Self triggering mutation concept

ReactorKit+Plugin.swift

extension Reactor {
  public func plugin<PluginReactor>(
    keyPath: KeyPath<State, PluginReactor?>,
    mutation mutationFactory: @escaping (PluginReactor) -> Mutation
  ) -> Observable<Mutation> where PluginReactor: Reactor {
    return self.stateDidCreate.flatMapLatest { [weak self] () -> Observable<Mutation> in
      guard let `self` = self else { return .empty() }
      return self.state.flatMapLatest { state -> Observable<Mutation> in
        guard let pluginReactor = state[keyPath: keyPath] else { return .empty() }
        let pluginStates = Observable.merge(pluginReactor.state.skip(1))
        return pluginStates.map { _ in mutationFactory(pluginReactor) }
      }
    }
  }

  public func plugin<PluginReactor>(
    keyPath: KeyPath<State, [PluginReactor]>,
    mutation mutationFactory: @escaping ([PluginReactor]) -> Mutation
  ) -> Observable<Mutation> where PluginReactor: Reactor {
    return self.stateDidCreate.flatMapLatest { [weak self] () -> Observable<Mutation> in
      guard let `self` = self else { return .empty() }
      return self.state.flatMapLatest { state -> Observable<Mutation> in
        let pluginReactors = state[keyPath: keyPath]
        let pluginStates = Observable.merge(pluginReactors.map { $0.state.skip(1) })
        return pluginStates.map { _ in mutationFactory(pluginReactors) }
      }
    }
  }

  public func plugin<PluginReactor>(
    keyPath: KeyPath<State, [PluginReactor]?>,
    mutation mutationFactory: @escaping ([PluginReactor]) -> Mutation
  ) -> Observable<Mutation> where PluginReactor: Reactor {
    return self.stateDidCreate.flatMapLatest { [weak self] () -> Observable<Mutation> in
      guard let `self` = self else { return .empty() }
      return self.state.flatMapLatest { state -> Observable<Mutation> in
        guard let pluginReactors = state[keyPath: keyPath] else { return .empty() }
        let pluginStates = Observable.merge(pluginReactors.map { $0.state.skip(1) })
        return pluginStates.map { _ in mutationFactory(pluginReactors) }
      }
    }
  }
}