docs: ensureInfiniteQueryData

Author: TkDodo

docs/reference/QueryClient.md

@@ -29,6 +29,7 @@ Its available methods are:
 - [`queryClient.prefetchInfiniteQuery`](#queryclientprefetchinfinitequery)
 - [`queryClient.getQueryData`](#queryclientgetquerydata)
 - [`queryClient.ensureQueryData`](#queryclientensurequerydata)
+- [`queryClient.ensureInfiniteQueryData`](#queryclientensureinfinitequerydata)
 - [`queryClient.getQueriesData`](#queryclientgetqueriesdata)
 - [`queryClient.setQueryData`](#queryclientsetquerydata)
 - [`queryClient.getQueryState`](#queryclientgetquerystate)
@@ -200,6 +201,31 @@ const data = await queryClient.ensureQueryData({ queryKey, queryFn })
 
 - `Promise<TData>`
 
+## `queryClient.ensureInfiniteQueryData`
+
+`ensureInfiniteQueryData` is an asynchronous function that can be used to get an existing infinite query's cached data. If the query does not exist, `queryClient.fetchInfiniteQuery` will be called and its results returned.
+
+```tsx
+const data = await queryClient.ensureInfiniteQueryData({
+  queryKey,
+  queryFn,
+  initialPageParam,
+  getNextPageParam,
+})
+```
+
+**Options**
+
+- the same options as [`fetchInfiniteQuery`](#queryclientfetchinfinitequery)
+- `revalidateIfStale: boolean`
+  - Optional
+  - Defaults to `false`
+  - If set to `true`, stale data will be refetched in the background, but cached data will be returned immediately.
+
+**Returns**
+
+- `Promise<InfiniteData<TData, TPageParam>>`
+
 ## `queryClient.getQueriesData`
 
 `getQueriesData` is a synchronous function that can be used to get the cached data of multiple queries. Only queries that match the passed queryKey or queryFilter will be returned. If there are no matching queries, an empty array will be returned.