Comprehensive Android Development Guide: Clean architecture, MVVM, UI & Unit & Screenshot Test (Compose Preview Screenshot Test and Paparazzi), Libraries (Compose Navigation 3, LiveData, StateFlow, Retrofit, Hilt, Coroutine, Compose, DataStore, Test Libraries and more)

I created different mini-apps for each item in the bottom navigation. Each mini-app shows a different way to use popular libraries, structures and best practices in Android development. This project is great for learning because it covers many important variable approaches that Android developers use.

Architecture & Design Principles

We adhere to clean architecture guidelines, structuring our application into multiple layers (Data, Domain, Presentation) to ensure decoupling and testability. The presentation layer is powered by MVVM (Model-View-ViewModel), utilizing Jetpack Compose for dynamic UIs and animations.

Key Libraries

• Jetpack Compose & Material3 & Compose Navigation 3 & Compose Preview Screenshot Test: For building modern UIs with a focus on material design principles.
• Dagger-Hilt: Dependency injection framework for Android, simplifying the provision of dependencies across the application.
• Retrofit & Gson: Networking and JSON serialization/deserialization for API communication.
• Jetpack Navigation: For handling in-app navigation in a modular and scalable way.
• Coroutines & Flow: For asynchronous programming and reactive data streams.
• Jetpack Lifecycle, LiveData, ViewModel: Lifecycle-aware components for robust and maintainable MVVM architecture.
• ExoPlayer-Compose: Media playback.
• Mockito & JUnit & Mockk & Espresso & Paparazzi & Compose Preview Screenshot Test: Testing libraries for Unit, UI, Integration & Screenshot tests.
• TOML Version Catalog: Centralizes and manages library versions across the project, enhancing maintainability and consistency in dependency management.
• DataStore with Serialization: For efficient and robust data storage and management, providing a reactive and secure way to handle preferences and structured data.
• Coil: For image loading and caching in applications, offering seamless integration with Jetpack Compose.
• Kover: Kotlin code coverage tool used to generate detailed test coverage reports. It helps monitor the effectiveness of tests and improve code quality.

Code Coverage Report

To generate a Kotlin code coverage report using Kover, run the following command:

./gradlew koverHtmlReport

Screenshot (e.g., data)

Compose Screenshot Testing

Compose Preview Screenshot Tests are used to verify UI consistency and detect unexpected layout changes during development.

To update the baseline screenshots and verify them for a specific module (e.g., musicplayer), run the following commands:

./gradlew :feature:musicplayer:updateDebugScreenshotTest

## After development to verify
./gradlew :feature:musicplayer:verifyDebugScreenshotTest

The generated screenshots can be found under:

feature/musicplayer/build/outputs/screenshotTest-results/preview

Custom Compose Animation

dynamicboxanimator library module is developed with Jetpack Compose, this is a custom animation created without the use of any external libraries. Designed using modern and flexible Compose APIs.

Unique Usage for Page 1:

weather-shot.mp4

• Clean Architecture: Demonstrated the use of Clean Architecture in the format of UI - Usecase(domain) - Data.
• Data Fetching: Provided examples of fetching data from an API and a local JSON file.
• Common usages

Special Usage for Page 2:

player-video.mp4

• Clean Architecture without Domain Module: Showed a different usage of Clean Architecture by directly connecting to the data module without a domain module.
• DataStore Usage: Demonstrated the use of DataStore for managing data.
• Common usages

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.