Vanilla JS Reset-form validation

validation.js

(function () {

    let password = document.getElementById("password");
    let confirmPass = document.getElementById("confirm_password");
    let submit = document.getElementById("submit");

    function isPasswordStrong() {
        const pattern = /^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.{8,})/g;
        return pattern.test(password.value);
    }

    function samePassword() {
        return password.value === confirmPass.value;
    }

    function PasswordStrength() {
        if (isPasswordStrong()) {
            password.nextElementSibling.style.display = 'none';
        } else {
            password.nextElementSibling.style.display = '';
        }
    }

    function PasswordMatch() {
        if (samePassword()) {
            confirmPass.nextElementSibling.style.display = 'none';
        } else {
            confirmPass.nextElementSibling.style.display = '';
        }
    }

    function canSubmit() {
        return samePassword() && isPasswordStrong();
    }

    function enableSubmitButton() {
        submit.disabled = !canSubmit();
    }

    // disable button by default
    enableSubmitButton();

    password.onkeyup = function () {
        PasswordStrength();
        PasswordMatch();
        enableSubmitButton();
    };

    confirmPass.onfocus = PasswordMatch;
    confirmPass.onkeyup = function () {
        PasswordMatch();
        enableSubmitButton();
    };

    submit.onclick = function (e) {
        e.preventDefault();
        const queryString = window.location.search;
        const urlParams = new URLSearchParams(queryString);
        const token = urlParams.get('token');

        fetch('/auth/change-password', {
            headers: {
                'Authorization': 'Bearer ' + token,
                "Content-Type": "application/json; charset=utf-8"
            },
            method: 'POST',
            body: JSON.stringify({
                password: password.value,
            })
        })
            .then(function (response) {
                return response.json();
            })
            .then(function (data) {
                let status = document.getElementById('status');

                if (data.hasOwnProperty('errorCode')) {
                    status.className = "fail";
                    status.innerText = "Something went wrong: " + data.message;
                } else {
                    status.className = "success";
                    status.innerHTML = "Password successfully changed";
                }
            })
            .catch(function (err) {
                console.log("Error: ", err);
            })
    };
})();