TanStack Query: need last-modified from response header

[topical]

Description

Hi,

I use the TanStack Query code generator and need access to response header.

In my scenario, REST-API requires 'If-Unmodified-Since' header to be passed to properly handle concurrent updates.

For this, I need to extract 'last-modified' from response headers. Actually, this looks like being almost impossible with code generated by HeyAPI.

E.g. I have an endpoint to retrieve information about a user. HeyAPI generates the following code for this:

export const getUserQueryQueryKey = (options?: OptionsLegacyParser<GetUserQueryData>) => [
  createQueryKey('getUserQuery', options),
]

export const getUserQueryOptions = (options?: OptionsLegacyParser<GetUserQueryData>) => {
  return queryOptions({
    queryFn: async ({ queryKey, signal }) => {
      // watch out: response header is discarded here!
      const { data } = await getUserQuery({
        ...options,
        ...queryKey[0],
        signal,
        throwOnError: true,
      })
      return data
    },
    queryKey: getUserQueryQueryKey(options),
  })
}

You see that the response header is discarded deeply inside.

Effectively, I have to rewrite getUserQueryQueryKey() and getUserQueryOptions(). That's kind of OK for a single API-endpoint, but not suitable for my application.

So: is there any idea to handle this more generic?

Thank you!

[MeCapron]

Hello,

I'm running into the same exact issue to extract the filename of a downloaded file using responseType blob!

[mrlubos]

@topical @MeCapron would you want to modify the response from TanStack query so that data becomes data.data and there'd be a new field data.headers?