defineAsyncComponent's loadingComponent option not working in ssr mode?

[linzhe141]

<script setup >
import { defineAsyncComponent} from 'vue'


const FooBar = defineAsyncComponent({
  loader: () => new Promise((resolve)=>{
    setTimeout(()=>{
      resolve({
        render(){
          return 'result!!!'
        }
      })
    },5000)
  }),
  loadingComponent: {
    render(){
      return 'loading...'
    }
  }
})
</script>

<template>
  <FooBar />
</template>

https://play.vuejs.org/#__SSR__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

In csr mode, everything is as expected. However, in ssr mode, we can see that there is no loading text. Is this intentional?

[edison1105]

This is expected behavior. When rendering asynchronous components in SSR, it will wait for them to resolve rather than immediately returning the rendering result of the loadingComponent. For example, it might use an asynchronous method in async setup to query a database or other asynchronous functions, and these asynchronous operations cannot be accessed on the client side.