clarification needed on imported types in defineProps

[comhon-project]

Hey! I was reading the docs about type-based defineProps and I think I found something that might be outdated or unclear.

What's the issue?

The docs say that imported types give null for runtime inference:

"If the type is a reference to an imported type, the inferred result will be foo: null (equal to any type) since the compiler does not have information of external files."

https://vuejs.org/guide/typescript/composition-api.html#typing-component-props

But I found that imported types from local project files actually work fine in dev mode.

Reproduction

// src/types/icons.ts
export type IconName = 'add' | 'delete' | 'close';

// src/components/Icon.vue
<script setup lang="ts">
import type { IconName } from '@/types/icons';

defineProps<{ icon: IconName }>();
</script>

What the docs suggest:

props: { icon: { type: null } }

What actually happens (dev mode):

props: { icon: { type: String, required: true } }

Vue correctly understands that IconName is a string literal union and infers type: String.

Environment

• Vue 3.5.26

Question

Does "imported type" in the docs specifically mean types from node_modules? If so, it would be helpful to clarify this because "imported type" sounds like any import.