main.ts

import Vue from 'vue';
import VanillaJsService from './vanilla-js-service';

var app = new Vue({
  el: '#app',
  data: function() {
    return{
      vanillaJsService: new VanillaJsService()
    }
  },
  methods: {
    useVanillaJsService: function() {
      this.vanillaJsService.sayHello();
    }
  }
})