mock+spy.kt

// Domain
class AppConfig(val name: String)

// Data
internal class AppConfigResponse(
    val id: String,
    val name: String
)

internal class AppConfigRepositoryImpl : AppConfigRepository {

    override suspend fun getConfig(
        onSuccess: (AppConfig) -> Unit, onFailure: (Throwable?) -> Unit
    ) {
        withContext(Dispatchers.IO) {
            try {
                val id = UUID.randomUUID().toString()
                val response = AppConfigResponse(id, id.substring(0, 10))
                onSuccess(AppConfig(name = response.name))
            } catch (e: Exception) {
                onFailure(e)
            }
        }
    }
}