Implement Feature

Skill: Implement a Feature

Description

A step-by-step workflow for implementing a new feature in the Meshtastic-Android codebase, ensuring KMP compatibility and proper architecture.

Workflow

1. Update Dependencies & Aliases

• Check gradle/libs.versions.toml before adding libraries.
• Use jetbrains-* aliases for lifecycle/navigation/adaptive dependencies in commonMain.
• Use compose-multiplatform-* aliases for CMP dependencies.

2. Define the State & ViewModels

• Follow MVI/UDF patterns.
• Extend shared ViewModel logic in feature/<name>/src/commonMain/kotlin/org/meshtastic/feature/<name>/<Name>ViewModel.kt.
• Use stateInWhileSubscribed (from core:ui) for sharing state flows.
• Keep the ViewModel free of Android framework dependencies.

3. Build the UI

• Use Jetpack Compose Multiplatform (CMP).
• Define strings in core:resources (see the compose-ui skill).
• Support adaptive layouts (Large/XL breakpoints).

4. Wire Navigation & DI

• Define typed route objects in core:navigation.
• Export the navigation graph as an extension function on EntryProviderScope<NavKey> in commonMain (e.g., fun EntryProviderScope<NavKey>.myFeatureGraph()).
• Add the required DI bindings via Koin Annotations (@Factory, @Single, @KoinViewModel) in commonMain.
• CRITICAL: Ensure the module is registered in the app root graphs (AppKoinModule.kt, DesktopKoinModule.kt) and the navigation is injected into the root entry provider in the host shell.

5. Validate Platform Separation

• If you need a platform-specific API (like camera or specific mapping SDK), define an interface in commonMain, implement it in the host shell, and inject it via CompositionLocal or Koin.

6. Verify Locally

• Run the baseline checks (see testing-ci skill):

  ./gradlew spotlessApply spotlessCheck detekt assembleDebug test allTests
  

• Add kmpSmokeCompile to the command when the feature touches a KMP module (most features do) so cross-target compile failures surface before merge.
• If the feature adds a new reflection-heavy dependency, add keep rules to both androidApp/proguard-rules.pro and desktopApp/proguard-rules.pro, then verify release builds:

  ./gradlew assembleFdroidRelease :desktopApp:runRelease