fuc-new/doc/node_modules/undici/docs/docs/api/WebSocket.md

Class: WebSocket

Extends: EventTarget

The WebSocket object provides a way to manage a WebSocket connection to a server, allowing bidirectional communication. The API follows the WebSocket spec and RFC 6455.

new WebSocket(url[, protocol])

Arguments:

• url URL | string
• protocol string | string[] | WebSocketInit (optional) - Subprotocol(s) to request the server use, or a Dispatcher.

Example:

This example will not work in browsers or other platforms that don't allow passing an object.

import { WebSocket, ProxyAgent } from 'undici'

const proxyAgent = new ProxyAgent('my.proxy.server')

const ws = new WebSocket('wss://echo.websocket.events', {
  dispatcher: proxyAgent,
  protocols: ['echo', 'chat']
})

If you do not need a custom Dispatcher, it's recommended to use the following pattern:

import { WebSocket } from 'undici'

const ws = new WebSocket('wss://echo.websocket.events', ['echo', 'chat'])

Class: WebSocketStream

⚠️ Warning: the WebSocketStream API has not been finalized and is likely to change.

See MDN for more information.

new WebSocketStream(url[, protocol])

Arguments:

• url URL | string
• options WebSocketStreamOptions (optional)

WebSocketStream Example

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

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

  while (true) {
    const { done, value } = await reader.read()
    if (done) break

    // do something with value
  }
}

async function write () {
  /** @type {WritableStreamDefaultWriter} */
  const writer = writable.getWriter()
  writer.write('Hello, world!')
  writer.releaseLock()
}

read()

setInterval(() => write(), 5000)

ping(websocket, payload)

Arguments:

• websocket WebSocket - The WebSocket instance to send the ping frame on
• payload Buffer|undefined (optional) - Optional payload data to include with the ping frame. Must not exceed 125 bytes.

Sends a ping frame to the WebSocket server. The server must respond with a pong frame containing the same payload data. This can be used for keepalive purposes or to verify that the connection is still active.

Example:

import { WebSocket, ping } from 'undici'

const ws = new WebSocket('wss://echo.websocket.events')

ws.addEventListener('open', () => {
  // Send ping with no payload
  ping(ws)

  // Send ping with payload
  const payload = Buffer.from('hello')
  ping(ws, payload)
})

Note: A ping frame cannot have a payload larger than 125 bytes. The ping will only be sent if the WebSocket connection is in the OPEN state.

Read More

• MDN - WebSocket
• The WebSocket Specification
• The WHATWG WebSocket Specification