ColumnDef

A column definition is one object. The variants differ only in where the value comes from: an accessor key, an accessor function, nothing at all (a display column), or nested columns (a group column).

Writing the type down

TValue is inferred by createColumnHelper, so cell and format see the narrowed value. That is also why ColumnDef<TData> is the wrong annotation for an array of them: it defaults TValue to unknown, and a helper-built column will not assign to it. Use AnyColumnDef<TData>, which is what the columns prop takes:

import type { AnyColumnDef } from '@kingtech/react-tablekit';

export const columns: AnyColumnDef<Person>[] = [
  col.accessor('name', { header: 'Name' }),
  col.accessor('score', { header: 'Score', format: (v) => v.toFixed(1) }),
];

If the array stays in the same module as the table, let it infer and skip the annotation.

Reference

Related

• Columns
• Column filters
• Column sizing