main.js

/* eslint-disable */
import app from './views/app';
import './assets/js/bootstrap.min';

// actually mount to DOM
app.$mount('#app');

if ('serviceWorker' in navigator && process.env.NODE_ENV === 'production') {
  navigator.serviceWorker.register('/service-worker.js').then(function(registration){
      console.log('Service worker registered : ', registration.scope);
    })
    .catch(function(err){
      console.log("Service worker registration failed : ", err);
    });
}

//array
Array.prototype.group = function(key) {
  var result = {};
  this.map(item => ({section: key(item), value: item})).forEach(item => {
    result[item.section] = result[item.section] || [];
    result[item.section].push(item.value);
  });
  return Object.keys(result).map(item => ({section: item, data: result[item]}));
}