Infinite Query

import { InfiniteQuery } from '@soulcache/core';

new InfiniteQuery<TData, TPageParam>(options: InfiniteQueryOptions<TData, TPageParam>)

interface InfiniteQueryOptions<TData, TPageParam> {
  readonly queryKey: QueryKey;
  readonly queryFn: (context: { pageParam: TPageParam; signal?: AbortSignal }) => Promise<TData>;
  readonly initialPageParam?: TPageParam;       // default: 0
  readonly getNextPageParam: (
    lastPage: TData, allPages: TData[],
    lastPageParam: unknown, allPageParams: unknown[],
  ) => TPageParam | undefined;
  readonly getPreviousPageParam?: (
    firstPage: TData, allPages: TData[],
    firstPageParam: unknown, allPageParams: unknown[],
  ) => TPageParam | undefined;
  readonly enabled?: boolean;
  readonly staleTime?: number;
  readonly gcTime?: number;
  readonly maxPages?: number;                   // default: Infinity
}

interface InfiniteQueryState<TData> {
  readonly pages: InfiniteQueryPage<TData>[];
  readonly pageParams: unknown[];
  readonly hasNextPage: boolean;
  readonly hasPreviousPage: boolean;
  readonly isFetchingNextPage: boolean;
  readonly isFetchingPreviousPage: boolean;
  readonly error: Error | null;
}

interface InfiniteQueryPage<TData> {
  readonly data: TData;
  readonly pageParam: unknown;
  readonly pageIndex: number;
}

fetch(): Promise<void>

fetchNextPage(): Promise<boolean>

fetchPreviousPage(): Promise<boolean>

subscribe(listener: () => void): () => void

cancel(): void

reset(): void

destroy(): void

import { InfiniteQuery } from '@soulcache/core';
 
const query = new InfiniteQuery({
  queryKey: ['posts'],
  queryFn: async ({ pageParam }) => {
    const response = await fetch(`/api/posts?page=${pageParam}`);
    return response.json();
  },
  getNextPageParam: (lastPage) => lastPage.nextCursor,
  getPreviousPageParam: (firstPage) => firstPage.prevCursor,
});
 
// Fetch first page
await query.fetch();
 
// Fetch next page
const hasNext = await query.fetchNextPage();
 
// Subscribe to updates
const unsubscribe = query.subscribe(() => {
  console.log(query.data);
  console.log(query.hasNextPage);
});