Develop Reference

Android HiltTest: The component was not created. Check that you have added the HiltAndroidRule

I have a util method which will go some actiivty by routing.
// RoutingUtil.java
public static void goRouting(Context context, String routing);
And I want test this method.
So I did something like this
#RunWith(AndroidJUnit4.class)
#HiltAndroidTest
public class RoutingUiUtilsTest {
#Rule
public HiltAndroidRule hiltRule = new HiltAndroidRule(this);
#Before
public void setUp() {
hiltRule.inject();
}
#Test
public void testSmartGo() {
ActivityScenario.launch(MainActivity.class);
Context context = InstrumentationRegistry.getInstrumentation().getTargetContext();
RoutingUtil.goRouting(context, "", "schema://a_activity_path");
}
}
The dest Activity is AActivity which used the hilt by annoutation #AndroidEntryPoint
#AndroidEntryPoint
class AActivity extends Activity {
}
Then I run test in terminal
./gradlew connectedAndroidTest
And error throws
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.somepackage/com.somepackage.AActivity}:
java.lang.IllegalStateException: The component was not created. Check
that you have added the HiltAndroidRule
I think the reason is I didn't start AActivity by hilt test componet, like ActivityScenario.launch(AActivity.class);, but what I want test is RoutingUtil.goRouting so I can't use hilt test component.
So how to test RoutingUtil.goRouting?

Getting null pointer object on hilt inject object in activity when run test cases

Please check below my Module class in which I have defined my object which need to be inject using Hilt
NVModule.kt
#Module
#InstallIn(SingletonComponent::class)
class NVModule {
#Provides
#Named("ProfileHelper")
fun abprovideProfileHelper(): ProfileHelper {
return ProfileHelper(AppController.getInstance())
}
}
And now please check my Interface by which i have used the EntryPoint to access my dependency injection outside the Activity/Fragment like Helper class.
#EntryPoint
#InstallIn(SingletonComponent.class)
public interface CommonHiltInterface {
#Named("ProfileHelper")
public ProfileHelper provideProfileHelper();
}
}
Now please check the my Activity class on which i have used the dependency injection like below and it is working fine here. Means getting dependency injection properly
public class HomeActivity extends BaseActivity{
private ActivityHomescreenBinding
activityHomescreenBinding;
private Activity context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = this;
activityHomescreenBinding =
DataBindingUtil.inflate(getLayoutInflater(),
R.layout.activity_homescreen, null, false);
setContentView(activityHomescreenBinding.getRoot());
CommonHiltInterface commonHiltInterface = EntryPointAccessors.fromApplication(context, CommonHiltInterface.class);
commonHiltInterface.provideProfileHelper().setData();
}
}
But in case of the Test cases , dependency injection getting NullPointerException . I am using the Robolectric for the test cases. Please check my below lines of code for the RobolectricTest case.
#HiltAndroidTest
#RunWith(RobolectricTestRunner.class)
#Config(application = HiltTestApplication.class,
sdk = Build.VERSION_CODES.N, manifest = Config.NONE)
public class HomeActivityTest {
#Rule
public HiltAndroidRule hiltRule = new
HiltAndroidRule(this);
#Before
public void setUp() throws Exception {
shadowOf(Looper.getMainLooper()).idle();
hiltRule.inject();
activity =
Robolectric.buildActivity(HomeActivity.class).
create().resume().get();
}
}
Note :- 1). I have also use #HiltAndroidApp() for application class.and using 2.36 version for hilt dependency
2). My dependency injection working fine for the Java classes like Activity/Fagment and Helper classes , But not working in test cases.
Please check my dependency for Hilt are as follow
testImplementation 'com.google.dagger:hilt-android-testing:2.36'
kaptTest 'com.google.dagger:hilt-android-compiler:2.36'
testAnnotationProcessor 'com.google.dagger:hilt-android-compiler:2.36'
androidTestImplementation 'com.google.dagger:hilt-android-testing:2.36'
kaptAndroidTest 'com.google.dagger:hilt-android-compiler:2.36'
Application runs successfully but in case of Test case I am getting the null pointer exception below lines of code in Activity (HomeActivity).
CommonHiltInterface commonHiltInterface = EntryPointAccessors.fromApplication(context, CommonHiltInterface.class);
commonHiltInterface.provideProfileHelper().setData();

Android Dagger 2 with MVP

Using Dagger 2 for the first time with MVP.
I am stuck at a very simple implementation.
my presenter module takes View Interface in constructor along with context and data manager,I am confused in how to send activity context to the constructor for the view interface..
Any help will be highly appreciated..
Here is my code for App class:
public class App extends Application {
private static App app;
public SampleComponent getSc() {
return sc;
}
private SampleComponent sc;
public static App getApp() {
return app;
}
#Override
public void onCreate() {
super.onCreate();
app = this;
sc = DaggerSampleComponent.builder()
//.sampleModule(new SampleModule())
.presenterModule(new PresenterModule(new MainActivity(), getApplicationContext(), new ModelManager()))
.build();
}
}
Code for Presenter Module :
#Module
public class PresenterModule {
ShowCountContract.view v;
ModelManager mm;
Context c;
public PresenterModule(MainActivity m, Context c,
ModelManager mm) {
this.c = c;
this.mm = mm;
this.v = m;
}
#Singleton
#Provides
PresenterClass getPresentationClass() {
return new PresenterClass(mm, v);
}
}

To handle the Android context the best approach is to create an Application Component with an Application Module. This module should be responsible to provide objects that are common in the entire application, as the Context. And based on that component you can create subcomponents for each feature/activity/etc.
#Module
public class ApplicationModule {
private final Application application;
public ApplicationModule(Application application) {
this.application = application;
}
#Provides
Context provideContext() {
return application;
}
}
If you choose to work with just one component (what I do not recommend), your code for DaggerComponent creation will look like this:
DaggerSampleComponent.builder()
.applicationModule(new ApplicationModule(this))
.otherModule(new OtherModule())
.build();
Or you can use Component.Builder
As the Activity instance is created by the Android Framework, we cannot pass the View interface as a constructor parameter. The common way is to create such a method as attachView(ViewInterface) in your Presenter to be able to set an internal property.
Another thing you should change is to remove the Presenter's constructor from App and let the OtherModule be responsible for that:
#Module
public class OtherModule {
#Singleton
#Provides
PresenterClass getPresentationClass(Context ctx) {
return new PresenterClass(ctx, new ModelManager());
}
}
I recommend you to check this article where it goes deeper on Dagger explanation and even shows another Dagger's version that is directly thought to the Android environment.

Dagger2 getting instance of activity presenter in fragment presenter

I'm really lost and hope you can help me. I'm programming app using MVP and dagger2. One of activities (let's say A ) contains fragments ( B ) in FragmentStatePagerAdapter. Both activity and fragments have their own presenters. I'm handling input in fragments ( B ), and transfer data from it "up" to main presenter ( B -> A ) (of activity holding fragments) and there ( A ) I'm handling network connection.
For this I need instance of main presenter ( A ) in fragment presenter ( B ). I've tried to use dependency on fragment graph but instead of getting already existing instance of presenter it's creating new one with every init. Any advises how I could get something similar to singleton but using ActivityScope?
A graph:
#ActivityScope
#Component(modules = GiftListModule.class, dependencies = AppGraph.class)
public interface GiftListGraph extends AppGraph{
void inject(GiftListActivity giftListActivity);
GiftListPresenter getGiftListPresenter();
final class Initializer {
public static GiftListGraph init(AppGraph appGraph, GiftListView giftListView) {
return DaggerGiftListGraph.builder()
.giftListModule(new GiftListModule(giftListView))
.appGraph(appGraph)
.build();
}
}
}
A module:
#Module
public class GiftListModule {
private final GiftListView giftListView;
public GiftListModule(GiftListView giftListView) {
this.giftListView = giftListView;
}
#Provides GiftListView provideGiftListView() {
return giftListView;
}
#Provides GiftListPresenter provideGiftListPresenter(GiftListView giftListView) {
return new GiftListPresenterImpl(giftListView);
}
}
B graph:
#FragmentScope
#Component(modules = GiftDetailsModule.class, dependencies = GiftListGraph.class)
public interface GiftDetailsGraph {
void inject(GiftDetailsFragment giftDetailsFragment);
GiftDetailsPresenter getGiftDetailsPresenter();
final class Initializer {
public static GiftDetailsGraph init(GiftListGraph giftListGraph, GiftDetailsView giftDetailsView) {
return DaggerGiftDetailsGraph.builder()
.giftDetailsModule(new GiftDetailsModule(giftDetailsView))
.giftListGraph(giftListGraph)
.build();
}
}
}
B module:
#Module
public class GiftDetailsModule {
private final GiftDetailsView giftDetailsView;
public GiftDetailsModule(GiftDetailsView giftDetailsView) {
this.giftDetailsView = giftDetailsView;
}
#Provides GiftDetailsView provideGiftDetailsView() {
return giftDetailsView;
}
#Provides GiftDetailsPresenter provideGiftDetailsPresenter(GiftDetailsView giftDetailsView,
GiftListPresenter giftListPresenter) {
return new GiftDetailsPresenterImpl(giftDetailsView, giftListPresenter);
}
}
Main App:
public class MainApp extends Application {
private static MainApp sInstance;
protected AppGraph appGraph;
protected GiftListGraph giftListGraph;
#Override
public void onCreate() {
super.onCreate();
sInstance = this;
appGraph = AppGraph.Initializer.init(this);
}
public static MainApp getInstance() {
return sInstance;
}
...
public GiftListGraph getGiftListGraph(GiftListView view) {
return giftListGraph = GiftListGraph.Initializer.init(appGraph, view);
}
public GiftDetailsGraph getGiftDetailsGraph(GiftDetailsView view) {
return GiftDetailsGraph.Initializer.init(giftListGraph, view);
}
...
}
Thanks for any help you can give me :)

From DI perspective you are seeing the correct behavior. When you are calling get list graph or detail graph, you are building entirely new graph. (See. new Module calls in your initializer calls). Hence you are getting new instance each time.
There are few options I would consider.
One:
Have a callback interface defined at the activity scope. Have activity implement it. In the process of creating fragment graphs pass the callback impl instance (activity or some impl class) as argument. Your fragment a/b presenter can use that as a dependency. Now both fragment presenter gets a call back.
Two:
Use event bus or broadcast receivers that run at app scope or activity scope. Use that to post message back and forth.
Hope this gives you some ideas.

How can I replace Activity scoped dependencies with mocks using Dagger2

I have a scoped dependency in my Activity and I want to test that activity with some mocks. I have read about different approach that suggest to replace Application component with a test component during the test, but what I want is to replace the Activity component.
For example, I want to test the Activity against mock presenter in my MVP setup.
I believe that replacing component by calling setComponent() on Activity will not work, because Activity dependencies already injected via field injection, so during the test, real object will be used.
How can I resolve this issue? What about Dagger1? Is it has the same issue?

Injecting the Component
First, you create a static class to act as a factory for your Activity. Mine looks a little like this:
public class ActivityComponentFactory {
private static ActivityComponentFactory sInstance;
public static ActivityComponentFactory getInstance() {
if(sInstance == null) sInstance = new ActivityComponentFactory();
return sInstance;
}
#VisibleForTesting
public static void setInstance(ActivityComponentFactory instance) {
sInstance = instance;
}
private ActivityComponentFactory() {
// Singleton
}
public ActivityComponent createActivityComponent() {
return DaggerActivityComponent.create();
}
}
Then just do ActivityComponentFactory.getInstance().createActivityComponent().inject(this); inside your Activities.
For testing, you can replace the factory in your method, before the Activity is created.
Providing mocks
As #EpicPandaForce's answer makes clear, doing this the officially-supported way currently involves a lot of boilerplate and copy/pasted code. The Dagger 2 team need to provide a simpler way of partially overriding Modules.
Until they do though, here's my unnoficial way: Just extend the module.
Let's say you want to replace your ListViewPresenter with a mock. Say you have a PresenterModule which looks like this:
#Module #ActivityScope
public class PresenterModule {
#ActivityScope
public ListViewPresenter provideListViewPresenter() {
return new ListViewPresenter();
}
#ActivityScope
public SomeOtherPresenter provideSomeOtherPresenter() {
return new SomeOtherPresenter();
}
}
You can just do this in your test setup:
ActivityComponentFactory.setInstance(new ActivityComponentFactory() {
#Override
public ActivityComponent createActivityComponent() {
return DaggerActivityComponent.builder()
.presenterModule(new PresenterModule() {
#Override
public ListViewPresenter provideListViewPresenter() {
// Note you don't have to use Mockito, it's just what I use
return Mockito.mock(ListViewPresenter.class);
}
})
.build();
}
});
...and it just works!
Note that you don't have to include the #Provides annotation on the #Override method. In fact, if you do then the Dagger 2 code generation will fail.
This works because the Modules are just simple factories - the generated Component classes take care of caching instances of scoped instances. The #Scope annotations are used by the code generator, but are irrelevant at runtime.

You cannot override modules in Dagger2 [EDIT: you can, just don't specify the #Provides annotation on the mock), which would obviously be the proper solution: just use the builder().somethingModule(new MockSomethingModule()).build() and be done with it!
If you thought mocking is not possible, then I would have seen two possible solutions to this problem. You can either use the modules to contain a pluggable "provider" that can have its implementation changed (I don't favor this because it's just too verbose!)
public interface SomethingProvider {
Something something(Context context);
}
#Module
public class SomethingModule {
private SomethingProvider somethingProvider;
public SomethingModule(SomethingProvider somethingProvider) {
this.somethingProvider = somethingProvider;
}
#Provides
#Singleton
public Something something(Context context) {
return somethingProvider.something(context);
}
}
public class ProdSomethingProvider implements SomethingProvider {
public Something something(Context context) {
return new SomethingImpl(context);
}
}
public class TestSomethingProvider implements SomethingProvider {
public Something something(Context context) {
return new MockSomethingImpl(context);
}
}
SomethingComponent somethingComponent = DaggerSomethingComponent.builder()
.somethingModule(new SomethingModule(new ProdSomethingProvider()))
.build();
Or you can bring the provided classes and injection targets out into their own "metacomponent" interface, which your ApplicationComponent and your TestApplicationComponent extend from.
public interface MetaApplicationComponent {
Something something();
void inject(MainActivity mainActivity);
}
#Component(modules={SomethingModule.class})
#Singleton
public interface ApplicationComponent extends MetaApplicationComponent {
}
#Component(modules={MockSomethingModule.class})
#Singleton
public interface MockApplicationComponent extends MetaApplicationComponent {
}
The third solution is to just extend the modules like in #vaughandroid 's answer. Refer to that, that is the proper way of doing it.
As for activity scoped components... same thing as I mentioned here, it's just a different scope, really.

I've found the following post that solves the problem:
http://blog.sqisland.com/2015/04/dagger-2-espresso-2-mockito.html
You need first to allow to modify the component of the activity:
#Override public void onCreate() {
super.onCreate();
if (component == null) {
component = DaggerDemoApplication_ApplicationComponent
.builder()
.clockModule(new ClockModule())
.build();
}
}
public void setComponent(DemoComponent component) {
this.component = component;
}
public DemoComponent component() {
return component;
}
And modify it in the test case
#Before
public void setUp() {
Instrumentation instrumentation = InstrumentationRegistry.getInstrumentation();
DemoApplication app
= (DemoApplication) instrumentation.getTargetContext().getApplicationContext();
TestComponent component = DaggerMainActivityTest_TestComponent.builder()
.mockClockModule(new MockClockModule())
.build();
app.setComponent(component);
component.inject(this);
}