Types of generic parameters in components defined with `defineComponent` are always `unknown`

[rijenkii]

Playground reproduction

I have defined the same component using <script setup> and defineComponent:

// CompSetup.vue
<script setup lang="ts" generic="T">
defineProps<{ msg: T; list: T[] }>();
</script>

// CompDefine.vue
<script lang="ts">
import { defineComponent } from 'vue';
export default defineComponent(<T>(_: { msg: T; list: T[] }) => () => null);
</script>

When using them, CompSetup automatically infers the types of arguments, however CompDefine does not:

<template>
  <CompSetup :msg="123" :list="['123']" />
  <!-- Displays an error saying that `'string' is not assignable to 'number'` -->

  <CompDefine :msg="123" :list="['123']" />
  <!-- Displays no errors, when hovering over `:msg` and `:list` displays types `unknown` and `unknown[]` respectively -->
</template>

[s-montigny-desautels]

Should be fixed with Vue 3.4.20.

[rijenkii]

This is not really fixed: Playground

<template>
  <CompSetup :msg="123" :list="['123']" />
  <!-- Displays an error saying that `'string' is not assignable to 'number'` -->

  <CompDefine :msg="123" :list="['123']" />
  <!-- Displays no errors, when hovering over `:msg` and `:list` displays types `number` and `string[]` respectively -->
</template>

So, unknown is not shown, but fields are still not linked together.
Maybe this should actually be tracked in #3782.

[so1ve]

This looks like a bug in volar. I'll reopen this issue.