From 9d5931a70851da9ee4f067a8a3448637d282bcf1 Mon Sep 17 00:00:00 2001
From: Dominik Dorfmeister <office@dorfmeister.cc>
Date: Sat, 14 May 2022 20:27:43 +0200
Subject: [PATCH] fix(queryClient): make sure that setQueryData can return
 undefined from the updater function on type level

the only runtime tests we had didn't use the previous value, so the generic defaults to unknown; the TS error becomes apparent when providing a generic to setQueryData
---
 src/core/queryClient.ts             | 2 +-
 src/core/tests/queryClient.test.tsx | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/core/queryClient.ts b/src/core/queryClient.ts
index 15afee437a..1656b955e2 100644
--- a/src/core/queryClient.ts
+++ b/src/core/queryClient.ts
@@ -128,7 +128,7 @@ export class QueryClient {
 
   setQueryData<TData>(
     queryKey: QueryKey,
-    updater: Updater<TData | undefined, TData> | undefined,
+    updater: Updater<TData | undefined, TData | undefined>,
     options?: SetDataOptions
   ): TData | undefined {
     const query = this.queryCache.find<TData>(queryKey)
diff --git a/src/core/tests/queryClient.test.tsx b/src/core/tests/queryClient.test.tsx
index e08c454c2a..3675f6c283 100644
--- a/src/core/tests/queryClient.test.tsx
+++ b/src/core/tests/queryClient.test.tsx
@@ -311,8 +311,8 @@ describe('queryClient', () => {
 
     test('should not update query data if updater returns undefined', () => {
       const key = queryKey()
-      queryClient.setQueryData(key, 'qux')
-      queryClient.setQueryData(key, () => undefined)
+      queryClient.setQueryData<string>(key, 'qux')
+      queryClient.setQueryData<string>(key, () => undefined)
       expect(queryClient.getQueryData(key)).toBe('qux')
     })