Documentation not generated for TypeScript Components

[TaylorFinklea]

Describe the bug
Documentation is generated for all .Vue components that have export default {} in the script section, but doesn't generate documentation for export default Vue.extend({}). If I remove Vue.extend then it works as expected.

To Reproduce
Steps to reproduce the behavior:

1. Create Vue component

<template>
  <p>{{date}}</p>
</template>
<script lang="ts">
import Vue from "vue"
export default Vue.extend({
  props: {
    date: {
      type: Date,
      required: true,
    },
  },
})
</script>

2. Run vuese gen

Expected behavior
A documentation page is created for this component.

Actual behavior
The Vue component is skipped.

Screenshots
na

Environmental information:
Environment Info:
System:
OS: Linux 4.19 Arch Linux
CPU: (8) x64 Intel(R) Xeon(R) CPU E3-1225 v3 @ 3.20GHz
Binaries:
Node: 13.12.0 - /usr/sbin/node
Yarn: 1.22.4 - /usr/sbin/yarn
npm: 6.14.4 - /usr/sbin/npm

Additional information
na