Removing keepPreviousData and using placeholderData

The keepPreviousData option and the isPreviousData flags have been removed. This is because they did almost the same task as the placeholderData option and the isPlaceholderData flag.

So that placeholderData can fully do exactly the same thing as keepPreviousData, the previous query data was added as an argument to the placeholderData function. This now means that by leveraging the keepPreviousData custom function from React Query, useQuery will allow placeholderData to work the same way as keepPreviousData did previously.

Let us see how our PaginatedQuery code changes in v5:

import { useQuery, keepPreviousData } from "@tanstack/react-query";
...
const PaginatedQuery = () => {
  ...
  const { isPending, isError, error, data, isFetching,
    isPlaceholderData } =
    useQuery({
      queryKey: userKeys.paginated(page),
&...