Маска для полей телефона — iMask

      IMask(SELECTOR, {
    mask: [
        {
            mask: '+{0}(000)000-00-00',
            startsWith: '7',
            lazy: false,
            country: 'Russia'
        },
        {
            mask: '{0}(000)000-00-00',
            startsWith: '8',
            lazy: false,
            country: 'Russia'
        },
    ],
    dispatch: (appended, dynamicMasked) => {
        const number = (dynamicMasked.value + appended).replace(/\D/g,'');
        return dynamicMasked.compiledMasks.find(m => number.indexOf(m.startsWith) === 0);
    }
});