vue-devtools/packages/shell-dev-vue3/src/SetupRender.js

import { defineComponent, h, reactive } from 'vue'

export default defineComponent({
  name: 'SetupRender',

  setup() {
    const state = reactive({
      name: 'Foo bar',
    })

    return () => {
      return h('h1', state.name)
    }
  },
})