Events Setup

This is a simple overview of how to set up a simple function that is called when the "ready" event is triggered. All this code does is log to the console when the bot is ready.

CommonJS

src/events/ready/console-log.js

module.exports = (c, client, handler) => {
  console.log(`${c.user.username} is ready!`);
};

ESM

src/events/ready/console-log.js

export default function (c, client, handler) {
  console.log(`${c.user.username} is ready!`);
};

TypeScript

src/events/ready/console-log.ts

import type { Client } from 'discord.js';
import type { CommandKit } from 'commandkit';

export default function (c: Client<true>, client: Client<true>, handler: CommandKit) {
  console.log(`${c.user.username} is ready!`);
};

Parameters explained

The parameters might look a bit confusing at first, but they're actually quite simple. The first parameter c is the client object that was returned as a parameter when the "ready" event was triggered. The second parameter client is the Discord.js client that was instantiated in your main entry point file. Finally, the handler parameter is the current CommandKit instance.

To better understand how the parameters work, here's another example but with the "messageCreate" event listener.

CommonJS

src/events/messageCreate/say-hi.js

module.exports = (message, client) => {
  if (message.content === 'hey') {
    message.reply('Hi!');
  }
};

ESM

src/events/messageCreate/say-hi.js

export default function (message, client, handler) {
  if (message.content === 'hey') {
    message.reply('Hi!');
  }
};

TypeScript

src/events/messageCreate/say-hi.ts

import type { Message, Client } from 'discord.js';
import type { CommandKit } from 'commandkit';

export default function (message: Message<true>, client: Client<true>, handler: CommandKit) {
  if (message.content === 'hey') {
    message.reply('Hi!');
  }
};

In this example you can see that the first parameter is the message object that was returned as a parameter when the "messageCreate" event was triggered. The client parameter is the same as the previous example.

Multiple parameters explained

But what if an event returns multiple parameters? Let's take for example the "messageUpdate" event. This event returns two parameters, oldMessage and newMessage. The parameters will follow the same behaviour as if you were using the client.on() method.

CommonJS

src/events/messageUpdate/log-message-update.js

module.exports = (oldMessage, newMessage, client) => {
  console.log(`Message edited from ${oldMessage.content} to ${newMessage.content}`);
};

ESM

src/events/messageUpdate/log-message-update.js

export default function (oldMessage, newMessage, client) {
  console.log(`Message edited from ${oldMessage.content} to ${newMessage.content}`);
};

TypeScript

src/events/messageUpdate/log-message-update.ts

import type { Message, PartialMessage } from 'discord.js';
import type { CommandKit } from 'commandkit';

export default function (oldMessage: Message<boolean> | PartialMessage, newMessage: Message<boolean> | PartialMessage, client: Client<true>, handler: CommandKit) {
  console.log(`Message edited from ${oldMessage.content} to ${newMessage.content}`);
};

As you can see, even with multiple parameters, the last parameter will always be the client object.

Stopping the event loop

The code above is just a simple example of how to set up an event function. But what if you want to stop the next event function in line from running? This is where the return statement comes in handy.

CommonJS

src/events/messageCreate/say-hi.js

module.exports = (message, client) => {
  if (message.content === 'hey') {
    message.reply('Hi!');

    return true; // This stops the event loop
  }
}

ESM

src/events/messageCreate/say-hi.js

export default function (message, client) {
  if (message.content === 'hey') {
    message.reply('Hi!');

    return true; // This stops the event loop
  }
}

TypeScript

src/events/messageCreate/say-hi.ts

import type { Message, Client } from 'discord.js';
import type { CommandKit } from 'commandkit';

export default function (message: Message<true>, client: Client<true>, handler: CommandKit) {
  if (message.content === 'hey') {
    message.reply('Hi!');

    return true; // This stops the event loop
  }
}

You can return any truthy value from this function to stop the next event function from running.