How to inject mocks with Dagger 2.11

Question

I am trying to inject mocks using the Android Injector of Dagger 2.11.

Before using the Android Inject I used to change the injector in the Application class so I can inject mocks. Like this:

class EGOApplication : Application() {

    lateinit var injectorComponent: InjectorComponent


    override fun onCreate() {
        super.onCreate()

        injectorComponent = DaggerInjectorComponent.builder()
                .appModule(AppModule(this))               
                .build()
}

And in my tests I used to change the injectorComponent like this:

app.injectorComponent = DaggerMockComponent.builder()
                .mockModule(MockModule(app))
                .build()

And then I can inject my mocks from MockModule.

But now I am using Android Injector form this tutorial: https://medium.com/@iammert/new-android-injector-with-dagger-2-part-1-8baa60152abe

Well... now I inject my dependencies like this:

override fun onCreate(savedInstanceState: Bundle?) {
        AndroidInjection.inject(this)
}

So my approach doesn't work anymore... How can I make Dagger injector dependencies from my MockModule?

Any help is appreciated!

Answer 1

I found a answer.

I were changing the injectorComponent in my tests... Like this:

@Inject
lateinit var someDependency: SomeDependency

val app = instrumentation.targetContext.applicationContext as MyApplication

app.injectorComponent = DaggerMockComponent.builder()
                .mockModule(MockModule(app))
                .build()

if (null == mockComponent) {
      mockComponent = app.injectorComponent as MockComponent
      mockComponent!!.inject(this)
}

My application were, more or less, like this:

open class MyApplication : Application(), HasActivityInjector {
        @Inject
        lateinit var androidInjector : DispatchingAndroidInjector<Activity>

    lateinit var injectorComponent: InjectorComponent

    override fun onCreate() {
        super.onCreate()              

        buildInjector()

    }


    open fun buildInjector() {
        injectorComponent = DaggerInjectorComponent.builder()
                .dataModule(DataModule())
                .appModule(AppModule(this))
                .trackerModule(TrackerModule(this, FirebaseAnalytics.getInstance(this)))
                .build()
    }

    override fun activityInjector(): AndroidInjector<Activity> = androidInjector

}

But now I am using a different Application for my tests where I extend the default Application (a TestApplication). In this application I construct a different injector:

class TestApplication : MyApplication() {

    override fun buildInjector() {
        injectorComponent = DaggerMockComponent.builder().mockModule(MockModule(this)).build()
    }
}

You will need create a MockComponent that extends the InjectorComponent and a MockModule that provides all the mocks that you need.

Then in your test just do:

@Before
fun setUp() {
    val app = instrumentation.targetContext.applicationContext as TestApplication
    (app.injectorComponent as MockComponent).inject(this)
}

It works just fine!