const Discord = require('discord.js');
const bot = new Discord.Client();
const token = "YOUR TOKEN";
const PREFIX = "!";

const fs = require('fs');
bot.commands = new Discord.Collection();

const commandFiles = fs.readdirSync('./commands/').filter(file => file.endsWith('.js'));
for(const file of commandFiles){
    const command = require(`./commands/${file}`);

    bot.commands.set(command.name, command);
}

bot.on('ready', () => {
    console.log("The bot is active and ready to go!");
});

bot.on('message', message => {
    let args = message.content.substring(PREFIX.length).split(" ");

    switch (args[0]) {

        case "ping":
            bot.commands.get('ping').execute(message, args);
        break;

        case "hello":
            bot.commands.get('hello').execute(message, args);
        break;
    }

});

bot.login(token);

----- Command JS File -----
module.exports = {
    name: 'ping',
    description: "says ping!",
    execute(message, args){
        message.channel.send('pong!');
    }
}