refactor(test): extract the duplicated Node 26 jsdom localStorage guard into a shared helper

apps/loopover-miner-ui/vitest.setup.ts

@@ -1,5 +1,6 @@
 import { cleanup } from "@testing-library/react";
 import { afterEach, vi } from "vitest";
+import { patchJsdomLocalStorageForNode26 } from "../../test/helpers/vitest-jsdom-node26-localstorage";
 
 // Unmount React trees between tests so jsdom state never leaks across cases.
 afterEach(() => {
@@ -16,24 +17,9 @@ class ResizeObserverStub {
 }
 globalThis.ResizeObserver ??= ResizeObserverStub as unknown as typeof ResizeObserver;
 
-// Node 26 predefines its own experimental `globalThis.localStorage` accessor (nodejs/node#60303) that
-// returns undefined unless the process was started with --localstorage-file. Because that property already
-// *exists* on globalThis before jsdom's env is installed, Vitest's populateGlobal skips copying jsdom's
-// working Storage over it, so any bare `localStorage.*` call (theme-toggle.test.tsx, mirroring
-// theme-toggle.tsx:39) throws "Cannot read properties of undefined". jsdom's real Storage still lives on the
-// raw JSDOM window (globalThis.jsdom.window, which is a distinct object from the `window`/globalThis alias);
-// point the global at it unconditionally -- a no-op on Node 22/24 where globalThis.localStorage already *is*
-// this object, and the actual fix on Node 26+. A `??=` guard would not help (the broken accessor already
-// counts as "present"); the property is configurable so redefining it is safe.
-const jsdomLocalStorage = (globalThis as { jsdom?: { window?: { localStorage?: Storage } } }).jsdom?.window
-  ?.localStorage;
-if (jsdomLocalStorage) {
-  Object.defineProperty(globalThis, "localStorage", {
-    value: jsdomLocalStorage,
-    configurable: true,
-    writable: true,
-  });
-}
+// See vitest-jsdom-node26-localstorage.ts's own header. Exercised directly by theme-toggle.test.tsx,
+// mirroring theme-toggle.tsx:39.
+patchJsdomLocalStorageForNode26();
 
 // #7075: ChatConversation wires handlePortfolioQueueChatCommand, which imports chat-action-registry →
 // governor-chokepoint → governor-ledger → node:sqlite. jsdom/Vite cannot bundle that builtin (same twin

apps/loopover-ui/vitest.setup.ts

@@ -1,5 +1,6 @@
 import { cleanup } from "@testing-library/react";
 import { afterEach } from "vitest";
+import { patchJsdomLocalStorageForNode26 } from "../../test/helpers/vitest-jsdom-node26-localstorage";
 
 // Unmount React trees between tests so jsdom state never leaks across cases.
 afterEach(() => {
@@ -16,24 +17,8 @@ class ResizeObserverStub {
 }
 globalThis.ResizeObserver ??= ResizeObserverStub as unknown as typeof ResizeObserver;
 
-// Node 26 predefines its own experimental `globalThis.localStorage` accessor (nodejs/node#60303) that
-// returns undefined unless the process was started with --localstorage-file. Because that property already
-// *exists* on globalThis before jsdom's env is installed, Vitest's populateGlobal skips copying jsdom's
-// working Storage over it, so any bare `localStorage.*` call (use-local-storage.test.ts most directly,
-// plus routes/index.test.tsx, api/try-it.test.ts, app-panels/onboarding-preview-card.test.tsx, and
-// lib/analytics-window.test.ts) throws "Cannot read properties of undefined". jsdom's real Storage still
-// lives on the raw JSDOM window (globalThis.jsdom.window, a distinct object from the `window`/globalThis
-// alias); point the global at it
-// unconditionally -- a no-op on Node 22/24 where globalThis.localStorage already *is* this object, and the
-// actual fix on Node 26+. A `??=` guard would not help (the broken accessor already counts as "present");
-// the property is configurable so redefining it is safe. Mirrors apps/loopover-miner-ui/vitest.setup.ts's
-// own guard (#7597), which fixed the identical gap there but not here.
-const jsdomLocalStorage = (globalThis as { jsdom?: { window?: { localStorage?: Storage } } }).jsdom
-  ?.window?.localStorage;
-if (jsdomLocalStorage) {
-  Object.defineProperty(globalThis, "localStorage", {
-    value: jsdomLocalStorage,
-    configurable: true,
-    writable: true,
-  });
-}
+// See vitest-jsdom-node26-localstorage.ts's own header: Node 26's broken globalThis.localStorage
+// accessor shadows jsdom's real Storage before Vitest can install it. Exercised directly by
+// use-local-storage.test.ts, plus routes/index, api/try-it, app-panels/onboarding-preview-card, and
+// lib/analytics-window.
+patchJsdomLocalStorageForNode26();

packages/loopover-ui-kit/vitest.setup.ts

@@ -1,29 +1,13 @@
 import { cleanup } from "@testing-library/react";
 import { afterEach } from "vitest";
+import { patchJsdomLocalStorageForNode26 } from "../../test/helpers/vitest-jsdom-node26-localstorage";
 
 // Unmount React trees between tests so jsdom state never leaks across cases (mirrors
 // apps/loopover-miner-ui/vitest.setup.ts's own cleanup).
 afterEach(() => {
   cleanup();
 });
 
-// Node 26 predefines its own experimental `globalThis.localStorage` accessor (nodejs/node#60303) that
-// returns undefined unless the process was started with --localstorage-file. Because that property already
-// *exists* on globalThis before jsdom's env is installed, Vitest's populateGlobal skips copying jsdom's
-// working Storage over it, so any bare `localStorage.*` call would throw "Cannot read properties of
-// undefined" on Node 26+ -- no component here calls it today, but this package is a shared UI kit other
-// workspaces build on, so the guard is preventive rather than a fix for a currently-red test. jsdom's real
-// Storage still lives on the raw JSDOM window (globalThis.jsdom.window, a distinct object from the
-// `window`/globalThis alias); point the global at it unconditionally -- a no-op on Node 22/24 where
-// globalThis.localStorage already *is* this object, and the actual fix on Node 26+. A `??=` guard would not
-// help (the broken accessor already counts as "present"); the property is configurable so redefining it is
-// safe. Mirrors apps/loopover-miner-ui/vitest.setup.ts's own guard (#7597).
-const jsdomLocalStorage = (globalThis as { jsdom?: { window?: { localStorage?: Storage } } }).jsdom?.window
-  ?.localStorage;
-if (jsdomLocalStorage) {
-  Object.defineProperty(globalThis, "localStorage", {
-    value: jsdomLocalStorage,
-    configurable: true,
-    writable: true,
-  });
-}
+// See vitest-jsdom-node26-localstorage.ts's own header. No component here calls localStorage today --
+// this package is a shared UI kit other workspaces build on, so the guard is preventive.
+patchJsdomLocalStorageForNode26();

test/helpers/vitest-jsdom-node26-localstorage.ts

@@ -0,0 +1,27 @@
+/**
+ * Node 26 predefines its own experimental `globalThis.localStorage` accessor (nodejs/node#60303) that
+ * returns undefined unless the process was started with --localstorage-file. Because that property
+ * already *exists* on globalThis before jsdom's environment is installed, Vitest's populateGlobal skips
+ * copying jsdom's working Storage over it, so any bare `localStorage.*` call throws "Cannot read
+ * properties of undefined" under Node 26 while passing on Node 22/24.
+ *
+ * Call this once from a jsdom-environment vitest.setup.ts. Points globalThis.localStorage at jsdom's
+ * real Storage from the raw JSDOM window unconditionally: a no-op where the global already is that
+ * object, the fix on Node 26+. A `??=` guard would not help (the broken accessor already counts as
+ * "present"); the property is configurable so redefining it is safe.
+ *
+ * Shared by apps/loopover-ui, apps/loopover-miner-ui, and packages/loopover-ui-kit's vitest.setup.ts
+ * (originally three separate copies of this same guard -- #7597, #7612) so a future jsdom-environment
+ * workspace only has to import this rather than rediscover the bug.
+ */
+export function patchJsdomLocalStorageForNode26(): void {
+  const jsdomLocalStorage = (globalThis as { jsdom?: { window?: { localStorage?: Storage } } }).jsdom
+    ?.window?.localStorage;
+  if (jsdomLocalStorage) {
+    Object.defineProperty(globalThis, "localStorage", {
+      value: jsdomLocalStorage,
+      configurable: true,
+      writable: true,
+    });
+  }
+}