app.js

const Discord = require('discord.js'); // remember to install discord.js via: npm install discord.js
const bot = new Discord.Client();
const token = "TOKEN" // to get your token go here: https://discordapp.com/developers/applications/me/
// don't share the token with anyone.

// Bot connexion
bot.on("ready", function () {

	console.log("The bot is online!");

    // Removes every game roles when the bot logs in
    bot.guilds.forEach(function(guild) { // For each guild
        guild.members.forEach(function(member) { // For each member
            member.roles.forEach(function(role) { // For each role
                if(role.name.startsWith("🎮 ")) {member.removeRole(role)} // If the role name starts with a controller, removes it
            });
        });
    });

});

// Bot disconnection
bot.on("disconnect", function () {
	console.log("Disconnected...");
});


// Feature : The bot gives members a role depending the game they are currently playing
bot.on("presenceUpdate", (oldMember, newMember) => {

    var guild = newMember.guild;

    if (newMember.user.presence.game) {

        // Removes every previous game roles
        newMember.roles.forEach(function(role) {
            if(role.name.startsWith("🎮 ")) {newMember.removeRole(role)}
        });

        var gamename = newMember.user.presence.game.name;

        if (gamename.startsWith("Counter-Strike")) { // EX : Specific to Counter-Strike : Global Offensive, because it's too long to create a role with this name
            newMember.addRole(guild.roles.find("name","🎮 Counter-Strike"))
                .then(function() {
                    console.log(`Role : Counter-Strike given to ${newMember.user.username}`);
                },function(e) {
                    console.error(e);
                });
        }
	    /*     
	    You've gotta make the role below.
	    The bot dosen't make it by its self
	    If the role is not there, it won't assign it. 
	    */
		    else { // If a role "🎮 [name]" exists, gives it
            var newrole = guild.roles.find("name",`🎮 ${gamename}`);
            if (newrole) {
                newMember.addRole(guild.roles.find("name",`🎮 ${gamename}`))
                    .then(function() {
                        console.log(`Role : ${gamename} given to ${newMember.user.username}`);
                    },function(e) {
                        console.error(e);
                    });
            }
        }
    }
    else if (!newMember.user.presence.game) {
        newMember.roles.forEach(function(role) {
            if(role.name.startsWith("🎮 ")) {newMember.removeRole(role)}
        });
    }

});

bot.login(token);