fix: answer an invitation whose event lies outside the calendar's loaded weeks

lib/__tests__/calendar-rsvp.test.ts

@@ -60,6 +60,13 @@ describe('answerInvitation', () => {
     expect(req.store.rsvpEvent).toHaveBeenCalledWith(req.client, 'new', 'p2', 'declined', { imip: 'mailto:alice@example.org' });
   });
 
+  it('finds the new copy on the server when the store doesn’t hold it', async () => {
+    const base = request();
+    const req = request({ store: { ...base.store, events: () => [] }, findImported: async () => ({ id: 'srv', uid: 'u1', participants: { p2: me } } as never) } as never);
+    expect(await answerInvitation(req, 'accepted')).toBe('answered');
+    expect(req.store.rsvpEvent).toHaveBeenCalledWith(req.client, 'srv', 'p2', 'accepted', { imip: 'mailto:alice@example.org' });
+  });
+
   it('says when a plugin stopped it, when it only added the event, and when it can\'t', async () => {
     expect(await answerInvitation(request({ store: { ...request().store, importEvents: vi.fn(async () => null) } } as never), 'accepted')).toBe('stopped');
     expect(await answerInvitation(request({ myParticipant: null, store: { ...request().store, events: () => [{ id: 'new', uid: 'u1', participants: {} } as never] } } as never), 'accepted')).toBe('added');

lib/calendar-rsvp.ts

@@ -44,6 +44,11 @@ export interface RsvpRequest {
   answerOptions?: { sentBy: string };
   /** The stored copy with its participants loaded (or the shared account's copy). */
   resolveExisting: () => Promise<CalendarEvent | null | undefined>;
+  /**
+   * The copy an import just made, from the server, when the store doesn't
+   * hold it (an event outside the range the calendar has loaded).
+   */
+  findImported?: (uid: string) => Promise<CalendarEvent | null>;
 }
 
 /**
@@ -113,7 +118,7 @@ export async function answerInvitation(req: RsvpRequest, status: RsvpStatus): Pr
   if (imported <= 0) return 'failed';
   const newEvent = store.events().find(
     (e) => e.uid === parsedEvent.uid && (sharedMailAccount ? e.accountId === sharedMailAccount : !e.isShared),
-  );
+  ) ?? (parsedEvent.uid && req.findImported ? await req.findImported(parsedEvent.uid) : null);
   const participant = myParticipant || (newEvent ? findParticipantByEmails(newEvent, actingEmails) : null);
   if (!newEvent || !participant) return 'added';
   return (await rsvp(newEvent.id, participant.id)) ? 'answered' : 'stopped';

lib/plugin-sandbox/assistant/c.calendar.ts

@@ -100,6 +100,7 @@ export async function doCalendarRespond(emailIdArg: unknown, statusArg: unknown)
     actingEmails: emails,
     calendarId,
     sharedMailAccount: null,
+    findImported: (uid) => ownCopy(client, uid),
     resolveExisting: async () => {
       if (!existing) return null;
       if (existing.participants && Object.keys(existing.participants).length > 0) return existing;