How to use TaskQueue class of PuppeteerSharp.Helpers package

...30    /// </example>31    [DebuggerDisplay("Page {Url}")]32    public class Page : IDisposable33    {34        private readonly TaskQueue _screenshotTaskQueue;35        private readonly EmulationManager _emulationManager;36        private readonly Dictionary<string, Delegate> _pageBindings;37        private readonly TaskCompletionSource<bool> _closeCompletedTcs = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);38        private TaskCompletionSource<bool> _sessionClosedTcs;39        private readonly TimeoutSettings _timeoutSettings;40        private static readonly Dictionary<string, decimal> _unitToPixels = new Dictionary<string, decimal> {41            {"px", 1},42            {"in", 96},43            {"cm", 37.8m},44            {"mm", 3.78m}45        };46        private Page(47            CDPSession client,48            Target target,49            TaskQueue screenshotTaskQueue)50        {51            Client = client;52            Target = target;53            Keyboard = new Keyboard(client);54            Mouse = new Mouse(client, Keyboard);55            Touchscreen = new Touchscreen(client, Keyboard);56            Coverage = new Coverage(client);57            //_fileChooserInterceptors = new ConcurrentDictionary<Guid, TaskCompletionSource<FileChooser>>();58            _timeoutSettings = new TimeoutSettings();59            _emulationManager = new EmulationManager(client);60            _pageBindings = new Dictionary<string, Delegate>();61            //_workers = new Dictionary<string, Worker>();62            Accessibility = new Accessibility(client);63            _screenshotTaskQueue = screenshotTaskQueue;64            _ = target.CloseTask.ContinueWith((arg) =>65            {66                try67                {68                    Close?.Invoke(this, EventArgs.Empty);69                }70                finally71                {72                    IsClosed = true;73                    _closeCompletedTcs.TrySetResult(true);74                }75            });76        }77        #region Public Properties78        /// <summary>79        /// Chrome DevTools Protocol session.80        /// </summary>81        public CDPSession Client { get; }82        /// <summary>83        /// Raised when the JavaScript <c>load</c> <see href="https://developer.mozilla.org/en-US/docs/Web/Events/load"/> event is dispatched.84        /// </summary>85        public event EventHandler Load;86        /// <summary>87        /// Raised when the page crashes88        /// </summary>89        public event EventHandler<ErrorEventArgs> Error;90        /// <summary>91        /// Raised when the JavaScript <c>DOMContentLoaded</c> <see href="https://developer.mozilla.org/en-US/docs/Web/Events/DOMContentLoaded"/> event is dispatched.92        /// </summary>93        public event EventHandler DOMContentLoaded;94        /// <summary>95        /// Raised when JavaScript within the page calls one of console API methods, e.g. <c>console.log</c> or <c>console.dir</c>. Also emitted if the page throws an error or a warning.96        /// The arguments passed into <c>console.log</c> appear as arguments on the event handler.97        /// </summary>98        /// <example>99        /// An example of handling <see cref="Console"/> event:100        /// <code>101        /// <![CDATA[102        /// page.Console += (sender, e) => 103        /// {104        ///     for (var i = 0; i < e.Message.Args.Count; ++i)105        ///     {106        ///         System.Console.WriteLine($"{i}: {e.Message.Args[i]}");107        ///     }108        /// }109        /// ]]>110        /// </code>111        /// </example>112        //public event EventHandler<ConsoleEventArgs> Console;113        /// <summary>114        /// Raised when a frame is attached.115        /// </summary>116        public event EventHandler<FrameEventArgs> FrameAttached;117        /// <summary>118        /// Raised when a frame is detached.119        /// </summary>120        public event EventHandler<FrameEventArgs> FrameDetached;121        /// <summary>122        /// Raised when a frame is navigated to a new url.123        /// </summary>124        public event EventHandler<FrameEventArgs> FrameNavigated;125        /// <summary>126        /// Raised when a <see cref="Response"/> is received.127        /// </summary>128        /// <example>129        /// An example of handling <see cref="Response"/> event:130        /// <code>131        /// <![CDATA[132        /// var tcs = new TaskCompletionSource<string>();133        /// page.Response += async(sender, e) =>134        /// {135        ///     if (e.Response.Url.Contains("script.js"))136        ///     {137        ///         tcs.TrySetResult(await e.Response.TextAsync());138        ///     }139        /// };140        ///141        /// await Task.WhenAll(142        ///     page.GoToAsync(TestConstants.ServerUrl + "/grid.html"),143        ///     tcs.Task);144        /// Console.WriteLine(await tcs.Task);145        /// ]]>146        /// </code>147        /// </example>148        public event EventHandler<ResponseCreatedEventArgs> Response;149        /// <summary>150        /// Raised when a page issues a request. The <see cref="Request"/> object is read-only.151        /// In order to intercept and mutate requests, see <see cref="SetRequestInterceptionAsync(bool)"/>152        /// </summary>153        public event EventHandler<RequestEventArgs> Request;154        /// <summary>155        /// Raised when a request finishes successfully.156        /// </summary>157        public event EventHandler<RequestEventArgs> RequestFinished;158        /// <summary>159        /// Raised when a request fails, for example by timing out.160        /// </summary>161        public event EventHandler<RequestEventArgs> RequestFailed;162        /// <summary>163        /// Raised when an uncaught exception happens within the page.164        /// </summary>165        public event EventHandler<PageErrorEventArgs> PageError;166        ///// <summary>167        ///// Emitted when a dedicated WebWorker (<see href="https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API"/>) is spawned by the page.168        ///// </summary>169        //public event EventHandler<WorkerEventArgs> WorkerCreated;170        ///// <summary>171        ///// Emitted when a dedicated WebWorker (<see href="https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API"/>) is terminated.172        ///// </summary>173        //public event EventHandler<WorkerEventArgs> WorkerDestroyed;174        /// <summary>175        /// Raised when the page closes.176        /// </summary>177        public event EventHandler Close;178        /// <summary>179        /// Raised when the page opens a new tab or window.180        /// </summary>181        public event EventHandler<PopupEventArgs> Popup;182        /// <summary>183        /// This setting will change the default maximum time for the following methods:184        /// - <see cref="GoToAsync(string, NavigationOptions)"/>185        /// - <see cref="GoBackAsync(NavigationOptions)"/>186        /// - <see cref="GoForwardAsync(NavigationOptions)"/>187        /// - <see cref="ReloadAsync(NavigationOptions)"/>188        /// - <see cref="SetContentAsync(string, NavigationOptions)"/>189        /// - <see cref="WaitForNavigationAsync(NavigationOptions)"/>190        /// **NOTE** <see cref="DefaultNavigationTimeout"/> takes priority over <seealso cref="DefaultTimeout"/>191        /// </summary>192        public int DefaultNavigationTimeout193        {194            get => _timeoutSettings.NavigationTimeout;195            set => _timeoutSettings.NavigationTimeout = value;196        }197        /// <summary>198        /// This setting will change the default maximum times for the following methods:199        /// - <see cref="GoBackAsync(NavigationOptions)"/>200        /// - <see cref="GoForwardAsync(NavigationOptions)"/>201        /// - <see cref="GoToAsync(string, NavigationOptions)"/>202        /// - <see cref="ReloadAsync(NavigationOptions)"/>203        /// - <see cref="SetContentAsync(string, NavigationOptions)"/>204        /// - <see cref="WaitForFunctionAsync(string, object[])"/>205        /// - <see cref="WaitForNavigationAsync(NavigationOptions)"/>206        /// - <see cref="WaitForRequestAsync(string, WaitForOptions)"/>207        /// - <see cref="WaitForResponseAsync(string, WaitForOptions)"/>208        /// - <see cref="WaitForXPathAsync(string, WaitForSelectorOptions)"/>209        /// - <see cref="WaitForSelectorAsync(string, WaitForSelectorOptions)"/>210        /// - <see cref="WaitForExpressionAsync(string, WaitForFunctionOptions)"/>211        /// </summary>212        public int DefaultTimeout213        {214            get => _timeoutSettings.Timeout;215            set => _timeoutSettings.Timeout = value;216        }217        /// <summary>218        /// Gets page's main frame219        /// </summary>220        /// <remarks>221        /// Page is guaranteed to have a main frame which persists during navigations.222        /// </remarks>223        public Frame MainFrame => FrameManager.MainFrame;224        /// <summary>225        /// Gets all frames attached to the page.226        /// </summary>227        /// <value>An array of all frames attached to the page.</value>228        public Frame[] Frames => FrameManager.GetFrames();229        ///// <summary>230        ///// Gets all workers in the page.231        ///// </summary>232        //public Worker[] Workers => _workers.Values.ToArray();233        /// <summary>234        /// Shortcut for <c>page.MainFrame.Url</c>235        /// </summary>236        public string Url => MainFrame.Url;237        /// <summary>238        /// Gets that target this page was created from.239        /// </summary>240        public Target Target { get; }241        /// <summary>242        /// Gets this page's keyboard243        /// </summary>244        public Keyboard Keyboard { get; }245        /// <summary>246        /// Gets this page's touchscreen247        /// </summary>248        public Touchscreen Touchscreen { get; }249        /// <summary>250        /// Gets this page's coverage251        /// </summary>252        public Coverage Coverage { get; }253        /// <summary>254        /// Gets this page's mouse255        /// </summary>256        public Mouse Mouse { get; }257        /// <summary>258        /// Gets this page's viewport259        /// </summary>260        public ViewPortOptions Viewport { get; private set; }261        /// <summary>262        /// List of supported metrics provided by the <see cref="Metrics"/> event.263        /// </summary>264        public static readonly IEnumerable<string> SupportedMetrics = new List<string>265        {266            "Timestamp",267            "Documents",268            "Frames",269            "JSEventListeners",270            "Nodes",271            "LayoutCount",272            "RecalcStyleCount",273            "LayoutDuration",274            "RecalcStyleDuration",275            "ScriptDuration",276            "TaskDuration",277            "JSHeapUsedSize",278            "JSHeapTotalSize"279        };280        /// <summary>281        /// Get the browser the page belongs to.282        /// </summary>283        public Browser Browser => Target.Browser;284        /// <summary>285        /// Get the browser context that the page belongs to.286        /// </summary>287        public BrowserContext BrowserContext => Target.BrowserContext;288        /// <summary>289        /// Get an indication that the page has been closed.290        /// </summary>291        public bool IsClosed { get; private set; }292        /// <summary>293        /// Gets the accessibility.294        /// </summary>295        public Accessibility Accessibility { get; }296        internal bool JavascriptEnabled { get; set; } = true;297        internal bool HasPopupEventListeners => Popup?.GetInvocationList().Any() == true;298        internal FrameManager FrameManager { get; private set; }299        private Task SessionClosedTask300        {301            get302            {303                if (_sessionClosedTcs == null)304                {305                    _sessionClosedTcs = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);306                    Client.Disconnected += clientDisconnected;307                    void clientDisconnected(object sender, EventArgs e)308                    {309                        _sessionClosedTcs.TrySetException(new TargetClosedException("Target closed", "Session closed"));310                        Client.Disconnected -= clientDisconnected;311                    }312                }313                return _sessionClosedTcs.Task;314            }315        }316        #endregion317        #region Public Methods318        /// <summary>319        /// A utility function to be used with <see cref="Extensions.EvaluateFunctionAsync{T}(Task{JSHandle}, string, object[])"/>320        /// </summary>321        /// <param name="selector">A selector to query page for</param>322        /// <returns>Task which resolves to a <see cref="JSHandle"/> of <c>document.querySelectorAll</c> result</returns>323        public Task<JSHandle> QuerySelectorAllHandleAsync(string selector)324            => EvaluateFunctionHandleAsync("selector => Array.from(document.querySelectorAll(selector))", selector);325        /// <summary>326        /// Executes a script in browser context327        /// </summary>328        /// <param name="script">Script to be evaluated in browser context</param>329        /// <remarks>330        /// If the script, returns a Promise, then the method would wait for the promise to resolve and return its value.331        /// </remarks>332        /// <returns>Task which resolves to script return value</returns>333        public async Task<JSHandle> EvaluateExpressionHandleAsync(string script)334        {335            var context = await MainFrame.GetExecutionContextAsync().ConfigureAwait(false);336            return await context.EvaluateExpressionHandleAsync(script).ConfigureAwait(false);337        }338        /// <summary>339        /// Executes a script in browser context340        /// </summary>341        /// <param name="pageFunction">Script to be evaluated in browser context</param>342        /// <param name="args">Function arguments</param>343        /// <remarks>344        /// If the script, returns a Promise, then the method would wait for the promise to resolve and return its value.345        /// <see cref="JSHandle"/> instances can be passed as arguments346        /// </remarks>347        /// <returns>Task which resolves to script return value</returns>348        public async Task<JSHandle> EvaluateFunctionHandleAsync(string pageFunction, params object[] args)349        {350            var context = await MainFrame.GetExecutionContextAsync().ConfigureAwait(false);351            return await context.EvaluateFunctionHandleAsync(pageFunction, args).ConfigureAwait(false);352        }353        /// <summary>354        /// Activating request interception enables <see cref="Request.AbortAsync(RequestAbortErrorCode)">request.AbortAsync</see>, 355        /// <see cref="Request.ContinueAsync(Payload)">request.ContinueAsync</see> and <see cref="Request.RespondAsync(ResponseData)">request.RespondAsync</see> methods.356        /// </summary>357        /// <returns>The request interception task.</returns>358        /// <param name="value">Whether to enable request interception..</param>359        public Task SetRequestInterceptionAsync(bool value)360            => FrameManager.NetworkManager.SetRequestInterceptionAsync(value);361        /// <summary>362        /// Set offline mode for the page.363        /// </summary>364        /// <returns>Result task</returns>365        /// <param name="value">When <c>true</c> enables offline mode for the page.</param>366        public Task SetOfflineModeAsync(bool value) => FrameManager.NetworkManager.SetOfflineModeAsync(value);367        /// <summary>368        /// Adds a <c><![CDATA[<script>]]></c> tag into the page with the desired url or content369        /// </summary>370        /// <param name="options">add script tag options</param>371        /// <remarks>372        /// Shortcut for <c>page.MainFrame.AddScriptTagAsync(options)</c>373        /// </remarks>374        /// <returns>Task which resolves to the added tag when the script's onload fires or when the script content was injected into frame</returns>375        /// <seealso cref="Frame.AddScriptTagAsync(AddTagOptions)"/>376        public Task<ElementHandle> AddScriptTagAsync(AddTagOptions options) => MainFrame.AddScriptTagAsync(options);377        /// <summary>378        /// Adds a <c><![CDATA[<script>]]></c> tag into the page with the desired url or content379        /// </summary>380        /// <param name="url">script url</param>381        /// <remarks>382        /// Shortcut for <c>page.MainFrame.AddScriptTagAsync(new AddTagOptions { Url = url })</c>383        /// </remarks>384        /// <returns>Task which resolves to the added tag when the script's onload fires or when the script content was injected into frame</returns>385        public Task<ElementHandle> AddScriptTagAsync(string url) => AddScriptTagAsync(new AddTagOptions { Url = url });386        /// <summary>387        /// Adds a <c><![CDATA[<link rel="stylesheet">]]></c> tag into the page with the desired url or a <c><![CDATA[<link rel="stylesheet">]]></c> tag with the content388        /// </summary>389        /// <param name="options">add style tag options</param>390        /// <remarks>391        /// Shortcut for <c>page.MainFrame.AddStyleTagAsync(options)</c>392        /// </remarks>393        /// <returns>Task which resolves to the added tag when the stylesheet's onload fires or when the CSS content was injected into frame</returns>394        /// <seealso cref="Frame.AddStyleTag(AddTagOptions)"/>395        public Task<ElementHandle> AddStyleTagAsync(AddTagOptions options) => MainFrame.AddStyleTagAsync(options);396        /// <summary>397        /// Adds a <c><![CDATA[<link rel="stylesheet">]]></c> tag into the page with the desired url or a <c><![CDATA[<link rel="stylesheet">]]></c> tag with the content398        /// </summary>399        /// <param name="url">stylesheel url</param>400        /// <remarks>401        /// Shortcut for <c>page.MainFrame.AddStyleTagAsync(new AddTagOptions { Url = url })</c>402        /// </remarks>403        /// <returns>Task which resolves to the added tag when the stylesheet's onload fires or when the CSS content was injected into frame</returns>404        public Task<ElementHandle> AddStyleTagAsync(string url) => AddStyleTagAsync(new AddTagOptions { Url = url });405        /// <summary>406        /// Adds a function called <c>name</c> on the page's <c>window</c> object.407        /// When called, the function executes <paramref name="puppeteerFunction"/> in C# and returns a <see cref="Task"/> which resolves when <paramref name="puppeteerFunction"/> completes.408        /// </summary>409        /// <param name="name">Name of the function on the window object</param>410        /// <param name="puppeteerFunction">Callback function which will be called in Puppeteer's context.</param>411        /// <remarks>412        /// If the <paramref name="puppeteerFunction"/> returns a <see cref="Task"/>, it will be awaited.413        /// Functions installed via <see cref="ExposeFunctionAsync(string, Action)"/> survive navigations414        /// </remarks>415        /// <returns>Task</returns>416        public Task ExposeFunctionAsync(string name, Action puppeteerFunction)417            => ExposeFunctionAsync(name, (Delegate)puppeteerFunction);418        /// <summary>419        /// Adds a function called <c>name</c> on the page's <c>window</c> object.420        /// When called, the function executes <paramref name="puppeteerFunction"/> in C# and returns a <see cref="Task"/> which resolves to the return value of <paramref name="puppeteerFunction"/>.421        /// </summary>422        /// <typeparam name="TResult">The result of <paramref name="puppeteerFunction"/></typeparam>423        /// <param name="name">Name of the function on the window object</param>424        /// <param name="puppeteerFunction">Callback function which will be called in Puppeteer's context.</param>425        /// <remarks>426        /// If the <paramref name="puppeteerFunction"/> returns a <see cref="Task"/>, it will be awaited.427        /// Functions installed via <see cref="ExposeFunctionAsync{TResult}(string, Func{TResult})"/> survive navigations428        /// </remarks>429        /// <returns>Task</returns>430        public Task ExposeFunctionAsync<TResult>(string name, Func<TResult> puppeteerFunction)431            => ExposeFunctionAsync(name, (Delegate)puppeteerFunction);432        /// <summary>433        /// Adds a function called <c>name</c> on the page's <c>window</c> object.434        /// When called, the function executes <paramref name="puppeteerFunction"/> in C# and returns a <see cref="Task"/> which resolves to the return value of <paramref name="puppeteerFunction"/>.435        /// </summary>436        /// <typeparam name="TResult">The result of <paramref name="puppeteerFunction"/></typeparam>437        /// <typeparam name="T">The parameter of <paramref name="puppeteerFunction"/></typeparam>438        /// <param name="name">Name of the function on the window object</param>439        /// <param name="puppeteerFunction">Callback function which will be called in Puppeteer's context.</param>440        /// <remarks>441        /// If the <paramref name="puppeteerFunction"/> returns a <see cref="Task"/>, it will be awaited.442        /// Functions installed via <see cref="ExposeFunctionAsync{T, TResult}(string, Func{T, TResult})"/> survive navigations443        /// </remarks>444        /// <returns>Task</returns>445        public Task ExposeFunctionAsync<T, TResult>(string name, Func<T, TResult> puppeteerFunction)446            => ExposeFunctionAsync(name, (Delegate)puppeteerFunction);447        /// <summary>448        /// Adds a function called <c>name</c> on the page's <c>window</c> object.449        /// When called, the function executes <paramref name="puppeteerFunction"/> in C# and returns a <see cref="Task"/> which resolves to the return value of <paramref name="puppeteerFunction"/>.450        /// </summary>451        /// <typeparam name="TResult">The result of <paramref name="puppeteerFunction"/></typeparam>452        /// <typeparam name="T1">The first parameter of <paramref name="puppeteerFunction"/></typeparam>453        /// <typeparam name="T2">The second parameter of <paramref name="puppeteerFunction"/></typeparam>454        /// <param name="name">Name of the function on the window object</param>455        /// <param name="puppeteerFunction">Callback function which will be called in Puppeteer's context.</param>456        /// <remarks>457        /// If the <paramref name="puppeteerFunction"/> returns a <see cref="Task"/>, it will be awaited.458        /// Functions installed via <see cref="ExposeFunctionAsync{T1, T2, TResult}(string, Func{T1, T2, TResult})"/> survive navigations459        /// </remarks>460        /// <returns>Task</returns>461        public Task ExposeFunctionAsync<T1, T2, TResult>(string name, Func<T1, T2, TResult> puppeteerFunction)462            => ExposeFunctionAsync(name, (Delegate)puppeteerFunction);463        /// <summary>464        /// Adds a function called <c>name</c> on the page's <c>window</c> object.465        /// When called, the function executes <paramref name="puppeteerFunction"/> in C# and returns a <see cref="Task"/> which resolves to the return value of <paramref name="puppeteerFunction"/>.466        /// </summary>467        /// <typeparam name="TResult">The result of <paramref name="puppeteerFunction"/></typeparam>468        /// <typeparam name="T1">The first parameter of <paramref name="puppeteerFunction"/></typeparam>469        /// <typeparam name="T2">The second parameter of <paramref name="puppeteerFunction"/></typeparam>470        /// <typeparam name="T3">The third parameter of <paramref name="puppeteerFunction"/></typeparam>471        /// <param name="name">Name of the function on the window object</param>472        /// <param name="puppeteerFunction">Callback function which will be called in Puppeteer's context.</param>473        /// <remarks>474        /// If the <paramref name="puppeteerFunction"/> returns a <see cref="Task"/>, it will be awaited.475        /// Functions installed via <see cref="ExposeFunctionAsync{T1, T2, T3, TResult}(string, Func{T1, T2, T3, TResult})"/> survive navigations476        /// </remarks>477        /// <returns>Task</returns>478        public Task ExposeFunctionAsync<T1, T2, T3, TResult>(string name, Func<T1, T2, T3, TResult> puppeteerFunction)479            => ExposeFunctionAsync(name, (Delegate)puppeteerFunction);480        /// <summary>481        /// Adds a function called <c>name</c> on the page's <c>window</c> object.482        /// When called, the function executes <paramref name="puppeteerFunction"/> in C# and returns a <see cref="Task"/> which resolves to the return value of <paramref name="puppeteerFunction"/>.483        /// </summary>484        /// <typeparam name="TResult">The result of <paramref name="puppeteerFunction"/></typeparam>485        /// <typeparam name="T1">The first parameter of <paramref name="puppeteerFunction"/></typeparam>486        /// <typeparam name="T2">The second parameter of <paramref name="puppeteerFunction"/></typeparam>487        /// <typeparam name="T3">The third parameter of <paramref name="puppeteerFunction"/></typeparam>488        /// <typeparam name="T4">The fourth parameter of <paramref name="puppeteerFunction"/></typeparam>489        /// <param name="name">Name of the function on the window object</param>490        /// <param name="puppeteerFunction">Callback function which will be called in Puppeteer's context.</param>491        /// <remarks>492        /// If the <paramref name="puppeteerFunction"/> returns a <see cref="Task"/>, it will be awaited.493        /// Functions installed via <see cref="ExposeFunctionAsync{T1, T2, T3, T4, TResult}(string, Func{T1, T2, T3, T4, TResult})"/> survive navigations494        /// </remarks>495        /// <returns>Task</returns>496        public Task ExposeFunctionAsync<T1, T2, T3, T4, TResult>(string name, Func<T1, T2, T3, T4, TResult> puppeteerFunction)497            => ExposeFunctionAsync(name, (Delegate)puppeteerFunction);498        /// <summary>499        /// Gets the full HTML contents of the page, including the doctype.500        /// </summary>501        /// <returns>Task which resolves to the HTML content.</returns>502        /// <seealso cref="Frame.GetContentAsync"/>503        public Task<string> GetContentAsync() => FrameManager.MainFrame.GetContentAsync();504        /// <summary>505        /// Sets the HTML markup to the page506        /// </summary>507        /// <param name="html">HTML markup to assign to the page.</param>508        /// <param name="options">The navigations options</param>509        /// <returns>Task.</returns>510        /// <seealso cref="Frame.SetContentAsync(string, NavigationOptions)"/>511        public Task SetContentAsync(string html, NavigationOptions options = null) => FrameManager.MainFrame.SetContentAsync(html, options);512        /// <summary>513        /// Navigates to an url514        /// </summary>515        /// <remarks>516        /// <see cref="GoToAsync(string, int?, WaitUntilNavigation[])"/> will throw an error if:517        /// - there's an SSL error (e.g. in case of self-signed certificates).518        /// - target URL is invalid.519        /// - the `timeout` is exceeded during navigation.520        /// - the remote server does not respond or is unreachable.521        /// - the main resource failed to load.522        /// 523        /// <see cref="GoToAsync(string, int?, WaitUntilNavigation[])"/> will not throw an error when any valid HTTP status code is returned by the remote server, 524        /// including 404 "Not Found" and 500 "Internal Server Error".  The status code for such responses can be retrieved by calling <see cref="Response.Status"/>525        /// 526        /// > **NOTE** <see cref="GoToAsync(string, int?, WaitUntilNavigation[])"/> either throws an error or returns a main resource response. 527        /// The only exceptions are navigation to `about:blank` or navigation to the same URL with a different hash, which would succeed and return `null`.528        /// 529        /// > **NOTE** Headless mode doesn't support navigation to a PDF document. See the <see fref="https://bugs.chromium.org/p/chromium/issues/detail?id=761295">upstream issue</see>.530        /// 531        /// Shortcut for <seealso cref="Frame.GoToAsync(string, int?, WaitUntilNavigation[])"/>532        /// </remarks>533        /// <param name="url">URL to navigate page to. The url should include scheme, e.g. https://.</param>534        /// <param name="options">Navigation parameters.</param>535        /// <returns>Task which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.</returns>536        /// <seealso cref="GoToAsync(string, int?, WaitUntilNavigation[])"/>537        public Task<Response> GoToAsync(string url, NavigationOptions options) => FrameManager.MainFrame.GoToAsync(url, options);538        /// <summary>539        /// Navigates to an url540        /// </summary>541        /// <param name="url">URL to navigate page to. The url should include scheme, e.g. https://.</param>542        /// <param name="timeout">Maximum navigation time in milliseconds, defaults to 30 seconds, pass <c>0</c> to disable timeout. </param>543        /// <param name="waitUntil">When to consider navigation succeeded, defaults to <see cref="WaitUntilNavigation.Load"/>. Given an array of <see cref="WaitUntilNavigation"/>, navigation is considered to be successful after all events have been fired</param>544        /// <returns>Task which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect</returns>545        /// <seealso cref="GoToAsync(string, NavigationOptions)"/>546        public Task<Response> GoToAsync(string url, int? timeout = null, WaitUntilNavigation[] waitUntil = null)547            => GoToAsync(url, new NavigationOptions { Timeout = timeout, WaitUntil = waitUntil });548        /// <summary>549        /// Navigates to an url550        /// </summary>551        /// <param name="url">URL to navigate page to. The url should include scheme, e.g. https://.</param>552        /// <param name="waitUntil">When to consider navigation succeeded.</param>553        /// <returns>Task which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect</returns>554        /// <seealso cref="GoToAsync(string, NavigationOptions)"/>555        public Task<Response> GoToAsync(string url, WaitUntilNavigation waitUntil)556            => GoToAsync(url, new NavigationOptions { WaitUntil = new[] { waitUntil } });557        /// <summary>558        /// generates a pdf of the page with <see cref="MediaType.Print"/> css media. To generate a pdf with <see cref="MediaType.Screen"/> media call <see cref="EmulateMediaAsync(MediaType)"/> with <see cref="MediaType.Screen"/>559        /// </summary>560        /// <param name="file">The file path to save the PDF to. paths are resolved using <see cref="Path.GetFullPath(string)"/></param>561        /// <returns></returns>562        /// <remarks>563        /// Generating a pdf is currently only supported in Chrome headless564        /// </remarks>565        public Task PdfAsync(string file) => PdfAsync(file, new PdfOptions());566        /// <summary>567        ///  generates a pdf of the page with <see cref="MediaType.Print"/> css media. To generate a pdf with <see cref="MediaType.Screen"/> media call <see cref="EmulateMediaAsync(MediaType)"/> with <see cref="MediaType.Screen"/>568        /// </summary>569        /// <param name="file">The file path to save the PDF to. paths are resolved using <see cref="Path.GetFullPath(string)"/></param>570        /// <param name="options">pdf options</param>571        /// <returns></returns>572        /// <remarks>573        /// Generating a pdf is currently only supported in Chrome headless574        /// </remarks>575        public async Task PdfAsync(string file, PdfOptions options)576            => await PdfInternalAsync(file, options).ConfigureAwait(false);577        /// <summary>578        /// generates a pdf of the page with <see cref="MediaType.Print"/> css media. To generate a pdf with <see cref="MediaType.Screen"/> media call <see cref="EmulateMediaAsync(MediaType)"/> with <see cref="MediaType.Screen"/>579        /// </summary>580        /// <returns>Task which resolves to a <see cref="Stream"/> containing the PDF data.</returns>581        /// <remarks>582        /// Generating a pdf is currently only supported in Chrome headless583        /// </remarks>584        public Task<Stream> PdfStreamAsync() => PdfStreamAsync(new PdfOptions());585        /// <summary>586        /// Generates a pdf of the page with <see cref="MediaType.Print"/> css media. To generate a pdf with <see cref="MediaType.Screen"/> media call <see cref="EmulateMediaAsync(MediaType)"/> with <see cref="MediaType.Screen"/>587        /// </summary>588        /// <param name="options">pdf options</param>589        /// <returns>Task which resolves to a <see cref="Stream"/> containing the PDF data.</returns>590        /// <remarks>591        /// Generating a pdf is currently only supported in Chrome headless592        /// </remarks>593        public async Task<Stream> PdfStreamAsync(PdfOptions options)594            => new MemoryStream(await PdfDataAsync(options).ConfigureAwait(false));595        /// <summary>596        /// Generates a pdf of the page with <see cref="MediaType.Print"/> css media. To generate a pdf with <see cref="MediaType.Screen"/> media call <see cref="EmulateMediaAsync(MediaType)"/> with <see cref="MediaType.Screen"/>597        /// </summary>598        /// <returns>Task which resolves to a <see cref="byte"/>[] containing the PDF data.</returns>599        /// <remarks>600        /// Generating a pdf is currently only supported in Chrome headless601        /// </remarks>602        public Task<byte[]> PdfDataAsync() => PdfDataAsync(new PdfOptions());603        /// <summary>604        /// Generates a pdf of the page with <see cref="MediaType.Print"/> css media. To generate a pdf with <see cref="MediaType.Screen"/> media call <see cref="EmulateMediaAsync(MediaType)"/> with <see cref="MediaType.Screen"/>605        /// </summary>606        /// <param name="options">pdf options</param>607        /// <returns>Task which resolves to a <see cref="byte"/>[] containing the PDF data.</returns>608        /// <remarks>609        /// Generating a pdf is currently only supported in Chrome headless610        /// </remarks>611        public Task<byte[]> PdfDataAsync(PdfOptions options) => PdfInternalAsync(null, options);612        internal async Task<byte[]> PdfInternalAsync(string file, PdfOptions options)613        {614            var paperWidth = PaperFormat.Letter.Width;615            var paperHeight = PaperFormat.Letter.Height;616            if (options.Format != null)617            {618                paperWidth = options.Format.Width;619                paperHeight = options.Format.Height;620            }621            else622            {623                if (options.Width != null)624                {625                    paperWidth = ConvertPrintParameterToInches(options.Width);626                }627                if (options.Height != null)628                {629                    paperHeight = ConvertPrintParameterToInches(options.Height);630                }631            }632            var marginTop = ConvertPrintParameterToInches(options.MarginOptions.Top);633            var marginLeft = ConvertPrintParameterToInches(options.MarginOptions.Left);634            var marginBottom = ConvertPrintParameterToInches(options.MarginOptions.Bottom);635            var marginRight = ConvertPrintParameterToInches(options.MarginOptions.Right);636            var result = await Client.SendAsync<PagePrintToPDFResponse>("Page.printToPDF", new PagePrintToPDFRequest637            {638                TransferMode = "ReturnAsStream",639                Landscape = options.Landscape,640                DisplayHeaderFooter = options.DisplayHeaderFooter,641                HeaderTemplate = options.HeaderTemplate,642                FooterTemplate = options.FooterTemplate,643                PrintBackground = options.PrintBackground,644                Scale = options.Scale,645                PaperWidth = paperWidth,646                PaperHeight = paperHeight,647                MarginTop = marginTop,648                MarginBottom = marginBottom,649                MarginLeft = marginLeft,650                MarginRight = marginRight,651                PageRanges = options.PageRanges,652                PreferCSSPageSize = options.PreferCSSPageSize653            }).ConfigureAwait(false);654            return await ProtocolStreamReader.ReadProtocolStreamByteAsync(Client, result.Stream, file).ConfigureAwait(false);655        }656        /// <summary>657        /// Enables/Disables Javascript on the page658        /// </summary>659        /// <returns>Task.</returns>660        /// <param name="enabled">Whether or not to enable JavaScript on the page.</param>661        public Task SetJavaScriptEnabledAsync(bool enabled)662        {663            if (enabled == JavascriptEnabled)664            {665                return Task.CompletedTask;666            }667            JavascriptEnabled = enabled;668            return Client.SendAsync("Emulation.setScriptExecutionDisabled", new EmulationSetScriptExecutionDisabledRequest669            {670                Value = !enabled671            });672        }673        /// <summary>674        /// Toggles bypassing page's Content-Security-Policy.675        /// </summary>676        /// <param name="enabled">sets bypassing of page's Content-Security-Policy.</param>677        /// <returns></returns>678        /// <remarks>679        /// CSP bypassing happens at the moment of CSP initialization rather then evaluation.680        /// Usually this means that <see cref="SetBypassCSPAsync(bool)"/> should be called before navigating to the domain.681        /// </remarks>682        public Task SetBypassCSPAsync(bool enabled) => Client.SendAsync("Page.setBypassCSP", new PageSetBypassCSPRequest683        {684            Enabled = enabled685        });686        /// <summary>687        /// Emulates a media such as screen or print.688        /// </summary>689        /// <returns>Task.</returns>690        /// <param name="media">Media to set.</param>691        [Obsolete("User EmulateMediaTypeAsync instead")]692        public Task EmulateMediaAsync(MediaType media) => EmulateMediaTypeAsync(media);693        /// <summary>694        /// Emulates a media such as screen or print.695        /// </summary>696        /// <param name="type">Media to set.</param>697        /// <example>698        /// <code>699        /// <![CDATA[700        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('screen').matches)");701        /// // → true702        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('print').matches)");703        /// // → true704        /// await page.EmulateMediaTypeAsync(MediaType.Print);705        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('screen').matches)");706        /// // → false707        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('print').matches)");708        /// // → true709        /// await page.EmulateMediaTypeAsync(MediaType.None);710        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('screen').matches)");711        /// // → true712        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('print').matches)");713        /// // → true714        /// ]]>715        /// </code>716        /// </example>717        /// <returns>Emulate media type task.</returns>718        public Task EmulateMediaTypeAsync(MediaType type)719            => Client.SendAsync("Emulation.setEmulatedMedia", new EmulationSetEmulatedMediaTypeRequest { Media = type });720        /// <summary>721        /// Given an array of media feature objects, emulates CSS media features on the page.722        /// </summary>723        /// <param name="features">Features to apply</param>724        /// <example>725        /// <code>726        /// <![CDATA[727        /// await page.EmulateMediaFeaturesAsync(new MediaFeature[]{ new MediaFeature { MediaFeature =  MediaFeature.PrefersColorScheme, Value = "dark" }});728        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: dark)').matches)");729        /// // → true730        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: light)').matches)");731        /// // → false732        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: no-preference)').matches)");733        /// // → false734        /// await page.EmulateMediaFeaturesAsync(new MediaFeature[]{ new MediaFeature { MediaFeature = MediaFeature.PrefersReducedMotion, Value = "reduce" }});735        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-reduced-motion: reduce)').matches)");736        /// // → true737        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: no-preference)').matches)");738        /// // → false739        /// await page.EmulateMediaFeaturesAsync(new MediaFeature[]740        /// { 741        ///   new MediaFeature { MediaFeature = MediaFeature.PrefersColorScheme, Value = "dark" },742        ///   new MediaFeature { MediaFeature = MediaFeature.PrefersReducedMotion, Value = "reduce" },743        /// });744        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: dark)').matches)");745        /// // → true746        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: light)').matches)");747        /// // → false748        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: no-preference)').matches)");749        /// // → false750        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-reduced-motion: reduce)').matches)");751        /// // → true752        /// await page.EvaluateFunctionAsync<bool>("() => matchMedia('(prefers-color-scheme: no-preference)').matches)");753        /// // → false754        /// ]]>755        /// </code>756        /// </example>757        /// <returns>Emulate features task</returns>758        public Task EmulateMediaFeaturesAsync(IEnumerable<MediaFeatureValue> features)759            => Client.SendAsync("Emulation.setEmulatedMedia", new EmulationSetEmulatedMediaFeatureRequest { Features = features });760        /// <summary>761        /// Sets the viewport.762        /// In the case of multiple pages in a single browser, each page can have its own viewport size.763        /// <see cref="SetViewportAsync(ViewPortOptions)"/> will resize the page. A lot of websites don't expect phones to change size, so you should set the viewport before navigating to the page.764        /// </summary>765        /// <example>766        ///<![CDATA[767        /// using(var page = await browser.NewPageAsync())768        /// {769        ///     await page.SetViewPortAsync(new ViewPortOptions770        ///     {771        ///         Width = 640, 772        ///         Height = 480, 773        ///         DeviceScaleFactor = 1774        ///     });775        ///     await page.goto('https://www.example.com');776        /// }777        /// ]]>778        /// </example>779        /// <returns>The viewport task.</returns>780        /// <param name="viewport">Viewport options.</param>781        public async Task SetViewportAsync(ViewPortOptions viewport)782        {783            var needsReload = await _emulationManager.EmulateViewport(viewport).ConfigureAwait(false);784            Viewport = viewport;785            if (needsReload)786            {787                await ReloadAsync().ConfigureAwait(false);788            }789        }790        /// <summary>791        /// Closes the page.792        /// </summary>793        /// <param name="options">Close options.</param>794        /// <returns>Task.</returns>795        public Task CloseAsync(PageCloseOptions options = null)796        {797            if (!(Client?.Connection?.IsClosed ?? true))798            {799                var runBeforeUnload = options?.RunBeforeUnload ?? false;800                if (runBeforeUnload)801                {802                    return Client.SendAsync("Page.close");803                }804                return Client.Connection.SendAsync("Target.closeTarget", new TargetCloseTargetRequest805                {806                    TargetId = Target.TargetId807                }).ContinueWith(task => Target.CloseTask);808            }809            return _closeCompletedTcs.Task;810        }811        /// <summary>812        /// Reloads the page813        /// </summary>814        /// <param name="options">Navigation options</param>815        /// <returns>Task which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect</returns>816        /// <seealso cref="ReloadAsync(int?, WaitUntilNavigation[])"/>817        public async Task<Response> ReloadAsync(NavigationOptions options)818        {819            var navigationTask = WaitForNavigationAsync(options);820            await Task.WhenAll(821              navigationTask,822              Client.SendAsync("Page.reload")823            ).ConfigureAwait(false);824            return navigationTask.Result;825        }826        /// <summary>827        /// Reloads the page828        /// </summary>829        /// <param name="timeout">Maximum navigation time in milliseconds, defaults to 30 seconds, pass <c>0</c> to disable timeout. </param>830        /// <param name="waitUntil">When to consider navigation succeeded, defaults to <see cref="WaitUntilNavigation.Load"/>. Given an array of <see cref="WaitUntilNavigation"/>, navigation is considered to be successful after all events have been fired</param>831        /// <returns>Task which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect</returns>832        /// <seealso cref="ReloadAsync(NavigationOptions)"/>833        public Task<Response> ReloadAsync(int? timeout = null, WaitUntilNavigation[] waitUntil = null)834            => ReloadAsync(new NavigationOptions { Timeout = timeout, WaitUntil = waitUntil });835        /// <summary>836        /// Waits for a function to be evaluated to a truthy value837        /// </summary>838        /// <param name="script">Function to be evaluated in browser context</param>839        /// <param name="options">Optional waiting parameters</param>840        /// <param name="args">Arguments to pass to <c>script</c></param>841        /// <returns>A task that resolves when the <c>script</c> returns a truthy value</returns>842        /// <seealso cref="Frame.WaitForFunctionAsync(string, WaitForFunctionOptions, object[])"/>843        public Task<JSHandle> WaitForFunctionAsync(string script, WaitForFunctionOptions options = null, params object[] args)844            => MainFrame.WaitForFunctionAsync(script, options ?? new WaitForFunctionOptions(), args);845        /// <summary>846        /// Waits for an expression to be evaluated to a truthy value847        /// </summary>848        /// <param name="script">Expression to be evaluated in browser context</param>849        /// <param name="options">Optional waiting parameters</param>850        /// <returns>A task that resolves when the <c>script</c> returns a truthy value</returns>851        /// <seealso cref="Frame.WaitForExpressionAsync(string, WaitForFunctionOptions)"/>852        public Task<JSHandle> WaitForExpressionAsync(string script, WaitForFunctionOptions options = null)853            => MainFrame.WaitForExpressionAsync(script, options ?? new WaitForFunctionOptions());854        /// <summary>855        /// Waits for a selector to be added to the DOM856        /// </summary>857        /// <param name="selector">A selector of an element to wait for</param>858        /// <param name="options">Optional waiting parameters</param>859        /// <returns>A task that resolves when element specified by selector string is added to DOM.860        /// Resolves to `null` if waiting for `hidden: true` and selector is not found in DOM.</returns>861        /// <seealso cref="WaitForXPathAsync(string, WaitForSelectorOptions)"/>862        /// <seealso cref="Frame.WaitForSelectorAsync(string, WaitForSelectorOptions)"/>863        public Task<ElementHandle> WaitForSelectorAsync(string selector, WaitForSelectorOptions options = null)864            => MainFrame.WaitForSelectorAsync(selector, options ?? new WaitForSelectorOptions());865        /// <summary>866        /// Waits for a xpath selector to be added to the DOM867        /// </summary>868        /// <param name="xpath">A xpath selector of an element to wait for</param>869        /// <param name="options">Optional waiting parameters</param>870        /// <returns>A task which resolves when element specified by xpath string is added to DOM. 871        /// Resolves to `null` if waiting for `hidden: true` and xpath is not found in DOM.</returns>872        /// <example>873        /// <code>874        /// <![CDATA[875        /// var browser = await Puppeteer.LaunchAsync(new LaunchOptions());876        /// var page = await browser.NewPageAsync();877        /// string currentURL = null;878        /// page879        ///     .WaitForXPathAsync("//img")880        ///     .ContinueWith(_ => Console.WriteLine("First URL with image: " + currentURL));881        /// foreach (var current in new[] { "https://example.com", "https://google.com", "https://bbc.com" })882        /// {883        ///     currentURL = current;884        ///     await page.GoToAsync(currentURL);885        /// }886        /// await browser.CloseAsync();887        /// ]]>888        /// </code>889        /// </example>890        /// <seealso cref="WaitForSelectorAsync(string, WaitForSelectorOptions)"/>891        /// <seealso cref="Frame.WaitForXPathAsync(string, WaitForSelectorOptions)"/>892        public Task<ElementHandle> WaitForXPathAsync(string xpath, WaitForSelectorOptions options = null)893            => MainFrame.WaitForXPathAsync(xpath, options ?? new WaitForSelectorOptions());894        /// <summary>895        /// This resolves when the page navigates to a new URL or reloads.896        /// It is useful for when you run code which will indirectly cause the page to navigate.897        /// </summary>898        /// <param name="options">navigation options</param>899        /// <returns>Task which resolves to the main resource response. 900        /// In case of multiple redirects, the navigation will resolve with the response of the last redirect.901        /// In case of navigation to a different anchor or navigation due to History API usage, the navigation will resolve with `null`.902        /// </returns>903        /// <remarks>904        /// Usage of the <c>History API</c> <see href="https://developer.mozilla.org/en-US/docs/Web/API/History_API"/> to change the URL is considered a navigation905        /// </remarks>906        /// <example>907        /// <code>908        /// <![CDATA[909        /// var navigationTask = page.WaitForNavigationAsync();910        /// await page.ClickAsync("a.my-link");911        /// await navigationTask;912        /// ]]>913        /// </code>914        /// </example>915        public Task<Response> WaitForNavigationAsync(NavigationOptions options = null) => FrameManager.WaitForFrameNavigationAsync(FrameManager.MainFrame, options);916        /// <summary>917        /// Waits for a request.918        /// </summary>919        /// <example>920        /// <code>921        /// <![CDATA[922        /// var firstRequest = await page.WaitForRequestAsync("http://example.com/resource");923        /// return firstRequest.Url;924        /// ]]>925        /// </code>926        /// </example>927        /// <returns>A task which resolves when a matching request was made.</returns>928        /// <param name="url">URL to wait for.</param>929        /// <param name="options">Options.</param>930        public Task<Request> WaitForRequestAsync(string url, WaitForOptions options = null)931            => WaitForRequestAsync(request => request.Url == url, options);932        /// <summary>933        /// Waits for a request.934        /// </summary>935        /// <example>936        /// <code>937        /// <![CDATA[938        /// var request = await page.WaitForRequestAsync(request => request.Url === "http://example.com" && request.Method === HttpMethod.Get;939        /// return request.Url;940        /// ]]>941        /// </code>942        /// </example>943        /// <returns>A task which resolves when a matching request was made.</returns>944        /// <param name="predicate">Function which looks for a matching request.</param>945        /// <param name="options">Options.</param>946        public async Task<Request> WaitForRequestAsync(Func<Request, bool> predicate, WaitForOptions options = null)947        {948            var timeout = options?.Timeout ?? DefaultTimeout;949            var requestTcs = new TaskCompletionSource<Request>(TaskCreationOptions.RunContinuationsAsynchronously);950            void requestEventListener(object sender, RequestEventArgs e)951            {952                if (predicate(e.Request))953                {954                    requestTcs.TrySetResult(e.Request);955                    FrameManager.NetworkManager.Request -= requestEventListener;956                }957            }958            FrameManager.NetworkManager.Request += requestEventListener;959            await Task.WhenAny(requestTcs.Task, SessionClosedTask).WithTimeout(timeout, t =>960            {961                FrameManager.NetworkManager.Request -= requestEventListener;962                return new TimeoutException($"Timeout of {t.TotalMilliseconds} ms exceeded");963            }).ConfigureAwait(false);964            if (SessionClosedTask.IsFaulted)965            {966                await SessionClosedTask.ConfigureAwait(false);967            }968            return await requestTcs.Task.ConfigureAwait(false);969        }970        /// <summary>971        /// Waits for a response.972        /// </summary>973        /// <example>974        /// <code>975        /// <![CDATA[976        /// var firstResponse = await page.WaitForResponseAsync("http://example.com/resource");977        /// return firstResponse.Url;978        /// ]]>979        /// </code>980        /// </example>981        /// <returns>A task which resolves when a matching response is received.</returns>982        /// <param name="url">URL to wait for.</param>983        /// <param name="options">Options.</param>984        public Task<Response> WaitForResponseAsync(string url, WaitForOptions options = null)985            => WaitForResponseAsync(response => response.Url == url, options);986        /// <summary>987        /// Waits for a response.988        /// </summary>989        /// <example>990        /// <code>991        /// <![CDATA[992        /// var response = await page.WaitForResponseAsync(response => response.Url === "http://example.com" && response.Status === HttpStatus.Ok;993        /// return response.Url;994        /// ]]>995        /// </code>996        /// </example>997        /// <returns>A task which resolves when a matching response is received.</returns>998        /// <param name="predicate">Function which looks for a matching response.</param>999        /// <param name="options">Options.</param>1000        public async Task<Response> WaitForResponseAsync(Func<Response, bool> predicate, WaitForOptions options = null)1001        {1002            var timeout = options?.Timeout ?? DefaultTimeout;1003            var responseTcs = new TaskCompletionSource<Response>(TaskCreationOptions.RunContinuationsAsynchronously);1004            void responseEventListener(object sender, ResponseCreatedEventArgs e)1005            {1006                if (predicate(e.Response))1007                {1008                    responseTcs.TrySetResult(e.Response);1009                    FrameManager.NetworkManager.Response -= responseEventListener;1010                }1011            }1012            FrameManager.NetworkManager.Response += responseEventListener;1013            await Task.WhenAny(responseTcs.Task, SessionClosedTask).WithTimeout(timeout).ConfigureAwait(false);1014            if (SessionClosedTask.IsFaulted)1015            {1016                await SessionClosedTask.ConfigureAwait(false);1017            }1018            return await responseTcs.Task.ConfigureAwait(false);1019        }1020        /// <summary>1021        /// Navigate to the previous page in history.1022        /// </summary>1023        /// <returns>Task that resolves to the main resource response. In case of multiple redirects, 1024        /// the navigation will resolve with the response of the last redirect. If can not go back, resolves to null.</returns>1025        /// <param name="options">Navigation parameters.</param>1026        public Task<Response> GoBackAsync(NavigationOptions options = null) => GoAsync(-1, options);1027        /// <summary>1028        /// Navigate to the next page in history.1029        /// </summary>1030        /// <returns>Task that resolves to the main resource response. In case of multiple redirects, 1031        /// the navigation will resolve with the response of the last redirect. If can not go forward, resolves to null.</returns>1032        /// <param name="options">Navigation parameters.</param>1033        public Task<Response> GoForwardAsync(NavigationOptions options = null) => GoAsync(1, options);1034        /// <summary>1035        /// Resets the background color and Viewport after taking Screenshots using BurstMode.1036        /// </summary>1037        /// <returns>The burst mode off.</returns>1038        public Task SetBurstModeOffAsync()1039        {1040            return Task.CompletedTask;1041        }1042        #endregion1043        internal void OnPopup(Page popupPage) => Popup?.Invoke(this, new PopupEventArgs { PopupPage = popupPage });1044        #region Private Method1045        internal static async Task<Page> CreateAsync(1046            CDPSession client,1047            Target target,1048            bool ignoreHTTPSErrors,1049            ViewPortOptions defaultViewPort,1050            TaskQueue screenshotTaskQueue)1051        {1052            var page = new Page(client, target, screenshotTaskQueue);1053            await page.InitializeAsync(ignoreHTTPSErrors).ConfigureAwait(false);1054            if (defaultViewPort != null)1055            {1056                await page.SetViewportAsync(defaultViewPort).ConfigureAwait(false);1057            }1058            return page;1059        }1060        private async Task InitializeAsync(bool ignoreHTTPSErrors)1061        {1062            FrameManager = await FrameManager.CreateFrameManagerAsync(Client, this, ignoreHTTPSErrors, _timeoutSettings).ConfigureAwait(false);1063            var networkManager = FrameManager.NetworkManager;1064            Client.MessageReceived += Client_MessageReceived;1065            FrameManager.FrameAttached += (sender, e) => FrameAttached?.Invoke(this, e);1066            FrameManager.FrameDetached += (sender, e) => FrameDetached?.Invoke(this, e);...

...46            Connection = connection;47            IgnoreHTTPSErrors = options.IgnoreHTTPSErrors;48            AppMode = options.AppMode;49            _targets = new Dictionary<string, Target>();50            ScreenshotTaskQueue = new TaskQueue();51            Connection.Closed += (object sender, EventArgs e) => Disconnected?.Invoke(this, new EventArgs());52            Connection.MessageReceived += Connect_MessageReceived;53            _closeCallBack = closeCallBack;54        }55        #region Private members56        private readonly Dictionary<string, Target> _targets;57        private readonly Func<Task> _closeCallBack;58        #endregion59        #region Properties60        /// <summary>61        /// 62        /// </summary>63        public event EventHandler Closed;64        /// <summary>65        /// Raised when puppeteer gets disconnected from the Chromium instance. This might happen because one of the following66        /// - Chromium is closed or crashed67        /// - <see cref="Disconnect"/> method was called68        /// </summary>69        public event EventHandler Disconnected;70        /// <summary>71        /// Raised when the url of a target changes72        /// </summary>73        public event EventHandler<TargetChangedArgs> TargetChanged;74        /// <summary>75        /// Raised when a target is created, for example when a new page is opened by <c>window.open</c> <see href="https://developer.mozilla.org/en-US/docs/Web/API/Window/open"/> or <see cref="NewPageAsync"/>.76        /// </summary>77        public event EventHandler<TargetChangedArgs> TargetCreated;78        /// <summary>79        /// Raised when a target is destroyed, for example when a page is closed80        /// </summary>81        public event EventHandler<TargetChangedArgs> TargetDestroyed;82        /// <summary>83        /// Gets the Browser websocket url84        /// </summary>85        /// <remarks>86        /// Browser websocket endpoint which can be used as an argument to <see cref="Puppeteer.ConnectAsync(ConnectOptions, ILoggerFactory)"/>.87        /// The format is <c>ws://${host}:${port}/devtools/browser/[id]</c>88        /// You can find the <c>webSocketDebuggerUrl</c> from <c>http://${host}:${port}/json/version</c>.89        /// Learn more about the devtools protocol <see href="https://chromedevtools.github.io/devtools-protocol"/> 90        /// and the browser endpoint <see href="https://chromedevtools.github.io/devtools-protocol/#how-do-i-access-the-browser-target"/>91        /// </remarks>92        public string WebSocketEndpoint => Connection.Url;93        /// <summary>94        /// Gets the spawned browser process. Returns <c>null</c> if the browser instance was created with <see cref="Puppeteer.ConnectAsync(ConnectOptions, ILoggerFactory)"/> method.95        /// </summary>96        public Process Process { get; }97        /// <summary>98        /// Gets or Sets whether to ignore HTTPS errors during navigation99        /// </summary>100        public bool IgnoreHTTPSErrors { get; set; }101        /// <summary>102        /// Gets or Sets whether to use appMode or not103        /// </summary>104        public bool AppMode { get; set; }105        /// <summary>106        /// Gets a value indicating if the browser is closed107        /// </summary>108        public bool IsClosed { get; internal set; }109        internal TaskQueue ScreenshotTaskQueue { get; set; }110        internal Connection Connection { get; }111        #endregion112        #region Public Methods113        /// <summary>114        /// Creates a new page115        /// </summary>116        /// <returns>Task which resolves to a new <see cref="Page"/> object</returns>117        public async Task<Page> NewPageAsync()118        {119            string targetId = (await Connection.SendAsync("Target.createTarget", new Dictionary<string, object>(){120                {"url", "about:blank"}121              })).targetId.ToString();122            var target = _targets[targetId];123            await target.InitializedTask;...

...15    /// A connection handles the communication with a Chromium browser16    /// </summary>17    public class Connection : IDisposable18    {19        private TaskQueue _callbackQueue = new TaskQueue();20        internal Connection(string url, int delay, IConnectionTransport transport)21        {22            Url = url;23            Delay = delay;24            Transport = transport;25            Transport.MessageReceived += Transport_MessageReceived;26            Transport.Closed += Transport_Closed;27            _callbacks = new ConcurrentDictionary<int, MessageTask>();28            _sessions = new ConcurrentDictionary<string, CDPSession>();29            _asyncSessions = new AsyncDictionaryHelper<string, CDPSession>(_sessions, "Session {0} not found");30        }31        #region Private Members32        private int _lastId;33        private readonly ConcurrentDictionary<int, MessageTask> _callbacks;...

...12    public class WebSocketTransport : IConnectionTransport13    {14        private readonly WebSocket _client;15        private readonly bool _queueRequests;16        private readonly TaskQueue _socketQueue;17        private CancellationTokenSource _readerCancellationSource { get; }18        /// <summary>19        /// Gets a value indicating whether this <see cref="PuppeteerSharp.Transport.IConnectionTransport"/> is closed.20        /// </summary>21        public bool IsClosed { get; private set; }22        /// <summary>23        /// Occurs when the transport is closed.24        /// </summary>25        public event EventHandler Closed;26        /// <summary>27        /// Occurs when a message is received.28        /// </summary>29        public event EventHandler<MessageReceivedEventArgs> MessageReceived;30        /// <summary>31        /// Initializes a new instance of the <see cref="PuppeteerSharp.Transport.WebSocketTransport"/> class.32        /// </summary>33        /// <param name="wsClient">WebSocket client.</param>34        /// <param name="queueRequests">If set to <c>true</c> to queue requests.</param>35        public WebSocketTransport(WebSocket wsClient, bool queueRequests = true)36        {37            _client = wsClient;38            _queueRequests = queueRequests;39            _socketQueue = new TaskQueue();40            _readerCancellationSource = new CancellationTokenSource();41            Task.Factory.StartNew(GetResponseAsync);42        }43        /// <summary>44        /// Sends a message using the transport.45        /// </summary>46        /// <returns>The task.</returns>47        /// <param name="message">Message to send.</param>48        public Task SendAsync(string message)49        {50            var encoded = Encoding.UTF8.GetBytes(message);51            var buffer = new ArraySegment<byte>(encoded, 0, encoded.Length);52            Task sendTask() => _client.SendAsync(buffer, WebSocketMessageType.Text, true, default);53            return _queueRequests ? _socketQueue.Enqueue(sendTask) : sendTask();...

2using System.Threading;3using System.Threading.Tasks;4namespace PuppeteerSharp.Helpers5{6    internal class TaskQueue7    {8        private SemaphoreSlim _semaphore;9        internal TaskQueue()10        {11            _semaphore = new SemaphoreSlim(1);12        }13        internal async Task<T> Enqueue<T>(Func<Task<T>> taskGenerator)14        {15            await _semaphore.WaitAsync();16            try17            {18                return await taskGenerator();19            }20            finally21            {22                _semaphore.Release();23            }...

1var browser = await Puppeteer.LaunchAsync(new LaunchOptions2{3    Args = new string[] { "--start-maximized" },4});5var page = await browser.NewPageAsync();6await page.TypeAsync("input[name='q']", "PuppeteerSharp");7await page.Keyboard.PressAsync("Enter");8await page.WaitForNavigationAsync();9await page.ScreenshotAsync("google.png");10await browser.CloseAsync();11var browser = await Puppeteer.LaunchAsync(new LaunchOptions12{13    Args = new string[] { "--start-maximized" },14});15var page = await browser.NewPageAsync();16await page.TypeAsync("input[name='q']", "PuppeteerSharp");17await page.Keyboard.PressAsync("Enter");18await page.WaitForNavigationAsync();19await page.ScreenshotAsync("google.png");20await browser.CloseAsync();21error CS0234: The type or namespace name 'Helpers' does not exist in the namespace 'PuppeteerSharp' (are you missing an assembly reference?)22error CS0234: The type or namespace name 'Helpers' does not exist in the namespace 'PuppeteerSharp' (are you missing an assembly reference?)23error CS0234: The type or namespace name 'Helpers' does not exist in the namespace 'PuppeteerSharp' (are you

1using PuppeteerSharp.Extra;2using PuppeteerSharp.Extra.Tasks;3Error CS0246 The type or namespace name 'Puppeteer' could not be found (are you missing a using directive or an assembly reference?)4using PuppeteerSharp;5Error CS0246 The type or namespace name 'PuppeteerSharp' could not be found (are you missing a using directive or an assembly reference?)6using PuppeteerSharp.Contrib;7Error CS0246 The type or namespace name 'PuppeteerSharp' could not be found (are you missing a using directive or an assembly reference?)

1var taskQueue = new TaskQueue();2await taskQueue.Enqueue(async () =>3{4});5await taskQueue.Enqueue(async () =>6{7});8var taskQueue = new TaskQueue();9await taskQueue.Enqueue(async () =>10{11});12await taskQueue.Enqueue(async () =>13{14});15var taskQueue = new TaskQueue();16await taskQueue.Enqueue(async () =>17{18});19await taskQueue.Enqueue(async () =>20{21});22var taskQueue = new TaskQueue();23await taskQueue.Enqueue(async () =>24{25});26await taskQueue.Enqueue(async () =>27{28});29var taskQueue = new TaskQueue();30await taskQueue.Enqueue(async () =>31{32});33await taskQueue.Enqueue(async () =>34{35});36var taskQueue = new TaskQueue();37await taskQueue.Enqueue(async () =>38{39});40await taskQueue.Enqueue(async () =>41{42});43var taskQueue = new TaskQueue();44await taskQueue.Enqueue(async () =>45{46});47await taskQueue.Enqueue(async () =>48{49});50var taskQueue = new TaskQueue();51await taskQueue.Enqueue(async () =>52{53});54await taskQueue.Enqueue(async () =>55{56});57var taskQueue = new TaskQueue();58await taskQueue.Enqueue(async () =>59{60});61await taskQueue.Enqueue(async () =>62{63});

1using PuppeteerSharp.Helpers;2var taskQueue = new TaskQueue();3await taskQueue.Enqueue(async () => {4    await page.ScreenshotAsync("google.png");5});6using PuppeteerSharp.Helpers;7var taskQueue = new TaskQueue();8await taskQueue.Enqueue(async () => {9    await page.ScreenshotAsync("bing.png");10});11using PuppeteerSharp.Helpers;12var taskQueue = new TaskQueue();13await taskQueue.Enqueue(async () => {14    await page.ScreenshotAsync("yahoo.png");15});16using PuppeteerSharp.Helpers;17using System;18using System.Threading.Tasks;19{20    {21        static async Task Main(string[] args)22        {23            var taskQueue = new TaskQueue();24            await taskQueue.Enqueue(async () => {25                await Task.Delay(5000);26                Console.WriteLine("Hello 1");27            });28            await taskQueue.Enqueue(async () => {29                await Task.Delay(5000);30                Console.WriteLine("Hello 2");31            });32            await taskQueue.Enqueue(async () => {33                await Task.Delay(5000);34                Console.WriteLine("Hello 3");35            });36        }37    }38}

1await new TaskQueue().RunAsync(async () => 2{3});4await new TaskQueue().RunAsync(async () => 5{6});7await new TaskQueue().RunAsync(async () => 8{9});10await new TaskQueue().RunAsync(async () => 11{12});13await new TaskQueue().RunAsync(async () => 14{15});16await new TaskQueue().RunAsync(async () => 17{18});19await new TaskQueue().RunAsync(async () => 20{21});22await new TaskQueue().RunAsync(async () => 23{24});25await new TaskQueue().RunAsync(async () => 26{27});28await new TaskQueue().RunAsync(async () => 29{30});31await new TaskQueue().RunAsync(async () => 32{33});34await new TaskQueue().RunAsync(async () => 35{36});37await new TaskQueue().RunAsync(async () => 38{

1using PuppeteerSharp.Helpers;2using System;3using System.Threading.Tasks;4{5    {6        static async Task Main(string[] args)7        {8            var queue = new TaskQueue();9            var browser = await Puppeteer.LaunchAsync(new LaunchOptions10            {11            });12            var page = await browser.NewPageAsync();13            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'red'");14            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'blue'");15            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'green'");16            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'yellow'");17            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'orange'");18            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'purple'");19            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'black'");20            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'white'");21            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'gray'");22            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'brown'");23            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'pink'");24            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'aqua'");25            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'silver'");26            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'maroon'");27            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'olive'");28            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'teal'");29            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'navy'");30            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'fuchsia'");31            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'lime'");32            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'red'");33            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'blue'");34            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'green'");35            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'yellow'");36            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'orange'");37            await page.EvaluateExpressionAsync("document.body.style.backgroundColor = 'purple'");38            await page.EvaluateExpressionAsync("document.body.style