pkg/dds/test/handles_shutdown_before_startup_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.

import 'dart:async';

import 'package:dds/dds.dart';
import 'package:dds/src/dds_impl.dart';
import 'package:test/test.dart';
import 'package:web_socket_channel/web_socket_channel.dart';

import 'common/fakes.dart';

class ImmediatelyClosedPeer extends FakePeer {
  // Immediately complete the returned future to act as if we've closed.
  @override
  Future<void> listen() => Future.value();
}

class ImmediatelyClosedErrorPeer extends FakePeer {
  // Immediately complete the returned future with an error to act as if we've
  // encountered a connection issue.
  @override
  Future<void> listen() => Future.error('Connection lost');
}

class StreamListenDisconnectPeer extends FakePeer {
  // Simulate connection disappearing while we're initializing the
  // streamManager.
  @override
  Future<dynamic> sendRequest(String method, [args]) async {
    final completer = Completer<dynamic>();
    switch (method) {
      case 'streamListen':
        completer.completeError(
          StateError('The client closed with pending request "streamListen".'),
        );
        // Notify listeners that this client is closed. This completer must be
        // completed _after_ the above completer to get the proper event queue
        // scheduling order.
        doneCompleter.complete();
        break;
      default:
        completer.complete(await super.sendRequest(method, args));
    }
    return completer.future;
  }
}

// Regression test for https://github.com/flutter/flutter/issues/86361.
void main() {
  webSocketBuilder = (Uri _) => FakeWebSocketChannel();

  test('Shutdown before server startup complete', () async {
    peerBuilder =
        (WebSocketChannel _, dynamic __) async => ImmediatelyClosedPeer();
    try {
      await DartDevelopmentService.startDartDevelopmentService(
        Uri(scheme: 'http'),
      );
    } on DartDevelopmentServiceException {
      /* We expect to fail to start */
    }
  });

  test('Error shutdown before server startup complete', () async {
    peerBuilder =
        (WebSocketChannel _, dynamic __) async => ImmediatelyClosedErrorPeer();
    try {
      await DartDevelopmentService.startDartDevelopmentService(
        Uri(scheme: 'http'),
      );
    } on DartDevelopmentServiceException {
      /* We expect to fail to start */
    }
  });

  test('Shutdown during initialization complete', () async {
    peerBuilder =
        (WebSocketChannel _, dynamic __) async => StreamListenDisconnectPeer();
    try {
      await DartDevelopmentService.startDartDevelopmentService(
        Uri(scheme: 'http'),
      );
      fail('Invalid DDS instance returned');
    } on DartDevelopmentServiceException {
      /* We expect to fail to start */
    }
  });
}