| id: query-options | |
| title: Mutation Options | |
| One of the best ways to share mutation options between multiple places, | |
| is to use the `mutationOptions` helper. At runtime, this helper just returns whatever you pass into it, | |
| but it has a lot of advantages when using it [with TypeScript](../../typescript#typing-query-options.md). | |
| You can define all possible options for a mutation in one place, | |
| and you'll also get type inference and type safety for all of them. | |
| ```ts | |
| export class QueriesService { | |
| private http = inject(HttpClient) | |
| updatePost(id: number) { | |
| return mutationOptions({ | |
| mutationFn: (post: Post) => Promise.resolve(post), | |
| mutationKey: ['updatePost', id], | |
| onSuccess: (newPost) => { | |
| // ^? newPost: Post | |
| this.queryClient.setQueryData(['posts', id], newPost) | |
| }, | |
| }) | |
| } | |
| } | |
| ``` | |