discord.js-x-captcha/src/createCaptcha.js

A powerful package for Discord.js v14 that allows you to easily create CAPTCHAs for Discord Servers.

const shuffle = (arr) => {
    let i = arr.length;
    while (i) {
        let j = Math.floor(Math.random() * i--);
        [arr[j], arr[i]] = [arr[i], arr[j]];
    }
    return arr;
};

/**
 * @typedef {Object} CaptchaImageData
 * @prop {Buffer} image The CAPTCHA Image.
 * @prop {String} text The Answer to the CAPTCHA.
 */

/**
 * Asynchronously Generates a CAPTCHA.
 * @param {Number} [length=6] The Text Length of the CAPTCHA. Defaults to 6.
 * @param {String} [blacklist=""] A List of Characters to Exclude from the CAPTCHA.
 * @returns {CaptchaImageData} The CAPTCHA Image Data.
 */

module.exports = async function createCaptcha(length = 6, blacklist = "") {

const {
    CaptchaGenerator
} = require('captcha-canvas')

let chars = [
        "a",
        "b",
        "c",
        "d",
        "e",
        "f",
        "g",
        "h",
        "i",
        "j",
        "k",
        "l",
        "m",
        "n",
        "o",
        "p",
        "q",
        "r",
        "s",
        "t",
        "u",
        "v",
        "w",
        "x",
        "y",
        "z",
        "A",
        "B",
        "C",
        "D",
        "E",
        "F",
        "G",
        "H",
        "I",
        "J",
        "K",
        "L",
        "M",
        "N",
        "O",
        "P",
        "Q",
        "R",
        "S",
        "T",
        "U",
        "V",
        "W",
        "X",
        "Y",
        "Z",
        "0",
        "1",
        "2",
        "3",
        "4",
        "5",
        "6",
        "7",
        "8",
        "9"
    ];

    if (Number.isNaN(length)) throw new Error("Discord.js Captcha Generation Error: Length must be a Number.");
    if (length < 1) throw new Error("Discord.js Captcha Generation Error: The CAPTCHA Length must be at least 1 character.\nNeed Help? Join our Discord Server at 'https://discord.gg/P2g24jp'");

    // Validate blacklist param
    if (typeof blacklist !== "string") throw new Error("Discord.js Captcha Generation Error: The blacklist parameter must be a string.\nNeed Help? Join our Discord Server at 'https://discord.gg/P2g24jp'");
    if (blacklist.match(/[^a-zA-Z0-9]/)) throw new Error("Discord.js Captcha Generation Error: The blacklist parameter must only contain alphanumeric characters.\nNeed Help? Join our Discord Server at 'https://discord.gg/P2g24jp'");

    // Remove blacklisted characters from the character list
    chars.splice(0, chars.length, ...chars.filter(c => !blacklist.includes(c)));
    chars = shuffle(chars);

    function generateCaptcha(charset, length) {
        var retVal = "";
        for (let i = 0; i < length; i++) retVal += charset[Math.floor(Math.random() * charset.length)];
        return retVal;
    }
    const genCaptcha = generateCaptcha(chars, length)

    const captcha = new CaptchaGenerator()
        .setDimension(150, 450)
        .setCaptcha({
            text: genCaptcha,
            size: 60,
            color: "deeppink"
        })
        .setDecoy({
            opacity: 1
        })
        .setTrace({
            color: "deeppink"
        })
    const buffer = captcha.generateSync()

    return {
        image: buffer,
        text: genCaptcha
    };
}