tests/standalone/io/socket_sigpipe_test.dart

// Copyright (c) 2021, 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.
//
// Tests that SIGPIPE won't terminate websocket client dart app.

import 'dart:async';
import 'dart:convert';
import 'dart:ffi';
import 'dart:io';

import "package:expect/async_helper.dart";
import "package:expect/expect.dart";
import 'package:ffi/ffi.dart';
import 'package:path/path.dart' as p;

import '../../../tests/ffi/dylib_utils.dart';

final class Isolate extends Opaque {}

abstract class FfiBindings {
  static final ffiTestFunctions = dlopenPlatformSpecific("ffi_test_functions");

  static final RestoreSIGPIPEHandler = ffiTestFunctions
      .lookupFunction<Void Function(), void Function()>(
        "RestoreSIGPIPEHandler",
      );
  static final SleepOnAnyOS = ffiTestFunctions
      .lookupFunction<Void Function(IntPtr), void Function(int)>(
        "SleepOnAnyOS",
      );
}

Future<void> main() async {
  asyncStart();

  final server = await Process.start(Platform.executable, <String>[
    p.join(
      p.dirname(Platform.script.toFilePath()),
      "socket_sigpipe_test_server.dart",
    ),
  ]);
  final serverPort = Completer<int>();
  server.stdout.transform(utf8.decoder).transform(LineSplitter()).listen((
    line,
  ) {
    print('server stdout: $line');
    if (!serverPort.isCompleted) {
      serverPort.complete(int.parse(line));
    }
  });
  server.stderr.transform(utf8.decoder).transform(LineSplitter()).listen((
    data,
  ) {
    print('server stderr: $data');
  });

  FfiBindings.RestoreSIGPIPEHandler();
  final ws = await WebSocket.connect(
    'ws://localhost:${await serverPort.future}',
  );
  ws.listen(
    (var data) {
      print('Got $data');
      // Sleep to prevent closed socket events coming through and being handled.
      // This way websocket stays open and writing into it should trigger SIGPIPE.
      // Unless of course we requested SIGPIPE not to be generated on broken socket
      // pipe. This is what this test is testing - that the SIGPIPE is not generated
      // on broken socket pipe.
      ws.add('foo');
      FfiBindings.SleepOnAnyOS(10 /*seconds*/); // give server time to exit
      ws.add('baz');
      ws.close();
    },
    onDone: () {
      asyncEnd();
    },
    onError: (e, st) {
      Expect.fail('Client websocket failed $e $st');
    },
  );
}