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

test で JSDoc1 を使用して例を再現し、その後 testInInterface と test2.test に不足しているコメントを比較します。typeof 式のコメントが、JSDoc2 や JSDoc3 を必要とせず、インターフェースの場合とプロパティアクセスの場合の両方で継承されるようになれば、変更は完了です。