From 3307ed642c9b2a36b25bdedba43d0676d57fadcf Mon Sep 17 00:00:00 2001
From: Kyle June <github@kylejune.com>
Date: Sat, 26 Sep 2026 22:22:56 -0400
Subject: [PATCH] fix(testing): use document browser storage

---
 src/utils/global-jsdom.test.ts | 20 ++++++++++++++++++++
 src/utils/global-jsdom.ts      | 11 +++++++++++
 2 files changed, 31 insertions(+)

diff --git a/src/utils/global-jsdom.test.ts b/src/utils/global-jsdom.test.ts
index edbe239..4f007fb 100644
--- a/src/utils/global-jsdom.test.ts
+++ b/src/utils/global-jsdom.test.ts
@@ -4,6 +4,26 @@ import { assert, assertEquals, assertInstanceOf } from "@std/assert";
 import { describe, it } from "@std/testing/bdd";
 
 describe("global-jsdom", () => {
+  it("uses the document's storage for browser globals", () => {
+    assertEquals(globalThis.localStorage, document.defaultView!.localStorage);
+    assertEquals(
+      globalThis.sessionStorage,
+      document.defaultView!.sessionStorage,
+    );
+    localStorage.setItem("browser-storage-test", "local");
+    sessionStorage.setItem("browser-storage-test", "session");
+    assertEquals(
+      document.defaultView!.localStorage.getItem("browser-storage-test"),
+      "local",
+    );
+    assertEquals(
+      document.defaultView!.sessionStorage.getItem("browser-storage-test"),
+      "session",
+    );
+    localStorage.removeItem("browser-storage-test");
+    sessionStorage.removeItem("browser-storage-test");
+  });
+
   it("defines ResizeObserver, which JSDOM omits", () => {
     assert(
       "ResizeObserver" in globalThis,
diff --git a/src/utils/global-jsdom.ts b/src/utils/global-jsdom.ts
index d95a7e7..6d2bfc2 100644
--- a/src/utils/global-jsdom.ts
+++ b/src/utils/global-jsdom.ts
@@ -52,6 +52,17 @@ globalJsdom(undefined, {
   pretendToBeVisual: true,
 });
 
+Object.defineProperties(globalThis, {
+  localStorage: {
+    configurable: true,
+    get: () => document.defaultView!.localStorage,
+  },
+  sessionStorage: {
+    configurable: true,
+    get: () => document.defaultView!.sessionStorage,
+  },
+});
+
 class NoopResizeObserver implements ResizeObserver {
   observe(): void {}
   unobserve(): void {}