Nuxt 3: SSR computed() memory leak, because the isInSSRComponentSetup variable is set to false on the server

[mrauhu]

Environment

• Operating System: Linux
• Node Version: v16.15.0
• Nuxt Version: 3.0.0-rc.11
• Nitro Version: 0.5.4
• Package Manager: npm@8.5.5
• Builder: vite
• User Config: -
• Runtime Modules: -
• Build Modules: -

Reproduction

<script setup lang="ts">
import { computed } from 'vue';

// ...

debugger;
const result = computed(() => processor(props.input));
</script>

Then run with debugger, and step into computed() function, you will see the isInSSRComponentSetup variable is set to false on the server.

Describe the bug

Nuxt 3 SSR is not setting the isInSSRComponentSetup variable to true on the server, that used in the computed() function, see:

• vuejs/core@f4f0966
• Memory leak when using computed is SSR mode vuejs/core#5208

Temporary fix

<script setup lang="ts">
// Importing original `computed()` function with three arguments, to use latest, the `isSSR`
// eslint-disable-next-line vue/prefer-import-from-vue
import { computed } from '@vue/reactivity';

// ...

// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
const result = computed(() => processor(props.input), undefined, process.server);
</script>

Additional context

Memory consumption

Production build of an application, 60 requests per second, 10 minutes of load (36 000 requests).

Before fixes

After fixes

Includes fix from #15093.

Memory difference

Flame graph

Table

Logs

No response

[danielroe]

let's track in #15093 as that's the presenting cause

[mrauhu]

@danielroe would you reopen this issue after #15093 is closed?

[danielroe]

I believe my comment is relevant here as well: #15093

If you are still experiencing an issue would you provide a reproduction please? 🙏

[mrauhu]

If you are still experiencing an issue would you provide a reproduction please?

I will check current Nuxt behavior of calling the computed() function on the server.