When using typeof for the interface, it is hoped that the jsdoc comments of the expression can inherit typeof by default

🔍 Search Terms

"typeof","jsdoc"

✅ Viability Checklist

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

/** JSDoc1 */
const test = { a: 0 }

declare module 'vue' {
  interface ComponentCustomProperties {
    /** JSDoc2 */
    testInInterface: typeof test,
  }
}

const test2 = {
  /** JSDoc3 */
  test
}

I hope that when not writing JSDoc2 or JSDoc3, testInInterface and test2.test can have comments for const test in JSDoc1

📃 Motivating Example

The interface has the feature of declaring and merging, allowing developers to extend the interfaces defined in the component library. In front-end development, extending Vue's global components, directives, and properties is often used.

Taking a Vue component as an example, including its global and local usage schemes, there is currently a lack of JSDoc comments

• global

import vueComponentWithJsDoc from './test.vue'

declare module 'vue' {
  interface GlobalComponents {
    vueComponentWithoutJsDoc: typeof vueComponentWithJsDoc
  }
}

• local

import vueComponentWithJsDoc from './test.vue'
import { defineComponent } from 'vue'

export default defineComponent({
  components: { vueComponentWithoutJsDoc: vueComponentWithJsDoc  }
})

When using components in the template, both of the above schemes lack JSDoc comments

<template>
  <vue-component-without-js-doc />
</template>

💻 Use Cases

1. JSDoc comments can be included when declaring a merge interface
2. The type obtained by the typeof instance is missing the jsdoc annotation
3. Manually copy a jsdoc comment onto the interface field

Reproduce the examples using JSDoc1 on test, then compare the missing comments on testInInterface and test2.test. The change is complete when comments from a typeof expression are inherited in both interface and property-access cases without requiring JSDoc2 or JSDoc3.