How to get a non-undefined initial pageParam when using useInfiniteQuery

[leanmiguel]

Hello,

Not well-versed in typescript so I've been having a hard time trying to figure out how to get a non-undefined initial pageParam returned from data when using useInfiniteQuery.

I've seen this on line 97 in the useInfiniteQuery.test.tsx file ,
expect(states[1]).toEqual({data: { pages: [0], pageParams: [undefined] },

and am wordering if it's even possible to get a pageParam that is not undefined for the first return.

[leanmiguel]

This was answered in the discord by @TkDodo

my codesandbox example is here: https://codesandbox.io/s/boring-resonance-rwito
and the answer is

for the first page, pageParams will always be undefined, as pageParams for each page is derived from the response of the previous page. The 0th page has no previous page to derive the data from