[🚀 Feature]: [dotnet] [bidi] Expose BiDi to be truly public low-level API

[nvborisenko]

Description

Now we hide some BiDi API from users (via internal modifier) because we want to hide the complexity of its usage. Great example is network interception: this operation requires to phases: AddIntercept and Subscribe on events. So right now we provide useful API for users to guide them to do the interception properly.

From one point of view Selenium tries to help users, but from other hand the question is why Selenium hides some BiDi spec defined capabilities.

Solution

• Revisit all internal modifiers and make it public
• Move all "helpers/extensions" to OpenQA.Selenium.BiDi.Extensions namespace

Usage

Now user will get all power of spec defined methods. If user starts typing bidi.Network.interce he will be promoted to use:

• AddInterceptAsync native low-level method
• InterceptRequestAsync/InterceptResponseAsync extension methods safe to do the interception properly

Note

There is:

context.Network.IntercepRequestAsync()

If we choose extensions .net model, then properties cannot be extensions. I guess we can mitigate it via flatten methods from all modules, like:

context.InterceptRequestAsync()

It is even simpler, and it even removes extra class.

Have you considered any alternatives or workarounds?

No response

[selenium-ci]

@nvborisenko, thank you for creating this issue. We will troubleshoot it as soon as we can.

Selenium Triage Team: remember to follow the Triage Guide

[nvborisenko]

I don't have arguments why low-level API should hide some methods. So decision will be just reveal it. Any hidden knowledge about its usage can be easily negotiated via documentation (for advanced users). In any case for us it means just follow BiDi spec without headache and hidden stones.

[ddepta-easyjet]

Hi @selenium-ci, @nvborisenko! When exactly can we expect to have this BiDi exposed for C#?

[nvborisenko]

@ddepta-easyjet it is already available for you. Start your journey with await using var bidi = await driver.AsBiDiAsync() and share feedback. BiDi namespace is still under construction, we are focusing on landing the basics to avoid any breaking changes in the future.

[ddepta-easyjet]

@nvborisenko Thanks for the update - I’ve just tried the await using var bidi = await driver.AsBiDiAsync() entry point and it works fine. That said, my main use case is intercepting requests - specifically modifying or mocking responses. From what I can see so far, it looks like only passive listening to request events is currently available, right?
Could you confirm whether full request interception (including response modification) is already supported?
If yes, could you kindly share a short code snippet showing how to achieve that in C# via the BiDi API?
Thanks again for the great work - really excited about where this is heading!

[nvborisenko]

Warning

This is just an example of API how it is implemented in v4.32. BiDi/.NET is still in beta and might be changed at any time.

Full example:

using OpenQA.Selenium.BiDi;
using OpenQA.Selenium.BiDi.Modules.BrowsingContext;
using OpenQA.Selenium.BiDi.Modules.Network;
using OpenQA.Selenium.Chrome;

using var driver = new ChromeDriver(new ChromeOptions { UseWebSocketUrl = true });

await using var bidi = await driver.AsBiDiAsync();

var context = (await bidi.BrowsingContext.GetTreeAsync())[0].Context;

await bidi.Network.InterceptRequestAsync(async req =>
{
    if (req.Request.Url.EndsWith(".png"))
    {
        await req.ProvideResponseAsync(new()
        {
            Body = new Base64BytesValue(Convert.ToBase64String(await File.ReadAllBytesAsync("smile.png")))
        });
    }
    else
    {
        await req.ContinueAsync();
    }
});

await context.NavigateAsync("https://www.selenium.dev", new() { Wait = ReadinessState.Complete });

Result:

[ddepta-easyjet]

Hi @nvborisenko, thank you for providing a working example! :) it's fine on my local, however once I trigger this tests via BrowserStack the test is not even able to navigate to the very first page (despite having seleniumBidi capability set to true and UseWebSocketUrl set to true as well), but I guess it's a topic for BS Support Team, not Selenium :)

[nvborisenko]

But from other point of view I understood why I hide AddIntercept method: this method doesn't make sense as standalone, without subscribing and filtering further events. This was a strong point just to make it internal and provide a composition InterceptRequest/InterceptResponse/InterceptAuth. One simple method which prevents a lot of mistakes.

So looks good as is, revoking my feature request. Currently there are no issues.