feat: implement WebSocketStream

[KhafraDev]

With better-organized internals, this is now much easier and almost completely detached from WebSocket. I could rewrite it to be completely independent of WebSocket, which would allow us to remove it at any time (the only shared internals are a new getURLRecord function and the closing logic).

const stream = new WebSocketStream('https://echo.websocket.org/')
const { readable, writable } = await stream.opened

;(async () => {
  /** @type {ReadableStreamReader} */
  const reader = readable.getReader()

  while (true) {
    const { done, value } = await reader.read()
    if (done) break
    console.log('received message', { value })
  }
})();

setInterval(() => {
  console.log('sending message.')
  /** @type {WritableStreamDefaultWriter} */
  const writer = writable.getWriter()

  writer.write('Hello, world!')

  writer.releaseLock()
}, 5000)

[KhafraDev]

@nodejs/undici This passes the same subset of WebSocketStream tests that Deno passes. It's missing types and docs now. Looking for code reviews before doing the trivial stuff.

[Uzlopak]

couldnt we reuse the already created deferred promise?

return promise.reject(e)
?

[Uzlopak]

I wanted to test the WebSocketError thing i mentioned above and found this.

const { WebSocketError } = require('./lib/web/websocket/stream/websocketerror');

console.log(Object.keys(new WebSocketError('asd')));

It is not possible to instantiate WebSocketError by requiring the file alone.

[KhafraDev]

@tsctx @Uzlopak PTAL.

[KhafraDev]

I wanted to test the WebSocketError thing i mentioned above and found this.

A limitation of cjs - there isn't much we can do about shared webidl declarations. If we moved them to webidl.js, we'd have circular imports, if we move them to another file, we have to import another file. You can const { WebSocketError } = require('.') instead. (once I export it... although I'd be willing to bet it's bug-free)

[tsctx]

Suggested change

	chunk = new Uint8Array(data.buffer, data.byteOffset, data.byteLength)
	chunk = data.byteLength === data.buffer.byteLength ? new Uint8Array(data.buffer, data.byteOffset, data.byteLength) : new Uint8Array(data)

Copy buffer if needed.

.

[KhafraDev]

please approve so I can land... nits can wait, this is experimental

I want to make websocket PRs but I don't want to manage multiple branches at once. ty