Mini wrapper around discord API. Dependencies: snekfetch, ws. Heavily based in rylib by ry00001 (https://github.com/ry00001)

wrapper.js

const fetch = require('snekfetch')
const ws = require("ws")

var logHeartbeat = false

// Weebsocket

get('gateway').then(gateway => {
  let weebsocket = new ws(gateway.url)
  
  
  
  weebsocket.onmessage = (message) => {
    let data = JSON.parse(message.data)
    let seq = data.s
    let parsed = data.d
    
    function send(opcode, d) {
      weebsocket.send(JSON.stringify({
        op: opcode,
        d: d
      }))
    }
    
    // Hello
    
    if(data.op == 10) {
      let interval = parsed.heartbeat_interval
      console.log('Hello received, heartbeat interval is: ' + interval + 'ms')
      
      setInterval(() => {
        send(1, seq)
        logHeartbeat ? console.log('Heartbeat sent.')
                     : null
      }, interval)
      
      send(2, {
        token: process.env.TOKEN,
        "properties": {
          "$os": "linux",
          "$browser": "etzyy-wrapper",
          "$device": "etzyy-wrapper"
        },
        compress: false,
        large_threshold: 250,
        presence: {
        game: {
          name: 'oof:hi',
          type: 0
        },
        status: 'online',
        since: new Date().valueOf(),
        afk: false
        }
      })
      console.log('Identified')
      
    }
    
    // Heartbeat
    
    if(data.op == 1) {
      send(1, seq)
    }
    
    // Events
    
    if(data.op == 0) {
      
      let event = data.t
      
      // Ready
      if(event == "READY") {
        let self = parsed
        console.log(`Ready as ` + self.user.username + ` (${self.user.id})`)
      }
      
      // Message
      if(event == "MESSAGE_CREATE") {
        let msg = parsed
        
        if(msg.content == "oof:hi") {
          send_message(msg.channel_id, 'Hoi!')
          react_message(msg.channel_id, msg.id, '👋')
        }
        
      }
    }
  }
  
  weebsocket.onclose = (why) => {
    console.log(`Disconnected to websocket: ${why.reason}. Terminating process...`)
    
    process.exit()
  }
  
  weebsocket.onopen = () => {
    console.log('Connected to websocket')
  }
})

// REST

async function get(endpoint, headers={}) {
  let url = 'https://discordapp.com/api/v6/' + endpoint
  headers.Authorization = 'Bot ' + process.env.TOKEN
  let req = await fetch.get(url, {headers: headers})
  return req.body
}

async function post(endpoint, headers={}, data) {
  let url = 'https://discordapp.com/api/v6/' + endpoint
  headers.Authorization = 'Bot ' + process.env.TOKEN
  let req = await fetch.post(url, {headers: headers}).send(data)
  return req.body
}

async function put(endpoint, headers={}, data={}) {
  let url = 'https://discordapp.com/api/v6/' + endpoint
  headers.Authorization = 'Bot ' + process.env.TOKEN
  let req = await fetch.put(url, {headers: headers}).send(data)
  return req.body
}

async function del(endpoint, headers={}) {
  let url = 'https://discordapp.com/api/v6/' + endpoint
  headers.Authorization = 'Bot ' + process.env.TOKEN
  let req = await fetch.delete(url, {headers: headers})
  return req.body
}

async function send_message(channel_id, content) {
  return await post(`channels/${channel_id}/messages`, {}, {content: content})
}

async function react_message(channel_id, message_id, unicode_emoji) {
  return await put(`/channels/${channel_id}/messages/${message_id}/reactions/${unicode_emoji}/@me`)
}