[Nexus]

<input type='text' id = 'username'>
<input type='text' id = 'pas'>
<button>Тест</button>
<script>
document.querySelector('button').onclick = validate;

function validate() {
    const expressions = {
        email: /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/,
        password: /(?=.*[0-9])(?=.*[!@#$%^&*])(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z!@#$%^&*]{6,}/g
    };


    return !['username', 'pas'].filter((id, i) => {
        const node = document.getElementById(id);
        const isValid = (node.value.length && expressions[!i ? 'email' : 'password'].test(node.value));

        node.style.borderColor = isValid ? 'green' : 'red';


        return !isValid;
    }).length;
}
</script>