formatools · stepango · Aug 6, 2026 · Aug 6, 2026
diff --git a/TICKETS.md b/TICKETS.md
@@ -187,7 +187,7 @@ Hygiene this promote: closed GH **#46** (nav — F-102/111/112) and **#43** (hyb
 
 | ID | Status | Title | Notes |
 |----|--------|-------|-------|
-| F-116 | todo | Sample clean architecture (domain use cases) | GH **#48** · **`priority: now`** · **`cron may continue`**. Gold sample: weaken presentation↔data coupling via **domain use cases**; kill `GlobalScope` / data-layer scope ownership (see legacy `CharacterPageDataSource` / `CharactersListViewModel` pattern if still present). Keep flat role graph — domain as `api`/`impl` (or util) ports, no `impl`→`impl`, no `androidLibrary`. Docs: `docs/SAMPLE-APP.md` + any progressive pointer if teaching-worthy. Close #48 on merge. |
+| F-116 | done | Sample clean architecture (domain use cases) | GH **#48**. Domain use cases on characters `core` (`IGetCharactersUseCase` / `IGetCharacterUseCase`); list paging via `viewModelScope` (no `GlobalScope`); detail VM on use case. Docs: `docs/SAMPLE-APP.md`. Close #48 on merge. |
 
 ## Backlog (lower priority / historical GitHub)
 

diff --git a/.../src/main/java/tools/forma/sample/feature/characters/core/api/di/CharactersCoreFeature.kt b/.../src/main/java/tools/forma/sample/feature/characters/core/api/di/CharactersCoreFeature.kt
@@ -1,8 +1,14 @@
 package tools.forma.sample.feature.characters.core.api.di
 
 import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharacterUseCase
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharactersUseCase
 
 interface CharactersCoreFeature {
 
     fun getMarvelRepository(): MarvelRepository
-}
+
+    fun getCharactersUseCase(): IGetCharactersUseCase
+
+    fun getCharacterUseCase(): IGetCharacterUseCase
+}
diff --git a/...ava/tools/forma/sample/feature/characters/core/api/domain/usecase/IGetCharacterUseCase.kt b/...ava/tools/forma/sample/feature/characters/core/api/domain/usecase/IGetCharacterUseCase.kt
@@ -0,0 +1,8 @@
+package tools.forma.sample.feature.characters.core.api.domain.usecase
+
+import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
+
+interface IGetCharacterUseCase {
+
+    suspend operator fun invoke(id: Long): ICharacter
+}
diff --git a/...va/tools/forma/sample/feature/characters/core/api/domain/usecase/IGetCharactersUseCase.kt b/...va/tools/forma/sample/feature/characters/core/api/domain/usecase/IGetCharactersUseCase.kt
@@ -0,0 +1,8 @@
+package tools.forma.sample.feature.characters.core.api.domain.usecase
+
+import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
+
+interface IGetCharactersUseCase {
+
+    suspend operator fun invoke(offset: Int, limit: Int): List<ICharacter>
+}
diff --git a/.../src/main/java/tools/forma/sample/feature/characters/core/impl/di/CharactersCoreModule.kt b/.../src/main/java/tools/forma/sample/feature/characters/core/impl/di/CharactersCoreModule.kt
@@ -8,32 +8,48 @@ import tools.forma.sample.feature.characters.core.api.data.response.CharacterRes
 import tools.forma.sample.feature.characters.core.api.data.service.MarvelService
 import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
 import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharacterUseCase
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharactersUseCase
 import tools.forma.sample.feature.characters.core.impl.data.mapper.CharacterMapper
 import tools.forma.sample.feature.characters.core.impl.domain.repository.ServiceMarvelRepository
+import tools.forma.sample.feature.characters.core.impl.domain.usecase.GetCharacterUseCase
+import tools.forma.sample.feature.characters.core.impl.domain.usecase.GetCharactersUseCase
+import dagger.Binds
 import dagger.Module
 import dagger.Provides
 import retrofit2.Retrofit
 import javax.inject.Singleton
 
 @Module
-internal class CharactersCoreModule {
+internal abstract class CharactersCoreModule {
 
     @Singleton
-    @Provides
-    fun provideMarvelService(retrofit: Retrofit): MarvelService =
-        retrofit.create(MarvelService::class.java)
+    @Binds
+    abstract fun bindGetCharactersUseCase(useCase: GetCharactersUseCase): IGetCharactersUseCase
 
     @Singleton
-    @Provides
-    fun provideMarvelRepository(
-        service: MarvelService,
-        config: Config,
-        clock: Clock,
-        characterMapper: Mapper<BaseResponse<CharacterResponse>, List<ICharacter>>,
-    ): MarvelRepository =
-        ServiceMarvelRepository(service, config, clock, characterMapper)
-
-    @Provides
-    fun provideCharacterMapper(): Mapper<BaseResponse<CharacterResponse>, List<ICharacter>> =
-        CharacterMapper()
-}
+    @Binds
+    abstract fun bindGetCharacterUseCase(useCase: GetCharacterUseCase): IGetCharacterUseCase
+
+    companion object {
+
+        @Singleton
+        @Provides
+        fun provideMarvelService(retrofit: Retrofit): MarvelService =
+            retrofit.create(MarvelService::class.java)
+
+        @Singleton
+        @Provides
+        fun provideMarvelRepository(
+            service: MarvelService,
+            config: Config,
+            clock: Clock,
+            characterMapper: Mapper<BaseResponse<CharacterResponse>, List<ICharacter>>,
+        ): MarvelRepository =
+            ServiceMarvelRepository(service, config, clock, characterMapper)
+
+        @Provides
+        fun provideCharacterMapper(): Mapper<BaseResponse<CharacterResponse>, List<ICharacter>> =
+            CharacterMapper()
+    }
+}
diff --git a/...ava/tools/forma/sample/feature/characters/core/impl/domain/usecase/GetCharacterUseCase.kt b/...ava/tools/forma/sample/feature/characters/core/impl/domain/usecase/GetCharacterUseCase.kt
@@ -0,0 +1,14 @@
+package tools.forma.sample.feature.characters.core.impl.domain.usecase
+
+import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
+import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharacterUseCase
+import javax.inject.Inject
+
+class GetCharacterUseCase @Inject constructor(
+    private val repository: MarvelRepository,
+) : IGetCharacterUseCase {
+
+    override suspend fun invoke(id: Long): ICharacter =
+        repository.getCharacter(id)
+}
diff --git a/...va/tools/forma/sample/feature/characters/core/impl/domain/usecase/GetCharactersUseCase.kt b/...va/tools/forma/sample/feature/characters/core/impl/domain/usecase/GetCharactersUseCase.kt
@@ -0,0 +1,14 @@
+package tools.forma.sample.feature.characters.core.impl.domain.usecase
+
+import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
+import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharactersUseCase
+import javax.inject.Inject
+
+class GetCharactersUseCase @Inject constructor(
+    private val repository: MarvelRepository,
+) : IGetCharactersUseCase {
+
+    override suspend fun invoke(offset: Int, limit: Int): List<ICharacter> =
+        repository.getCharacters(offset, limit)
+}
diff --git a/...ools/forma/sample/feature/characters/detail/impl/presentation/CharacterDetailViewModel.kt b/...ools/forma/sample/feature/characters/detail/impl/presentation/CharacterDetailViewModel.kt
@@ -21,7 +21,7 @@ import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
-import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharacterUseCase
 import tools.forma.sample.feature.characters.detail.api.presentation.ICharacterDetailViewModel
 import tools.forma.sample.feature.characters.detail.api.presentation.ICharacterDetailViewState
 import tools.forma.sample.feature.characters.favorite.api.domain.usecase.IGetCharacterFavoriteUseCase
@@ -30,7 +30,7 @@ import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 class CharacterDetailViewModel @Inject constructor(
-        private val marvelRepository: MarvelRepository,
+        private val getCharacterUseCase: IGetCharacterUseCase,
         private val getCharacterFavoriteUseCase: IGetCharacterFavoriteUseCase,
         private val setCharacterFavoriteUseCase: ISetCharacterFavoriteUseCase,
 ) : ViewModel(), ICharacterDetailViewModel {
@@ -47,7 +47,7 @@ class CharacterDetailViewModel @Inject constructor(
         _state.postValue(CharacterDetailViewState.Loading)
         viewModelScope.launch {
             try {
-                val result = marvelRepository.getCharacter(characterId)
+                val result = getCharacterUseCase(characterId)
                 _data.postValue(result)
 
                 getCharacterFavoriteUseCase(characterId)?.let {

diff --git a/...ols/forma/sample/feature/characters/list/impl/data/datasource/CharactersPageDataSource.kt b/...ols/forma/sample/feature/characters/list/impl/data/datasource/CharactersPageDataSource.kt
@@ -20,24 +20,25 @@ import androidx.lifecycle.MutableLiveData
 import androidx.paging.PageKeyedDataSource
 import tools.forma.sample.core.network.library.NetworkState
 import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
-import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharactersUseCase
 import kotlinx.coroutines.CoroutineExceptionHandler
-import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 
 const val PAGE_INIT_ELEMENTS = 0
 const val PAGE_MAX_ELEMENTS = 50
 
 /**
- * Incremental data loader for page-keyed content, where requests return keys for next/previous
- * pages. Obtaining paginated the Marvel characters.
+ * Incremental data loader for page-keyed content. Thin paging adapter: loads via
+ * [IGetCharactersUseCase] on a [CoroutineScope] owned by the presentation layer
+ * (typically [androidx.lifecycle.viewModelScope]). Does not own a scope or call
+ * the repository directly.
  *
  * @see PageKeyedDataSource
  */
-// TODO https://github.com/formatools/forma/issues/48
-// Rewrite on clean version with separate Repository with local/remote datasource
 open class CharacterPageDataSource(
-    private val repository: MarvelRepository,
+    private val getCharactersUseCase: IGetCharactersUseCase,
+    private val scope: CoroutineScope,
 ) : PageKeyedDataSource<Int, ICharacter>() {
 
     val networkState = MutableLiveData<NetworkState>()
@@ -48,16 +49,13 @@ open class CharacterPageDataSource(
         callback: LoadInitialCallback<Int, ICharacter>
     ) {
         networkState.postValue(NetworkState.Loading())
-        // TODO https://github.com/formatools/forma/issues/48
-        // Don't do that!!! Using GlobalScope here only for first working version
-        // Make it from UseCase and calling it from View Model scope
-        GlobalScope.launch(CoroutineExceptionHandler { _, _ ->
+        scope.launch(CoroutineExceptionHandler { _, _ ->
             retry = {
                 loadInitial(params, callback)
             }
             networkState.postValue(NetworkState.Error())
         }) {
-            val response = repository.getCharacters(
+            val response = getCharactersUseCase(
                 offset = PAGE_INIT_ELEMENTS,
                 limit = PAGE_MAX_ELEMENTS
             )
@@ -79,16 +77,13 @@ open class CharacterPageDataSource(
         callback: LoadCallback<Int, ICharacter>
     ) {
         networkState.postValue(NetworkState.Loading(true))
-        // TODO https://github.com/formatools/forma/issues/48
-        // Don't do that!!! Using GlobalScope here only for first working version
-        // Make it from UseCase and calling it from View Model scope
-        GlobalScope.launch(CoroutineExceptionHandler { _, _ ->
+        scope.launch(CoroutineExceptionHandler { _, _ ->
             retry = {
                 loadAfter(params, callback)
             }
             networkState.postValue(NetworkState.Error(true))
         }) {
-            val response = repository.getCharacters(
+            val response = getCharactersUseCase(
                 offset = params.key,
                 limit = PAGE_MAX_ELEMENTS
             )

diff --git a/...ma/sample/feature/characters/list/impl/data/datasource/CharactersPageDataSourceFactory.kt b/...ma/sample/feature/characters/list/impl/data/datasource/CharactersPageDataSourceFactory.kt
@@ -19,19 +19,21 @@ package tools.forma.sample.feature.characters.list.impl.data.datasource
 import androidx.lifecycle.MutableLiveData
 import androidx.paging.DataSource
 import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
-import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
-import javax.inject.Inject
-import javax.inject.Provider
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharactersUseCase
+import kotlinx.coroutines.CoroutineScope
 
 /**
  * Data source factory which also provides a way to observe the last created data source.
  * This allows us to channel its network request status etc back to the UI.
  *
+ * Constructed by the ViewModel with [IGetCharactersUseCase] and the ViewModel's
+ * [CoroutineScope] so paging loads never use a process-global scope.
+ *
  * @see DataSource.Factory
  */
-@Deprecated("Seems this class invoke some domain logic. It's wrong!", ReplaceWith("On target UseCase"))
-class CharactersPageDataSourceFactory @Inject constructor(
-    private val repository: MarvelRepository,
+class CharactersPageDataSourceFactory(
+    private val getCharactersUseCase: IGetCharactersUseCase,
+    private val scope: CoroutineScope,
 ) : DataSource.Factory<Int, ICharacter>() {
 
     var sourceLiveData = MutableLiveData<CharacterPageDataSource>()
@@ -43,7 +45,7 @@ class CharactersPageDataSourceFactory @Inject constructor(
      * @see DataSource.Factory.create
      */
     override fun create(): DataSource<Int, ICharacter> {
-        val dataSource = CharacterPageDataSource(repository)
+        val dataSource = CharacterPageDataSource(getCharactersUseCase, scope)
         sourceLiveData.postValue(dataSource)
         return dataSource
     }

diff --git a/.../src/main/java/tools/forma/sample/feature/characters/list/impl/di/CharactersListModule.kt b/.../src/main/java/tools/forma/sample/feature/characters/list/impl/di/CharactersListModule.kt
@@ -17,14 +17,10 @@
 package tools.forma.sample.feature.characters.list.impl.di
 
 import androidx.lifecycle.ViewModel
-import tools.forma.sample.core.di.library.scopes.FeatureScope
 import tools.forma.sample.core.mvvm.library.di.ViewModelKey
-import tools.forma.sample.feature.characters.core.api.domain.repository.MarvelRepository
-import tools.forma.sample.feature.characters.list.impl.data.datasource.CharacterPageDataSource
 import tools.forma.sample.feature.characters.list.impl.ui.CharactersListViewModel
 import dagger.Binds
 import dagger.Module
-import dagger.Provides
 import dagger.multibindings.IntoMap
 
 @Module
@@ -34,15 +30,4 @@ internal abstract class CharactersListModule {
     @IntoMap
     @ViewModelKey(CharactersListViewModel::class)
     abstract fun bindsCharactersListViewModel(viewModel: CharactersListViewModel): ViewModel
-
-    companion object {
-
-        @FeatureScope
-        @Provides
-        fun providesCharactersPageDataSource(
-            repository: MarvelRepository,
-        ) = CharacterPageDataSource(
-            repository = repository,
-        )
-    }
 }
diff --git a/...c/main/java/tools/forma/sample/feature/characters/list/impl/ui/CharactersListViewModel.kt b/...c/main/java/tools/forma/sample/feature/characters/list/impl/ui/CharactersListViewModel.kt
@@ -20,24 +20,29 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.map
 import androidx.lifecycle.switchMap
+import androidx.lifecycle.viewModelScope
 import androidx.paging.LivePagedListBuilder
 import androidx.paging.PagedList
 import tools.forma.sample.core.mvvm.library.lifecycle.SingleLiveData
 import tools.forma.sample.core.network.library.NetworkState
+import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
+import tools.forma.sample.feature.characters.core.api.domain.usecase.IGetCharactersUseCase
 import tools.forma.sample.feature.characters.list.impl.data.datasource.CharactersPageDataSourceFactory
 import tools.forma.sample.feature.characters.list.impl.data.datasource.PAGE_MAX_ELEMENTS
-import tools.forma.sample.feature.characters.core.api.domain.model.ICharacter
 import tools.forma.sample.feature.characters.list.viewbinding.domain.model.ICharactersListViewEvent
 import tools.forma.sample.feature.characters.list.viewbinding.domain.model.ICharactersListViewModel
 import tools.forma.sample.feature.characters.list.viewbinding.domain.model.ICharactersListViewState
 import javax.inject.Inject
 
 class CharactersListViewModel @Inject constructor(
-    // TODO https://github.com/formatools/forma/issues/48
-    // Aggregate UseCase here
-    private val dataSourceFactory: CharactersPageDataSourceFactory
+    getCharactersUseCase: IGetCharactersUseCase,
 ) : ViewModel(), ICharactersListViewModel {
 
+    private val dataSourceFactory = CharactersPageDataSourceFactory(
+        getCharactersUseCase = getCharactersUseCase,
+        scope = viewModelScope,
+    )
+
     override val networkState = dataSourceFactory.sourceLiveData.switchMap {
         it.networkState
     }

diff --git a/docs/PROGRESS.md b/docs/PROGRESS.md
@@ -2,6 +2,22 @@
 
 Newest entries first.
 
+## 2026-08-06 — F-116: sample domain use cases; kill GlobalScope
+
+- **Ticket:** F-116 → `done` (GH #48)
+- **Branch:** `forma/F-116-sample-clean-arch` (from `origin/v2`)
+- **Actions:**
+  - Added `IGetCharactersUseCase` / `IGetCharacterUseCase` on `feature/characters/core/api`; impls + `@Binds` in `core/impl`; exposed on `CharactersCoreFeature`
+  - List paging: `CharacterPageDataSource` takes use case + `CoroutineScope` (from VM `viewModelScope`); zero `GlobalScope`; no direct `MarvelRepository`
+  - `CharactersListViewModel` depends on `IGetCharactersUseCase`; owns factory with scope
+  - `CharacterDetailViewModel` uses `IGetCharacterUseCase` (not repository)
+  - Docs: `docs/SAMPLE-APP.md` characters layering section
+- **Verify (real):**
+  - `application/` `./gradlew :feature-characters-list-impl:compileDebugKotlin :feature-characters-detail-impl:compileDebugKotlin :feature-characters-core-impl:compileDebugKotlin :binary:assembleDebug` → **BUILD SUCCESSFUL** in 2m30s
+  - `grep -R GlobalScope application --include='*.kt'` → empty (product sources)
+- **Not in slice:** Paging3 migration; Forma engine changes; progressive example module
+- **Next:** close GH #48 on merge; board open item remains F-094 (human Portal)
+
 ## 2026-08-06 — P13: promote remaining open GH into TICKETS
 
 - **Context:** Empty gated coding board post F-115/#250; Stepan: **Promote gh issues**