UITestDemo - Modern Android App Template

A production-ready Android application demonstrating modern Android development best practices, including Clean Architecture, MVVM pattern, Jetpack Compose, offline-first approach with Room database, comprehensive testing, and CI/CD.

📱 Screenshots

✨ Features

• 🏗️ Clean Architecture - Separation of concerns with clear layer boundaries
• 📱 MVVM Pattern - Reactive UI with ViewModels and StateFlow
• 🎨 Jetpack Compose - Modern declarative UI toolkit
• 💾 Offline-First - Room database with cache-first strategy (5-minute cache timeout)
• 🔌 Networking - Retrofit with proper error handling
• 💉 Dependency Injection - Hilt for clean, testable code
• 🧪 Comprehensive Testing - Unit tests, UI tests, and integration tests (33 tests total)
• 🔍 Code Quality - Detekt static analysis with custom rules
• 🚀 CI/CD - GitHub Actions for automated testing and builds
• 🎯 Edge-to-Edge UI - Modern Material 3 design with proper window insets
• ⚡ Performance - ProGuard/R8 optimization for release builds

🛠️ Tech Stack

Core

• Kotlin 2.3.10
• Min SDK 30 (Android 11)
• Target SDK 36

UI

• Jetpack Compose 2026.02.00 BOM
• Material 3 - Modern Material Design
• Compose Navigation - For multi-screen apps
• Hilt Navigation Compose - ViewModel integration

Architecture

• Hilt 2.59.2 - Dependency Injection
• Coroutines 1.10.2 - Asynchronous programming
• StateFlow - Reactive state management

Networking

• Retrofit 3.0.0 - HTTP client
• Gson - JSON serialization
• OkHttp Logging Interceptor - Network debugging

Database

• Room 2.8.4 - Local persistence
• Room KTX - Coroutines support

Testing

• JUnit 4.13.2 - Unit testing framework
• Kotlin Test - Kotlin-specific assertions
• MockK 1.14.9 - Mocking library
• Turbine 1.2.1 - Flow testing
• Coroutines Test - Coroutine testing utilities
• Compose UI Test - UI testing
• Hilt Testing - DI testing support

Code Quality

• Detekt 1.23.8 - Static code analysis
• KSP 2.3.4 - Annotation processing

🏗️ Architecture

This project follows Clean Architecture principles with three main layers:

┌─────────────────────────────────────────┐
│         Presentation Layer              │
│  - UI (Compose)                         │
│  - ViewModels                           │
│  - UI State                             │
└─────────────────────────────────────────┘
              ↓ ↑
┌─────────────────────────────────────────┐
│         Domain Layer                    │
│  - Use Cases                            │
│  - Domain Models                        │
│  - Repository Interfaces                │
└─────────────────────────────────────────┘
              ↓ ↑
┌─────────────────────────────────────────┐
│         Data Layer                      │
│  - Repository Implementations           │
│  - Local Database (Room)                │
│  - Remote API (Retrofit)                │
└─────────────────────────────────────────┘

Package Structure

app/src/main/java/io/codetheworld/uitestdemo/
├── core/
│   ├── di/                 # Dependency injection modules
│   │   ├── AppModule.kt
│   │   ├── DatabaseModule.kt
│   │   └── NetworkModule.kt
│   └── network/            # Network utilities
│       ├── ApiService.kt
│       ├── NetworkConstants.kt
│       └── NetworkResult.kt
├── data/
│   ├── local/             # Room database
│   │   ├── AppDatabase.kt
│   │   ├── dao/
│   │   │   └── PostDao.kt
│   │   └── entity/
│   │       └── PostEntity.kt
│   └── repository/        # Repository implementations
│       └── PostRepositoryImpl.kt
├── domain/
│   ├── model/             # Domain models
│   │   └── Post.kt
│   ├── repository/        # Repository interfaces
│   │   └── PostRepository.kt
│   └── usecase/           # Business logic
│       └── GetPostsUseCase.kt
└── ui/
    ├── post/              # Post feature
    │   ├── PostScreen.kt
    │   ├── PostUiState.kt
    │   ├── PostViewModel.kt
    │   └── UiError.kt
    └── theme/             # App theming
        ├── Color.kt
        ├── Theme.kt
        └── Type.kt

🚀 Getting Started

Prerequisites

• Android Studio Ladybug | 2024.2.1 or later
• JDK 17 or later
• Android SDK 36
• Gradle 9.2.1

Installation

1. Clone the repository

git clone https://github.com/yourusername/UITestDemo.git
cd UITestDemo

2. Open the project in Android Studio

3. Sync Gradle files

4. Run the app

./gradlew assembleDebug

Running Tests

Unit Tests:

./gradlew test

UI Tests:

./gradlew connectedAndroidTest

Code Quality Check:

./gradlew detekt

All Quality Checks:

./gradlew test detekt assembleDebug

🧪 Testing Strategy

The project includes comprehensive testing:

• Unit Tests (27 tests)

  • ViewModel tests with Turbine
  • Repository tests with MockK
  • Use case tests
  • Error mapping tests

• UI Tests (3 tests)

  • Compose UI tests
  • Hilt integration tests
  • End-to-end flows

• Integration Tests

  • Repository with fake dependencies

Test Coverage: ~85%

Test Examples

ViewModel Test:

@Test
fun `init loads posts successfully`() = runTest {
    // Given
    coEvery { getPostsUseCase() } returns NetworkResult.Success(testPosts)

    // When
    viewModel = PostViewModel(getPostsUseCase)
    testDispatcher.scheduler.advanceUntilIdle()

    // Then
    viewModel.uiState.test {
        val state = awaitItem()
        assertFalse(state.isLoading)
        assertEquals(testPosts, state.posts)
    }
}

🎯 Key Features Explained

Offline-First Architecture

The app implements a cache-first strategy:

1. Check local cache first - Always try to serve from cache
2. Validate cache - Check if cache is fresh (< 5 minutes)
3. Return valid cache immediately - No network call needed
4. Fetch on stale/empty - Only call network if necessary
5. Fallback to cache - On network errors, return stale cache

Benefits:

• ⚡ Instant app startup
• 📴 Works offline
• 🔋 Reduced battery usage
• 📊 Lower data consumption

Error Handling

Type-safe error handling with sealed classes:

sealed class NetworkResult<out T> {
    data class Success<T>(val data: T) : NetworkResult<T>()
    sealed class Error : NetworkResult<Nothing>() {
        data object NetworkError : Error()
        data class ServerError(val code: Int) : Error()
        data class UnknownError(val message: String?) : Error()
    }
}

User-friendly error messages:

• Network errors: "No internet connection. Please check your network."
• Server errors: Specific messages based on HTTP status codes
• Unknown errors: Graceful degradation

Dependency Injection

Using Hilt for dependency management:

@HiltViewModel
class PostViewModel @Inject constructor(
    private val getPostsUseCase: GetPostsUseCase
) : ViewModel()

All dependencies are provided through DI, making the code:

• Testable (easy to inject mocks)
• Maintainable (centralized dependency management)
• Scalable (easy to swap implementations)

📊 Code Quality

Detekt Configuration

The project uses Detekt with custom rules:

complexity:
  LongMethod: threshold: 60
  LargeClass: threshold: 600
  CyclomaticComplexMethod: threshold: 15

style:
  MaxLineLength: 120

Run code quality checks:

./gradlew detekt

View HTML report:

app/build/reports/detekt/detekt.html

🔄 CI/CD Pipeline

GitHub Actions workflow runs on every push and PR:

✅ Code quality check (Detekt) ✅ Unit tests ✅ Build debug APK ✅ Build Android test APK ✅ Upload test results

See .github/workflows/ci.yml for details.

🛣️ Roadmap

• Add pagination for large lists
• Implement pull-to-refresh
• Add search functionality
• Implement multi-module architecture
• Add more comprehensive UI tests
• Integrate Firebase Analytics
• Add crash reporting (Firebase Crashlytics)
• Implement dark theme support
• Add accessibility features
• Baseline profiles for performance

🤝 Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Code Style

• Follow Kotlin coding conventions
• Run Detekt before committing: ./gradlew detekt
• Ensure all tests pass: ./gradlew test
• Add tests for new features

📝 License

This project is licensed under the MIT License - see the LICENSE file for details.

👨‍💻 Author

Your Name

• GitHub: @yourusername
• LinkedIn: Your LinkedIn

🙏 Acknowledgments

• JSONPlaceholder - Free fake API for testing
• Android Developers - Official documentation
• Jetpack Compose - Modern UI toolkit
• Hilt - Dependency injection library

📚 Resources

• Clean Architecture Guide
• Android Architecture Guidelines
• Compose Best Practices
• Testing Guide

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Built with ❤️ using Kotlin and Jetpack Compose

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