Captcha finder

captcha.js

const doesClassExist = (c)=>{
    let item = document.getElementsByClassName(c);
    if (item.length > 0) {
        return true;
    } else {
        return false;
    }
}

const detectCaptcha = ()=>{
    return new Promise((resolve, reject)=>{
        let res = false
        let t1 = doesClassExist("recaptcha");
        let t2 = doesClassExist("coinhive-captcha");
        let t3 = doesClassExist("BDC_CaptchaDiv");
        let t4 = doesClassExist("tdImage_captchaImage");
        if (t1 === true || t2 === true || t3 === true || t4 === true) {
            res = true;
        } else {
            let cCount = 0;
            var word = "captcha",
                queue = [document.body],
                curr;

            while (curr = queue.pop()) {
                if (!curr.textContent.match(word)) continue;
                for (var i = 0; i < curr.childNodes.length; ++i) {
                    switch (curr.childNodes[i].nodeType) {
                        case Node.TEXT_NODE :
                            if (curr.childNodes[i].textContent.match(word)) {
                                cCount++;
                            }
                            break;
                        case Node.ELEMENT_NODE :
                            queue.push(curr.childNodes[i]);
                            break;
                    }
                }
            }
            if (cCount > 1) {
                res = true;
            }
        }
        resolve(res);
    })
}

// Example:

function documentReady(callback){
    // in case the document is already rendered
    if (document.readyState!='loading') callback();
    // modern browsers
    else if (document.addEventListener) document.addEventListener('DOMContentLoaded', callback);
    // IE <= 8
    else document.attachEvent('onreadystatechange', function(){
        if (document.readyState=='complete') callback();
    });
}

documentReady(() => {
    detectCaptcha().then(res=>{
        if (res) {
            console.log("Found a captcha, fill info but don't submit login form.")
        } else {
            console.log("Found no captcha. Continue with login automatically.")
        }
    })
})