test:
public class TPresenter implements TContract.Presenter {
private CompositeSubscription viewSubscription;
//.......
#Override public void onCreate(.......) {
this.viewSubscription = new CompositeSubscription();
//.......
}
#Override public void onDestroy() {
if(viewSubscription != null && !viewSubscription.isUnsubscribed()) {
viewSubscription.unsubscribe();
}
}
Now I want to write a test for onDestroy() namely to verify that after executing onDestroy the subscription is unsubscribed. I found several examples to use doAnswer for testing void methods, for example here, and also here but I do not understand them.
Please show how to test the method onDestroy.
The normal way how you could test your onDestroy() would be based on viewSubscription being a mocked object. And then you would do something like:
#Test
public testOnDestroyWithoutUnsubscribe() {
when(mockedSubscription.isUnsubscribed()).thenReturn(false);
//... trigger onDestroy()
verifyNoMoreInteractions(mockedSubscription);
}
#Test
public testOnDestroyWithUnsubscribe() {
when(mockedSubscription.isUnsubscribed()).thenReturn(true);
//... trigger onDestroy()
verify
verify(mockedSubscription, times(1)).unsubscribe();
}
In other words: you create a mocked object, and you configure it to take both paths that are possible. Then you verify that the expected actions took place (or not, that is what the first test case does: ensure you do not unsubscribe).
Of course, you can't test the "subscription object is null" case (besides making it null, and ensuring that no NPE gets thrown when triggering the onDestroy()!
Given the comment by the OP: one doesn't necessarily have to use mocking here. But when you want to test a void method, your options are pretty limited. You have to observe side effects somehow!
If you can get a non-mocked viewSubscription instance to do that, fine, then do that. But if not, then somehow inserting a mocked instance is your next best choice. How to do the "dependency injection" depends on the exact context, such as the mocking/testing frameworks you are using.
Testing void methods in your main class under test is not a problem as does not require doAnswer.
Here is an example of how could you go about testing the call to unsubscribe.
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
#RunWith(MockitoJUnitRunner.class)
public class TPresenterTest {
#InjectMocks
private TPresenter target = new TPresenter();
#Mock
private CompositeSubscription viewSubscription;
#Test
public void onDestroyShouldUnsubscribeWhenSubscriptionNotNullAndUnsubscribed() {
when(viewSubscription.isUnsubscribed()).thenReturn(false);
target.onDestroy();
verify(viewSubscription).unsubscribe();
}
#Test
public void onDestroyShouldNotUnsubscribeWhenSubscriptionNotNullAndNotUnsubscribed() {
when(viewSubscription.isUnsubscribed()).thenReturn(true);
target.onDestroy();
verify(viewSubscription, never()).unsubscribe();
}
}
As I mentioned in my comment to #GhostCat 's answer, my example is in fact un-testable because of the "new" instance of CompositeSubscription class. I would have to re-factor it and #GhostCat 's comment to his/her answer shows a way to do it.

Patterns.EMAIL_ADDRESS returns null

#RunWith(MockitoJUnitRunner.Silent.class)
public class LoginActivityTest {
#InjectMocks
LoginActivity loginActivity;
private Pattern emailPattern;
#Before
public void createLogin(){
this.emailPattern = Patterns.EMAIL_ADDRESS;
}
#Test
public void checkValidation(){
mock(LoginActivity.class);
UserVO userVO = new UserVO();
userVO.setEmailID("invalid");
userVO.setPassword("a");
boolean b = loginActivity.validatesFields(userVO);
assertFalse(b);
}
}
this.emailPattern = Patterns.EMAIL_ADDRESS; This is creating null pointer object in MockitoJunitTestClass. But, when I run this on Activity it gets initialized properly.
Use PatternsCompat instead of Patterns
I was having a similar problem because it was just a simple test, but when I added #RunWith(AndroidJUnit4::class) the problem was fixed. Check if this is test that must run with Android resources or not.
I am a little confuse with your test:
You are mocking LoginActivity.class but not setting anything with that. I believe you want to do something like loginActivity = mock(LoginActivity.class); instead.
Also, your are mocking instead spying the class, so it won't access the real method in order to verify the flow of this method. In other words, your test is doing nothing in fact.
Finally, this emailPattern is never used on your test (probably it is used on you code), so I believe you want to mock it (I am supposing it). What I recommend you do is something like this:
#RunWith(MockitoJUnitRunner.Silent.class)
public class LoginActivityTest {
#Spy
#InjectMocks
private LoginActivity loginActivity;
#Mock
private OtherStuff otherStuff;
#Test
public void checkValidation(){
UserVO userVO = new UserVO();
userVO.setEmailID("invalid");
userVO.setPassword("a");
doReturn(Patterns.EMAIL_ADDRESS).when(otherStuff).doStuff();
boolean result = loginActivity.validatesFields(userVO);
assertFalse(result);
}
}
What I did here is just an example of unit test which is validating what validateFields() is doing. I suppose that inside this method you have some method on, what I name otherStuff, which calls a method that returns Patterns.EMAIL_ADDRESS, which is what you want to mock.
It would be really better if you insert the LoginActivity code to be more precise here, but I hope I helped you.

How to mock and verify a callback in method using Mockito

Within this method, I want to mock and ensure that mSharedPrefsManager gets called when I don't pass in a certain email string.
#Override
public void retrieveWithEmail(final String email, final WelcomeContract.Presenter presenter)
{
retrieveInteractor.buildRetrieveRequest(email, new RetrieveImpl.OnRetrieveCompletedListener()
{
#Override
public void onRetrieveCompleted(final MaitreBaseGson retrieveResponse, RetrieveImpl retrieveClass)
{
if (retrieveResponse.getStatus().equals(mContext.getString(R.string.ok)))
{
if (!email.equals("certain#email.com"))
mSharedPrefsManager.storePoints(Integer.parseInt(retrieveResponse.getData().getPoints()));
presenter.updateSilhouette(retrieveResponse);
}
// Silently swallow failures
}
});
}
However, with my test I'm not able to catch whether mSharedPrefsManager is called. Mockito says that .storePoints() is never called. I thought about doing a doReturn().when() but as this is within the method that wouldn't work, would it?
How do I catch the interactions on sharedPrefsManager?
Mockito also says that .updateSilhouette() is not called. Do I need to mock onRetrieveCompleted() somehow?
#RunWith(MockitoJUnitRunner.class)
public class WelcomeInteractorTest
{
#Mock
RetrieveImpl retrieveInteractor;
#Mock
WelcomePresenter welcomePresenter;
#Mock
SharedPrefsManager sharedPrefsManager;
#Mock
Context context;
#InjectMocks WelcomeInteractorImpl welcomeInteractor;
#Mock
RetrieveImpl.OnRetrieveCompletedListener onRetrieveCompletedListener;
#Test
public void RetrieveWithCertainEmail_SavePoints()
{
welcomeInteractor.retrieveWithEmail("certain#email.com", welcomePresenter);
verify(retrieveInteractor).buildRetrieveRequest(eq("certain#email.com"), any(RetrieveImpl.OnRetrieveCompletedListener.class));
verify(sharedPrefsManager).storePoints(any(Integer.class));
verify(welcomePresenter).updateSilhouette(any(MaitreBaseGson.class));
}
}
Attempting to use #Spy caused a lot of issues for me as RetrieveImpl interacts with a network.
I instead used a Captor and captured the callback.
#Captor
private ArgumentCaptor<RetrieveImpl.OnRetrieveCompletedListener> mOnRetrieveCompletedListenerCaptor;
...
#Test
public void isTest()
{
...
verify(retrieveInteractor).buildRetrieveRequest(eq(email), mOnRetrieveCompletedListenerCaptor.capture());
mOnRetrieveCompletedListenerCaptor.getValue().onRetrieveCompleted(mockMaitreBaseGsonSuccessful, retrieveInteractor);
}
You are mocking:
#Mock
RetrieveImpl retrieveInteractor;
This means that when you call retrieveInteractor.buildRetrieveRequest(..), the real implementation is not invoked and eventually the methods that you expect to be called within that method call are never called..
Try using #Spy instead, this will actually allow for the real implementation to be called and you can verify that object also:
#Spy
RetrieveImpl retrieveInteractor;
Just one the side.. in think you are testing too much there and going to deep in your verifications.
That test in my opinion should be done for the RetrieveImpl.OnRetrieveCompletedListener class. Not the one that is in your question.
But thats just to my taste..

Unit testing Realm + Dagger 2 with Robolectric & Mockito

So I am working on this little project that uses Dagger 2 for dependency injection and Realm as a database.
I am unit testing it with Robolectric and Mockito (with Powermock). From previous research (and a lot of pain) I realised testing Realm is pretty laborious, but has been done in the past here.
Now, my project has a very similar setup and structure to the one linked above.
When I run my unit tests, all of them pass except for one that gives me a very cryptic message that looks as follows:
java.lang.NullPointerException
at org.robolectric.internal.ShadowExtractor.extract(ShadowExtractor.java:5)
at org.robolectric.Shadows.shadowOf(Shadows.java:1190)
at org.robolectric.shadows.CoreShadowsAdapter.getMainLooper(CoreShadowsAdapter.java:37)
at org.robolectric.util.ComponentController.<init>(ComponentController.java:31)
at org.robolectric.util.ComponentController.<init>(ComponentController.java:23)
at org.robolectric.util.ActivityController.<init>(ActivityController.java:40)
at org.robolectric.util.ActivityController.of(ActivityController.java:32)
at org.robolectric.Robolectric.buildActivity(Robolectric.java:82)
at org.robolectric.Robolectric.buildActivity(Robolectric.java:78)
at org.robolectric.Robolectric.setupActivity(Robolectric.java:86)
at uk.co.placona.tradesafe.view.EditActivityTest.ActivityShouldNotBeNull(EditActivityTest.java:54)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
at org.powermock.modules.junit4.internal.impl
The line of code specified on the error above is:
activity = Robolectric.setupActivity(EditActivity.class);
The activity exists, and has a TradeRepository injected to it when it starts up.
The activity in question can be found here along with the rest of the code. I have been trying to debug this for about 3 days now with no success. Every other unit test I create works fine, except any unit test that is used by an Activity, which makes me think I'm probably missing something really obvious.
Would be happy to clarify any questions here. With many thanks!
static is evil, powermock is evil :).
I think you should get rid of your class Injector. You don't need it because you have only one CustomApplication object during the lifetime of your application.
You should modify your code as follow:
In CustomApplication.java, the application component is created, set in a field variable, and injected
private ApplicationComponent applicationComponent;
public void setup(){
getOrCreateApplicationComponent().inject(this);
databaseRealm.setup();
stethoDebug.setup(this);
}
public ApplicationComponent getOrCreateApplicationComponent() {
if (applicationComponent == null) {
applicationComponent = DaggerApplicationComponent.builder()
.applicationContextModule(new ApplicationContextModule(this))
.repositoryModule(new RepositoryModule())
.build();
}
return applicationComponent;
}
In the methods onCreate of CreateActivity, EditActivity, and MainActivity, Injector is replaced with
((CustomApplication) getApplication())
.getOrCreateApplicationComponent()
.inject(this);
In RepositoryModule we will use Dagger 2 to inject dependencies into constructors so we don't need to inject manually the Context and the DatabaseRealm
#Provides
#Singleton
public TradeRepository provideTradeRepository(DatabaseRealm databaseRealm) {
return new TradeRepositoryImpl(databaseRealm);
}
#Provides
#Singleton
public DatabaseRealm provideDatabaseRealm(Context context) {
return new DatabaseRealm(context);
}
then in DatabaseRealm we add a constructor with Context as parameter
Context mContext;
RealmConfiguration realmConfiguration;
public DatabaseRealm(Context context) {
mContext = context;
}
and same in TradeRepositoryImpl, a constructor with databaseRealm is added
DatabaseRealm databaseRealm;
public TradeRepositoryImpl(DatabaseRealm databaseRealm) {
this.databaseRealm = databaseRealm;
}
For RepositoryTestModule, we add databaseRealm as parameter:
#Provides
#Singleton
public TradeRepository provideTradeRepository(DatabaseRealm databaseRealm) {
return isMocked ? mock(TradeRepository.class) : new TradeRepositoryImpl(databaseRealm);
}
in your TestCustomApplication we override the getOrCreateApplicationComponent
#Override
public ApplicationComponent getOrCreateApplicationComponent() {
return DaggerApplicationComponentTest.builder()
.applicationContextModuleTest(new ApplicationContextModuleTest())
.repositoryModuleTest(new RepositoryModuleTest(false))
.build();
}
Now for each of your tests we run them with RobolectricGradleTestRunner and add TestCustomApplication.class as application tag
#RunWith(RobolectricGradleTestRunner.class)
#Config(constants = BuildConfig.class, sdk = 21, application = TestCustomApplication.class)
when we need to inject dependencies into ours tests we will inject like this:
#Before
public void setupDagger() {
DaggerApplicationComponentTest.builder()
.applicationContextModuleTest(new ApplicationContextModuleTest())
.repositoryModuleTest(new RepositoryModuleTest(false))
.build().inject(this);
}
We still have a NullPointerException in our EditActivityTest because this line:
loadTrade(intent.getExtras().getString("ID"));
Either you check the intent is not null or you provide one in your test.
Looking to your test class, I don't see that you use any of Robolectric test runners.
You must use RobolectricGradleTestRunner or RobolectricTestRunner to trigger Robolecric functionality about loading manifest, parsing resources, creating main looper, etc.
If you don't use them, you probably can achieve it with own code in setup, but it is not the usual way, and I'm not sure that many people here can explain to you how to achieve it.
As well, Robolectric and PowerMock are modifying java ClassLoader both. That is why it is so hard (maybe impossible) to get them together working. So check #Steve answer how to modify your code to remove PowerMock necessity for your test.

Confused how to use Mockito for an android test

I'm trying to write a unit test for my android app but having trouble doing what I want with mockito. This is being used in conjunction with Robolectric which I have working just fine and have demonstrated that unit tests work.
I want to test whether or not a button will open a new activity depending on whether there is some bluetooth device connected. Obviously, there is no device connected with bluetooth in my test, however I want to pretend as though there is. The state of the bluetooth connection is stored in my Application class. There is no publicly accessible method to change this value.
So basically the logic in the app is like this:
HomeActivity.java:
//this gets called when the button to open the list is clicked.
public void openListActivity(View button) {
MyApplication myApplication = (MyApplication) getApplication();
if (myApplication.isDeviceConnected() {
startActivity(new intent(this, ListActivity.class));
}
}
So to test this I did the following:
TestHomeActivity.java:
#Test
public void buttonShouldOpenListIfConnected() {
FlexApplication mockedApp = Mockito.mock(MyApplication.class);
Mockito.when(mockedApp.isDeviceConnected()).thenReturn(true);
//listViewButton was setup in #Before
listViewButton.performClick();
ShadowActivity shadowActivity = Robolectric.shadowOf(activity);
Intent intent = shadowActivity.getNextStartedActivity();
assertNotNull(intent); //this fails because no new activity was opened. I debugged this and found that isDeviceConnected returned false.
ShadowIntent shadowIntent = Robolectric.shadowOf(intent);
assertThat(shadowIntent.getComponent().getClassName(), equalTo(ListActivity.class.getName()));
}
So my unit test fails because the call (in the activity) to isDeviceConnected returns false even though I thought I told it to return true with the mock framework. I want my test to have this method return true though. Isn't this what mockito does or am I totally mistaken on how to use mockito?
That's how mockito works, but the problem is: is your listViewButton using your mockedApp? Seems not, because you're creating mockedApp at the test method and never setting it anywhere. Mockito will not mock the method calls of all instances of Application, only from what you declared as a mock.
I personally don't know how android works with the Application class, but you will have to set it somewhere so listView use your mockedApp instead of what it receives normally.
EDIT
After the updated question, you can transform your getApplication in a protected method, spy you listViewButton and make it return your mockedApp. That smells a little bad, but it's one way if you can not set your application mocked object to listViewButton.
EDIT2
Example of using spy in your test using BDDMockito for readability :)
public HomeActivity {
...
protected MyApplication getApplication() {
// real code
}
...
}
public void TestHomeActivity {
private HomeActivity homeActivity;
#Before
public void setUp() {
this.homeActivity = spy(new HomeActivity());
}
#Test
public void buttonShouldOpenListIfConnected() {
// given
FlexApplication mockedApp = Mockito.mock(MyApplication.class);
Mockito.when(mockedApp.isDeviceConnected()).thenReturn(true);
// IMPORTANT PART
given(homeActivity.getApplication()).willReturn(mockedApp);
...
}
}
After that, your test should work as expected. But I reinforce: Use spy only if you can't inject your mockedApp inside HomeActivity.
Your mocked version isn't being called.
See that call, getApplication()? (below). That's returning a real copy of your MyApplication class, not your mocked version. You'd need to intercept the getApplication() call and pass in your mocked Application object.
HomeActivity.java:
//this gets called when the button to open the list is clicked.
public void openListActivity(View button) {
MyApplication myApplication = (MyApplication) getApplication(); // returns the real thing
if (myApplication.isDeviceConnected() {
startActivity(new intent(this, ListActivity.class));
}
}
I'm not sure this is possible with Mockito. Have you tried customizing the ShadowActivity#getApplication() method?

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