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

Playwright recommends to use their assertions, since they retry until either the timeout is reached or the condition is met.

Normal assertions like Assert.Equal don't retry.

See here: https://playwright.dev/dotnet/docs/test-assertions#locator-assertions-to-have-text

For your use-case it would be the following:

var locator = Page.Locator(".title");
await Expect(locator).ToHaveTextAsync("Welcome, Test User");

Your page might be recreating the DOM. To overcome that you can use the locator feature from playwright.

var locator = page.Locator("inputSelector");
await locator.ClickAsync();

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;
}
}

You can use the selecting selectors based on layout for this.

await page.Locator("span:below(:text(\" Status :\"))").TextContentAsync()

# 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>

# 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.)

Playwright for .NET discourages using xunit see here. Also the playwright.config file does only work for Node.js.

I'd recommend to set the DEBUG=pw:api env var to get more logs. Most likely your site is not reachable or hangs.

Found the issue: I was running Visual Studio without admin privileges. Once I chose, "Run as administrator", the local MS Edge launched and the test succeeded. Apparently, Playwright needs elevated rights to launch the Channel local browsers vs. its own binaries, at least on some setups.

I wish, though, that Playwright could launch the stock browsers without having to have elevated privs.