FU1 of the Notification Outbox follow-ups. EmailNotificationDeliveryAdapter
carried verbatim private copies of credential redaction, SMTP error
classification, and address validation because the NotificationService
helpers were internal. This eliminates the divergence risk by promoting the
helpers to public and deleting the adapter's copies.
- CredentialRedactor: internal -> public.
- Extract SmtpErrorClassifier + SmtpErrorClass enum into a new public static
class; NotificationDeliveryService now routes classification through it
(behavior unchanged). Adds focused SmtpErrorClassifierTests.
- NotificationDeliveryService.ValidateAddresses: internal -> public; the
adapter calls it directly.
- EmailNotificationDeliveryAdapter: deleted ScrubCredentials, ClassifySmtpError,
SmtpErrorClass, IsTransientSmtpError and ValidateAddresses copies.
No InternalsVisibleTo hack — specific helpers promoted to public. Both test
suites green; full solution builds clean.
Resolves StoreAndForward-001, ExternalSystemGateway-001, NotificationService-001
— one systemic gap where buffered messages were persisted but never delivered,
and the active node never replicated its buffer to the standby.
Delivery handlers (ExternalSystemGateway-001 / NotificationService-001):
- AkkaHostedService registers delivery handlers for the ExternalSystem,
CachedDbWrite and Notification categories after StoreAndForwardService starts;
each resolves its scoped consumer in a fresh DI scope.
- ExternalSystemClient, DatabaseGateway and NotificationDeliveryService each
gain a DeliverBufferedAsync method: re-resolve the target and re-attempt
delivery, returning true/false/throwing per the transient-vs-permanent contract.
- EnqueueAsync gains an attemptImmediateDelivery flag; CachedCallAsync and
NotificationDeliveryService.SendAsync pass false (they already attempted
delivery themselves) so registering a handler does not dispatch twice.
Replication (StoreAndForward-001):
- ReplicationService is injected into StoreAndForwardService; a new BufferAsync
helper replicates every enqueue, and successful-retry removes and parks are
replicated too. Fire-and-forget, no-op when replication is disabled.
Tests: StoreAndForwardReplicationTests (Add/Remove/Park observed),
attemptImmediateDelivery behaviour, and DeliverBufferedAsync paths for each
consumer. Full solution builds; StoreAndForward/ExternalSystemGateway/
NotificationService suites green.