Literally the simplest Discord bot.

config.json

{
  "token": "test token"
}

index.js

const Discord = require('discord.js');
const config = require('./config.json');

const client = new Discord.client();

client.on('message', msg => {
  console.log(`[${msg.createdAt}] ${msg.author}: ${msg.content}`);
});

client.login(config.token);

package.json

{
  "name": "test-bot",
  "dependencies": {
    "discord.js": "^10.0.1"
  }
}