fix(types): make sure queryClient.setQueryData can return undefined from the updater

Author: TkDodo

src/core/queryClient.ts

@@ -148,19 +148,19 @@ export class QueryClient {
 
   setQueriesData<TData>(
     queryKey: QueryKey,
-    updater: Updater<TData | undefined, TData>,
+    updater: Updater<TData | undefined, TData | undefined>,
     options?: SetDataOptions
-  ): [QueryKey, TData][]
+  ): [QueryKey, TData | undefined][]
 
   setQueriesData<TData>(
     filters: QueryFilters,
-    updater: Updater<TData | undefined, TData>,
+    updater: Updater<TData | undefined, TData | undefined>,
     options?: SetDataOptions
-  ): [QueryKey, TData][]
+  ): [QueryKey, TData | undefined][]
 
   setQueriesData<TData>(
     queryKeyOrFilters: QueryKey | QueryFilters,
-    updater: Updater<TData | undefined, TData>,
+    updater: Updater<TData | undefined, TData | undefined>,
     options?: SetDataOptions
   ): [QueryKey, TData | undefined][] {
     return notifyManager.batch(() =>

src/core/tests/queryClient.test.tsx

@@ -386,9 +386,8 @@ describe('queryClient', () => {
       queryClient.setQueryData(['key', 1], 1)
       queryClient.setQueryData(['key', 2], 2)
 
-      const result = queryClient.setQueriesData<number>(
-        ['key'],
-        old => old! + 5
+      const result = queryClient.setQueriesData<number>(['key'], old =>
+        old ? old + 5 : undefined
       )
 
       expect(result).toEqual([