Discord Bot using Eris

const bot = new Eris();

bot.on("ready", () => {
  console.log("connected");
});

const WebSocket = require("ws");

require("dotenv").config();
const token = process.env.BOT_TOKEN;

const baseUrl = "wss://gateway.discord.gg";
const queryParams = "?v=10&encoding=json";
const gatewayUrl = `${baseUrl}${queryParams}`;

const ws = new WebSocket(gatewayUrl);

ws.on("open", () => {
  console.log('Socket opened. Initializing connection ...');
})

ws.on("message", e => {
  const msg = JSON.parse(e.toString());
  const { op, t, s, d } = msg; // the arguments of the message sent by discord

  // s stands for 'sequence'. this is a number used to keep track of our 'conversation' and we use it to 'acknowledge' messages
  if (s) {
    last_sequence = s;
  } 

  // confirm that connection is established - start heartbeat interval
  switch (op) {
    case 10: {
      console.log(`Received opcode 10`);
      // d stands for 'data'
      heartBeatIntervalMS = d.heartbeat_interval;
      heartbeat = startHeartbeat(ws, last_sequence, heartBeatIntervalMS);
      sendIdentify(ws);
      break;
    }
  }
})

1const startHeartbeat = (socket, sequence, interval) => {
2  const int = setInterval(() => {
3    if (socket.readyState !== WebSocket.OPEN) return;
4    const d = sequence || null;
5    const payload = { op: 1, d };
6    socket.send(JSON.stringify(payload));
7    console.log('heartbeat sent');
8  }, interval);
9
10  return int;
11}

1const sendIdentify = (socket, token) => {
2  const payload = {
3    op: 2,
4    d: {
5      token,
6      intents:
7        INTENTS.GUILDS |
8        INTENTS.GUILD_MESSAGES |
9        INTENTS.GUILD_MESSAGE_REACTIONS |
10        INTENTS.DIRECT_MESSAGES |
11        INTENTS.DIRECT_MESSAGE_REACTIONS,
12      properties: {
13        os: "macintosh",
14        device: "pc"
15      }
16    }
17  };
18
19  socket.send(JSON.stringify(payload));
20}

1const INTENTS = {
2  GUILDS: 1 << 0,
3  GUILD_PRESENCES: 1 << 8,
4  GUILD_MESSAGES: 1 << 9,
5  GUILD_MESSAGE_REACTIONS: 1 << 10,
6  DIRECT_MESSAGES: 1 << 12,
7  DIRECT_MESSAGE_REACTIONS: 1 << 13,
8};

1const Eris = require("eris");
2require("dotenv").config();
3
4const bot = new Eris.CommandClient(
5  `Bot ${process.env.BOT_TOKEN}`,
6  {
7    intents: [
8      "guilds",
9      "guildMessages",
10      "messageContent",
11      "directMessages",
12    ],
13  },
14  { prefix: "!" }
15);
16
17bot.on("ready", () => {
18  console.log("Bot is connected and ready.");
19});
20
21bot.on("messageCreate", (msg) => {
22  if (msg.author.bot) return;
23
24  if (msg.content === "!echo") {
25    bot.createMessage(msg.channel.id, "receiving");
26  }
27});
28
29bot.connect();

1bot.on("ready", async () => {
2  console.log("Bot is connected and ready.");
3
4  await bot.createCommand({
5    name: "ping",
6    description: "Replies with Pong!",
7    type: Eris.Constants.ApplicationCommandTypes.CHAT_INPUT,
8  });
9
10  await bot.createCommand({
11    name: "hello",
12    description: "Greets you with your username.",
13    type: Eris.Constants.ApplicationCommandTypes.CHAT_INPUT,
14  });
15});

1bot.on("interactionCreate", async (interaction) => {
2  if (interaction instanceof Eris.CommandInteraction) {
3    const commandName = interaction.data.name;
4
5    if (commandName === "ping") {
6      await interaction.createMessage("Pong!");
7    }
8
9    if (commandName === "hello") {
10      const user = interaction.member?.user ?? interaction.user;
11      await interaction.createMessage(`Hello, ${user.username}!`);
12    }
13  }
14});