Vue 3's Suspense component, ready for use in Nuxtjs 2.x (TypeScript)

Suspense.ts

import Vue from 'vue'

export default Vue.extend({
  name: 'Suspense',

  render(createElement) {
    const defaultVNode = this.$slots.default![0]
    const isdefaultVNodeExist =
      defaultVNode.elm !== undefined ||
      defaultVNode.componentOptions !== undefined ||
      defaultVNode.tag?.startsWith('vue-component')

    if (isdefaultVNodeExist) {
      return createElement('div', this.$slots.default)
    } else {
      return createElement('div', this.$slots.fallback)
    }
  },
})