[Vue 2.7] Type of annotated prop not recognized in the component

[rchl]

Repro:

Repository: https://github.com/rchl/volar-vue2-test (pages/typeless.vue file)

<template>
    <div>noop</div>
</template>

<script>
export default {
    props: {
        tracks: {
            /** @type {import('vue').PropType<MyNamespace.Track[]>} */
            type: Array,
            required: true,
        },
    },
    data() {
        return {
            inputs: this.tracks.map(track => track),
        };
    },
};
</script>

declare namespace MyNamespace {
    type Track = {
        id: number;
        title: string;
    };
}

Expected

The type of this.tracks is correctly reported as Track[]

Actual

[rchl]

I guess the example is needlessly complicated. It could even not have any JSDoc annotation probably and would still reproduce.

[rchl]

Or is it about JSDoc just not working in this context?

This TS file seems to work:

import { defineComponent, PropType } from 'vue'

export default defineComponent({
    props: {
        tracks: {
            type: Array as PropType<string[]>,
            required: true,
        },
    },
    data() {
        return {
            inputs: this.tracks.map(track => track),
        };
    },
})

but not this JS file:

import { defineComponent } from 'vue'

export default defineComponent({
    props: {
        tracks: {
            /** @type {import('vue').PropType<string[]>} */
            type: Array,
            required: true,
        },
    },
    data() {
        return {
            inputs: this.tracks.map(track => track),
        };
    },
})

[zcf0508]

vuejs/vue#13063