static type checking ES module exports

[acfasj]

Suggestion

🔍 Search Terms

List of keywords you searched for before creating this issue. Write them down here so that others can find this suggestion more easily and help provide feedback.

✅ Viability Checklist

My suggestion meets these guidelines:

• 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 feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

Add a feature that can static type checking ES module exports

📃 Motivating Example

it may looks like

// file.ts
export const x = 4
export const y = 'whatever'
export const foo = () => 2

// the interface describes the what file.ts  exports
export interface module {
    x: 4
    y: string
    foo: () => number
}

💻 Use Cases

Actually I asked a question on stackoverflow, and not really konw what the sugar syntax looks like if the the feature could be implemented.

// file.ts
export const x = 4
export const y = 'whatever'
export const foo = () => 2

// the interface describes the what the module exports
interface Module {
    x: 4
    y: string
    foo: () => number
}

I want the exports in file.ts satisfy the interface Module, and typescript can tell me that I export right or not

[MartinJohns]

Duplicate of #38511.

[acfasj]

closed since duplicated