Test JSON-RPC over UNIX socket in Dart/Flutter

test_rpc.dart

import 'dart:async';
import 'dart:io';
import 'package:json_rpc_2/json_rpc_2.dart';
import 'package:stream_channel/stream_channel.dart';

StreamChannel<String> unixSocketChannel(String path) {
  final host = InternetAddress(path, type: InternetAddressType.unix);
  final controller = StreamChannelController<String>(sync: true);
  Socket.connect(host, 0).then((socket) {
    socket.cast<String>().pipe(controller.local.sink);
    controller.local.stream.pipe(socket as StreamConsumer<String>);
  }, onError: controller.local.sink.addError).catchError((err) {
    print('Error: $err');
  });
  return controller.foreign;
}

void main() async {
  print("Calling Hello RPC...");

  try {
    var client = Client(unixSocketChannel("test.sock"));
    try {
      var echo = await client.sendRequest("Hello");
      print('Echo says "$echo"!');
    } on RpcException catch (error) {
      print('RPC error ${error.code}: ${error.message}');
    }
  } on Exception catch (error) {
    print('error ${error.toString()}');
  }
}