<script type="text/javascript">
        const app = new Vue({
          el: '#app',
          data: {
            items: []
          },
          created: function () {
            fetch('test.json')
              .then(resp => resp.json())
              .then(items => {
                this.items = [].concat.apply([], items);
              })
          }
        });
      </script>