minimal-discord-deno-connection.js

const ws = new WebSocket(`wss://gateway.discord.gg/?v=8&encoding=json`)

const ONCE = {}
const ON = {}
let s = null
let heartbeatAc
const heartbeat = () => {
  console.log('heartbeat')
  heartbeatAc = setTimeout(() => {
    console.log('the client was ZOMBIFED')
    console.log('TODO: try too reconnect+resume!')
    Deno.exit(1)
  }, 1000)
  ws.send(JSON.stringify({ op: 1, d: s }))
}

ws.addEventListener('close', (event) => {
  console.log(event)
  Deno.exit(1)
})

ws.addEventListener('message', (event) => {
  const { t, s, op, d } = JSON.parse(event.data)
  switch (op) {
    case 0: // DISPATCH
      const on = ON[t]
      const once = ONCE[t]
      if (!on) return
      for (const fn of on) fn(d)
      for (const fn of once) fn(d)
      once.clear()
      return
    case 1: // HEARTBEAT
      return heartbeat()
    case 2: // IDENTIFY
      return console.log('IDENTIFY', d)
    case 3: // STATUSUPDATE
      return console.log('STATUSUPDATE', d)
    case 4: // VOICESTATEUPDATE
      return console.log('VOICESTATEUPDATE', d)
    case 6: // RESUME
      return console.log('RESUME', d)
    case 7: // RECONNECT
      return console.log('RECONNECT', d)
    case 8: // REQUESTGUILDMEMBERS
      return console.log('REQUESTGUILDMEMBERS', d)
    case 9: {
      // INVALIDSESSION
      console.log('Invalid Session, verify your token')
      Deno.exit(1)
    }
    case 10: // HELLO
      ws.send(
        JSON.stringify({
          op: 2, // IDENTIFY
          d: {
            token: Deno.env.get('BOT_TOKEN'),
            intents: 1 << 1, // GUILD_MEMBERS
            properties: { $os: 'linux', $browser: 'janus', $device: 'janus' },
          },
        }),
      )
      setInterval(heartbeat, d.heartbeat_interval)
      return
    case 11: // HEARTBEATAC
      return clearTimeout(heartbeatAc)
    default:
      console.log(`OP_${op}`, d)
  }
})

const eventTypes = [
  //'APPLICATION_COMMAND_CREATE',
  //'CHANNEL_CREATE',
  //'CHANNEL_DELETE',
  //'CHANNEL_UPDATE',
  //'GUILD_CREATE',
  //'GUILD_DELETE',
  //'GUILD_UPDATE',
  //'GUILD_BAN_ADD',
  //'GUILD_BAN_REMOVE',
  //'GUILD_EMOJIS_UPDATE',
  //'GUILD_MEMBER_ADD',
  //'GUILD_MEMBER_REMOVE',
  'GUILD_MEMBER_UPDATE',
  //'GUILD_MEMBERS_CHUNK',
  //'GUILD_ROLE_CREATE',
  //'GUILD_ROLE_DELETE',
  //'GUILD_ROLE_UPDATE',
  //'INTERACTION_CREATE',
  //'MESSAGE_CREATE',
  //'MESSAGE_DELETE',
  //'MESSAGE_DELETE_BULK',
  //'MESSAGE_UPDATE',
  //'MESSAGE_REACTION_ADD',
  //'MESSAGE_REACTION_REMOVE',
  //'MESSAGE_REACTION_REMOVE_ALL',
  //'MESSAGE_REACTION_REMOVE_EMOJI',
  //'PRESENCE_UPDATE',
  'READY',
  //'TYPING_START',
  //'USER_UPDATE',
  //'VOICE_STATE_UPDATE',
  //'WEBHOOKS_UPDATE',
]

const janus = { once: {}, on: {} }
for (const type of eventTypes) {
  const on = (ON[type] = new Set())
  const once = (ONCE[type] = new Set())
  const next = (fn) => once.add(fn)
  janus.on[type] = (fn) => on.add(fn)
  janus.once[type] = () => new Promise(next)
}

await janus.once.READY()
console.log('ready!')

janus.on.GUILD_MEMBER_UPDATE(({ user, roles }) => {
  console.log(user.id, 'has', roles.length, 'roles')
})