原理から完全理解するDagger Hilt Migration

原理から完全理解する Dagger Hilt Migration Keita Kagurazaka

本発表について • 話すこと ◦ 素のDaggerとdagger.android、Hiltの違い ◦ Hiltへの移行方法 ◦ 移行する際によく当たる問題とその解決方法 •
話さないこと / 前提とする知識 ◦ DIとは何か、その必要性 ◦ Daggerの使い方、どんなクラスがあるかなど

Agenda Daggerの捉え方 dagger.androidとHiltの思想 Hiltに段階的に移行する FAQ 01 02 03 04

コンセプト • 「段階的」なHilt移行 ◦ 日々のプロジェクトと並行して進められるように • 原理から理解する ◦ 実際に移行する際に自ら壁を乗り越えられるように

Daggerの捉え方 dagger.androidとHiltの思想 Hiltに段階的に移行する FAQ Agenda 01 02 03 04

Dagger = Component Tree

Componentの提供サービス 1. 依存性(インスタンス)の受け渡し 2. 依存性(インスタンス)の同一性保証

Componentの提供サービス 1. 依存性(インスタンス)の受け渡し 2. 依存性(インスタンス)の同一性保証 = 何回受け渡しても同じインスタンス

@Component(modules = [RepositoryModule::class]) interface ApplicationComponent { fun getUserRepository(): UserRepository fun
inject(app: App) } Componentによる依存性の受け渡し

@Singleton @Component(modules = [ApplicationModule::class]) interface ApplicationComponent { /* 省略 */
} @Module class ApplicationModule { @Singleton @Provides fun providesThirdPartyLibrary(): ThirdPartyLibrary = ThirdPartyLibrary.Builder.build() } Componentによる同一性保証

倉庫預かりオプション ThirdPartyLibrary ください ThirdParty Library 倉庫 ApplicationComponent 以前と同じブツです

} @Module class ApplicationModule { @Singleton @Provides fun providesThirdPartyLibrary(): ThirdPartyLibrary = ThirdPartyLibrary.Builder.build() } Componentによる同一性保証

} @Module class ApplicationModule { @Provides fun providesThirdPartyLibrary(): ThirdPartyLibrary = ThirdPartyLibrary.Builder.build() } Componentによる同一性保証毎回作り直し！

Component = 工場倉庫受け渡し窓口

Dagger = Component Tree

インスタンスのライフタイム管理アプリのプロセス終了まで残ってるよ！ ThirdParty Library ApplicationComponentが消えるまで残ってるよ！倉庫 ApplicationComponent

インスタンスのライフタイム管理 LoginActivityComponent ApplicationComponent アプリのプロセス終了まで残ってるよ！ LoginActivityが消えるまで残ってるよ！

インスタンスのライフタイム管理 LoginActivityComponent ApplicationComponent 先輩のインスタンスもこちらで受け渡します！

インスタンスのライフタイム管理 LoginActivityComponent ApplicationComponent 苦しゅうない先輩のインスタンスもこちらで受け渡します！

インスタンスのライフタイム管理 LoginActivityComponent ApplicationComponent Component Tree

@Scope @Retention(AnnotationRetention.RUNTIME) annotation class ActivityScope @ActivityScope @Subcomponent interface LoginActivityComponent {
fun inject(activity: LoginActivity) @Subcomponent.Factory interface Factory { fun create(): LoginActivityComponent } } SubcomponentによるTree定義

@Module(subcomponents = [LoginActivityComponent::class]) interface ActivityModule @Singleton @Component(modules = [ ApplicationModule::class,
ActivityModule::class ]) interface ApplicationComponent SubcomponentによるTree定義

Component Tree ApplicationComponent ActivityModule LoginActivityComponent ApplicationModule

Component Tree ApplicationComponent ApplicationModule LoginActivityComponent

Component Tree ApplicationC ApplicationM LoginActivityC

interface ApplicationComponent { fun loginActivityComponent(): LoginActivityComponent.Factory } class LoginActivity :
AppCompatActivity() { lateinit var component: LoginActivityComponent override fun onCreate(savedInstanceState: Bundle?) { component = (applicationContext as App).component .loginActivityComponent().create() component.inject(this) super.onCreate(savedInstanceState) } } Boilerplate問題

dagger.android

dagger.android 書くのが大変ならコード生成すればいいじゃない

@Module interface MainActivityModule { @ActivityScope @ContributesAndroidInjector fun contributesMainActivity(): MainActivity }
@Module( includes = [MainActivityModule::class], subcomponents = [LoginActivityComponent::class] ) interface ActivityModule dagger.androidの解法 - コード生成

@Module( includes = [MainActivityModule::class], subcomponents = [LoginActivityComponent::class] ) interface ActivityModule dagger.androidの解法 - コード生成 MainActivitySubC

@Module( includes = [MainActivityModule::class], subcomponents = [LoginActivityComponent::class] ) interface ActivityModule dagger.androidの解法 - コード生成

@Module( includes = [MainActivityModule::class], subcomponents = [LoginActivityComponent::class] ) interface ActivityModule dagger.androidの解法 - コード生成 MainActivitySubC

@Module( includes = [MainActivityModule::class], subcomponents = [LoginActivityComponent::class] ) interface ActivityModule dagger.androidの解法 - コード生成 ApplicationC MainActivitySubC

@Module(subcomponents = MainActivityModule_ContributesMainActivity.MainActivitySubcomponent.class) public abstract class MainActivityModule_ContributesMainActivity { private MainActivityModule_ContributesMainActivity()
{} @Binds @IntoMap @ClassKey(MainActivity.class) abstract AndroidInjector.Factory<?> bindAndroidInjectorFactory( MainActivitySubcomponent.Factory builder); @Subcomponent @ActivityScope public interface MainActivitySubcomponent extends AndroidInjector<MainActivity> { @Subcomponent.Factory interface Factory extends AndroidInjector.Factory<MainActivity> {} } }

{} @Binds @IntoMap @ClassKey(MainActivity.class) abstract AndroidInjector.Factory<?> bindAndroidInjectorFactory( MainActivitySubcomponent.Factory builder); @Subcomponent @ActivityScope public interface MainActivitySubcomponent extends AndroidInjector<MainActivity> { @Subcomponent.Factory interface Factory extends AndroidInjector.Factory<MainActivity> {} } } MainActivity

{} @Binds @IntoMap @ClassKey(MainActivity.class) abstract AndroidInjector.Factory<?> bindAndroidInjectorFactory( MainActivitySubcomponent.Factory builder); @Subcomponent @ActivityScope public interface MainActivitySubcomponent extends AndroidInjector<MainActivity> { @Subcomponent.Factory interface Factory extends AndroidInjector.Factory<MainActivity> {} } } MainActivitySubC MainActivity

dagger.androidのinjection

dagger.androidのinjection 1. AndroidInjection.inject

dagger.androidのinjection 1. AndroidInjection.inject DispatchingAndroidInjector

dagger.androidのinjection 1. AndroidInjection.inject DispatchingAndroidInjector ︙ MainActivitySubC MainActivity MainFragmentSubC MainFragment LoginActivitySubC
LoginActivity

dagger.androidのinjection 1. AndroidInjection.inject 2. 渡されたインスタンスのクラスを keyにSubCを見つける DispatchingAndroidInjector ︙ MainActivitySubC MainActivity
MainFragmentSubC MainFragment LoginActivitySubC LoginActivity

dagger.androidのinjection 1. AndroidInjection.inject 2. 渡されたインスタンスのクラスを keyにSubCを見つける 3. SubCをインスタンス化して injection DispatchingAndroidInjector
︙ MainActivitySubC MainActivity MainFragmentSubC MainFragment LoginActivitySubC LoginActivity

class App : Application(), HasAndroidInjector { @Inject lateinit var androidInjector:
DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector } dagger.androidのinjection

dagger.androidのComponent Tree ApplicationC MainActivitySubC MainFragmentSubC HogeFragmentSubC HugaActivitySubC HugaFragmentSubC PiyoFragmentSubC

Hilt Componentはこっちで用意するからそれ使ってね

https://dagger.dev/hilt/components より引用 Hiltの解法 - プリセットComponent

HiltのComponent Tree (simple ver.) SingletonC ActivityC FragmentC

@InstallIn(SingletonComponent::class) @Module class ApplicationModule { @Singleton @Provides fun providesThirdPartyLibrary(): ThirdPartyLibrary
= ThirdPartyLibrary.Builder.build() } プリセットComponentの使い方

@InstallIn(SingletonComponent::class) @Module class ApplicationModule @Singleton @Component(modules = [ApplicationModule::class]) interface ApplicationComponent
プリセットComponentの使い方

@Component(modules = [AllApplicationModule::class]) interface ApplicationComponent { fun inject(instance: NeedInjectionClass) fun
getUserRepository(): UserRepository } インスタンス受け渡し窓口閉鎖のご連絡

@InstallIn(SingletonComponent::class) @EntryPoint interface ApplicationEntryPoint { fun inject(instance: NeedInjectionClass) fun getUserRepository():
UserRepository } EntryPoint

@InstallIn(SingletonComponent::class) @EntryPoint interface ApplicationEntryPoint { fun inject(instance: NeedInjectionClass) fun getUserRepository():
UserRepository } public abstract static class SingletonC implements SingletonComponent, ApplicationEntryPoint { /* 省略 */ } EntryPoint = Componentの1窓口

interface RepositoryProvider { fun getUserRepository(): UserRepository } interface ApplicationInjector {
fun inject(instance: NeedInjectionClass) } @Singleton @Component(modules = [ApplicationModule::class]) interface ApplicationComponent : RepositoryProvider, ApplicationInjector EntryPoint ≈ Componentの分割定義

class MainActivity : AppCompatActivity() class MainFragment : Fragment() HiltのInjection

@AndroidEntryPoint class MainActivity : AppCompatActivity() @AndroidEntryPoint class MainFragment : Fragment()
HiltのInjection

public abstract class Hilt_MainActivity extends AppCompatActivity implements GeneratedComponentManagerHolder { Hilt_MainActivity()
{ super(); _initHiltInternal(); } private void _initHiltInternal() { addOnContextAvailableListener(new OnContextAvailableListener() { @Override public void onContextAvailable(Context context) { inject(); } }); } }

{ super(); _initHiltInternal(); } private void _initHiltInternal() { addOnContextAvailableListener(new OnContextAvailableListener() { @Override public void onContextAvailable(Context context) { inject(); } }); } } ボイラープレート全部ここでやります

{ super(); _initHiltInternal(); } private void _initHiltInternal() { addOnContextAvailableListener(new OnContextAvailableListener() { @Override public void onContextAvailable(Context context) { inject(); } }); } }

@AndroidEntryPoint class MainActivity : AppCompatActivity() Bytecode transformation in .kt

@AndroidEntryPoint class MainActivity : Hilt_MainActivity() Bytecode transformation in .dex

@AndroidEntryPoint class MainActivity : AppCompatActivity() @AndroidEntryPoint class MainFragment : Fragment()
HiltのInjection

サンプルプロジェクト • https://github.com/k-kagurazaka/hilt-migration • main branch ◦ raw Dagger +
dagger.androidの構成 • hilt-migration branch ◦ Hilt化済み ◦ 各commitはbuild pass

サンプルプロジェクトのComponent Tree ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC EmailSignupActivityC UserRegistrationFragmentC SnsSignupActivityC
UserRegistrationFragmentC

raw Dagger ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC EmailSignupActivityC UserRegistrationFragmentC SnsSignupActivityC
UserRegistrationFragmentC

dagger.android ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC EmailSignupActivityC UserRegistrationFragmentC SnsSignupActivityC UserRegistrationFragmentC

同一Fragment、別Component ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC EmailSignupActivityC UserRegistrationFragmentC SnsSignupActivityC UserRegistrationFragmentC

移行スタート

移行ステップ 1. gradleの設定 2. Component Treeの接ぎ木 3. Scopeアノテーションの置き換え 4. MainActivityの移行
5. Loginの移行 6. MainFragmentの移行 7. Activityのお掃除 8. dagger.androidの除去 9. ApplicationComponentの削除

Component Treeの接ぎ木 ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC
ApplicationM RepositoryM

@Singleton @Component(modules = [ AndroidInjectionModule::class, ApplicationModule::class, RepositoryModule::class, ActivityModule::class,]) interface ApplicationComponent
: AndroidInjector<App> { fun loginActivityComponent(): LoginActivityComponent.Factory @Component.Factory interface Factory { fun create(@BindsInstance app: App): ApplicationComponent } } Component Treeの接ぎ木

@Singleton @Component(modules = [ AndroidInjectionModule::class, ApplicationModule::class, RepositoryModule::class, ActivityModule::class,]) interface ApplicationComponent
: AndroidInjector<App> { fun loginActivityComponent(): LoginActivityComponent.Factory } Component Treeの接ぎ木

@Singleton @Component(modules = [ AndroidInjectionModule::class, ApplicationModule::class, RepositoryModule::class, ActivityModule::class,]) @InstallIn(SingletonComponent::class) @EntryPoint
interface ApplicationComponent : AndroidInjector<App> { fun loginActivityComponent(): LoginActivityComponent.Factory } Component Treeの接ぎ木

SingletonCImpl Component Treeの接ぎ木 ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC
FragmentC ApplicationM RepositoryM

@Singleton @Component(modules = [ AndroidInjectionModule::class, ApplicationModule::class, RepositoryModule::class, ActivityModule::class,]) @InstallIn(SingletonComponent::class) @EntryPoint
interface ApplicationComponent : AndroidInjector<App> { fun loginActivityComponent(): LoginActivityComponent.Factory } Component Treeの接ぎ木

@InstallIn(SingletonComponent::class) @Module(includes = [ AndroidInjectionModule::class, ApplicationModule::class, RepositoryModule::class, ActivityModule::class,]) interface AggregatorModule
@InstallIn(SingletonComponent::class) @EntryPoint interface ApplicationComponent : AndroidInjector<App> { fun loginActivityComponent(): LoginActivityComponent.Factory } Component Treeの接ぎ木

SingletonCImpl Component Treeの接ぎ木 ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC

class App : Application(), HasAndroidInjector { val component: ApplicationComponent =
DaggerApplicationComponent.factory().create(this) @Inject lateinit var androidInjector: DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector } Applicationの変更

class App : Application(), HasAndroidInjector { val component: ApplicationComponent by
lazy { EntryPoints.get(this, ApplicationComponent::class.java) } @Inject lateinit var androidInjector: DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector } Applicationの変更

@HiltAndroidApp class App : Application(), HasAndroidInjector { val component: ApplicationComponent
by lazy { EntryPoints.get(this, ApplicationComponent::class.java) } @Inject lateinit var androidInjector: DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector } Applicationの変更

SingletonCImpl 現時点のComponent Tree ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC

現時点のComponent Tree ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC
ApplicationM RepositoryM

@Module interface MainActivityModule { @ActivityScope @ContributesAndroidInjector(modules = [MainFragmentModule::class]) fun contributesMainActivity():
MainActivity } @Module interface MainFragmentModule { @FragmentScope @ContributesAndroidInjector fun contributesMainFragment(): MainFragment } Scopeアノテーションの置き換え

import dagger.hilt.android.scopes.ActivityScoped import dagger.hilt.android.scopes.FragmentScoped @Module interface MainActivityModule { @ActivityScoped @ContributesAndroidInjector(modules
= [MainFragmentModule::class]) fun contributesMainActivity(): MainActivity } @Module interface MainFragmentModule { @FragmentScoped @ContributesAndroidInjector fun contributesMainFragment(): MainFragment } Scopeアノテーションの置き換え

移行 = 担当Component変更 ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC
FragmentC

移行 = 担当Component変更 ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC
FragmentC MainActivity担当

class MainActivity : AppCompatActivity(), HasAndroidInjector { @Inject lateinit var androidInjector:
DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector override fun onCreate(savedInstanceState: Bundle?) { AndroidInjection.inject(this) super.onCreate(savedInstanceState) } } MainActivityの移行

class MainActivity : AppCompatActivity(), HasAndroidInjector { @Inject lateinit var androidInjector:
DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) } } MainActivityの移行

@AndroidEntryPoint class MainActivity : AppCompatActivity(), HasAndroidInjector { @Inject lateinit var
androidInjector: DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) } } MainActivityの移行

MainActivityのComponent削除 ApplicationC MainActivityC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC

MainActivityのComponent削除 ApplicationC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC

MainFragmentのComponent接ぎ木 ApplicationC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC

MainFragmentのComponent接ぎ木 ApplicationC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC MainFragmentModule

@InstallIn(ActivityComponent::class) @Module( includes = [ MainFragmentModule::class, ] ) interface DaggerAndroidActivityModule
MainFragmentのComponent接ぎ木

Loginの移行 ApplicationC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC

Loginの移行 ApplicationC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC LoginActivity担当 LoginFragment担当

class LoginActivity : AppCompatActivity() { lateinit var component: LoginActivityComponent override
fun onCreate(savedInstanceState: Bundle?) { component = (applicationContext as App).component .loginActivityComponent().create(this) component.inject(this) super.onCreate(savedInstanceState) } } LoginActivityの移行

class LoginActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState) } } LoginActivityの移行

@AndroidEntryPoint class LoginActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?)
{ super.onCreate(savedInstanceState) } } LoginActivityの移行

@AndroidEntryPoint class LoginActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?)
{ super.onCreate(savedInstanceState) /* 省略 */ } } LoginActivityの移行

class LoginFragment: Fragment() { lateinit var component: LoginFragmentComponent override fun
onAttach(context: Context) { super.onAttach(context) component = (requireActivity() as LoginActivity).component .loginFragmentComponent().create(this) component.inject(this) } } LoginFragmentの移行

class LoginFragment: Fragment() { override fun onAttach(context: Context) { super.onAttach(context)
} } LoginFragmentの移行

@AndroidEntryPoint class LoginFragment: Fragment() { override fun onAttach(context: Context) {
super.onAttach(context) } } LoginFragmentの移行

@AndroidEntryPoint class LoginFragment: Fragment() { override fun onAttach(context: Context) {
super.onAttach(context) /* 省略 */ } } LoginFragmentの移行

LoginのComponent削除 ApplicationC MainFragmentC LoginActivityC LoginFragmentC SingletonC ActivityC FragmentC

LoginのComponent削除 ApplicationC MainFragmentC SingletonC ActivityC FragmentC

MainFragmentの移行 ApplicationC MainFragmentC SingletonC ActivityC FragmentC MainFragment担当

class MainFragment : Fragment() { override fun onAttach(context: Context) {
AndroidSupportInjection.inject(this) super.onAttach(context) /* 省略 */ } } MainFragmentの移行

class MainFragment : Fragment() { override fun onAttach(context: Context) {
super.onAttach(context) /* 省略 */ } } MainFragmentの移行

@AndroidEntryPoint class MainFragment : Fragment() { override fun onAttach(context: Context)
{ super.onAttach(context) /* 省略 */ } } MainFragmentの移行

MainFragmentのComponent削除 ApplicationC MainFragmentC SingletonC ActivityC FragmentC

MainFragmentのComponent削除 ApplicationC SingletonC ActivityC FragmentC

@AndroidEntryPoint class MainActivity : AppCompatActivity(), HasAndroidInjector { @Inject lateinit var
androidInjector: DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector /* 省略 */ } MainActivityからdagger.androidを除去

@AndroidEntryPoint class MainActivity : AppCompatActivity() { /* 省略 */ }
MainActivityからdagger.androidを除去

Activity / Fragmentの移行が完了したら ApplicationC SingletonC ActivityC FragmentC

@HiltAndroidApp class App : Application(), HasAndroidInjector { @Inject lateinit var
androidInjector: DispatchingAndroidInjector<Any> override fun androidInjector(): AndroidInjector<Any> = androidInjector val component: ApplicationComponent by lazy { EntryPoints.get(this, ApplicationComponent::class.java) } } Appからdagger.androidを除去

@HiltAndroidApp class App : Application() { val component: ApplicationComponent by
lazy { EntryPoints.get(this, ApplicationComponent::class.java) } } Appからdagger.androidを除去

@InstallIn(SingletonComponent::class) @EntryPoint interface ApplicationComponent : AndroidInjector<App> @InstallIn(SingletonComponent::class) @Module( includes =
[ AndroidInjectionModule::class, ApplicationModule::class, RepositoryModule::class, ] ) interface AggregatorModule Component Treeからdagger.androidを除去

@InstallIn(SingletonComponent::class) @EntryPoint interface ApplicationComponent @InstallIn(SingletonComponent::class) @Module( includes = [ ApplicationModule::class,
RepositoryModule::class, ] ) interface AggregatorModule Component Treeからdagger.androidを除去

ApplicationComponent削除 ApplicationC SingletonC ActivityC FragmentC

@HiltAndroidApp class App : Application() { val component: ApplicationComponent by
lazy { EntryPoints.get(this, ApplicationComponent::class.java) } } @InstallIn(SingletonComponent::class) @EntryPoint interface ApplicationComponent ApplicationComponentを削除

@HiltAndroidApp class App : Application() { /* 省略 */ }
ApplicationComponentを削除

Well done 👏

Q. LoginActivityのような具象クラスを扱いたい @ActivityScope @Subcomponent interface LoginActivityComponent { @Subcomponent.Factory interface Factory
{ fun create(@BindsInstance activity: LoginActivity): LoginActivityComponent } }

Q. LoginActivityのような具象クラスを扱いたい A. castしましょう @InstallIn(ActivityComponent::class) @Module class LoginActivityModule { @Provides
fun providesLoginActivity(activity: Activity): LoginActivity? = activity as? LoginActivity? }

Q. LoginActivityのような具象クラスを扱いたい A. castしましょう @InstallIn(ActivityComponent::class) @Module class LoginFeatureModule { @Provides
fun providesLoginActivity(activity: Activity): LoginFeature? = (activity as? HasLoginFeature?)?.loginFeature }

Q. ActivityごとにModuleを切り替えたい @Module interface SignupActivityModule { @ActivityScope @ContributesAndroidInjector(modules = [EmailModule::class])
fun contributesEmailSignupActivity(): EmailSignupActivity @ActivityScope @ContributesAndroidInjector(modules = [SnsModule::class]) fun contributesSnsSignupActivity(): SnsSignupActivity }

Q. ActivityごとにModuleを切り替えたい @Module interface EmailModule { @Binds fun bindsFeature(feature: EmailSignupFeature):
SignupFeature } @Module interface SnsModule { @Binds fun bindsFeature(feature: SnsSignupFeature): SignupFeature }

Q. ActivityごとにModuleを切り替えたい A. 切り替えたいのはModuleではなくインスタンス @InstallIn(ActivityComponent::class) @Module class SignupModule { @Provides
fun providesFeature(activity: Activity): SignupFeature = when (activity) { is EmailSignupActivity -> EmailSignupFeature() is SnsSignupActivity -> SnsSignupFeature() else -> error("Invalid Activity") } }

Q. FCMServiceにinjectするとUIテストが落ちるのですが @AndroidEntryPoint class MyFirebaseMessagingService : FirebaseMessagingService() { @Inject lateinit
var useCase: RegisterToken override fun onNewToken(token: String) { super.onNewToken(token) useCase.execute(token) } }

Q. FCMServiceにinjectするとUIテストが落ちるのですが C Tree @Before @After C Tree @Before @After
C Tree @Before @After

Q. FCMServiceにinjectするとUIテストが落ちるのですが ContentProvider 初期化 C Tree @Before @After C Tree
@Before @After C Tree @Before @After

Q. FCMServiceにinjectするとUIテストが落ちるのですが A. テストでuseCase実行を諦めましょう class MyFirebaseMessagingService : FirebaseMessagingService() { @EntryPoint
@InstallIn(SingletonComponent::class) interface LocalEntryPoint { fun useCase(): RegisterToken } }

Q. FCMServiceにinjectするとUIテストが落ちるのですが A. テストでuseCase実行を諦めましょう class MyFirebaseMessagingService : FirebaseMessagingService() { private
val useCase: RegisterToken? by lazy { try { EntryPointAccessors.fromApplication( applicationContext, LocalEntryPoint::class.java ).useCase() } catch (t: Throwable) { null } } }

Q. FCMServiceにinjectするとUIテストが落ちるのですが A. テストでuseCase実行を諦めましょう class MyFirebaseMessagingService : FirebaseMessagingService() { override
fun onNewToken(token: String) { super.onNewToken(token) useCase?.execute(token) } }

Q. 今度はApplicationでUIテストが落ちるのですが ContentProvider 初期化 C Tree @Before @After C Tree
@Before @After C Tree @Before @After

Q. 今度はApplicationでUIテストが落ちるのですが App#onCreate ContentProvider 初期化 C Tree @Before @After C
Tree @Before @After C Tree @Before @After

Q. 今度はApplicationでUIテストが落ちるのですが A. 初期化処理を遅延実行しましょう

open class BaseApp : Application() { @EntryPoint @InstallIn(SingletonComponent::class) interface AppEntryPoint
{ fun appDependencies(): AppDependencies } private val entryPoint: AppEntryPoint by lazy { EntryPointAccessors.fromApplication(this, AppEntryPoint::class.java) } }

open class BaseApp : Application() { override fun onCreate() {
super.onCreate() initializeOnCreate() } protected open fun initializeOnCreate() { // ここに必要な初期化処理 } }

@CustomTestApplication(AndroidTestApp::class) interface HiltAndroidTestApp class AndroidTestApp : BaseApp() { private val
isInitialized = AtomicBoolean(false) override fun initializeOnCreate() { // 初期化はここでは実施しない } fun initialize() { if (isInitialized.compareAndSet(false, true)) { super.initializeOnCreate() } } }

class AppInitializeAndroidTestRule : TestRule { override fun apply(base: Statement, description:
Description): Statement = object : Statement() { override fun evaluate() { val app = ApplicationProvider.getApplicationContext<AndroidTestApp>() app.initialize() base.evaluate() } } }

fun androidTestRule(testInstance: Any): TestRule = RuleChain.outerRule(HiltAndroidRule(testInstance)) .around(AppInitializeAndroidTestRule()) @HiltAndroidTest @RunWith(AndroidJUnit4::class) class
SomeUiTest { @get:Rule val rule = androidTestRule(this) }

Q. 〇〇を□□したい！

Q. 〇〇を□□したい！ A. Component Treeを思い浮かべて、原理から考えよう

Thanks!

原理から完全理解するDagger Hilt Migration

原理から完全理解するDagger Hilt Migration

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