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">
    <button @click='doSmt'>
    Click
    </button>
    <label> {{ test }} </label>
    <el-tree
      :data="data2"
      node-key="id"
      :props="defaultProps"
      @node-click="handleNodeClick"
      :default-expanded-keys="expandedKeys"
      :expand-on-click-node="false"
      >
    </el-tree>
</div>

CSS

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

JavaScript

new Vue({
	el: '#app',
  data() {
      return {
        data2: [{
          id: 1,
          label: '1st 1',
          children: [{
            id: 4,
            label: '2nd 1-1',
            children: [{
              id: 9,
              label: '3rd 1-1-1'
            }, {
              id: 10,
              label: '3rd 1-1-2'
            }]
          }]
        }, {
          id: 2,
          label: '1st 2',
          children: [{
            id: 5,
            label: '2nd 2-1'
          }, {
            id: 6,
            label: '2nd 2-2'
          }]
        }, {
          id: 3,
          label: '1st 3',
          children: [{
            id: 7,
            label: '2nd 3-1'
          }, {
            id: 8,
            label: '2nd 3-2'
          }]
        }],
        defaultProps: {
          children: 'children',
          label: 'label'
        },
        selectedData: null,
        selectedNode: null,
        test: '',
        expandedKeys: []
      }
    },

    methods: {
      handleNodeClick (data, node) {
      this.selectedData = data
      this.selectedNode = node
      this.test = node.data.label
     
      },
      doSmt () {
      /* this.selectedData.label = 'I click this node' */
var data = this.selectedData
/*                  const newChild = { id: 15, label: 'newNode', children: [] };
                     if (!data.children) {
                       this.$set(data, 'children', []);
                     }
                     data.children.push(newChild); */
/* try {
              var node = this.selectedNode
                      const parent = node.parent;
                      const children = parent.data.children || parent.data;
                      const index = children.findIndex(d => d.id === data.id);
                      this.test = 'Im here'
                      children.splice(index, 1);
              }
                      catch (error) {
                      this.test = error.message
                      }...