From e7592de518ed226b4eb2fc44036bd8588c3e7c43 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Fri, 24 Mar 2023 16:44:26 +0100
Subject: [PATCH 1/4] useEffectEvent: Highlight wrong types

---
 packages/react/src/ReactHooks.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react/src/ReactHooks.js b/packages/react/src/ReactHooks.js
index 7f1bc8d5e133b..4c6a065b7e7dc 100644
--- a/packages/react/src/ReactHooks.js
+++ b/packages/react/src/ReactHooks.js
@@ -236,6 +236,6 @@ export function useMemoCache(size: number): Array<any> {
 
 export function useEffectEvent<T>(callback: T): void {
   const dispatcher = resolveDispatcher();
-  // $FlowFixMe This is unstable, thus optional
+  // $FlowFixMe[not-a-function]
   return dispatcher.useEffectEvent(callback);
 }

From d849cbc70c82e82d0ff131a7b19bd6969de0b155 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Fri, 24 Mar 2023 16:44:57 +0100
Subject: [PATCH 2/4] Fix Flow types of useEffectEvent

---
 packages/react/src/ReactHooks.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/react/src/ReactHooks.js b/packages/react/src/ReactHooks.js
index 4c6a065b7e7dc..d7e7aa5458c9f 100644
--- a/packages/react/src/ReactHooks.js
+++ b/packages/react/src/ReactHooks.js
@@ -234,8 +234,10 @@ export function useMemoCache(size: number): Array<any> {
   return dispatcher.useMemoCache(size);
 }
 
-export function useEffectEvent<T>(callback: T): void {
+export function useEffectEvent<Args, Return, F: (...Array<Args>) => Return>(
+  callback: F,
+): F {
   const dispatcher = resolveDispatcher();
-  // $FlowFixMe[not-a-function]
+  // $FlowFixMe[not-a-function] This is unstable, thus optional
   return dispatcher.useEffectEvent(callback);
 }

From 048d91b016cfcda766ea91084ee39e73fca3d92c Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Fri, 24 Mar 2023 16:50:34 +0100
Subject: [PATCH 3/4] Narrow down FlowFixMe for other hooks as well

---
 packages/react/src/ReactHooks.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/react/src/ReactHooks.js b/packages/react/src/ReactHooks.js
index d7e7aa5458c9f..d80a8c3b56a24 100644
--- a/packages/react/src/ReactHooks.js
+++ b/packages/react/src/ReactHooks.js
@@ -218,19 +218,19 @@ export function useSyncExternalStore<T>(
 
 export function useCacheRefresh(): <T>(?() => T, ?T) => void {
   const dispatcher = resolveDispatcher();
-  // $FlowFixMe This is unstable, thus optional
+  // $FlowFixMe[not-a-function] This is unstable, thus optional
   return dispatcher.useCacheRefresh();
 }
 
 export function use<T>(usable: Usable<T>): T {
   const dispatcher = resolveDispatcher();
-  // $FlowFixMe This is unstable, thus optional
+  // $FlowFixMe[not-a-function] This is unstable, thus optional
   return dispatcher.use(usable);
 }
 
 export function useMemoCache(size: number): Array<any> {
   const dispatcher = resolveDispatcher();
-  // $FlowFixMe This is unstable, thus optional
+  // $FlowFixMe[not-a-function] This is unstable, thus optional
   return dispatcher.useMemoCache(size);
 }
 

From f932f3450913fa48672ca867af405b7d00fb2001 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 25 Mar 2023 18:41:58 +0100
Subject: [PATCH 4/4] Simplify useEffectEvent types

---
 packages/react-reconciler/src/ReactInternalTypes.js | 4 +---
 packages/react/src/ReactHooks.js                    | 2 +-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/packages/react-reconciler/src/ReactInternalTypes.js b/packages/react-reconciler/src/ReactInternalTypes.js
index 7f01daa5240da..a672b9669abcf 100644
--- a/packages/react-reconciler/src/ReactInternalTypes.js
+++ b/packages/react-reconciler/src/ReactInternalTypes.js
@@ -383,9 +383,7 @@ export type Dispatcher = {
     create: () => (() => void) | void,
     deps: Array<mixed> | void | null,
   ): void,
-  useEffectEvent?: <Args, Return, F: (...Array<Args>) => Return>(
-    callback: F,
-  ) => F,
+  useEffectEvent?: <Args, F: (...Array<Args>) => mixed>(callback: F) => F,
   useInsertionEffect(
     create: () => (() => void) | void,
     deps: Array<mixed> | void | null,
diff --git a/packages/react/src/ReactHooks.js b/packages/react/src/ReactHooks.js
index d80a8c3b56a24..6d157cbc60289 100644
--- a/packages/react/src/ReactHooks.js
+++ b/packages/react/src/ReactHooks.js
@@ -234,7 +234,7 @@ export function useMemoCache(size: number): Array<any> {
   return dispatcher.useMemoCache(size);
 }
 
-export function useEffectEvent<Args, Return, F: (...Array<Args>) => Return>(
+export function useEffectEvent<Args, F: (...Array<Args>) => mixed>(
   callback: F,
 ): F {
   const dispatcher = resolveDispatcher();