WebSocketStream is not a shipped API so normally we wouldn't announce changes, but I know some people are trying it out using the experimental flag, so I am sending this PSA.
From Chromium version 117.0.5914.0 onwards, the "connection" attribute has been renamed to "opened".
Where previously you would have written
const { readable, writable, protocol, extensions } = await wss.connection;
now you should write:
const { readable, writable, protocol, extensions } = await wss.opened;
This change was made for alignment with the Direct Sockets API.
Shipping WebSocketStream is currently stalled on the standardisation process. We don't yet have a concrete timeline for when it will be shipped.