[api-extractor] Inconsistent rollups behaviour between moduleResolution

[Lukinoh]

Summary

In my project, I have libraries that generate types using vite-plugin-dts which uses underneath api-extractor.
When I migrated the tsconfig.json from moduleResolution: node to moduleResolution: bundler I realised that the output .d.ts was not identical.

Repro steps

The following repository is configured to use the api-extractor on the same code, but with 3 different moduleResolution: node, node16 and bundler.`

• git clone [email protected]:Lukinoh/repro-api-extractor-bug (Stackblitz)
• cd repro-api-extractor-bug
• npm install
• npm run build
• Look at the dist folders, it contains for each moduleResolution:
  • The result of the tsc build
  • The extracted .d.ts
  • The diagnostics

The extracted .d.ts of node16 and bundler are different from node.
I would have expected to have the content.

Expected result:

declare class ClassExample {
    field1: number;
    field2: string;
}

export declare const functions: ClassExample[];

export { }

Actual result:

import { ClassExample } from './hop/f1.ts';

export declare const functions: ClassExample[];

export { }

Standard questions

Please answer these questions to help us investigate your issue more quickly:

Question	Answer
@microsoft/api-extractor version?	7.49.2
Operating system?	Linux (WSL2)
API Extractor scenario?	rollups (.d.ts)
Would you consider contributing a PR?	No
TypeScript compiler version?	5.7.2
Node.js version (node -v)?	22.14.0