feat: play the Involved sound for calendar reminders

android/app/src/main/res/raw/keep.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- The calendar reminder channel names its sound by resource name from JS
+     (src/lib/calendar-notifications.ts), which the release resource shrinker
+     can't see. -->
+<resources xmlns:tools="http://schemas.android.com/tools"
+    tools:keep="@raw/involved_notification" />

app.config.js

@@ -106,6 +106,15 @@ module.exports = {
         },
       ],
       ['./plugins/ios-push', { apsEnvironment: APS_ENVIRONMENT, teamId: APPLE_TEAM_ID }],
+      // Bundles the Involved sound calendar reminders play on iOS
+      // (src/lib/calendar-notifications.ts). Android has it in res/raw.
+      [
+        'expo-notifications',
+        {
+          mode: APS_ENVIRONMENT,
+          sounds: ['./assets/sounds/involved_notification.wav'],
+        },
+      ],
     ],
     extra: {
       commit: COMMIT,

src/lib/__tests__/calendar-notifications.test.ts

@@ -1,4 +1,6 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import fs from 'node:fs';
+import path from 'node:path';
 
 type Listener = (state: Record<string, unknown>, prev: Record<string, unknown>) => void;
 
@@ -24,6 +26,8 @@ const h = vi.hoisted(() => ({
   // Device sync (#34): which events the device's calendar app reminds of.
   onDevice: null as ((event: { id: string }) => boolean) | null,
   reminderListener: null as (() => void) | null,
+  // The reminder channel earlier versions created, if any.
+  legacyChannel: null as { id: string; importance: number } | null,
 }));
 
 vi.mock('react-native', () => ({
@@ -35,6 +39,8 @@ vi.mock('expo-notifications', () => ({
   getPermissionsAsync: vi.fn(async () => ({ ...h.permission })),
   requestPermissionsAsync: vi.fn(async () => ({ granted: true })),
   setNotificationChannelAsync: vi.fn(async () => undefined),
+  getNotificationChannelAsync: vi.fn(async (id: string) => (h.legacyChannel?.id === id ? h.legacyChannel : null)),
+  deleteNotificationChannelAsync: vi.fn(async () => undefined),
   getAllScheduledNotificationsAsync: vi.fn(async () => h.pending),
   cancelScheduledNotificationAsync: vi.fn(async () => undefined),
   scheduleNotificationAsync: vi.fn(async () => 'id'),
@@ -46,7 +52,7 @@ vi.mock('expo-notifications', () => ({
     return { remove: vi.fn() };
   }),
   DEFAULT_ACTION_IDENTIFIER: 'expo.modules.notifications.actions.DEFAULT',
-  AndroidImportance: { HIGH: 4 },
+  AndroidImportance: { NONE: 2, DEFAULT: 5, HIGH: 6 },
   IosAuthorizationStatus: { PROVISIONAL: 3 },
   SchedulableTriggerInputTypes: { DATE: 'date' },
 }));
@@ -91,7 +97,7 @@ const upcoming = {
 const upcomingKey = `ev1:a1:${new Date('2026-09-24T09:45:00Z').getTime()}`;
 
 function reminder(identifier: string, key: string) {
-  return { identifier, content: { data: { tag: TAG, key } } };
+  return { identifier, content: { data: { tag: TAG, key, delivery: 'calendar-reminders-involved' } } };
 }
 
 let mod: typeof import('../calendar-notifications');
@@ -115,6 +121,7 @@ beforeEach(async () => {
   h.calendarListener = null;
   h.onDevice = null;
   h.reminderListener = null;
+  h.legacyChannel = null;
   h.loadEventsInRange.mockResolvedValue([upcoming]);
   mod = await import('../calendar-notifications');
   N = await import('expo-notifications');
@@ -322,6 +329,7 @@ describe('tapping a calendar reminder', () => {
       tag: TAG,
       key: expect.any(String),
       locale: 'en',
+      delivery: 'calendar-reminders-involved',
       eventId: 'acc-2:ev1:2026-09-24T10:00:00Z',
       kind: 'event',
       serverId: 'ev1',
@@ -366,3 +374,55 @@ describe('tapping a calendar reminder', () => {
     expect(open).toHaveBeenCalledTimes(1);
   });
 });
+
+describe('the Involved sound on calendar reminders', () => {
+  it('schedules reminders on a channel of its own that plays the Involved sound', async () => {
+    await mod.rescheduleCalendarNotifications();
+    expect(N.setNotificationChannelAsync).toHaveBeenCalledWith('calendar-reminders-involved', expect.objectContaining({
+      sound: 'involved_notification.mp3',
+    }));
+    const request = vi.mocked(N.scheduleNotificationAsync).mock.calls[0][0];
+    expect(request.trigger).toMatchObject({ channelId: 'calendar-reminders-involved' });
+    expect(request.content.sound).toBe('involved_notification.mp3');
+  });
+
+  it('leaves the channel of earlier versions alone', async () => {
+    h.legacyChannel = { id: 'calendar-reminders', importance: 6 };
+    await mod.rescheduleCalendarNotifications();
+    const ids = vi.mocked(N.setNotificationChannelAsync).mock.calls.map((call) => call[0]);
+    expect(ids).toEqual(['calendar-reminders-involved']);
+    expect(N.deleteNotificationChannelAsync).not.toHaveBeenCalled();
+    expect(vi.mocked(N.scheduleNotificationAsync).mock.calls[0][0].trigger).toMatchObject({ channelId: 'calendar-reminders-involved' });
+  });
+
+  it('keeps reminders off for someone who switched the old channel off', async () => {
+    h.legacyChannel = { id: 'calendar-reminders', importance: 2 };
+    await mod.rescheduleCalendarNotifications();
+    expect(N.setNotificationChannelAsync).not.toHaveBeenCalled();
+    expect(vi.mocked(N.scheduleNotificationAsync).mock.calls[0][0].trigger).toMatchObject({ channelId: 'calendar-reminders' });
+  });
+
+  it('schedules again a reminder pending from before, so it plays the new sound', async () => {
+    h.pending = [{ identifier: 'old', content: { data: { tag: TAG, key: upcomingKey, locale: 'en' } } }];
+    await mod.rescheduleCalendarNotifications();
+    expect(N.cancelScheduledNotificationAsync).toHaveBeenCalledWith('old');
+    const request = vi.mocked(N.scheduleNotificationAsync).mock.calls[0][0];
+    expect(request.content.data).toMatchObject({ key: upcomingKey, delivery: 'calendar-reminders-involved' });
+
+    // Once moved, it stays.
+    h.pending = [{ identifier: 'new', content: { data: request.content.data as Record<string, unknown> } }];
+    vi.mocked(N.scheduleNotificationAsync).mockClear();
+    vi.mocked(N.cancelScheduledNotificationAsync).mockClear();
+    await mod.rescheduleCalendarNotifications();
+    expect(N.cancelScheduledNotificationAsync).not.toHaveBeenCalled();
+    expect(N.scheduleNotificationAsync).not.toHaveBeenCalled();
+  });
+
+  it('ships the sound for Android, kept from the resource shrinker, and for iOS', () => {
+    const root = path.resolve(__dirname, '../../..');
+    expect(fs.existsSync(path.join(root, 'android/app/src/main/res/raw/involved_notification.mp3'))).toBe(true);
+    expect(fs.readFileSync(path.join(root, 'android/app/src/main/res/raw/keep.xml'), 'utf8')).toContain('@raw/involved_notification');
+    expect(fs.existsSync(path.join(root, 'assets/sounds/involved_notification.wav'))).toBe(true);
+    expect(fs.readFileSync(path.join(root, 'app.config.js'), 'utf8')).toContain("sounds: ['./assets/sounds/involved_notification.wav']");
+  });
+});

src/lib/calendar-notifications.ts

@@ -22,7 +22,17 @@ import { startCalendarEventNotificationSync } from './calendar-event-notificatio
 // don't depend on the Calendar tab being open. Honours the
 // `calendarNotificationsEnabled` setting.
 
-const CHANNEL_ID = 'calendar-reminders';
+// Reminders play the webmail's default notification sound, Involved
+// (webmail lib/notification-sound.ts, stores/settings-store.ts
+// notificationSoundChoice). An Android channel keeps the sound it was created
+// with, so the Involved channel has an id of its own; the channel earlier
+// versions created stays as the user left it. Its sound file ships as
+// android/app/src/main/res/raw/involved_notification.mp3 and, for iOS,
+// assets/sounds/involved_notification.wav.
+export const CHANNEL_ID = 'calendar-reminders-involved';
+export const LEGACY_CHANNEL_ID = 'calendar-reminders';
+const ANDROID_SOUND = 'involved_notification.mp3';
+const IOS_SOUND = 'involved_notification.wav';
 const DAY_MS = 24 * 60 * 60 * 1000;
 const HORIZON_MS = 7 * DAY_MS;
 // The events loaded for the horizon: from a day back (an end-relative alert
@@ -42,6 +52,8 @@ let permissionRequested = false;
 let mayAskPermission = false;
 // The language the Android channel was last named in; null until created.
 let channelLocale: string | null = null;
+// The channel reminders go to; decided once per run.
+let activeChannelId: string | null = null;
 let rescheduleTimer: ReturnType<typeof setTimeout> | null = null;
 let rescheduling: Promise<void> | null = null;
 let queued = false;
@@ -68,25 +80,48 @@ async function ensurePermission(): Promise<boolean> {
   return permissionGranted;
 }
 
+/**
+ * The channel reminders go to, given the channel earlier versions created
+ * (null when there is none). Someone who switched those reminders off in the
+ * system settings keeps them off: they stay on that channel. Everyone else
+ * gets the Involved channel.
+ */
+export function reminderChannelFor(legacy: { importance?: number } | null): string {
+  if (legacy && legacy.importance === Notifications.AndroidImportance.NONE) return LEGACY_CHANNEL_ID;
+  return CHANNEL_ID;
+}
+
 // The channel's name shows in the system notification settings, so it is
 // (re)named in the app language; setting an existing channel only renames it.
+// The old channel is never touched.
 async function ensureChannel(): Promise<void> {
   if (Platform.OS !== 'android') return;
   const { locale, t } = useLocaleStore.getState();
   if (channelLocale === locale) return;
   try {
-    await Notifications.setNotificationChannelAsync(CHANNEL_ID, {
-      name: t('calendar.notifications.channel_name', 'Calendar reminders'),
-      importance: Notifications.AndroidImportance.HIGH,
-      sound: 'default',
-      vibrationPattern: [0, 250, 250, 250],
-    });
+    if (activeChannelId === null) {
+      const legacy = await Notifications.getNotificationChannelAsync(LEGACY_CHANNEL_ID).catch(() => null);
+      activeChannelId = reminderChannelFor(legacy);
+    }
+    if (activeChannelId === CHANNEL_ID) {
+      await Notifications.setNotificationChannelAsync(CHANNEL_ID, {
+        name: t('calendar.notifications.channel_name', 'Calendar reminders'),
+        importance: Notifications.AndroidImportance.HIGH,
+        sound: ANDROID_SOUND,
+        vibrationPattern: [0, 250, 250, 250],
+      });
+    }
   } catch {
     // Channel creation failing only degrades to the default channel.
   }
   channelLocale = locale;
 }
 
+/** What a reminder is scheduled with: its channel on Android, its sound on iOS. */
+function deliveryTag(): string {
+  return Platform.OS === 'android' ? activeChannelId ?? CHANNEL_ID : IOS_SOUND;
+}
+
 function alertKeyOf(request: Notifications.NotificationRequest): string | null {
   const data = request.content.data as { tag?: string; key?: string } | undefined;
   return data?.tag === DATA_TAG && typeof data.key === 'string' ? data.key : null;
@@ -99,6 +134,13 @@ function isStaleLanguage(request: Notifications.NotificationRequest, locale: str
   return typeof data?.locale === 'string' && data.locale !== locale;
 }
 
+// A reminder scheduled for another channel or sound, such as the default one
+// before the Involved sound: scheduled again, so it plays the new sound.
+function isStaleDelivery(request: Notifications.NotificationRequest): boolean {
+  const data = request.content.data as { delivery?: unknown } | undefined;
+  return data?.delivery !== deliveryTag();
+}
+
 /** Cancel every calendar reminder this app scheduled. */
 export async function cancelAllCalendarNotifications(): Promise<void> {
   try {
@@ -119,6 +161,8 @@ async function scheduleOne(alert: ScheduledAlert, locale: string): Promise<void>
     key: alert.key,
     // The language the title and body are in, to reword it on a switch.
     locale,
+    // The channel (Android) or sound (iOS) it goes out with.
+    delivery: deliveryTag(),
     eventId: alert.eventId,
     kind: alert.kind,
     // Enough to find the event again when the reminder is tapped.
@@ -133,13 +177,15 @@ async function scheduleOne(alert: ScheduledAlert, locale: string): Promise<void>
     content: {
       title: alert.title,
       body: alert.body,
-      sound: 'default',
+      // iOS plays the bundled file, or the default sound without it. Android
+      // takes the channel's sound.
+      sound: Platform.OS === 'ios' ? IOS_SOUND : ANDROID_SOUND,
       data,
     },
     trigger: {
       type: Notifications.SchedulableTriggerInputTypes.DATE,
       date: new Date(alert.fireTimeMs),
-      ...(Platform.OS === 'android' ? { channelId: CHANNEL_ID } : {}),
+      ...(Platform.OS === 'android' ? { channelId: activeChannelId ?? CHANNEL_ID } : {}),
     },
   });
 }
@@ -251,7 +297,7 @@ export async function rescheduleCalendarNotifications(): Promise<void> {
       for (const request of pending) {
         const key = alertKeyOf(request);
         if (key === null) continue;
-        if (wantedByKey.has(key) && !isStaleLanguage(request, locale)) {
+        if (wantedByKey.has(key) && !isStaleLanguage(request, locale) && !isStaleDelivery(request)) {
           present.add(key);
         } else {
           await Notifications.cancelScheduledNotificationAsync(request.identifier);