Meshtastic-Android/conductor/tech-stack.md

Tech Stack

Programming Language

• Kotlin Multiplatform (KMP): The core logic is shared across Android, Desktop, and iOS using commonMain.

Frontend Frameworks

• Compose Multiplatform: Shared UI layer for rendering on Android and Desktop.
• Jetpack Compose: Used where platform-specific UI (like charts or permissions) is necessary on Android.

Background & Services

• Platform Services: Core service orchestrations and background work are abstracted into core:service to maximize logic reuse across targets, using platform-specific implementations (e.g., WorkManager/Service on Android) only where necessary.

Architecture

• MVI / Unidirectional Data Flow: Shared view models using the multiplatform androidx.lifecycle.ViewModel.
• JetBrains Navigation 3: Multiplatform fork for state-based, compose-first navigation without relying on NavController. Navigation graphs are decoupled and extracted into their respective feature:* modules, allowing a thinned out root app module.

Dependency Injection

• Koin 4.2: Leverages Koin Annotations and the K2 Compiler Plugin for pure compile-time DI, completely replacing Hilt.

Database & Storage

• Room 3 KMP: Shared local database using multiplatform DatabaseConstructor and platform-appropriate SQLite drivers (e.g., BundledSQLiteDriver for JVM/Desktop, Framework driver for Android).
• Jetpack DataStore: Shared preferences.

Networking & Transport

• Ktor: Multiplatform HTTP client for web services and TCP streaming.
• Kable: Multiplatform BLE library used as the primary BLE transport for all targets (Android, Desktop, and future iOS).
• jSerialComm: Cross-platform Java library used for direct Serial/USB communication with Meshtastic devices on the Desktop (JVM) target.
• KMQTT: Kotlin Multiplatform MQTT client and broker used for MQTT transport, replacing the Android-only Paho library.
• Coroutines & Flows: For asynchronous programming and state management.

Testing (KMP)

• Shared Tests First: The majority of business logic, ViewModels, and state interactions are tested in the commonTest source set using standard kotlin.test.
• Coroutines Testing: Use kotlinx-coroutines-test for virtual time management in asynchronous flows.
• Mocking Strategy: Avoid JVM-specific mocking libraries. Prefer Mokkery or Mockative for multiplatform-compatible mocking interfaces, alongside handwritten fakes in core:testing.
• Platform-Specific Verification: Use Robolectric on the Android host target to verify KMP modules that interact with Android framework components (like Uri or Room).
• Subclassing Pattern: Maintain a unified test suite by defining abstract base tests in commonTest and platform-specific subclasses in jvmTest and androidHostTest for initialization (e.g., calling setupTestContext()).
• Flow Assertions: Use Turbine for testing multiplatform Flow emissions and state updates.
• Property-Based Testing: Use Kotest for multiplatform data-driven and property-based testing scenarios.