Invalid Typescript of "getRowId" props when "isLoading" is true and "data" is empty

[peanudge]

material-react-table version

v3.2.1

react & react-dom versions

v19.2.0

Describe the bug and the steps to reproduce it

This issue is just typescript bug, but i hope MRT has better typescript for safety type.

When insert data: [] and state: { isLoading: true } and getRowId: (data) => data.id.toString() as useMeterialReactTable props, getRowId function raise exception (Cannot read properties of null (reading 'toString')).

=> i believe natuaral situation with empty data and loading.

useMaterialReactTable's getRowId function prop requires always TData extends MRT_RowData.

On runtime with above conditions, row data can be null-optional object by this logic for loading skeleton UI.

Minimal, Reproducible Example - (Optional, but Recommended)

https://stackblitz.com/edit/github-fofcgbmf?file=src%2FTS.tsx

Screenshots or Videos (Optional)

• getRowId argument type allows to use TData type itself

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

Yes, I think I know how to fix it and will discuss it in the comments of this issue

Terms

• I understand that if my bug cannot be reliably reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.

[stanislawski64]

I can confirm this issue - I'm also running into it in my project.

Having async data fetching (data initially []) with isLoading set to true, and conforming to typescript in getRowId, causes the app to crash at runtime.