fix: let the desktop notice about keeping mail on this device close by itself

components/offline/__tests__/offline-default-notice.test.tsx

@@ -0,0 +1,38 @@
+import { cleanup, render } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import type { OfflineNotice } from '@/lib/offline/offline-mode';
+import { useToastStore } from '@/stores/toast-store';
+
+// mail-26: the desktop app's "Bulwark keeps your mail on this device" notice
+// stayed over the quick reply box until someone closed it.
+
+const notifier = vi.hoisted(() => ({ show: null as ((notice: OfflineNotice) => void) | null }));
+vi.mock('@/lib/offline/offline-mode', () => ({
+  setOfflineNotifier: (fn: ((notice: OfflineNotice) => void) | null) => {
+    notifier.show = fn;
+  },
+  startOfflineMode: () => () => {},
+  confirmLoss: () => {},
+  unsentCount: async () => ({ messages: 0, changes: 0 }),
+}));
+
+const { OfflineHost } = await import('../offline-host');
+
+beforeEach(() => {
+  useToastStore.getState().clearToasts();
+});
+
+afterEach(() => {
+  cleanup();
+});
+
+describe('the notice that the desktop app keeps mail on this device', () => {
+  it('goes away by itself, and still offers Settings', () => {
+    render(<OfflineHost />);
+    notifier.show!({ kind: 'default-on' });
+    const [notice] = useToastStore.getState().toasts;
+    expect(notice.title).toBe('default_on');
+    expect(notice.duration).toBeGreaterThan(0);
+    expect(notice.action?.label).toBe('open_settings');
+  });
+});

components/offline/offline-host.tsx

@@ -11,6 +11,9 @@ import { buildSettingsPath } from '@/lib/deep-links';
 import { confirmLoss, setOfflineNotifier, startOfflineMode, unsentCount, type OfflineNotice } from '@/lib/offline/offline-mode';
 import { toast } from '@/stores/toast-store';
 
+/** How long the notice that the desktop app keeps mail stays: a long sentence, so twice a plain toast. */
+const DEFAULT_ON_NOTICE_MS = 10_000;
+
 /**
  * Runs offline mode (#523) in this tab: the JMAP client's offline hooks,
  * the outbox, the wipes. Its notices become toasts, and a sign-out the
@@ -74,7 +77,8 @@ export function OfflineHost() {
           toast.warning(tStorageRef.current('storage_full_title'), { message: tStorageRef.current('storage_full_text'), duration: 0, action: openStorage });
           break;
         case 'default-on':
-          toast.info(tStorageRef.current('default_on'), { duration: 0, action: openStorage });
+          // Said once; it goes like other notices, and Settings has the switch.
+          toast.info(tStorageRef.current('default_on'), { duration: DEFAULT_ON_NOTICE_MS, action: openStorage });
           break;
         case 'legacy-stranded':
           toast.warning(tConflictsRef.current('legacy_stranded'), { duration: 0 });