bfx-api-node-core/lib/ws2/open.js

Core Bitfinex Node API

'use strict'

const debug = require('debug')('bfx:api:ws2:open')
const { EventEmitter } = require('events')
const WebSocket = require('ws')
const { WS_URL } = require('../config')
const bindEV = require('./bind_ev')

/**
 * Opens a websocket connection to the provided Bitfinex API URL and prepares
 * an event emitter to capture and report API stream events.
 *
 * @param {string?} url - defaults to production Bitfinex WSv2 API url
 * @param {Object?} agent - connection agent
 * @return {Object} connectionState - see @initState
 */
const open = (url = WS_URL, agent) => {
  debug('connecting to %s...', url)

  const ws = new WebSocket(url, { agent })
  const ev = new EventEmitter()

  ev.setMaxListeners(1000)

  bindEV({ ws, ev })

  return { ws, ev }
}

module.exports = open