work on turning pl-hooks into a separate library

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

packages/pl-hooks/lib/utils/queries.ts

@@ -0,0 +1,12 @@
+import type { InfiniteData } from '@tanstack/react-query';
+import type { PaginatedResponse } from 'pl-api';
+
+/** Flatten paginated results into a single array. */
+const flattenPages = <T>(queryData: InfiniteData<Pick<PaginatedResponse<T>, 'items'>> | undefined) => {
+  return queryData?.pages.reduce<T[]>(
+    (prev: T[], curr) => [...prev, ...(curr.items)],
+    [],
+  );
+};
+
+export { flattenPages };