From cb15b6af3dfb8d1e3801d6e85ac54a364784d7ae Mon Sep 17 00:00:00 2001
From: Dominik Dorfmeister <office@dorfmeister.cc>
Date: Fri, 26 May 2023 13:58:30 +0200
Subject: [PATCH 1/3] fix: have `onSuccess` return a promise too so that we can
 await it

that way, invalidation or mutations that run in onSuccess will still keep isRestoring to be false, which avoids race conditions
---
 .../src/PersistQueryClientProvider.tsx                | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/packages/react-query-persist-client/src/PersistQueryClientProvider.tsx b/packages/react-query-persist-client/src/PersistQueryClientProvider.tsx
index ecfc916a2b..fa4f8ec5b9 100644
--- a/packages/react-query-persist-client/src/PersistQueryClientProvider.tsx
+++ b/packages/react-query-persist-client/src/PersistQueryClientProvider.tsx
@@ -8,7 +8,7 @@ import { QueryClientProvider, IsRestoringProvider } from '@tanstack/react-query'
 
 export type PersistQueryClientProviderProps = QueryClientProviderProps & {
   persistOptions: Omit<PersistQueryClientOptions, 'queryClient'>
-  onSuccess?: () => void
+  onSuccess?: () => Promise<unknown> | unknown
 }
 
 export const PersistQueryClientProvider = ({
@@ -33,10 +33,13 @@ export const PersistQueryClientProvider = ({
       queryClient: client,
     })
 
-    promise.then(() => {
+    promise.then(async () => {
       if (!isStale) {
-        refs.current.onSuccess?.()
-        setIsRestoring(false)
+        try {
+          await refs.current.onSuccess?.()
+        } finally {
+          setIsRestoring(false)
+        }
       }
     })
 

From 6fb80194c6d12a701822b0e5b9111b94f5b20b1f Mon Sep 17 00:00:00 2001
From: Dominik Dorfmeister <office@dorfmeister.cc>
Date: Fri, 26 May 2023 14:03:16 +0200
Subject: [PATCH 2/3] test: test for awaiting onSuccess

---
 .../PersistQueryClientProvider.test.tsx       | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/packages/react-query-persist-client/src/__tests__/PersistQueryClientProvider.test.tsx b/packages/react-query-persist-client/src/__tests__/PersistQueryClientProvider.test.tsx
index 8c3a0c59c4..a9013eefab 100644
--- a/packages/react-query-persist-client/src/__tests__/PersistQueryClientProvider.test.tsx
+++ b/packages/react-query-persist-client/src/__tests__/PersistQueryClientProvider.test.tsx
@@ -401,6 +401,66 @@ describe('PersistQueryClientProvider', () => {
     await waitFor(() => rendered.getByText('fetched'))
   })
 
+  test('should await onSuccess after successful restoring', async () => {
+    const key = queryKey()
+
+    const queryClient = createQueryClient()
+    await queryClient.prefetchQuery({
+      queryKey: key,
+      queryFn: () => Promise.resolve('hydrated'),
+    })
+
+    const persister = createMockPersister()
+
+    await persistQueryClientSave({ queryClient, persister })
+
+    queryClient.clear()
+
+    const states: Array<string> = []
+
+    function Page() {
+      const { data, fetchStatus } = useQuery({
+        queryKey: key,
+        queryFn: async () => {
+          states.push('fetching')
+          await sleep(10)
+          states.push('fetched')
+          return 'fetched'
+        },
+      })
+
+      return (
+        <div>
+          <h1>{data}</h1>
+          <h2>fetchStatus: {fetchStatus}</h2>
+        </div>
+      )
+    }
+
+    const rendered = render(
+      <PersistQueryClientProvider
+        client={queryClient}
+        persistOptions={{ persister }}
+        onSuccess={async () => {
+          states.push('onSuccess')
+          await sleep(20)
+          states.push('onSuccess done')
+        }}
+      >
+        <Page />
+      </PersistQueryClientProvider>,
+    )
+
+    await waitFor(() => rendered.getByText('hydrated'))
+    await waitFor(() => rendered.getByText('fetched'))
+    expect(states).toEqual([
+      'onSuccess',
+      'onSuccess done',
+      'fetching',
+      'fetched',
+    ])
+  })
+
   test('should remove cache after non-successful restoring', async () => {
     const key = queryKey()
     const consoleMock = vi.spyOn(console, 'error')

From 6ba2dac0ef85f46ec76f5cdc3e19ac8f85fa5607 Mon Sep 17 00:00:00 2001
From: Dominik Dorfmeister <office@dorfmeister.cc>
Date: Fri, 26 May 2023 15:10:03 +0200
Subject: [PATCH 3/3] docs: onSuccess

---
 docs/react/plugins/persistQueryClient.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/docs/react/plugins/persistQueryClient.md b/docs/react/plugins/persistQueryClient.md
index e673c33813..2f116599fc 100644
--- a/docs/react/plugins/persistQueryClient.md
+++ b/docs/react/plugins/persistQueryClient.md
@@ -212,10 +212,11 @@ ReactDOM.createRoot(rootElement).render(
 
 - `persistOptions: PersistQueryClientOptions`
   - all [options](#options) you can pass to [persistQueryClient](#persistqueryclient) minus the QueryClient itself
-- `onSuccess?: () => void`
+- `onSuccess?: () => Promise<unknown> | unknown`
   - optional
   - will be called when the initial restore is finished
   - can be used to [resumePausedMutations](../reference/QueryClient#queryclientresumepausedmutations)
+  - if a Promise is returned, it will be awaited; restoring is seen as ongoing until then
 
 ### useIsRestoring