fix(types): allow returning of any promise in the mutation callbacks (TanStack#2189)

Author: TkDodo

docs/src/pages/reference/useMutation.md

@@ -46,15 +46,15 @@ mutate(variables, {
   - This function will fire before the mutation function is fired and is passed the same variables the mutation function would receive
   - Useful to perform optimistic updates to a resource in hopes that the mutation succeeds
   - The value returned from this function will be passed to both the `onError` and `onSettled` functions in the event of a mutation failure and can be useful for rolling back optimistic updates.
-- `onSuccess: (data: TData, variables: TVariables, context?: TContext) => Promise<void> | void`
+- `onSuccess: (data: TData, variables: TVariables, context?: TContext) => Promise<unknown> | void`
   - Optional
   - This function will fire when the mutation is successful and will be passed the mutation's result.
   - If a promise is returned, it will be awaited and resolved before proceeding
-- `onError: (err: TError, variables: TVariables, context?: TContext) => Promise<void> | void`
+- `onError: (err: TError, variables: TVariables, context?: TContext) => Promise<unknown> | void`
   - Optional
   - This function will fire if the mutation encounters an error and will be passed the error.
   - If a promise is returned, it will be awaited and resolved before proceeding
-- `onSettled: (data: TData, error: TError, variables: TVariables, context?: TContext) => Promise<void> | void`
+- `onSettled: (data: TData, error: TError, variables: TVariables, context?: TContext) => Promise<unknown> | void`
   - Optional
   - This function will fire when the mutation is either successfully fetched or encounters an error and be passed either the data or error
   - If a promise is returned, it will be awaited and resolved before proceeding

src/core/types.ts

@@ -225,7 +225,13 @@ export interface FetchInfiniteQueryOptions<
   TError = unknown,
   TData = TQueryFnData,
   TQueryKey extends QueryKey = QueryKey
-> extends FetchQueryOptions<TQueryFnData, TError, InfiniteData<TData>, TQueryKey> {}
+>
+  extends FetchQueryOptions<
+    TQueryFnData,
+    TError,
+    InfiniteData<TData>,
+    TQueryKey
+  > {}
 
 export interface ResultOptions {
   throwOnError?: boolean
@@ -474,23 +480,25 @@ export interface MutationOptions<
   mutationFn?: MutationFunction<TData, TVariables>
   mutationKey?: MutationKey
   variables?: TVariables
-  onMutate?: (variables: TVariables) => Promise<TContext> | Promise<undefined> | TContext | undefined
+  onMutate?: (
+    variables: TVariables
+  ) => Promise<TContext> | Promise<undefined> | TContext | undefined
   onSuccess?: (
     data: TData,
     variables: TVariables,
     context: TContext
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   onError?: (
     error: TError,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   onSettled?: (
     data: TData | undefined,
     error: TError | null,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   retry?: RetryValue<TError>
   retryDelay?: RetryDelayValue<TError>
   _defaulted?: boolean
@@ -515,18 +523,18 @@ export interface MutateOptions<
     data: TData,
     variables: TVariables,
     context: TContext
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   onError?: (
     error: TError,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   onSettled?: (
     data: TData | undefined,
     error: TError | null,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
 }
 
 export type MutateFunction<

src/react/types.ts

@@ -85,18 +85,18 @@ export interface UseMutationOptions<
     data: TData,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   onError?: (
     error: TError,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   onSettled?: (
     data: TData | undefined,
     error: TError | null,
     variables: TVariables,
     context: TContext | undefined
-  ) => Promise<void> | void
+  ) => Promise<unknown> | void
   retry?: RetryValue<TError>
   retryDelay?: RetryDelayValue<TError>
   useErrorBoundary?: boolean