Unputmask + autofill

script.js

jQuery(function(){
    
    //autofill event hack
    $('input.phone').one('animationstart', function(e, f) {
        var animationName = e.originalEvent.animationName;
        console.log(animationName);
        if (animationName == 'onAutoFillCancel') {
            $(this).inputmask("+7 (999) 999-99-99");
        }
    });
});

style.css

//autofill event hack
@keyframes onAutoFillStart {  from {/**/}  to {/**/}}
@keyframes onAutoFillCancel {  from {/**/}  to {/**/}}
input.phone:-webkit-autofill {
    // Expose a hook for JavaScript when autofill is shown
    // JavaScript can capture 'animationstart' events
    animation-name: onAutoFillStart;

    // Make the background color become yellow really slowly
    transition: background-color 50000s ease-in-out 0s;
}
input.phone:not(:-webkit-autofill) {
    // Expose a hook for JS onAutoFillCancel
    // JavaScript can capture 'animationstart' events
    animation-name: onAutoFillCancel;
}