From 18a9d6f7c8e0d4b687f1bb8b6a3478ab9beee0f0 Mon Sep 17 00:00:00 2001
From: SukkaW <isukkaw@gmail.com>
Date: Sat, 16 Sep 2023 15:36:03 +0800
Subject: [PATCH] fix(#9): disallow debounce of a function

---
 src/use-debounced-value/index.ts | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/use-debounced-value/index.ts b/src/use-debounced-value/index.ts
index 3e91c7e2..3ab6e7ff 100644
--- a/src/use-debounced-value/index.ts
+++ b/src/use-debounced-value/index.ts
@@ -1,8 +1,15 @@
 import 'client-only';
 import { useEffect, useState, useRef } from 'react';
 
+// eslint-disable-next-line @typescript-eslint/ban-types -- explicitly baning ALL functions
+type NotFunction<T> = T extends Function ? never : T;
+
 /** @see https://foxact.skk.moe/use-debounced-value */
-export function useDebouncedValue<T>(value: T, wait: number, leading = false) {
+export function useDebouncedValue<T>(value: NotFunction<T>, wait: number, leading = false) {
+  if (typeof value === 'function') {
+    throw new TypeError('useDebouncedValue does not support function as value');
+  }
+
   const [outputValue, setOutputValue] = useState(value);
   const leadingRef = useRef(true);