Module Definition Patterns

Use constructor reference DSL (singleOf, factoryOf, viewModelOf) with optional bind<Interface>():

kotlin

val featureModule: Module = module {
    singleOf(::DataStoreProvider)
    singleOf(::RepositoryImpl) {
        bind<Repository>()
    }
    factoryOf(::Mapper)
    viewModelOf(::FeatureViewModel)
}

Avoid lambda definitions with get() when constructor references suffice:

kotlin

// Avoid
single { Repository(get(), get(), get()) }

Annotations

NEVER use Koin annotations (@Single, @Factory, @KoinViewModel, @Module, etc.).

Exception: @InjectedParam is permitted on constructor parameters that are injected at runtime (not from the Koin graph). This enables Koin module verification tests to pass.

Complex Object Creation

NEVER put complex object creation logic directly in module definitions.

Use a factory function:

kotlin

// FlavorFactory.kt
fun createFlavor(): Flavor = Flavor(
    flavor = BuildConfig.FLAVOR,
    buildType = BuildConfig.BUILD_TYPE,
    versionCode = BuildConfig.VERSION_CODE.toLong(),
    versionName = BuildConfig.VERSION_NAME,
    gitBranch = BuildConfig.GIT_BRANCH_NAME,
    gitCommit = BuildConfig.GIT_COMMIT_HASH,
)

// Module
val featureModule: Module = module {
    single<Flavor> { createFlavor() }
}