App.vue

<script setup lang="ts">
import { ref } from "vue"
import TreeComponent from "./TreeComponent.vue"
const treeData = ref([{
  key: '1',
  title: 'Parent 1',
  children: [{
    key: '1-1',
    title: 'child 1',
  }, {
    key: '1-2',
    title: 'child 2',
    children: [{
      key: '1-2-1',
      title: 'grandchild 1',
    }, {
      key: '1-2-2',
      title: 'grandchild 2',
    },]
  },]
}, {
  key: '2',
  title: 'Parent 2',
  children: [{
    key: '2-1',
    title: 'child 1',
    children: [{
      key: '2-1-1',
      title: 'grandchild 1',
    }, {
      key: '2-1-2',
      title: 'grandchild 2',
    },]
  }, {
    key: '2-2',
    title: 'child 2',
  },]
}])
</script>

<template>
  <TreeComponent :data="treeData" />
</template>