command.js

const { readdirSync } = require("fs")

module.exports = (client) => {
    const load = dirs => {
        const commands = readdirSync(`./commands/${dirs}/`).filter(d => d.endsWith('.js'));
        for (let file of commands) {
            let pull = require(`../commands/${dirs}/${file}`);
            client.commands.set(pull.config.name, pull);
            if (pull.config.aliases) pull.config.aliases.forEach(a => client.aliases.set(a, pull.config.name));
          };
        };
       readdirSync('./commands/').forEach(x => load(x));
};

event.js

const { readdirSync } = require("fs")

module.exports = (client) => {
    const load = dirs => {    
        const events = readdirSync(`./events/${dirs}/`).filter(d => d.endsWith('.js'));
        for (let file of events) {
            const evt = require(`../events/${dirs}/${file}`);
            let eName = file.split('.')[0];
            client.on(eName, evt.bind(null, client));
          };
        };
        readdirSync('./events/').forEach(x => load(x));
};

index.js

const { Client, Collection } = require("discord.js");
const { token } = require("./config.js");
const client = new Client();

["aliases", "commands"].forEach(x => client[x] = new Collection());
["command", "event"].forEach(x => require(`./utilities/${x}`)(client));

client.login(token);