From 6ac153ef595f823ec29a131fa00143fcbd837a28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89verton=20Toffanetto?= <evertondgn@hotmail.com>
Date: Thu, 5 Nov 2026 00:37:29 -0300
Subject: [PATCH] fix(store): support null-prototype objects on the server

---
 .changeset/server-null-prototype-stores.md    |  5 +++
 packages/solid/store/src/server.ts            |  3 +-
 .../test/server/null-prototype-store.spec.ts  | 41 +++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/server-null-prototype-stores.md
 create mode 100644 packages/solid/test/server/null-prototype-store.spec.ts

diff --git a/.changeset/server-null-prototype-stores.md b/.changeset/server-null-prototype-stores.md
new file mode 100644
index 0000000000..0d3aa1ecc5
--- /dev/null
+++ b/.changeset/server-null-prototype-stores.md
@@ -0,0 +1,5 @@
+---
+"solid-js": patch
+---
+
+Support null-prototype objects in server store producers, reconciliation, and nested partial updates.
diff --git a/packages/solid/store/src/server.ts b/packages/solid/store/src/server.ts
index 127c908545..5b007fb1f9 100644
--- a/packages/solid/store/src/server.ts
+++ b/packages/solid/store/src/server.ts
@@ -18,10 +18,11 @@ export type {
 export const $RAW = Symbol("state-raw");
 
 export function isWrappable(obj: any) {
+  let proto;
   return (
     obj != null &&
     typeof obj === "object" &&
-    (Object.getPrototypeOf(obj) === Object.prototype || Array.isArray(obj))
+    (!(proto = Object.getPrototypeOf(obj)) || proto === Object.prototype || Array.isArray(obj))
   );
 }
 
diff --git a/packages/solid/test/server/null-prototype-store.spec.ts b/packages/solid/test/server/null-prototype-store.spec.ts
new file mode 100644
index 0000000000..9c629c7e3b
--- /dev/null
+++ b/packages/solid/test/server/null-prototype-store.spec.ts
@@ -0,0 +1,41 @@
+import { describe, expect, test } from "vitest";
+import { createStore, produce, reconcile } from "../../store/src/server.js";
+
+describe("null-prototype stores on the server", () => {
+  test("runs producers on a null-prototype object", () => {
+    const original = Object.assign(Object.create(null), { count: 1 });
+    const [state, setState] = createStore<{ count: number }>(original);
+
+    setState(produce(state => state.count++));
+
+    expect(state.count).toBe(2);
+    expect(state).toBe(original);
+    expect(Object.getPrototypeOf(state)).toBeNull();
+  });
+
+  test("reconciles removed properties of a null-prototype object", () => {
+    const original = Object.assign(Object.create(null), { count: 1, removed: true });
+    const [state, setState] = createStore<{ count: number; removed?: boolean }>(original);
+
+    setState(reconcile({ count: 2 }));
+
+    expect(state.count).toBe(2);
+    expect("removed" in state).toBe(false);
+    expect(state).toBe(original);
+    expect(Object.getPrototypeOf(state)).toBeNull();
+  });
+
+  test("merges partial updates into a nested null-prototype object", () => {
+    const original = Object.assign(Object.create(null), { count: 1, label: "kept" });
+    const [state, setState] = createStore<{ data: { count: number; label: string } }>({
+      data: original
+    });
+
+    setState("data", { count: 2 });
+
+    expect(state.data.count).toBe(2);
+    expect(state.data.label).toBe("kept");
+    expect(state.data).toBe(original);
+    expect(Object.getPrototypeOf(state.data)).toBeNull();
+  });
+});