bot.js

// Get the discord.js library, and assign it to a variable
// If Discord.JS is not installed, hit the WINDOWS+R keys, and type CMD
// use the CD command to change to the directory where your bot is
// ex: CD C:\Programs\MyDiscordBot
// then: npm install discord.js --save
// If Node.JS is not installed install it from https://nodejs.org/
// run bot with the command from CMD (in the directory the bot files are in): node bot.js
// or if you have sharder.js, use: node sharder.js
const Discord = require('discord.js');

// Initiate the discord client
const client = new Discord.Client();

// Bot token
// Get from your bot application
// https://discordapp.com/developers/applications/me
const token="BOT_TOKEN";

// Bot Prefix
const prefix="!";

// Changes the bots activity message between these every five seconds
setInterval(() => {
	// Changes the bots status to "Watching ${client.guilds.size} Guilds"
	// client.guilds.size = total count of guilds the bot is in
	// Function: https://discord.js.org/#/docs/main/stable/class/ClientUser?scrollTo=setActivity
	// Type Values: https://discord.js.org/#/docs/main/stable/typedef/ActivityType
	client.user.setActivity(`${client.guilds.size} Guilds`,{"type":"WATCHING"});
	setTimeout(() => {
		// Changes the bots status to "Listening to ${client.channels.size} Channels"
		// client.channels.size = total count of channels the bot can see throughout all guilds
		// Function: https://discord.js.org/#/docs/main/stable/class/ClientUser?scrollTo=setActivity
		// Type Values: https://discord.js.org/#/docs/main/stable/typedef/ActivityType
		client.user.setActivity(`${client.channels.size} Channels`,{"type":"LISTENING"});
	}, 7e3);
	setTimeout(() => {
		// Changes the bots status to "Playing With ${client.users.size} Users"
		// client.users.size = total users the bot can see throughout all guilds
		// Function: https://discord.js.org/#/docs/main/stable/class/ClientUser?scrollTo=setActivity
		// Type Values: https://discord.js.org/#/docs/main/stable/typedef/ActivityType
		client.user.setActivity(`With ${client.users.size} Users`,{"type":"PLAYING"});
	}, 14e3);
}, 21e3);


// This event will run if the bot starts, and logs in, successfully.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-ready
client.on("ready", () => {
  // logs a message to console with how man guilds the bot is in, how many channels it can see (sharding will change this valyue), and how many users it is handling (user cache and sharding will change this value).
  // client.guilds: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=guilds
  // client.users: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=users
  console.log(`Bot has started, with ${client.users.size} users, in ${client.channels.size} channels of ${client.guilds.size} guilds.`); 
  // Example of changing the bot's playing game to something useful. `client.user` is what the
  // Change the bots game to "Watching ${client.guilds.size} Guilds"
  // client.guilds.size = total count of guilds the bot is in
  // Function: https://discord.js.org/#/docs/main/stable/class/ClientUser?scrollTo=setActivity
  // Type Values: https://discord.js.org/#/docs/main/stable/typedef/ActivityType
	 client.user.setActivity(`${client.guilds.size} Guilds`,{"type":"WATCHING"});
});

// This event will run when the bot is added to a guild.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-guildCreate
client.on("guildCreate", async (guild) => {
  // Guild Class: https://discord.js.org/#/docs/main/stable/class/Guild
  console.log(`New Guild: ${guild.name} (id: ${guild.id}). This guild has ${guild.memberCount} members!`);
});


// This event will run when the bot is removed from a guild.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-guildDelete
client.on("guildDelete", async (guild) => {
  // Guild Class: https://discord.js.org/#/docs/main/stable/class/Guild
  console.log(`Removed from: ${guild.name} (id: ${guild.id})`);
});


// This event will run when a member joins a guild.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-guildMemberAdd
client.on("guildMemberAdd", async (member) => {
	// GuildMember Class: https://discord.js.org/#/docs/main/stable/class/GuildMember
	console.log(`New Member: ${member.user.tag} in guild ${member.guild.name} (${member.guild.id})`);
});


// This event will run when a member leaves or is kicked from a guild.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-guildMemberRemove
client.on("guildMemberRemove", async (member) => {
	// Member Object: https://discord.js.org/#/docs/main/stable/class/GuildMember
	console.log(`Member Left: ${member.user.tag} in guild ${member.guild.name} (${member.guild.id})`);
});


// This event will run when a member is banned from a guild.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-guildBanAdd
client.on("guildBanAdd", async (member) => {
	// Guild Class: https://discord.js.org/#/docs/main/stable/class/Guild
	// User Class: https://discord.js.org/#/docs/main/stable/class/User
	console.log(`Member Banned: ${member.user.tag} in guild ${member.guild.name} (${member.guild.id})`);
});


// This event will run when a member is unbanned from a guild.
// Event: https://discord.js.org/#/docs/main/stable/class/Client?scrollTo=e-guildBanRemove
client.on("guildBanRemove", async (member) => {
	// Guild Class: https://discord.js.org/#/docs/main/stable/class/Guild
	// User Class: https://discord.js.org/#/docs/main/stable/class/User
	console.log(`Member UnBanned: ${member.user.tag} in guild ${member.guild.name} (${member.guild.id})`);
});


// This event will run when a member sends a message in a channel the bot can see
// Message Class: https://discord.js.org/#/docs/main/stable/class/Message
client.on("message", async (message) => {
	
	// Its best to ignore all messages from other bots
	// this makes it ignore itself, and all other bots.
	if(message.author.bot) return;
	
	if(message.content.indexOf(prefix) !== 0) return;
  
	// Here we separate our "command" name, and our "arguments" for the command. 
	// e.g. if we have the message "!say Is this the real life?" , we'll get the following:
	// command = say
	// args = ["Is", "this", "the", "real", "life?"]
	var args = message.content.slice(prefix.length).trim().split(/\s+/g);
	var command = args.shift().toLowerCase();

	switch(command) {
		case "ping":
			// Calculates ping between sending a message and editing it, giving a nice round-trip latency.
			// The second ping is an average latency between the bot and the websocket server (one-way, not round-trip)
			// Message Class: https://discord.js.org/#/docs/main/stable/class/Message
			// Channel Class: https://discord.js.org/#/docs/main/stable/class/Channel
			var m = await message.channel.send("Ping?");
			m.edit(`Pong! Latency is ${m.createdTimestamp - message.createdTimestamp}ms. API Latency is ${Math.round(client.ping)}ms`);
		break;

		case "kick":
			// This command should be limited to staff. In this example we just hardcode the role names.
			// Please read on Array.some() to understand this bit: 
			// https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/some
			if(!message.member.roles.some(r=>["STAFF","ROLE2"].includes(r.name))) {
			  return message.reply("Sorry, you don't have permissions to use this!");
			}
			
			// Let's first check if we have a member and if we can kick them!
			// message.mentions.members is a collection of people that have been mentioned, as GuildMembers.
			// GuildMember Class: https://discord.js.org/#/docs/main/stable/class/GuildMember
			// Message Class: https://discord.js.org/#/docs/main/stable/class/Message
			// message.mentions: https://discord.js.org/#/docs/main/stable/class/Message?scrollTo=mentions
			// MessageMentions Class: https://discord.js.org/#/docs/main/stable/class/MessageMentions
			let kickmember = message.mentions.members.first();
			if(!kickmember) {
			  return message.reply("Please mention a valid member of this server");
			}
			
			if(!kickmember.kickable) {
				//kickable: https://discord.js.org/#/docs/main/stable/class/GuildMember?scrollTo=kickable
			  	return message.reply("I cannot kick this user! Do they have a higher role? Do I have kick permissions?");
			}
			// slice(1) removes the first part, which here should be the user mention!
			// .join(" ") joins all arguments (other than the mention) back together with spaces for the reason
			let kickreason = args.slice(1).join(" ");
			if(!kickreason) {
			 	//if no reason is specified end execution and reply with the error message
				//to disable this comment out the NEXT LINE ONLY
			 	return message.reply("Please indicate a reason for the kick!");
			}
			
			// Now, time to kick them!
			// catch and log error to console if error is thrown, without catch, the bot would stop after the error
			await kickmember.kick(kickreason)
			  .catch(error => message.reply(`Sorry ${message.author} I couldn't kick ${kickmember.user.tag} because of : ${error}`));
			//also send error to channel
			message.reply(`${member.user.tag} has been kicked by ${kickmessage.author.tag} because: ${reason}`);
		break;
		
		case "ban":
			// This command will be similar to kick, but here we'll check for permissions
			// Permission Strings: https://discord.js.org/#/docs/main/stable/class/Permissions?scrollTo=s-FLAGS
			// .hasPermission Function: https://discord.js.org/#/docs/main/stable/class/GuildMember?scrollTo=hasPermission
			// .hasPermissions [DEPRECATED] [DO NOT USE]: https://discord.js.org/#/docs/main/stable/class/GuildMember?scrollTo=hasPermissions
			// People with the ADMINISTRATOR permission, and the OWNER will bypass this, the last 2 parameters cause this.
			if(!message.member.hasPermission("BAN_MEMBERS",null,true,true)) {
			// Example with Multiple Permissions:
			// changed to .hasPermission(Array()) after .hasPermissions() deprecation.
			// .hasPermission(Array("BAN_MEMBERS","KICK_MEMBERS"),null,true,true)) {
			  return message.reply("Sorry, you don't have permissions to use this!");
			}
			
			// Let's first check if we have a member and if we can ban them!
			// message.mentions.members is a collection of people that have been mentioned, as GuildMembers.
			// GuildMember Class: https://discord.js.org/#/docs/main/stable/class/GuildMember
			// Message Class: https://discord.js.org/#/docs/main/stable/class/Message
			// message.mentions: https://discord.js.org/#/docs/main/stable/class/Message?scrollTo=mentions
			// MessageMentions Class: https://discord.js.org/#/docs/main/stable/class/MessageMentions
			let banmember = message.mentions.members.first();
			if(!banmember) {
				//if no reason is specified end execution and reply with the error message
				//to disable this comment out the NEXT LINE ONLY
				return message.reply("Please mention a valid member of this server");
			}
			
			if(!banmember.bannable) {
				//bannable: https://discord.js.org/#/docs/main/stable/class/GuildMember?scrollTo=bannable
			 	return message.reply("I cannot ban this user! Do they have a higher role? Do I have ban permissions?");
			}
			
			// slice(1) removes the first part, which here should be the user mention!
			// .join(" ") joins all arguments (other than the mention) back together with spaces for the reason
			let banreason = args.slice(1).join(" ");
			
			if(!banreason) {
			  return message.reply("Please indicate a reason for the ban!");
			}
			// Now, time to ban them!
			await banmember.ban(banreason)
			  .catch(error => message.reply(`Sorry ${message.author} I couldn't ban ${banmember.user.tag} because of : ${error}`));
			message.reply(`${banmember.user.tag} has been banned by ${message.author.tag} because: ${banreason}`);
		break;
		
		default:
			return;
	}
});

// This will connect the bot with discords API
// Client Class: https://discord.js.org/#/docs/main/stable/class/Client
client.login(token);