Strict mode

@Rpc
interface Service : RemoteService {
    suspend fun old(): StateFlow<Int> // deprecated

    suspend fun new(): Flow<Int> // use .stateIn on the client side
}

@Rpc
interface Service : RemoteService {
    val old: Flow<Int> // deprecated

    suspend fun new(): Flow<Int> // store flow locally
}

@Rpc
interface Service : RemoteService {
    suspend fun old(): Flow<Flow<Int>> // deprecated

    // no particular alternative, depends on the use case
}

data class SpotifyWrapped(val myMusicFlow: Flow<Rap>, val extra: Data)

@Rpc
interface Service : RemoteService {
    suspend fun old(): SpotifyWrapped // deprecated

    // one should consider message delivery order when calling these
    suspend fun new(): Flow<Rap>
    suspend fun getData(): Data
}

data class SpotifyWrapped(val extra: Data)

@Rpc
interface Service : RemoteService {
    suspend fun old(): Flow<SpotifyWrapped> // deprecated

    fun new(): Flow<SpotifyWrapped>
}

@Rpc
interface Service : RemoteService {
    suspend fun oldClient(flow: Flow<Int>)
    suspend fun oldServer(): Flow<Int>
}

suspend fun consumer(service: Service) {
    streamScoped {
        service.oldClient(flow { /* ... */ })

        service.oldServer().collect {
            // ...
        }
    }
}

@Rpc
interface Service : RemoteService {
    suspend fun newClient(flow: Flow<Int>)
    fun newServer(): Flow<Int>
}

fun consumer(service: Service, scope: CoroutineScope) {
    val flow = service.new()
    scope.launch {
        service.newClient(flow { /* ... */ })

        flow.collect {
            // ...
        }
    }
}

// or
suspend fun consumer(service: Service) {
    service.newClient(flow { /* ... */ })

    service.new().collect {
        // ...
    }
}

// build.gradle.kts
plugins {
    id("org.jetbrains.kotlinx.rpc.plugin")
}

rpc {
    strict {
        stateFlow = RpcStrictMode.WARNING
        sharedFlow = RpcStrictMode.WARNING
        nestedFlow = RpcStrictMode.WARNING
        notTopLevelServerFlow = RpcStrictMode.WARNING
        fields = RpcStrictMode.WARNING
        suspendingServerStreaming = RpcStrictMode.WARNING
        streamScopedFunctions = RpcStrictMode.WARNING
    }
}