fixes https://github.com/TryGhost/Team/issues/2310
This moves the processing of the events from the event-processor to a
new email-event-processor in the email-service package.
- The `EmailEventProcessor` only translates events from
providerId/emailId to their known emailId, memberId and recipientId, and
dispatches the corresponding events.
- Since `EmailEventProcessor` runs in a separate worker thread, we can't
listen for the dispatched events on the main thread. To accomplish this
communication, the events dispatched from the `EmailEventProcessor`
class are 'posted' via the postMessage method and redispatched on the
main thread.
- A new `EmailEventStorage` class reacts to the email events and stores
it in the database. This code mostly corresponds to the (now deleted)
subclass of the old `EmailEventProcessor`
- Updating a members last_seen_at timestamp has moved to the
lastSeenAtUpdater.
- Email events no longer store `ObjectID` because these are not
encodable across threads via postMessage
- Includes new E2E tests that test the storage of all supported Mailgun
events. Note that in these tests we run the processing on the main
thread instead of on a separate thread (couldn't do this because
stubbing is not possible across threads)
There are some missing pieces that will get added in later PRs (this PR
focuses on porting the existing functionality):
- Handling temporary failures/bounces
- Capturing the error messages of bounce events
refs https://github.com/TryGhost/Ghost/pull/12541
- make `EventProcessor` a super-class designed to be inherited from in consumer applications for application-level implementation
- helps to keep application-level concerns for event handling (eg, what to do with spam complaints) and things like application database knowledge in the consumer
- removed all database knowledge from `EmailAnalyticsService`
- requires a `queries` option to be passed in that lets the consuming application provide knowledge and define how fetched stats should be aggregated
no issue
- added `EmailAnalyticsService`
- `.fetchAll()` grabs and processes all available events
- `.fetchLatest()` grabs and processes all events since the last seen event timestamp
- `EventProcessor` passed event objects and updates `email_recipients` or `members` records depending on the event being analytics or list hygiene
- always returns a `EventProcessingResult` instance so that progress can be tracked and merged across individual events, batches (pages of events), and total runs
- adds email_id and member_id to the returned result where appropriate so that the stats aggregator can limit processing to data that has changed
- sets `email_recipients.{delivered_at, opened_at, failed_at}` for analytics events
- sets `members.subscribed = false` for permanent failure/unsubscribed/complained list hygiene events
- `StatsAggregator` takes an `EventProcessingResult`-like object containing arrays of email ids and member ids on which to aggregate statistics.
- jobs for `fetch-latest` and `fetch-all` ready for use with the JobsService
- added `initialiseRecurringJobs()` function to Ghost bootup procedure that schedules the email analytics "fetch latest" job to run every minute
