JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//unpkg.com/vue/dist/vue.js"></script>
<script src="//unpkg.com/[email protected]/lib/index.js"></script>
<div id="app">
<el-tree :data="data" default-expand-all :props="defaultProps" ref="tree" node-key="id" highlight-current></el-tree>
</div>

SCSS

@import url("//unpkg.com/[email protected]/lib/theme-chalk/index.css");

Babel + JSX

var Main = {
    data() {
      return {
        data: [{
          label: '一级 1',
          children: [{
            label: '二级 1-1',
            children: [{
              label: '三级 1-1-1'
            }]
          }]
        }, {
          label: '一级 2',
          children: [{
            label: '二级 2-1',
            children: [{
              label: '三级 2-1-1'
            }]
          }, {
            label: '二级 2-2',
            children: [{
              label: '三级 2-2-1'
            }]
          }]
        }, {
          label: '一级 3',
          children: [{
            label: '二级 3-1',
            children: [{
              label: '三级 3-1-1'
            }]
          }, {
            label: '二级 3-2',
            children: [{
            	id:22,
              label: '三级 3-2-1'
            }]
          }]
        }],
        defaultProps: {
          children: 'children',
          label: 'label'
        }
      };
    },
    mounted() {
      this.$refs.tree.setCurrentKey(22)
    }
  };
var Ctor = Vue.extend(Main)
var vm=new Ctor().$mount('#app');