feat: Calendar Sync

[volnei]

What does this PR do?

Implements calendar sync functionality that allows Cal.com to sync booking changes from external calendars (Google Calendar, Office365) back to Cal.com. When a user cancels or reschedules a Cal.com booking directly in their external calendar, the change is synced back to Cal.com.

Key Changes

1. Infinite Loop Prevention: Added flags to prevent infinite loops when calendar events are cancelled/rescheduled from external calendars:

   • skipCalendarSyncTaskCancellation flag in handleCancelBooking - skips calendar event deletion
   • skipCalendarSyncTaskCreation flag in handleNewBooking - skips calendar event creation (existing)

   The flow is:

   • User deletes/modifies event in Google Calendar
   • Google sends webhook to Cal.com
   • CalendarSyncService processes the change
   • handleCancelBooking/RegularBookingService is called with the appropriate skip flag set to true
   • This prevents Cal.com from trying to update the external calendar again

2. CalendarSyncService Implementation:

   • cancelBooking(): Cancels a booking when the corresponding calendar event is deleted (uses handleCancelBooking)
   • rescheduleBooking(): Updates booking times when the calendar event is rescheduled (uses RegularBookingService.createBooking() directly with rescheduleUid)
   • Error handling: Errors are caught and logged but don't block the calendar sync operation
   • Uses safeStringify(error) for proper error serialization in logs

3. Schema Update: Added skipCalendarSyncTaskCancellation to bookingCancelSchema in zod-utils.ts

4. Booking Reference Consistency: Moved booking reference update (deleted: true) outside the skipCalendarSyncTaskCancellation conditional block - references are always marked as deleted for data consistency since the external event is already deleted

5. Comprehensive Test Suite: Added 16 unit tests covering:

   • Event filtering (only Cal.com events processed)
   • Booking cancellation scenarios
   • Booking rescheduling scenarios
   • Edge cases (null UIDs, malformed UIDs, missing bookings)
   • Error handling (verifies errors are caught and logged, not thrown)

Updates since last revision

• Added Sentry metrics telemetry to CalendarSyncService for observability:
  • calendar.sync.handleEvents.calls - tracks sync invocations by integration
  • calendar.sync.handleEvents.events_count - distribution of Cal.com events per sync
  • calendar.sync.cancelBooking.calls / calendar.sync.rescheduleBooking.calls - tracks success/error/skipped status
  • Duration metrics (duration_ms) for cancel and reschedule operations
• Fixed null assertions by replacing ! operators with proper null checks:
  • booking.userId and booking.userPrimaryEmail checked before cancellation
  • booking.eventTypeId checked before rescheduling
  • Returns early with warning log and "skipped" metric when required data is missing
• Fixed RAQB import error:
  • CalendarSyncService.ts: Changed getRegularBookingService to use dynamic import
  • getRoutedUsers.ts: Changed findTeamMembersMatchingAttributeLogic to use dynamic import (root cause fix)
  • This prevents react-awesome-query-builder from being loaded at module evaluation time, fixing the "Super expression must either be null or a function" error in the calendar-subscription webhook endpoint

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A - internal implementation detail.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

1. Set up a calendar subscription webhook for Google Calendar or Office365
2. Create a booking in Cal.com that syncs to the external calendar
3. Delete the event directly in Google Calendar/Office365
4. Verify the booking is cancelled in Cal.com without creating an infinite loop
5. Similarly test rescheduling by modifying the event time in the external calendar

Human Review Checklist

• Verify the hardcoded values in rescheduleBooking are acceptable: language: "en", metadata: {}, timeZone: event.timeZone ?? "UTC"
• Verify that using rescheduleUid triggers a proper reschedule flow (not creating a duplicate booking)
• Verify that removing allRemainingBookings/cancelSubsequentBookings is correct - now only cancels single bookings, not recurring series
• Review edge cases where the skip flags might incorrectly skip legitimate calendar updates
• Verify that silently catching errors in CalendarSyncService (logging but not throwing) is acceptable behavior
• Verify the dynamic imports in CalendarSyncService.ts and getRoutedUsers.ts don't introduce any timing/race condition issues

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have checked if my changes generate no new warnings

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Link to Devin run: https://app.devin.ai/sessions/20575cfa274d4721bc8badeda938cc93
Requested by: Volnei Munhoz (volnei@cal.com) (@volnei)

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[github-actions]

E2E results are ready!

• Workflow #100177.1 latest results

[devin-ai-integration]

Devin Review found 1 potential issue.

View issue and 5 additional flags in Devin Review.

[cubic-dev-ai]

1 issue found across 5 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="packages/features/bookings/lib/handleCancelBooking.ts">

<violation number="1" location="packages/features/bookings/lib/handleCancelBooking.ts:623">
P2: Avoid logging raw ZodError objects; log only sanitized fields (message/name) to prevent leaking sensitive data.

(Based on your team's feedback about not logging raw ZodError objects.) [FEEDBACK_USED]</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[github-actions]

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