Future _terminate()

in lib/src/connection.dart [403:439]
24 lines of code
4 McCabe index (conditional complexity)

  Future _terminate(int errorCode,
      {bool causedByTransportError = false, String? message}) {
    // TODO: When do we complete here?
    if (_state.state != ConnectionState.Terminated) {
      _state.state = ConnectionState.Terminated;

      var cancelFuture = Future.sync(_frameReaderSubscription.cancel);
      if (!causedByTransportError) {
        _outgoingQueue.enqueueMessage(GoawayMessage(
            _streams.highestPeerInitiatedStream,
            errorCode,
            message != null ? utf8.encode(message) : []));
      }
      var closeFuture = _frameWriter.close().catchError((e, s) {
        // We ignore any errors after writing to [GoawayFrame]
      });

      // Close all lower level handlers with an error message.
      // (e.g. if there is a pending connection.ping(), it's returned
      //  Future will complete with this error).
      var exception = TransportConnectionException(
          errorCode, 'Connection is being forcefully terminated.');

      // Close all streams & stream queues
      _streams.terminate(exception);

      // Close the connection queues
      _incomingQueue.terminate(exception);
      _outgoingQueue.terminate(exception);

      _pingHandler.terminate(exception);
      _settingsHandler.terminate(exception);

      return Future.wait([cancelFuture, closeFuture]).catchError((_) {});
    }
    return Future.value();
  }