fix: let accessibility reset bring back the organisation's defaults and cover every option

components/settings/__tests__/accessibility-settings.test.tsx

@@ -99,6 +99,29 @@ describe('reset', () => {
     // A shared everyday preference is not an accessibility setting to reset.
     expect(settings().disableThreading).toBe(true);
   });
+
+  it("gives back the organisation's defaults instead of writing Bulwark's as the user's choice", () => {
+    usePolicyStore.setState({ policy: { ...DEFAULT_POLICY, defaults: { appFont: 'atkinson', fontSize: 'large' } }, loaded: true });
+    settings().applyAdminPolicy();
+    settings().updateSetting('appFont', 'lexend');
+    settings().updateSetting('fontSize', 'huge');
+    render(<AccessibilitySettings />);
+    fireEvent.click(screen.getByRole('button', { name: 'settings.accessibility.reset.button' }));
+    expect(settings().appFont).toBe('atkinson');
+    expect(settings().fontSize).toBe('large');
+    // Nothing is left marked as chosen, so a later change of the default reaches the user.
+    expect(settings().explicitSettings).not.toContain('appFont');
+    expect(settings().explicitSettings).not.toContain('fontSize');
+  });
+
+  it('also resets the plain text font and the send confirmation', () => {
+    settings().updateSetting('plainTextFont', 'mono');
+    settings().updateSetting('sendConfirmation', true);
+    render(<AccessibilitySettings />);
+    fireEvent.click(screen.getByRole('button', { name: 'settings.accessibility.reset.button' }));
+    expect(settings().plainTextFont).toBe('sans');
+    expect(settings().sendConfirmation).toBe(false);
+  });
 });
 
 describe('toast duration', () => {

components/settings/accessibility-settings.tsx

@@ -14,7 +14,6 @@ import { voicesForLocale } from '@/lib/read-aloud';
 import { useSpeechVoices } from '@/hooks/use-read-aloud';
 import { NOTIFICATION_SOUNDS, playNotificationSound, type NotificationSoundChoice } from '@/lib/notification-sound';
 import {
-  ACCESSIBILITY_DEFAULTS,
   ACCESSIBILITY_KEYS,
   FONT_SIZES,
   MAIL_MIN_FONT_SIZES,
@@ -37,6 +36,9 @@ import type { Density, SendDelaySeconds } from '@/stores/settings-store';
 
 type SettingKey = Parameters<ReturnType<typeof useSettingsStore.getState>['updateSetting']>[0];
 
+/** What Reset gives back: the settings only this page has. */
+const RESET_KEYS: SettingKey[] = [...ACCESSIBILITY_KEYS, 'fontSize', 'plainTextFont', 'sendConfirmation'];
+
 /** Opens another settings page (and section) the way deep links do. */
 function goToSettings(tab: string, section?: string) {
   window.dispatchEvent(new CustomEvent('settings-tab-change', { detail: section ? { tab, section } : tab }));
@@ -64,7 +66,7 @@ export function AccessibilitySettings() {
   const tNotifications = useTranslations('settings.notifications');
   const tCalendar = useTranslations('calendar.settings');
   const settings = useSettingsStore();
-  const { updateSetting } = settings;
+  const { updateSetting, resetSettings } = settings;
   const { isSettingLocked, isSettingHidden, getRestriction } = usePolicyStore();
   const faviconsAllowed = !useNoThirdPartyTraffic();
   const [applied, setApplied] = useState<{ id: AccessibilityPresetId; changes: PresetChange[] } | null>(null);
@@ -91,12 +93,10 @@ export function AccessibilitySettings() {
     setApplied(null);
   };
 
+  // Forgets the user's own values, so the organisation's defaults (or
+  // Bulwark's) apply again. Shared everyday settings shown here too stay.
   const resetAll = () => {
-    for (const key of ACCESSIBILITY_KEYS) {
-      if (isSettingLocked(key)) continue;
-      set(key, ACCESSIBILITY_DEFAULTS[key]);
-    }
-    set('fontSize', 'medium');
+    resetSettings(RESET_KEYS.filter((key) => !isSettingLocked(key)));
     setApplied(null);
     setResetDone(true);
   };

stores/settings-store.ts

@@ -804,6 +804,12 @@ interface SettingsState extends AccessibilitySettings {
     opts?: { internal?: boolean }
   ) => void;
   resetToDefaults: () => void;
+  /**
+   * Forgets the user's own value for each of `keys`: the setting loses its
+   * "chosen by the user" mark and takes the admin default (policy.defaults)
+   * again, or the built-in one when the admin set none.
+   */
+  resetSettings: (keys: readonly string[]) => void;
   /**
    * Applies the admin policy (#1248): `policy.defaults` to every setting the
    * user has not chosen, and a locked restriction's value to its setting
@@ -1495,6 +1501,26 @@ export const useSettingsStore = create<SettingsState>()(
         void settingsHooks.onSettingsReset.emit({});
       },
 
+      resetSettings: (keys) => {
+        const own = keys.filter((key) => hasOwn(DEFAULT_SETTINGS, key) && key !== 'explicitSettings' && !BOOKKEEPING_SETTING_KEYS.has(key));
+        if (own.length === 0) return;
+        const before = get() as unknown as Record<string, unknown>;
+        const previous = Object.fromEntries(own.map((key) => [key, before[key]]));
+        const dropped = new Set(own);
+        set({
+          ...Object.fromEntries(own.map((key) => [key, builtInDefault(key)])),
+          explicitSettings: get().explicitSettings.filter((key) => !dropped.has(key)),
+        } as Partial<SettingsState>);
+        applyAdminPolicyPatch();
+        applyVisualSettings();
+        const after = get() as unknown as Record<string, unknown>;
+        for (const key of own) {
+          if (after[key] !== previous[key]) {
+            void settingsHooks.onSettingChange.emit({ key, value: after[key], previous: previous[key] });
+          }
+        }
+      },
+
       exportSettings: (opts) => {
         const json = buildExport(opts);
         if (!opts?.forSync) {