From 0fd9503a53ad6836ac445d7d384b8f153b93a158 Mon Sep 17 00:00:00 2001
From: Marvin Hagemeister <hello@marvinh.dev>
Date: Tue, 29 Jul 2025 13:37:21 +0200
Subject: [PATCH] fix: make prefresh hmr integration easier

The callback to `useMemo` is assumed to be pure during HMR and will be re-triggered. This in turn broke the `useSignal` hooks HMR as they used side-effectful callbacks.
---
 .changeset/odd-tigers-remember.md | 5 +++++
 packages/preact/src/index.ts      | 9 ++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/odd-tigers-remember.md

diff --git a/.changeset/odd-tigers-remember.md b/.changeset/odd-tigers-remember.md
new file mode 100644
index 000000000..dc713a33c
--- /dev/null
+++ b/.changeset/odd-tigers-remember.md
@@ -0,0 +1,5 @@
+---
+"@preact/signals": patch
+---
+
+Fix prefresh HMR not working with `useSignal`.
diff --git a/packages/preact/src/index.ts b/packages/preact/src/index.ts
index 466b957ae..58b59ca11 100644
--- a/packages/preact/src/index.ts
+++ b/packages/preact/src/index.ts
@@ -1,5 +1,5 @@
 import { options, Component, isValidElement, Fragment } from "preact";
-import { useRef, useMemo, useEffect } from "preact/hooks";
+import { useRef, useMemo, useEffect, useState } from "preact/hooks";
 import {
 	signal,
 	computed,
@@ -387,10 +387,9 @@ Component.prototype.shouldComponentUpdate = function (
 export function useSignal<T>(value: T, options?: SignalOptions<T>): Signal<T>;
 export function useSignal<T = undefined>(): Signal<T | undefined>;
 export function useSignal<T>(value?: T, options?: SignalOptions<T>) {
-	return useMemo(
-		() => signal<T | undefined>(value, options as SignalOptions),
-		[]
-	);
+	return useState(() =>
+		signal<T | undefined>(value, options as SignalOptions)
+	)[0];
 }
 
 export function useComputed<T>(compute: () => T, options?: SignalOptions<T>) {