Vue Query's `onPaginationChange` has incorrect union type/unexpected behavior, unexpected API, "This expression is not callable. Not all constituents of type "Updater<PaginationState>" are callable"

[braden-w]

TanStack Table version

v8.11.7

Framework/Library version

Vue v3.4.15

Describe the bug and the steps to reproduce it

The onPaginationChange function in useVueTable is typed as OnChangeFn<PaginationState>, but the actual type seems to always be

(updater: (args: PaginationState) => PaginationState) => void

In my the reproduction, you'll see that the printed value for updater is

(old) => {
        let newState = functionalUpdate(updater, old);
        return newState;
      }

if you click a button to update the pagination.

This type, (updater: (args: PaginationState) => PaginationState) => void, is different than its provided unioned definition, and it's causing a type error (could I get some clarification if I'm wrong here?).

The Type Error

If you see the images, I'm getting various Typescript errors in my editor. In my first picture, it insists that my type for onPaginationChange is incorrect, despite me being sure that the implementation is working. In the second picture, when I'm inlining the function, I'm getting "This expression is not callable. Not all constituents of type "Updater<PaginationState>" are callable". This seems to be due to the definition of

export type OnChangeFn<T> = (updaterOrValue: Updater<T>) => void;
export type Updater<T> = T | ((old: T) => T)

the Union type of type Updater<T> = T | ((old: T) => T) seems to be causing this constant Typescript error, and I have been unable to resolve it without a Type assertion.

Separate Issue: onPaginationChange type was not what I expected, and the docs compounded this

I expected the onPaginationChange function to have a type

(newPaginationState: PaginationState, oldPaginationState: PaginationState) => void

rather than of type

(updater: (args: PaginationState) => PaginationState) => void

to more closely mimic the style of Vue's watch function.

Instead, I'm calling pagination.value = updatePagination(pagination.value) inside onPaginationChange, which feels somewhat cumbersome and unintuitive.

The ambiguity of current documentation and the naming of the Updater type suggest a more straightforward update mechanism, akin to typical state updates in Vue. This discrepancy between the expected and actual behavior can lead to misunderstandings about how to properly use the onPaginationChange function. In the docs, it is said:

If this function is provided, it will be called when the pagination state changes and you will be expected to manage the state yourself. You can pass the managed state back to the table via the tableOptions.state.pagination option.

This creates ambiguity and potentially misleads new users. More information on how to pass the managed state back in the table would be appreciated (such as showing an example onPaginationChange function.

Your Minimal, Reproducible Example - (Sandbox Highly Recommended)

https://stackblitz.com/edit/tanstack-table-rsbmuy?file=src%2FApp.vue

Screenshots or Videos (Optional)

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

Maybe, I'll investigate and start debugging

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• [X] I agree to follow this project's Code of Conduct
• [X] 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.

[ammuench]

+1 to this issue. docs are incredible unclear. @braden-w's solution worked but required me to pass in a ts-ignore