False negative with vue/require-valid-default-prop on props with type assertion

[frozenbonito]

Checklist

• I have tried restarting my IDE and the issue persists.
• I have read the FAQ and my problem is not listed.

Tell us about your environment

• ESLint version: 7.23.0
• eslint-plugin-vue version: 7.8.0
• Node version: 14.16.0
• Operating System: Windows 10 Pro

Please show your full configuration:

module.exports = {
  root: true,
  env: {
    node: true,
  },
  extends: [
    "plugin:vue/essential",
    "eslint:recommended",
    "@vue/typescript/recommended",
    "@vue/prettier",
    "@vue/prettier/@typescript-eslint",
  ],
  parserOptions: {
    ecmaVersion: 2020,
  },
  rules: {},
};

What did you do?

I annotated type to array prop with typescript according to the following documentations.

• https://vuejs.org/v2/guide/typescript.html#Annotating-Props
• https://v3.vuejs.org/guide/typescript-support.html#annotating-return-types

If the prop is an array, the default should be a function, but I set empty array directly by mistake.

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

export default Vue.extend({
  props: {
    foo: {
      type: Array as PropType<string[]>,
      default: [],
    },
  },
});
</script>

What did you expect to happen?

eslint reports type of the default value for 'foo' prop must be a function.

What actually happened?

eslint did not report that. If there is no type assertion, it reports correctly.

[VRuzhentsov]

Will this work with the next case?