Vue3 Ref 组件类型定义

<!-- Home.vue -->
<template>
  <MyForm :ref="$form" />
</template>

<script>
import { defineComponent, ref, onMounted } from '@vue/runtime-core'
import MyForm, { MyFormExpose } from '@/components/MyForm'
export default defineComponent({
  components: { MyForm }
  
  setup(){
    const $form = ref<InstanceType<typeof MyForm> & MyFormExpose>(null)
    
    onMounted(() => {
       $form?.value.validate // 类型正确
    })
  }
})
</script>