Show a confirmation message on plugin deactivation

I had trouble with the dirname(__FILE__) for some reason, so I changed my code to this, where bkj-functions is my plugin slug.

wp_enqueue_script('wp-deactivation-message', plugins_url('js/message-deactivate.js', __FILE__), array());

with the following contents for js/message-dactivate.js (since I only need an "Alert" and not a "Confirm"):

window.onload = function(){
    document.querySelector('[data-slug="bkj-functions"] .deactivate a').addEventListener('click', function(event){
        //event.preventDefault()
        alert("Reminder: If you are using the 'class' taxonomy for styling, that may disappear when this plugin has been deactivated.")
    })
}

I have implemented a workaround with JavaScript. I'm loading my own JavaScript file:

wp_enqueue_script('wp-deactivation-message', plugins_url('js/message.js', dirname(__FILE__)), array());

which contains a script that adds following Event Listener - when user clicks on our plugin deactivate button it prevent it from performing this action and display a JavaScript popup asking what you need, if user accepts it will be deactivated, if user press 'cancel' nothing happens:

message.js

window.onload = function(){
        document.querySelector('[data-slug="plugin-name-here"] a').addEventListener('click', function(event){
            event.preventDefault()
            var urlRedirect = document.querySelector('[data-slug="plugin-name-here"] a').getAttribute('href');
            if (confirm('Are you sure you want to save this thing into the database?')) {
                window.location.href = urlRedirect;
            } else {
                console.log('Ohhh, you are so sweet!')
            }
        })
}