🐛 BUG: Durable Objects: ws argument in webSocketClose() handler is invalid

[majames]

Which Cloudflare product(s) does this pertain to?

Other

What version(s) of the tool(s) are you using?

wrangler@npm:3.60.3, @cloudflare/next-on-pages@npm:1.11.3

What version of Node are you using?

20.13.1

What operating system and version are you using?

MacOS

Describe the Bug

Observed behavior

In development when I log the ws passed to webSocketClose the result is:

WebSocket { extensions: '', protocol: '', url: null, readyState: 2 }

Expected behavior

The ws passed to the close handler to have the correct url.

Steps to reproduce

  async webSocketClose(ws: WebSocket) {
    console.log(ws);
  }

At this stage it's unclear to me whether this is also an issue when in prod (i.e. running on cloudflare)

[threepointone]

This is a tricky one. The WebSocket standard was based on the idea that it would be used from a browser, created with new WebSocket(url), However, inside durable objects, they're created with new WebSocketPair() to connect an incoming connection with itself, and doesn't have a URL per se (or doesn't have to be "truthful" about the incoming connection url, since you can use an URL to connect to a DO via .fetch()).

If you need to attach a url to the websocket (and have it persist through hibernation), a workaround here could be to use .serializeAttachment() to attach some state.

I'll transfer this to the workerd repo since that's where any changes would be made, let's see what the team says there.

[MellowYarker]

I'm inclined to agree with @threepointone. It's not really clear when we would set it on the server side with new WebSocketPair() and the URL you use to connect to a Durable Object doesn't need to be the same as the URL used to connect to the Worker. Using .serializeAttachment() sounds like the right approach here.

[majames]

Thank you both for your clear responses. In my case I was able to retrieve the data I needed from the associated websocket via getTags().

The serializeAttachment() also sounds like a great approach if i didn't already have the required data in a tag. Thanks!