How to use PageWaitForWorkerOptions method of Microsoft.Playwright.PageWaitForWorkerOptions class

Using ideas from comments on my answer I was able to accomplish the goal. I ended up passing a cancellation token to a Task.Delay(30000, token). Then if I got the data I wanted and set the result value, I just cancelled the token.

string? result = null;
var tokenSource = new CancellationTokenSource();
var cancelToken = tokenSource.Token;

// Start listening for new pages (ClickAsync below opens in a new page)
context.Page += (_, newPage) =>
{
  // From the new page, start listening for requests that page generates
  newPage.Request += async (_, request) =>
  {
    if (request.Url.Contains("some_identifier"))
    {
      await newPage.GotoAsync(request.Url);
      result = await newPage.InnerTextAsync("body");
      tokenSource.Cancel(); // <-- Got what we needed, cancel 30 second timer
    }
  };
};

await mainPage.Locator("a#somelink").ClickAsync();

try {
  await Task.Delay(30000, cancelToken); // <-- Timeout after 30 seconds.
}
catch
{
  // Not a fan of tokenSource.Cancel() throwing an exception, but I can deal with it.
}

return result;

I ended up raising a bug and it seems others had the same issue

https://github.com/microsoft/playwright-dotnet/issues/1841

So I resolved this with the following logic.

I created two variables:

1. List<string> downloadedFiles = new List<string>();
2. List<string> fileDownloadSession = new();

I then created a method to add as a handler to the page.Download that looks like this:

private async void downloadHandler(object sender, IDownload download)
{
    fileDownloadSession.Add("Downloading...");
    var waiter = await download.PathAsync();
    downloadedFiles.Add(waiter);
    fileDownloadSession.Remove(fileDownloadSession.First());
}

Afterwards, I created a public method to get the downloaded files that looks like this:

public List<string> GetDownloadedFiles()
{
    while (fileDownloadSession.Any())
    {
        
    }
    
    var downloadedFilesList = downloadedFiles;
    downloadedFiles = new List<string>();
    return downloadedFilesList;
}

All these methods and planning are in a separate class of their own so that they can monitor the downloaded files properly, and also to freeze the main thread so it can grab all of the required files.

All in all it seems just as sketchy of a solution, similarly to how you would implement it in Selenium, nothing much has changed in terms of junkyard implementations in the new frameworks.

You can find my custom class here: https://paste.mod.gg/rztmzncvtagi/0, enjoy, there is no other topic that answers this specific question for playwright on C#.

Code here, in case it gets deleted from paste.mod.gg:

using System.Net;
using System.Runtime.InteropServices.JavaScript;
using Flanium;
using FlaUI.UIA3;
using Microsoft.Playwright;
using MoreLinq;
using Polly;

namespace Fight;

public class WebBrowser
{
    private IBrowser _browser;
    private IBrowserContext _context;
    private IPage _page;
    private bool _force;
    private List<string> downloadedFiles = new List<string>();
    private List<string> fileDownloadSession = new();

    public void EagerMode()
    {
        _force = true;
    }
    
    public enum BrowserType
    {
        None,
        Chrome,
        Firefox,
    }

    public IPage GetPage()
    {
        return _page;
    }
    public WebBrowser(BrowserType browserType = BrowserType.Chrome, bool headlessMode = false)
    {
        var playwright = Playwright.CreateAsync().Result;

        _browser = browserType switch
        {
            BrowserType.Chrome => playwright.Chromium.LaunchAsync(new BrowserTypeLaunchOptions {Headless = headlessMode}).Result,
            BrowserType.Firefox => playwright.Firefox.LaunchAsync(new BrowserTypeLaunchOptions {Headless = headlessMode}).Result,
            _ => null
        };

        _context = _browser.NewContextAsync().Result;
        _page = _context.NewPageAsync().Result;
        _page.Download += downloadHandler;
        
        Console.WriteLine("WebBrowser was successfully started.");
    }

    private async void downloadHandler(object sender, IDownload download)
    {
        fileDownloadSession.Add("Downloading...");
        var waiter = await download.PathAsync();
        downloadedFiles.Add(waiter);
        fileDownloadSession.Remove(fileDownloadSession.First());
    }
    
    public List<string> GetDownloadedFiles()
    {
        while (fileDownloadSession.Any())
        {
            
        }
        
        var downloadedFilesList = downloadedFiles;
        downloadedFiles = new List<string>();
        return downloadedFilesList;
    }
    
    
    public void Navigate(string url)
    {
        _page.GotoAsync(url).Wait();
    }

    public void Close(string containedURL)
    {
        var pages = _context.Pages.Where(x => x.Url.Contains(containedURL));
        if (pages.Any())
            pages.ForEach(x => x.CloseAsync().Wait());
    }





    public IElementHandle Click(string selector, int retries = 15, int retryInterval = 1)
    {
        var element = Policy.HandleResult<IElementHandle>(result => result == null)
            .WaitAndRetry(retries, interval => TimeSpan.FromSeconds(retryInterval))
            .Execute(() =>
            {
                var element = FindElement(selector);
                if (element != null)
                {
                    try
                    {
                        element.ClickAsync(new ElementHandleClickOptions() {Force = _force}).Wait();
                        element.DisposeAsync();
                        return element;
                    }
                    catch (Exception e)
                    {
                        return null;
                    }
                }

                return null;
            });
        
        return element;
    }

    public IElementHandle FindElement(string selector)
    {
        IElementHandle element = null;

        var Pages = _context.Pages.ToArray();

        foreach (var w in Pages)
        {
            //============================================================
            element = w.QuerySelectorAsync(selector).Result;
    

    if (element != null)
        {
            return element;
        }

        //============================================================
        var iframes = w.Frames.ToList();
        var index = 0;

        for (; index < iframes.Count; index++)
        {
            var frame = iframes[index];

            
            element = frame.QuerySelectorAsync(selector).Result;
            if (element is not null)
            {
                return element;
            }

            var children = frame.ChildFrames;

            if (children.Count > 0 && iframes.Any(x => children.Any(y => y.Equals(x))) == false)
            {
                iframes.InsertRange(index + 1, children);
                index--;
            }
        }
    }

    return element;
}
}

# Install the CLI once.
dotnet tool install --global Microsoft.Playwright.CLI
# Install the browsers
playwright install

(The current error description is a bug in 1.14, it gets fixed with 1.15.)

With Visual Studio projects you can add post-build-events, which will run on you dev machine and in the Azure Pipeline during a build (tested with VSBuild@1)

Example using the VS UI: (you will need to adjust paths for ubuntu)

echo $(TargetDir).playwright\node\win32_x64\playwright.cmd install
$(TargetDir).playwright\node\win32_x64\playwright.cmd install
echo Done

or adding directly to a .csproj

  <Target Name="PostBuild" AfterTargets="PostBuildEvent">
    <Exec Command="echo $(TargetDir).playwright\node\win32_x64\playwright.cmd install;$(TargetDir).playwright\node\win32_x64\playwright.cmd install;echo Done" />
  </Target>

According to their documentation it should be possible. I see you are using StorageState maybe try StorageStatePath instead. Their example:

var context = await browser.NewContextAsync(new()
{
    StorageStatePath = "userCookies.json"
});

https://playwright.dev/dotnet/docs/auth

It's not clear from their documentation, and I never used this library before and could be wrong, but I believe StorageState expects the stringified JSON and not a file path. While StorageStatePath expects a file path / file name to the JSON and will read the file for you.

https://www.javadoc.io/static/com.microsoft.playwright/playwright/1.12.1/com/microsoft/playwright/Browser.NewContextOptions.html#storageState

Using ideas from comments on my answer I was able to accomplish the goal. I ended up passing a cancellation token to a Task.Delay(30000, token). Then if I got the data I wanted and set the result value, I just cancelled the token.

string? result = null;
var tokenSource = new CancellationTokenSource();
var cancelToken = tokenSource.Token;

// Start listening for new pages (ClickAsync below opens in a new page)
context.Page += (_, newPage) =>
{
  // From the new page, start listening for requests that page generates
  newPage.Request += async (_, request) =>
  {
    if (request.Url.Contains("some_identifier"))
    {
      await newPage.GotoAsync(request.Url);
      result = await newPage.InnerTextAsync("body");
      tokenSource.Cancel(); // <-- Got what we needed, cancel 30 second timer
    }
  };
};

await mainPage.Locator("a#somelink").ClickAsync();

try {
  await Task.Delay(30000, cancelToken); // <-- Timeout after 30 seconds.
}
catch
{
  // Not a fan of tokenSource.Cancel() throwing an exception, but I can deal with it.
}

return result;

The author is available via:

var author = (string)TestContext.CurrentContext.Test.Properties.Get("Author");

If there are multiple Author attributes, this will retrieve the first one. If you want to see them all, use

var authors = (IList)TestContext.CurrentContext.Test.Properties["Author"];

# Install the CLI once.
dotnet tool install --global Microsoft.Playwright.CLI
# Install the browsers
playwright install

(The current error description is a bug in 1.14, it gets fixed with 1.15.)