Strict mode

Starting with version 0.5.0, the library introduces major changes to the service APIs. The following declarations will be gradually restricted:

• StateFlow and SharedFlow

  Deprecation level: WARNING

  @Rpc
  interface Service : RemoteService {
      suspend fun old(): StateFlow<Int> // deprecated
  
      suspend fun new(): Flow<Int> // use .stateIn on the client side
  }

• Fields

  Deprecation level: WARNING

  @Rpc
  interface Service : RemoteService {
      val old: Flow<Int> // deprecated
  
      suspend fun new(): Flow<Int> // store flow locally
  }

• Nested Flows

  Deprecation level: WARNING

  @Rpc
  interface Service : RemoteService {
      suspend fun old(): Flow<Flow<Int>> // deprecated
  
      // no particular alternative, depends on the use case
  }

• Not top-level server flows

  Deprecation level: WARNING

  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
  }

Deprecation levels are controlled by the Gradle rpc extension:

// 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
    }
}

Modes RpcStrictMode.NONE and RpcStrictMode.ERROR are available.

warning

Note that setting RpcStrictMode.NONE should not be done permanently. All deprecated APIs will become errors in future without an option to suppress it. Consider your migration path in advance.