Typescript - 'Cannot find name ____' when annotating props with interface

[sergmister]

• I have searched through existing issues
• I have read through docs
• I have read FAQ
• I have tried restarting VS Code or running Vetur: Restart VLS

Info

• Platform: Linux
• Vetur version: 0.33.1
• VS Code version: 1.55.1

Problem

When I use an interface to annotate props Vetur gives give the error 'Cannot find name 'Foo'. Vetur(2304)'.

Reproducible Case

This setup works perfectly fine:
Test.vue

<script lang="ts">
import { defineComponent, PropType } from "vue";

export interface Foo {
  name: string;
}

export default defineComponent({
  props: {
    foo: { type: Object as PropType<{ name: string }> },
  },
});
</script>

App.vue

<template>
  <p>hi</p>
</template>

<script lang="ts">
import { defineComponent } from "vue";
import Test from "@/test.vue";

export default defineComponent({
  components: { Test },
});
</script>

However, when I change props in Test.vue to

  props: {
    foo: { type: Object as PropType<Foo> },
  },

Vetur give the error 'Cannot find name 'Foo'. Vetur(2304)' at the top of App.vue. The code runs just fine in Vue.

[HayasyLL]

same issue when pass props as PropType

in child component

in parent component, pass object to child component

first line of parent component

[yoyo930021]

Duplicate of #2668