Add User-Agent with Playwright version to WebSocket requests

[headlesstesting (headlesstesting)]

This adds a Playwright: {version} user-agent header to WebSocket requests.

The reason why we think this PR is useful, is because for people using Playwright with our service, we can automatically determine the most compatible browser version by looking at the Playwright version string.

[Yury Semikhatsky (yury-s)]

The idea of passing version info in a header sgtm, I'm a bit concerned that this approach may not work if the client runs in a web page in the future.

[Joel Einbinder (JoelEinbinder)]

Super interesting patch!

I agree with Yury that it would be nice if this was done in a web compatible way. From my research, it looks like document.cookie or the protocols parameter in the websocket constructor can be used for this. But neither option is very clean.

I'm also interested as to why you want the version number of playwright, but not which browser (firefox, webkit, chromium) that the user wants to connect to. Do you have some other way of distinguishing these connections?

[headlesstesting (headlesstesting)]

Hi Joel Einbinder (@JoelEinbinder) , Yury Semikhatsky (@yury-s) : your comment about web compatibility makes sense.
Perhaps an alternative solution would indeed be to specify the version with the protocols parameter.

In Javascript:

var ws = new WebSocket('wss://example.com/path', ['Playwright v.x.y'])

Node:

this._ws = new WebSocket(URL, ['Playwright v.x.y'], {
      perMessageDeflate: false,
      maxPayload: 256 * 1024 * 1024, // 256Mb
});

I think this would be better than using document.cookie as that will not work with cross-domain requests?

The browser can be specified with the wsEndpoint, we provide several options:

• wss://chrome.headlesstesting.com
• wss://firefox.headlesstesting.com
• ...

[Andrey Lushnikov (aslushnikov)]

So what is the status of this? It hasn't been updated for a few months and doesn't seem to attract much interest...

headlesstesting (@headlesstesting) did you guys workaround this on your end?

[Andrey Lushnikov (aslushnikov)]

I guess it's not relevant any more :)

[headlesstesting (headlesstesting)]

Hi, we've not pursued this, perhaps at a later stage, we can come back with a new PR. Thanks!