PicFind App

Build ⚠️

🚨 Before building the app, make sure to include your API_KEY at your local local.properties file.

Architecture

The app uses a straightforward MVI approach that targets small to mid sized apps, however it can be scaled to for larger apps when adding additional classes to split responsibilities (e.g. Actor, Reducer).

At it's core:

• It uses AndroidX ViewModel, for persisting state across configuration changes
• It uses Kotlin's MutableStateFlow (exposed as StateFlow) to store the UI's state.
• Exposes functions that represent User Events
• Interacts with a Repository interface (injected at runtime), in an asynchronous way, to cover the client's needs.

PicturesViewModel

Here we also leverage the handy powerful Flow APIs (debounce, collectLatest) to minimize our calls to the back-end, as well handle gracefully changes of the user's query.

Additionally, Result4k for type safety and idiomatic handling of the responses from the "outer-world".

Modularization

Build logic

First and foremost, we leverage the Version Catalog feature of Gradle together with the libs.versions.toml file. However, where our build-logic shines is by making use of Composite Builds and Idiomatic Gradle.

This allows us to have a single source of truth regarding our dependencies, as well quickly configure new modules (from kotlin/java libs to apps). See build-logic/convention & organising build logic

Modules

Our app consists of:

• 1 :app module, that interwines everything together
• 2 :feature odules, that define the UI logic of our business
• 4 :core modules, that handle
  • sharing UI resources (:core:design)
  • sharing our domain models as well defining our API (:core:domain)
  • communication with the "outer world", mapping raw to domain models (:core:network)
  • providing handy libs and fake data for testing (:core:test)

Testing

Our business logic is covered with Unit tests, backed by JUnit5 and Kotest.

Our presentation logic is covered with:

1. Integration tests for our ViewModels: here we leverage Turbine and our custom runTestWithDispatcher fun.
2. UI tests for our Composables.

Libraries

• Compose
• Datastore
• Hilt
• Compose Navigation
• Coil
• Result4k
• Kotlin Coroutines & Flows
• Kotlinx Serialization
• Kotest
• JUnit4 & JUnit5
• Okhttp Logging
• Retrofit
• Turbine
• Spotless + tlint