👉 ComposeTemplate

A clean, modular, and testable Jetpack Compose + Kotlin Inject template designed for building scalable Android apps using modern architectural patterns like MVI, DI, Middleware, and Reducer separation.

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🧭 MVI Architecture Overview – NewsList Feature

📐 Architecture Diagram

        ┌─────────────┐
        │ Composable  │
        │ (UI Layer)  │◄───── Collects ─────┐
        └────┬────────┘                     │
             │                              │
             ▼                              │
        ┌───────────────┐       Emits       │
        │  ViewModel    │─────────────────► SideEffect (e.g., NavigateToDetail)
        │  (MVI entry)  │                   │
        └────┬──────────┘                   │
             │ dispatches                   ▼
             ▼                         ┌─────────────┐
        ┌───────────────┐              │NavController│
        │   Delegate    │              └─────────────┘
        │ (MVI Engine)  │
        └────┬──────┬───┘
             │      │
             │      │
             ▼      ▼
        ┌────────┐ ┌────────────────────────────┐
        │Reducer │ │        Middleware          │
        │(Sync)  │ │(Async: API, Storage, etc.) │
        └────────┘ └────────────────────────────┘

🧱 Layer Responsibilities

🧩 1. Composable (UI Layer)

• Collects state with collectAsStateWithLifecycle
• Collects side effects via flowWithLifecycle
• Sends user events to ViewModel.onAction(...)

🧠 2. ViewModel (Entry Point)

• Delegates to MVI engine (MVIDelegate)
• Triggers initial actions like FetchNews
• Exposes state (StateFlow) and side-effects (Flow)
• DI-friendly using @Inject, @Assisted, etc.

⚙️ 3. MVIDelegate (Engine)

• Central coordinator
• Calls reducer first
• Then calls middleware(s) after state update
• Emits side-effects (e.g., navigation or toasts)

🔁 4. Reducer

• Pure, synchronous state transition
• No side-effects beyond Effect? return
• Fully testable and predictable

🌐 5. Middleware

• Handles asynchronous operations
  • Network calls
  • Database access
  • Logging
• Never updates state directly — only dispatches actions back to the delegate

✅ Key Features

Concern	Implementation
Async Handling	CoroutineScope + Middleware
Lifecycle-aware	collectAsStateWithLifecycle, flowWithLifecycle
Testability	Reducer & Middleware testable in isolation
DI Friendly	Uses @Inject, @Assisted, Set<Middleware>
Navigation	Triggered via SideEffect.NavigateToDetail(...)
Error Handling	AppError, CoroutineExceptionHandler inside Middleware
Threading	AppCoroutineDispatchers abstracts IO/Main/etc.
Scalability	Middleware is a Set = easily extendable

✅ Completed Features

Category	Feature	Status
🔌 Dependency Injection	Kotlin Inject with @Component, @Provides, @IntoSet	✅ Completed
🎨 UI	Jetpack Compose Screens (NewsList, NewsDetail)	✅ Completed
🧱 Navigation	Navigation with AppRouteFactory injection per feature	✅ Completed
🧠 State Management	MVI pattern (Reducer + Middleware + Delegate)	✅ Completed
🌐 Networking	Ktor-based HttpClient integration	✅ Completed
🧺 UI Testing	Compose UI + Navigation tests with custom TestApp	✅ Completed
🧲 DI for Testing	Custom TestApplicationComponent	✅ Completed
⚡ Coroutine Dispatchers	AppCoroutineDispatchers abstraction	✅ Completed
🩵 Logging	Kermit Logging via AppInitializers	✅ Completed
🛠 Environment Info	Dynamic ApplicationInfo (debug, flavor, version)	✅ Completed

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🔧 Pending / Upcoming Features

Feature	Priority	Notes
🔐 Authentication Module	🔜 Medium	Needs route factory, middleware, reducer setup
💃 Room Database Integration	🔜 Medium	For local caching, data source abstraction
🌙 Dark Theme Support	🔜 Low	Basic theming with system override
📀 Pull-to-Refresh	🔜 Low	Add to NewsListScreen for refresh API
🩵 Paging	🔜 Medium	Lazy load support for large news lists
🥐 Unit Test Coverage	🔜 High	Reducer, Middleware, UseCases
📊 Analytics Module	🔜 Low	Plug-in via middleware pipeline
🔄 Multi-Module Structure	🔜 High	Split :core, :features, :test-support, etc.

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🧲 UI Testing Strategy

• Test Harness: Custom TestApp bootstrapped with TestApplicationComponent
• Compose Rule: Uses createAndroidComposeRule<MainActivity>()
• DI Swapping: Inject Dispatchers and Dependencies to be changed
• Navigation Verification: End-to-end test across route boundaries

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📦 Tech Stack

• Jetpack Compose
• Kotlin 1.9+
• Kotlin Inject (by @evant)
• Ktor for networking
• MVI (Middleware + Reducer pattern)
• Coroutine Dispatchers abstraction
• Kermit Logging
• JUnit + Compose UI Test
• Gradle Kotlin DSL

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🧱 Architecture

App
│
├── di/
│   ├── AndroidApplicationComponent
│   ├── AndroidActivityComponent
│   └── CommonAppComponent
│
├── features/
│   └── newsList/
│       ├── presentation/
│       │   ├── ui/                <-- Composables
│       │   ├── viewmodel/         <-- Reducer + Middleware
│       └── domain/
│
├── util/
│   └── AppCoroutineDispatchers.kt
│   └── ApplicationInfo.kt
│
└── e2e/
    ├── TestApp.kt
    └── NewsListScreenE2ETest.kt

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📢 How to Run

# Run the app
./gradlew installDebug

# Run UI tests
./gradlew connectedAndroidTest (make allTest)

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🤝 Contributions Welcome

If you'd like to contribute or test-drive a feature like Authentication, Paging, or DB caching — feel free to fork and PR. Open to feedback and pairing on key improvements.

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🔗 Links

• 🔗 Heavily inspired by Tivi(https://github.com/chrisbanes/tivi)
• 🔗 Kotlin Inject Docs
• 🔗 Jetpack Compose Testing

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