Remove seeing useContext as HOOKS_STATE

Author: JoviDeCroock

.changeset/lucky-pears-brake.md

@@ -0,0 +1,5 @@
+---
+"@preact/signals": patch
+---
+
+Stop treating `useContext` as hook state in the auto-memoization heuristic. Context updates force-update their subscribers in Preact, bypassing `shouldComponentUpdate` entirely, so context consumers can safely keep the props-based render skipping.

packages/preact/src/index.ts

@@ -387,9 +387,14 @@ hook(OptionsTypes.UNMOUNT, (old, vnode: VNode) => {
 	old(vnode);
 });
 
-/** Mark components that use hook state so we can skip sCU optimization. */
+/**
+ * Mark components that use hook state so we can skip sCU optimization.
+ * Note: useContext (type 9) is deliberately not included — context updates
+ * force-update their subscribers, bypassing shouldComponentUpdate entirely:
+ * https://github.com/preactjs/preact/blob/main/src/create-context.js#L24
+ */
 hook(OptionsTypes.HOOK, (old, component, index, type) => {
-	if (type < 3 || type === 9)
+	if (type < 3)
 		(component as AugmentedComponent)._updateFlags |= HAS_HOOK_STATE;
 	old(component, index, type);
 });