Issue with Typescript exported namespaces and rollup

Question

I am converting some projects that used webpack to vite. I'm having a weird issue where rollup doesn't seem to recognize exported namespaces. Had no issues before with webpack.

Here is an example:

// types.ts
export namespace Test {
  export interface Tester {
    field: string;
  }
}
export interface TestInterface {
  field: string;
}

// index.ts
import {Test, TestInterface} from './types.ts';

If I do it like this I get an error saying: 'Test' is not exported by ./types.ts

However it works correctly if I change the code to this:

// index.ts
import * as Types from './types.ts';
import Test = Types.Test;
import TestInterface = Types.TestInterface;

Is there another option besides having to do a wildcard import then reassigning each individually?

Answer 1

Figured it out you have to use the keyword type on the import.

import type {Test, TestInterface} from './types.ts';

I somehow skipped over the few lines that talked about it in the documentation. https://vitejs.dev/guide/features.html#typescript