Unlock 30% off on Manual Testing Annual Plans this Holiday Season. 
Use Code: LCMYEARENDEXCL30
Use Code: LCMYEARENDEXCL30Check icon
Copied to Clipboard!
How to use WaitForExpressionAsync method of PuppeteerSharp.Page class
Best Puppeteer-sharp code snippet using PuppeteerSharp.Page.WaitForExpressionAsync
WebScraper.cs
Source:WebScraper.cs 
...238 WaitOnScriptAsync(expression).Wait();239 }240 private async Task WaitOnScriptAsync(string expression)241 {242 await m_page.WaitForExpressionAsync(expression);243 }244 /// <summary>245 /// Selects element on page to have focus.246 /// </summary>247 /// <param name="target">Javascript selector to make have focus.</param>248 public void Focus(string target)249 {250 FocusAsync(target).Wait();251 }252 private async Task FocusAsync(string target)253 {254 await m_page.FocusAsync(target);255 }256 /// <summary>...
Program.cs
Source:Program.cs
...52 });53 await RacePageUtils.AcceptEverything();54 await RacePageUtils.LaunchRace();55 56 await Page.WaitForExpressionAsync(57 "document.querySelector('#inputtextblock #inputtext').disabled===false",58 new WaitForFunctionOptions() { Timeout = 666666 }59 );60 await Page.WaitForTimeoutAsync(300);61 var text = await Page.EvaluateExpressionAsync<string>("document.querySelector('#typetext').innerText");62 #region Detect alphabet and game mode63 bool isCyrillicMode = isCyrillicRgx.IsMatch(text);64 var gameTypeExp = "document.querySelector('#gamedesc').innerText.split(',')[0]";65 var gameType = await Page.EvaluateExpressionAsync<string>(gameTypeExp);66 gameType = gameType.Trim().TrimStart('«').TrimEnd('»');67 var noErrorMode = gameType == "ÐезоÑибоÑнÑй";68 #endregion69 await Page.FocusAsync("#inputtextblock #inputtext");70 foreach (char c in text)...
PuppeteerBannerGenerator.cs
Source:PuppeteerBannerGenerator.cs
...38 await StartBrowserAsync();39 using var page = await _browser.NewPageAsync();40 await page.GoToAsync("https://localhost:5001/erikolsson.html?identifier=" + identifier);41 // Wait for window.documentReady to be set to true (needs to be handled by the page after all images have loaded)42 await page.WaitForExpressionAsync("window.documentReady === true", new WaitForFunctionOptions { Polling = WaitForFunctionPollingOption.Raf });43 // Puppeteer starts with a too small viewport so we need to resize it44 await page.SetViewportAsync(new ViewPortOptions { Width = 1500, Height = 1500 });45 // Get the main element and create a PNG screenshot of it46 var mainElement = await page.QuerySelectorAsync("main");47 using var screenshotStream = await mainElement.ScreenshotStreamAsync(new ScreenshotOptions { Type = ScreenshotType.Png });48 using var ms = new MemoryStream();49 await screenshotStream.CopyToAsync(ms, cancellationToken);50 return ms.ToArray().AsMemory();51 }52 public async ValueTask DisposeAsync() {53 if(_browser != null) {54 await _browser.DisposeAsync();55 }56 }...
test vueJS - Example1 - Refresh Top System Processes.csx
Source:test vueJS - Example1 - Refresh Top System Processes.csx
...76 ()=> {77 window.programDone = false;78 }79 ");80 await page.WaitForExpressionAsync("window.programDone === true", new WaitForFunctionOptions{81 Timeout = 0 // disable the timeout82 });83 Console.WriteLine("Program finished triggered");84 // program is done so close everything out85 await page.CloseAsync();86 await browser.CloseAsync();87}88await waitForProgramEnd();...
SearchPage.cs
Source:SearchPage.cs
...16[0]17";18 static async Task WaitForSearchResultCount(Page page)19 {20 await page.WaitForExpressionAsync(SearchResultCount);21 }22 static async Task<int?> GetSearchResultCount(Page page)23 {24 return await page.EvaluateExpressionAsync<int?>(SearchResultCount);25 }26 public static async Task ClickSearchButton(Page page)27 {28 await page.ClickAsync(".btn.btn-lg.btn-primary.track-event");29 }30 public static async Task WaitForFilledAndSubmittedSearchPage(Page page)31 {32 while (true)33 {34 try35 {36 if (await GetSearchResultCount(page) != null) break;37 }38 catch (PuppeteerException) { }39 await Task.Delay(1000);40 }41 }42 public static async Task WaitForFirstPageLoad(Page page)43 {44 var script = @"document.querySelector(""[src^='/assets/looading-gif']"") == null";45 await page.WaitForExpressionAsync(script);46 await WaitForSearchResultCount(page);47 var count = await GetSearchResultCount(page);48 if (count == 0) return;49 await page.WaitForExpressionAsync("document.querySelector('.lazy-load-image') == null");50 }51 public static async Task<bool> CanGoToNextPage(Page page)52 {53 await WaitForFirstPageLoad(page);54 const string script = @"(() => document.querySelector('.btn.btn-default.btn-lg') !== null )()";55 var result = await page.EvaluateExpressionAsync<bool>(script);56 return result;57 }58 public static async Task GoToNextPage(Page page)59 {60 await page.WaitForSelectorAsync(".btn.btn-default.btn-lg");61 try62 {63 await page.EvaluateExpressionAsync("document.querySelector('.btn.btn-default.btn-lg').click()");...
ScreenshotService.cs
Source:ScreenshotService.cs
...36 }37 var browser = await GetBrowser();38 var page = await browser.NewPageAsync();39 await page.GoToAsync(uri);40 await page.WaitForExpressionAsync("arma3TacMapLoaded", new WaitForFunctionOptions() { PollingInterval = 500, Timeout = 7500 });41 var bytes = await page.ScreenshotDataAsync();42 await page.CloseAsync();43 return bytes;44 }45 private async Task<Browser> GetBrowser()46 {47 if (browserTask == null)48 {49 await semaphoreSlim.WaitAsync();50 try51 {52 if (browserTask == null)53 {54 browserTask = GetBrowserTask();...
test vueJS.csx
Source:test vueJS.csx
...55 ()=> {56 window.programDone = false;57 }58 ");59 await page.WaitForExpressionAsync("window.programDone === true", new WaitForFunctionOptions{60 Timeout = 0 // disable timeout61 });62 Console.WriteLine("Program finished triggered");63 // program is done so close everything out64 await page.CloseAsync();65 await browser.CloseAsync();66}67await waitForProgramEnd();...
PuppeteerExtensions.cs
Source:PuppeteerExtensions.cs
...24 await (await frame.QuerySelectorAsync(selector)).ClickAsync();25 }26 public static async Task WaitForTruth(this Page page, string script, WaitForFunctionOptions opts = null)27 {28 var jsHandle = await page.WaitForExpressionAsync(script, opts);29 await jsHandle.DisposeAsync();30 }31 public static async Task WaitForDocumentInteractiveState(this Page page, int? timeout = null)32 {33 await page.WaitForTruth("document.readyState === 'interactive' || document.readyState === 'complete'", new WaitForFunctionOptions { Timeout = timeout ?? page.Browser.DefaultWaitForTimeout });34 }35 }36}
WaitForExpressionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 var options = new LaunchOptions { Headless = false, SlowMo = 50 };9 var browser = await Puppeteer.LaunchAsync(options);10 var page = await browser.NewPageAsync();11 await page.WaitForSelectorAsync("input[title='Search']");12 await page.TypeAsync("input[title='Search']", "PuppeteerSharp");13 await page.Keyboard.PressAsync("Enter");14 await page.WaitForNavigationAsync();15 await page.WaitForExpressionAsync("document.querySelector('h3').textContent.includes('PuppeteerSharp')");16 Console.WriteLine("PuppeteerSharp is found!");17 await browser.CloseAsync();18 }19 }20}
WaitForExpressionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 {9 Args = new string[] { "--no-sandbox" }10 };11 using (var browser = await Puppeteer.LaunchAsync(options))12 using (var page = await browser.NewPageAsync())13 {14 await page.WaitForExpressionAsync("document.querySelector('input[name=q]').value == 'puppeteer'");15 Console.WriteLine("Page loaded");16 }17 }18 }19}
WaitForExpressionAsync
Using AI Code Generation
1var browser = await Puppeteer.LaunchAsync(new LaunchOptions2{3});4var page = await browser.NewPageAsync();5await page.WaitForExpressionAsync("document.querySelector('input[name=q]').value");6await browser.CloseAsync();7var browser = await Puppeteer.LaunchAsync(new LaunchOptions8{9});10var page = await browser.NewPageAsync();11await page.WaitForSelectorAsync("input[name=q]");12await browser.CloseAsync();13var browser = await Puppeteer.LaunchAsync(new LaunchOptions14{15});16var page = await browser.NewPageAsync();17await page.WaitForFunctionAsync("document.querySelector('input[name=q]').value");18await browser.CloseAsync();19var browser = await Puppeteer.LaunchAsync(new LaunchOptions20{21});22var page = await browser.NewPageAsync();23await page.WaitForNavigationAsync();24await browser.CloseAsync();25var browser = await Puppeteer.LaunchAsync(new LaunchOptions26{27});28var page = await browser.NewPageAsync();29await browser.CloseAsync();30var browser = await Puppeteer.LaunchAsync(new LaunchOptions31{32});
WaitForExpressionAsync
Using AI Code Generation
1var browser = await Puppeteer.LaunchAsync(new LaunchOptions2{3});4var page = await browser.NewPageAsync();5var result = await page.WaitForExpressionAsync("document.querySelector('input') != null");6if (result)7{8 Console.WriteLine("WaitForExpressionAsync succeeded");9}10{11 Console.WriteLine("WaitForExpressionAsync failed");12}13await page.CloseAsync();14await browser.CloseAsync();15var browser = await Puppeteer.LaunchAsync(new LaunchOptions16{17});18var page = await browser.NewPageAsync();19var result = await page.WaitForFunctionAsync("document.querySelector('input') != null");20if (result)21{22 Console.WriteLine("WaitForFunctionAsync succeeded");23}24{25 Console.WriteLine("WaitForFunctionAsync failed");26}27await page.CloseAsync();28await browser.CloseAsync();29var browser = await Puppeteer.LaunchAsync(new LaunchOptions30{31});32var page = await browser.NewPageAsync();33var response = await page.WaitForNavigationAsync();34if (response != null)35{36 Console.WriteLine("WaitForNavigationAsync succeeded");37}38{39 Console.WriteLine("WaitForNavigationAsync failed");40}41await page.CloseAsync();42await browser.CloseAsync();43var browser = await Puppeteer.LaunchAsync(new LaunchOptions44{45});46var page = await browser.NewPageAsync();47if (request != null)48{49 Console.WriteLine("WaitForRequestAsync succeeded");50}51{52 Console.WriteLine("WaitForRequestAsync failed
WaitForExpressionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);9 using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))10 using (var page = await browser.NewPageAsync())11 {12 await page.WaitForExpressionAsync("document.querySelector('input[name=\"q\"]').value == 'puppeteer'");13 }14 }15 }16}17using System;18using System.Threading.Tasks;19using PuppeteerSharp;20{21 {22 static async Task Main(string[] args)23 {24 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);25 using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))26 using (var page = await browser.NewPageAsync())27 {28 await page.WaitForFunctionAsync("document.querySelector('input[name=\"q\"]').value == 'puppeteer'");29 }30 }31 }32}33using System;34using System.Threading.Tasks;35using PuppeteerSharp;36{37 {38 static async Task Main(string[] args)39 {40 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);41 using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))42 using (var page = await browser.NewPageAsync())43 {44 await page.WaitForSelectorAsync("input[name=\"q\"]");45 }46 }47 }48}
WaitForExpressionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 public static async Task<string> Run()7 {8 var browser = await Puppeteer.LaunchAsync(new LaunchOptions9 {10 });11 var page = await browser.NewPageAsync();12 var result = await page.WaitForExpressionAsync("window.innerWidth < 100");13 var result2 = await page.WaitForExpressionAsync("window.innerWidth < 100", new WaitForOptions14 {15 });16 var result3 = await page.WaitForExpressionAsync(() => page.EvaluateFunctionAsync("() => window.innerWidth < 100"), new WaitForOptions17 {18 });19 await browser.CloseAsync();20 return "ok";21 }22 }23}
WaitForExpressionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 var browser = await Puppeteer.LaunchAsync(new LaunchOptions9 {10 });11 var page = await browser.NewPageAsync();12 await page.WaitForNavigationAsync();13 await page.WaitForExpressionAsync("document.readyState === 'complete'");14 await browser.CloseAsync();15 }16 }17}18using System;19using System.Threading.Tasks;20using PuppeteerSharp;21{22 {23 static async Task Main(string[] args)24 {25 var browser = await Puppeteer.LaunchAsync(new LaunchOptions26 {27 });28 var page = await browser.NewPageAsync();29 await page.WaitForNavigationAsync();
WaitForExpressionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 public static async Task Main(string[] args)7 {8 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);9 var browser = await Puppeteer.LaunchAsync(new LaunchOptions10 {11 });12 var page = await browser.NewPageAsync();13 await page.WaitForExpressionAsync("x == 5");14 Console.WriteLine("x is 5");15 await browser.CloseAsync();16 }17 }18}19using System;20using System.Threading.Tasks;21using PuppeteerSharp;22{23 {24 public static async Task Main(string[] args)25 {26 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);27 var browser = await Puppeteer.LaunchAsync(new LaunchOptions28 {29 });30 var page = await browser.NewPageAsync();31 await page.WaitForFunctionAsync("x == 5");32 Console.WriteLine("x is 5");33 await browser.CloseAsync();34 }35 }36}37using System;38using System.Threading.Tasks;39using PuppeteerSharp;40{41 {42 public static async Task Main(string[] args)43 {44 await new BrowserFetcher().DownloadAsync(BrowserFetcher.Default
Automation Testing Tutorials
Learn to execute automation testing from scratch with LambdaTest Learning Hub. Right from setting up the prerequisites to run your first automation test, to following best practices and diving deeper into advanced test scenarios. LambdaTest Learning Hubs compile a list of step-by-step guides to help you be proficient with different test automation frameworks i.e. Selenium, Cypress, TestNG etc.
LambdaTest Learning Hubs:
- JUnit Tutorial
- TestNG Tutorial
- Webdriver Tutorial
- WebDriverIO Tutorial
- Protractor Tutorial
- Selenium 4 Tutorial
- Jenkins Tutorial
- NUnit Tutorial
- Jest Tutorial
- Playwright Tutorial
- Cypress Tutorial
- PyTest Tutorial
YouTube
You could also refer to video tutorials over LambdaTest YouTube channel to get step by step demonstration from industry experts.
Run Puppeteer-sharp automation tests on LambdaTest cloud grid
Perform automation testing on 3000+ real desktop and mobile devices online.
Most used method in Page
- FrameManagerGetFrames
- workersValuesToArray
- PopupGetInvocationList
- clientDisconnected
- SetGeolocationAsync
- SetDragInterceptionAsync
- MetricsAsync
- TapAsync
- QuerySelectorAsync
- QuerySelectorAllAsync
- QuerySelectorAllHandleAsync
- XPathAsync
- EvaluateExpressionHandleAsync
- EvaluateFunctionHandleAsync
- EvaluateOnNewDocumentAsync
- EvaluateFunctionOnNewDocumentAsync
- EvaluateExpressionOnNewDocumentAsync
- QueryObjectsAsync
- SetRequestInterceptionAsync
- SetOfflineModeAsync
- EmulateNetworkConditionsAsync
- GetCookiesAsync
- SetCookieAsync
- DeleteCookieAsync
- AddScriptTagAsync
- AddStyleTagAsync
- ExposeFunctionAsync
- TResult
- GetContentAsync
- SetContentAsync
- GoToAsync
- PdfAsync
- PdfStreamAsync
- PdfDataAsync
- SetJavaScriptEnabledAsync
- SetBypassCSPAsync
- EmulateMediaAsync
- EmulateMediaTypeAsync
- EmulateMediaFeaturesAsync
- SetViewportAsync
- EmulateAsync
- ScreenshotAsync
- ScreenshotStreamAsync
- ScreenshotBase64Async
- ScreenshotDataAsync
- GetTitleAsync
- CloseAsync
- SetCacheEnabledAsync
- ClickAsync
- HoverAsync
- FocusAsync
- TypeAsync
- EvaluateExpressionAsync
- EvaluateFunctionAsync
- SetUserAgentAsync
- SetExtraHttpHeadersAsync
- AuthenticateAsync
- ReloadAsync
- SelectAsync
- WaitForTimeoutAsync
- WaitForFunctionAsync
- WaitForExpressionAsync
- WaitForSelectorAsync
- WaitForXPathAsync
- WaitForNavigationAsync
- WaitForNetworkIdleAsync
- Evaluate
- requestEventListener
- responseEventListener
- Cleanup
- WaitForRequestAsync
- WaitForResponseAsync
- WaitForFileChooserAsync
- GoBackAsync
- GoForwardAsync
- SetBurstModeOffAsync
- BringToFrontAsync
- EmulateVisionDeficiencyAsync
- EmulateTimezoneAsync
- EmulateIdleStateAsync
- EmulateCPUThrottlingAsync
- OnPopup
- InitializeAsync
- GoAsync
- ClientMessageReceived
- OnDetachedFromTarget
- OnTargetCrashed
- EmitMetrics
- HandleException
- OnDialog
- Dispose
- DisposeAsync
Try LambdaTest Now !!
Get 100 minutes of automation test minutes FREE!!
Was this article helpful?
