TanStack Table version

v8.21.3

Framework/Library version

React v18

Describe the bug and the steps to reproduce it

This is a very similar issue to #5444
Due to this type not being exported, creating declaration files for objects that uses columnHelper.group throws a TypeScript error:

Exported variable 'foo' has or is using name 'GroupColumnDefBase' from external module "/.../@tanstack/table-core/build/lib/types" but cannot be named.

Exporting this variable resolves this issue

Your Minimal, Reproducible Example - (Sandbox Highly Recommended)

Screenshots or Videos (Optional)

No response

Do you intend to try to help solve this bug with your own PR?

Yes

Terms & Code of Conduct

• I agree to follow this project's Code of Conduct
• I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.