[Feature Request] getQueryKey() function to help with optimistic updates in tanstack-Query

[ErikDakoda]

Background: In tanstack-query the query key is required for queryClient.setQueryData() to implement optimistic updates.

Currently a query key is a triad of :[ModelName, QueryURL, QueryArgs], so for example for useUserFindUnique, the key will be: ['User', 'http://.../user/findUnique%60, queryArgs]. Computing it manually is not recommended, as it may change in the future.

Here is how this may work:

import { getQueryKey } from "@zenstackhq/tanstack-query";

const queryClient = useQueryClient();

// get query key for the current post
const postKey = getQueryKey('Post', 'findUnique', { where: { id: postId } });

const updatePost = useUpdatePost({
  onMutate: (newData) => {
    const previous = queryClient.getQueryData(postKey);
    // optimistically update the current post
    queryClient.setQueryData(postKey, (old) => ({...old, ...newData.data});
    return { previous };
  },
  onError: (err, newData, context) => {
    queryClient.setQueryData(postKey, context.previous);
  }
});

const onUpdate = () => {
  updatePost.mutate(...);
};

It would be great to also have a getQueryKeys() function that accepts partial parameters and returns an array of matches. For example getQueryKeys({ modelName: 'Post' }) for all Post queries or getQueryKeys({ queryArgs: { select: { posts: true } } }) for all queries with a relation to posts.

It would also be nice if the result object returned by query functions like findUnique would also include the query key. Of course, if you are just passing the result returned by tanstack-query you may not want to mutate that object.

[Azzerty23]

I've just seen that React Query v5 has re-implemented optimistic updates. As I understand it, we don't need to retrieve the old cached data anymore. Instead useMutation() hook returns variables directly, and if we want to retrieve these variables in another place, we can do so via useMutationState() by passing the mutationKey. So, we shouldn't need a function like getQueryKey() I guess.

Waiting #780 from now 😄

[Azzerty23]

Sorry, still needed for invalidate cache

[ymc9]

getQueryKey function is now available in v1.2.0 through @zenstackhq/tanstack-query/runtime and @zenstackhq/swr/runtime.

Closing this issue for now. Automatic optimistic update is tracked separately here: #795