rewriteRelativeImportExtensions: tsc doesn't rewrite extensions in emitted declaration files

🔎 Search Terms

"rewriteRelativeImportExtensions", "extensions", "declaration", ".d.ts"

🕗 Version & Regression Information

• This is the behavior in every version I tried (even in the next 5.8.0), and I reviewed the FAQ for entries about "rewriteRelativeImportExtensions"

⏯ Playground Link

No response

💻 Code

In an index.ts file:

export * from './file.ts';

then build it with tsc and "rewriteRelativeImportExtensions": true & "declaration": true in the compilerOptions of your tsconfig.json

🙁 Actual behavior

Built files content:
In the JS file, index.js, the extension is rewritten to .js:

export * from './file.js';

In the declaration file, index.d.ts, the extension is not rewritten to .js:

export * from './file.ts';

🙂 Expected behavior

In the declaration file, the extension should be rewritten to .js too:

export * from './file.js';

Additional information about the issue

It occurs in the current TS 5.7.3 and in the next version (5.8.0-dev.20250123 at this time). Even if TS correctly interprets .d.ts files with .ts extensions in import/export, it's not the case of the IDE I use, PhpStorm. It can't provide a real code assistance with these declaration files.
In fact, I don't really know if it's a feature, a bug or an oversight in tsc, or if rewriteRelativeImportExtensions is just too new to be completely supported by all IDEs! Let me know!

Reproduziere das Problem mit index.ts und einer tsconfig.json, die rewriteRelativeImportExtensions und declaration aktiviert, und verfolge anschließend den Declaration-Emit-Pfad von tsc für diese Option. Als abgeschlossen gilt die Aufgabe, wenn der erzeugte .d.ts-Verweis './file.ts' konsistent mit der JavaScript-Ausgabe in './file.js' umgeschrieben wird und der gemeldete Fall durch Tests abgedeckt ist.