xiao/types/image.js

const { ArgumentType } = require('discord.js-commando');
const fileTypeRe = /\.(jpe?g|png|gif)$/i;
const request = require('node-superfetch');

module.exports = class ImageArgumentType extends ArgumentType {
	constructor(client) {
		super(client, 'image');
	}

	async validate(value, msg, arg) {
		const attachment = msg.attachments.first();
		if (attachment) {
			if (!attachment.height || !attachment.width) return false;
			if (attachment.size > 8e+6) return 'Please provide an image under 8 MB.';
			if (!fileTypeRe.test(attachment.name)) return 'Please only send PNG, JPG, or GIF format images.';
			return true;
		}
		if (fileTypeRe.test(value.toLowerCase())) {
			try {
				await request.get(value);
				return true;
			} catch {
				return false;
			}
		}
		return this.client.registry.types.get('user').validate(value, msg, arg);
	}

	async parse(value, msg, arg) {
		const attachment = msg.attachments.first();
		if (attachment) return attachment.url;
		if (fileTypeRe.test(value.toLowerCase())) return value;
		const user = await this.client.registry.types.get('user').parse(value, msg, arg);
		return user.displayAvatarURL({ format: 'png', size: 512 });
	}

	isEmpty(value, msg, arg) {
		if (msg.attachments.size) return false;
		return this.client.registry.types.get('user').isEmpty(value, msg, arg);
	}
};