Cancellation notification sent to customer

A customer who cancels an order — or whose order is admin-cancelled — and receives no email confirmation is left wondering whether the cancellation actually went through. Without notification, they may place a duplicate order, not monitor their bank account for the refund, or contact support unnecessarily. If the admin cancels an order on behalf of a customer (for a fraud flag, inventory issue, or address problem), the customer deserves immediate notification with context. The iso-25010:2011 reliability dimension: the cancellation event occurred in the system but the customer has no evidence of it.

Add a cancellation email call to the cancellation handler at app/api/orders/[id]/cancel/route.ts, fired after the successful transitionOrder call.

// After transitionOrder(orderId, 'cancelled', ...) in app/api/orders/[id]/cancel/route.ts:
await sendCancellationEmail({
  to: order.user.email,
  orderNumber: order.id,
  refundExpected: order.total > 0,
  refundTimelineDays: REFUND_WINDOW_DAYS,
  supportUrl: 'https://yoursite.com/support',
})

Add sendCancellationEmail to lib/email/order-emails.ts and ensure the admin cancellation path also sends the same notification.

• ID: ecommerce-order-management.notifications.cancellation-email

• Severity: low

• What to look for: When an order is cancelled, count the email service calls in the cancellation handler (at least 1 required). Enumerate which cancellation paths (customer-initiated and admin-initiated) trigger emails. The cancellation email should communicate at least 2 of: which order was cancelled, whether a refund will be issued, expected refund timeline, or how to contact support. Check both customer-initiated cancellations and admin-initiated cancellations.

• Pass criteria: At least 1 cancellation email is sent to the customer when an order is cancelled, regardless of whether the cancellation was customer-initiated or admin-initiated. The email includes at least 2 data fields (order number and refund status or support contact). A cancellation handler with 0 email calls does not count as pass.

• Fail criteria: No email is sent on cancellation (0 email calls in cancellation handlers). The customer must check their order status page to discover that their order was cancelled, with no proactive communication.

• Skip (N/A) when: The project does not support order cancellation. No cancellation handler exists in the codebase.

• Detail on fail: "The cancellation handler triggers a status update and history entry but makes 0 email service calls. Customers are not notified when their order is cancelled — they only find out by checking their account."

• Remediation: Add cancellation notification to the cancellation handler at app/api/orders/[id]/cancel/route.ts:

  // After transitionOrder(orderId, 'cancelled', ...) in app/api/orders/[id]/cancel/route.ts:
  await sendCancellationEmail({
    to: order.user.email,
    orderNumber: order.id,
    refundExpected: order.total > 0,
    refundTimelineDays: REFUND_WINDOW_DAYS,
    supportUrl: 'https://yoursite.com/support',
  })