From e12a9dfc96be12ea8e5c759986041ee5308e8e06 Mon Sep 17 00:00:00 2001
From: Douglas Armstrong <dougarmstrong@fb.com>
Date: Thu, 20 Jan 2022 07:22:17 -0800
Subject: [PATCH] Fix production-only updateSyncExternalStore() crash when
 doing setState in render (#23150)

* Update ReactFiberHooks.new.js

* Add regression test + replace-fork

* Prettier

Co-authored-by: Dan Abramov <dan.abramov@me.com>
---
 .../src/ReactFiberHooks.new.js                |  2 +-
 .../src/ReactFiberHooks.old.js                |  2 +-
 .../useSyncExternalStoreShared-test.js        | 27 +++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/packages/react-reconciler/src/ReactFiberHooks.new.js b/packages/react-reconciler/src/ReactFiberHooks.new.js
index cf8086b075aa2..7747a25c858ed 100644
--- a/packages/react-reconciler/src/ReactFiberHooks.new.js
+++ b/packages/react-reconciler/src/ReactFiberHooks.new.js
@@ -2471,7 +2471,7 @@ const HooksDispatcherOnRerender: Dispatcher = {
   useDeferredValue: rerenderDeferredValue,
   useTransition: rerenderTransition,
   useMutableSource: updateMutableSource,
-  useSyncExternalStore: mountSyncExternalStore,
+  useSyncExternalStore: updateSyncExternalStore,
   useId: updateId,
 
   unstable_isNewReconciler: enableNewReconciler,
diff --git a/packages/react-reconciler/src/ReactFiberHooks.old.js b/packages/react-reconciler/src/ReactFiberHooks.old.js
index ff2aff6720e11..d7137e8cd7f66 100644
--- a/packages/react-reconciler/src/ReactFiberHooks.old.js
+++ b/packages/react-reconciler/src/ReactFiberHooks.old.js
@@ -2471,7 +2471,7 @@ const HooksDispatcherOnRerender: Dispatcher = {
   useDeferredValue: rerenderDeferredValue,
   useTransition: rerenderTransition,
   useMutableSource: updateMutableSource,
-  useSyncExternalStore: mountSyncExternalStore,
+  useSyncExternalStore: updateSyncExternalStore,
   useId: updateId,
 
   unstable_isNewReconciler: enableNewReconciler,
diff --git a/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js b/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js
index 5af9e9767ab0c..cb3a40aa13ab7 100644
--- a/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js
+++ b/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js
@@ -745,6 +745,33 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
     });
   });
 
+  test('regression test for #23150', async () => {
+    const store = createExternalStore('Initial');
+
+    function App() {
+      const text = useSyncExternalStore(store.subscribe, store.getState);
+      const [derivedText, setDerivedText] = useState(text);
+      useEffect(() => {}, []);
+      if (derivedText !== text.toUpperCase()) {
+        setDerivedText(text.toUpperCase());
+      }
+      return <Text text={derivedText} />;
+    }
+
+    const container = document.createElement('div');
+    const root = createRoot(container);
+    await act(() => root.render(<App />));
+
+    expect(Scheduler).toHaveYielded(['INITIAL']);
+    expect(container.textContent).toEqual('INITIAL');
+
+    await act(() => {
+      store.set('Updated');
+    });
+    expect(Scheduler).toHaveYielded(['UPDATED']);
+    expect(container.textContent).toEqual('UPDATED');
+  });
+
   // The selector implementation uses the lazy ref initialization pattern
   // @gate !(enableUseRefAccessWarning && __DEV__)
   test('compares selection to rendered selection even if selector changes', async () => {