test/lib/src/runner/node/socket_channel.dart

// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

@JS()
library _;

import 'package:js/js.dart';
import 'package:stream_channel/stream_channel.dart';

import '../../utils.dart';

@JS("require")
external _Net _require(String module);

@JS("process.argv")
external List<String> get _args;

@JS()
class _Net {
  external _Socket connect(int port);
}

@JS()
class _Socket {
  external setEncoding(String encoding);
  external on(String event, void callback(String chunk));
  external write(String data);
}

/// Returns a [StreamChannel] of JSON-encodable objects that communicates over a
/// socket whose port is given by `process.argv[2]`.
StreamChannel socketChannel() {
  var controller = new StreamChannelController<String>(
      allowForeignErrors: false, sync: true);
  var net = _require("net");
  var socket = net.connect(int.parse(_args[2]));
  socket.setEncoding("utf8");

  controller.local.stream.listen((chunk) => socket.write(chunk));
  socket.on("data", allowInterop(controller.local.sink.add));

  return controller.foreign.transform(chunksToLines).transform(jsonDocument);
}