Is the typing on MutationUpdaterFn correct?

[dphrag]

In node_modules\@apollo\client\core\watchQueryOptions.d.ts the MutationUpdaterFn is defined as

export declare type MutationUpdaterFn<T = { [key: string]: any; }> = (cache: ApolloCache<T>, mutationResult: FetchResult<T>) => void;

The generic T type gets passed into ApolloCache, however this cache object doesn't have anything to do with the fetch result. To me this looks wrong, and ends up describing parts of the ApolloCache incorrectly.

[benjamn]

@dphrag You're right about this! We've rewritten these types in the upcoming Apollo Client v3.4 release (see #7902), and the MutationUpdaterFunction type now looks like this:

export type MutationUpdaterFunction<
  TData,
  TVariables,
  TContext,
  TCache extends ApolloCache<any>
> = (
  cache: TCache,
  result: Omit<FetchResult<TData>, 'context'>,
  options: {
    context?: TContext,
    variables?: TVariables,
  },
) => void;

If you have a chance, try updating with npm i @apollo/client@beta. We're in the Release Candidate phase of testing, so the prerelease versions should be pretty stable at this point.

[dphrag]

Thanks!! I was worried I had gone mad, typing can be confusing :P