From 1d3dddac984c3a7870ff1ac3eebcb6a78e303269 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BA=8C=E8=B4=A7=E6=9C=BA=E5=99=A8=E4=BA=BA?=
 <smith3816@gmail.com>
Date: Wed, 5 Nov 2025 15:23:56 +0800
Subject: [PATCH 1/2] chore: useEvent type support undefined

---
 src/hooks/useEvent.ts | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/hooks/useEvent.ts b/src/hooks/useEvent.ts
index f9bb7dce..1a821eff 100644
--- a/src/hooks/useEvent.ts
+++ b/src/hooks/useEvent.ts
@@ -2,12 +2,14 @@
 /* eslint-disable react-hooks/exhaustive-deps */
 import * as React from 'react';
 
-function useEvent<T extends Function>(callback: T): T {
-  const fnRef = React.useRef<any>();
+function useEvent<T extends (...args: any[]) => any>(
+  callback: T | undefined,
+): T {
+  const fnRef = React.useRef<T | undefined>(callback);
   fnRef.current = callback;
 
-  const memoFn = React.useCallback<T>(
-    ((...args: any) => fnRef.current?.(...args)) as any,
+  const memoFn = React.useCallback(
+    ((...args) => fnRef.current?.(...args)) as T,
     [],
   );
 

From 7eb618d78aa1c4604d891ce93bf6bf125c0b1d54 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BA=8C=E8=B4=A7=E6=9C=BA=E5=99=A8=E4=BA=BA?=
 <smith3816@gmail.com>
Date: Wed, 5 Nov 2025 15:43:04 +0800
Subject: [PATCH 2/2] chore: update

---
 src/hooks/useEvent.ts | 12 ++++++++----
 tests/hooks.test.tsx  | 20 ++++++++++++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/hooks/useEvent.ts b/src/hooks/useEvent.ts
index 1a821eff..4c6f92a0 100644
--- a/src/hooks/useEvent.ts
+++ b/src/hooks/useEvent.ts
@@ -2,14 +2,18 @@
 /* eslint-disable react-hooks/exhaustive-deps */
 import * as React from 'react';
 
-function useEvent<T extends (...args: any[]) => any>(
-  callback: T | undefined,
-): T {
+function useEvent<T extends ((...args: any[]) => any) | undefined>(
+  callback: T,
+): undefined extends T
+  ? (
+      ...args: Parameters<NonNullable<T>>
+    ) => ReturnType<NonNullable<T>> | undefined
+  : T {
   const fnRef = React.useRef<T | undefined>(callback);
   fnRef.current = callback;
 
   const memoFn = React.useCallback(
-    ((...args) => fnRef.current?.(...args)) as T,
+    (...args: any[]) => fnRef.current?.(...args),
     [],
   );
 
diff --git a/tests/hooks.test.tsx b/tests/hooks.test.tsx
index b8154c66..fc096500 100644
--- a/tests/hooks.test.tsx
+++ b/tests/hooks.test.tsx
@@ -9,6 +9,7 @@ import useMobile from '../src/hooks/useMobile';
 import useState from '../src/hooks/useState';
 import useSyncState from '../src/hooks/useSyncState';
 import useControlledState from '../src/hooks/useControlledState';
+import useEvent from '../src/hooks/useEvent';
 
 global.disableUseId = false;
 
@@ -706,4 +707,23 @@ describe('hooks', () => {
       expect(container.textContent).toEqual('2');
     });
   });
+
+  describe('useEvent', () => {
+    it('extract type', () => {
+      const Demo = (props: {
+        canUndefined?: (a: number) => boolean;
+        notUndefined: (a: number) => boolean;
+      }) => {
+        const ua = useEvent(props.canUndefined);
+        const ub = useEvent(props.notUndefined);
+
+        ua(1);
+        ub(2);
+
+        return null;
+      };
+
+      expect(Demo).toBeTruthy();
+    });
+  });
 });