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.