Allow module syntaxes for namespaces

[karikera]

Suggestion

🔍 Search Terms

export all from namespace
export default with namespace #24164
export from namespace

✅ Viability Checklist

My suggestion meets these guidelines:

• [v] This wouldn't be a breaking change in existing TypeScript/JavaScript code
• [v] This wouldn't change the runtime behavior of existing JavaScript code
• [v] This could be implemented without emitting different JS based on the types of the expressions
• [v] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• [v] This feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

some namespace syntaxes are not compatible with module syntaxes.
It will be more flexible if they are supported.

📃 Motivating Example

1. export * from namespace
   It's hard to export all identifiers in the namespace.

// sources

// module1.d.ts
export const a:number;
export const b:number;
export const c:number;
export ...

// index.d.ts
export * from "./module1";
declare let a:number;
export { a as foobar };

// bundled (by my program)

declare namespace module1 {
   export const a:number;
   export const b:number;
   export const c:number;
   export ...
}
// ***  suggestion ***
export * from module1;
declare let a:number;
export { a as foobar };
// current solution
import a_ = module1.a; // need to avoid the name dupplication
import b = module1.b;
import c = module1.c;
import ...
export { a_ as a, b, c, ... };
declare let a:number;
export { a as foobar };

2. export default
   Support export { x as default } in namespace declarations #24164

// sources

// module1.d.ts
declare const a:number;
export default a;

// index.d.ts
import a from './module1';

// bundled (by my program)

declare namespace module1 {
  const a:number;
  // export default a; // suggesstion
  export { a as default }; // possible but not much meaning
  export { a as default_}; // bypass
}
// *** suggestion ***
import a from module1;
// current solution
import a = module1.default_; // TS does not allow 'default' even at this point. bypass it.

3. import { ... } from namespace, export { ... } from namespace

// sources

// module1.d.ts
export const a:number;
export const b:number;
export const c:number;
export const d:number;

// index.d.ts
import { a as c, b as d } from './module1';
export { c, d } from './module1';

// bundled (by my program)
declare namespace module1 {
  export const a:number;
  export const b:number;
  export const c:number;
  export const d:number;
}

// *** suggestion **
import { a as c, b as d } from module1;
export { c, d } from module1;
// current solution
import c = module1.a;
import d = module1.b;
import c_ = module1.c; // need to avoid the name dupplication
import d_ = module1.d;
export { c_ as c, d_ as d };

💻 Use Cases

I'm trying to bundle d.ts files programmatically.
and replacing modules with namespaces.
but it's a little hard to bundle them perfectly with the current syntaxes.

[andrewbranch]

Duplicate of #39865

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.