city_autocomplete.dart

import 'package:puppeteer/puppeteer.dart';
import "package:test/test.dart";

cityAutocomplete(Browser browser) {
  test("City Autocomplete include New York", () async {
    // Open a new tab
    var page = await browser.newPage();

    // Go to a page and wait to be fully loaded
    await page.goto(...);
    
    await page.waitForSelector(".angucomplete-title");

    // Find "New York" in autocomplete results

    // Get city lookup results from autocomplete popup
    List<dynamic> titles = await page.$$eval(
        ".angucomplete-title", 'titles => titles.map(t => t.innerText)');

    await expect(titles, contains("New York, NY"));

    await page.close();
  });
}

main.dart

import 'dart:io';

import 'package:puppeteer/puppeteer.dart';

import 'city_autocomplete.dart';

main() async {
  // Download the Chromium binaries, launch it and connect to the "DevTools"
  var browser = await puppeteer.launch(headless: false);

  cityAutocomplete(browser);

  print("sleep starts");
  sleep(Duration(seconds: 5));
  print("sleep complete");

  // Gracefully close the browser's process
  await browser.close();
}

output

▶ dart src/main.dart
sleep starts
sleep complete
00:00 +0: City Autocomplete include New York

00:00 +0 -1: City Autocomplete include New York [E]

  TargetClosedException(method: Target.createTarget, reason: Websocket.done(code: 1002, reason: null))

  package:puppeteer/protocol/target.dart 141:18      TargetApi.createTarget
  ===== asynchronous gap ===========================
  dart:async/zone.dart 1062:19                       _CustomZone.registerBinaryCallback
  dart:async-patch/async_patch.dart 80:23            _asyncErrorWrapperHelper
  package:test_api/src/backend/invoker.dart          Invoker.waitForOutstandingCallbacks.<fn>
  dart:async/zone.dart 1124:13                       _rootRun
  dart:async/zone.dart 1021:19                       _CustomZone.run
  dart:async/zone.dart 1516:10                       _runZoned
  dart:async/zone.dart 1463:12                       runZoned
  package:test_api/src/backend/invoker.dart 239:5    Invoker.waitForOutstandingCallbacks
  package:test_api/src/backend/declarer.dart 169:33  Declarer.test.<fn>.<fn>
  dart:async/zone.dart 1124:13                       _rootRun
  dart:async/zone.dart 1021:19                       _CustomZone.run
  dart:async/zone.dart 1516:10                       _runZoned
  dart:async/zone.dart 1463:12                       runZoned
  package:test_api/src/backend/declarer.dart 168:13  Declarer.test.<fn>
  ===== asynchronous gap ===========================
  dart:async/zone.dart 1045:19                       _CustomZone.registerCallback
  dart:async/zone.dart 962:22                        _CustomZone.bindCallbackGuarded
  dart:async/timer.dart 52:45                        new Timer
  dart:async/timer.dart 87:9                         Timer.run
  dart:async/future.dart 174:11                      new Future
  package:test_api/src/backend/invoker.dart 391:21   Invoker._onRun.<fn>.<fn>.<fn>
  

00:00 +0 -1: Some tests failed.


Unhandled exception:
Dummy exception to set exit code.
#0      _rootHandleUncaughtError.<anonymous closure> (dart:async/zone.dart:1112:29)
#1      _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#2      _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#3      _Timer._runTimers (dart:isolate-patch/timer_impl.dart:391:30)
#4      _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:416:5)
#5      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)