feat: support for generic outbox

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ## Version 0.4.0 - TBD
 
+### Added
+
+- Support for generic outbox
+
 ### Changed
 
 - Always use outbox (as configured in project)

srv/service.js

@@ -1,10 +1,11 @@
 const cds = require('@sap/cds')
 
-// REVISIT: cds.OutboxService or technique to avoid extending OutboxService
-const OutboxService = require('@sap/cds/libx/_runtime/messaging/Outbox')
+const Base = cds.outboxed ? cds.Service : require('@sap/cds/libx/_runtime/messaging/Outbox')
 
-module.exports = class AuditLogService extends OutboxService {
+module.exports = class AuditLogService extends Base {
   async init() {
+    const outboxed = this.immediate instanceof cds.Service
+
     // add common audit log entry fields
     this.before('*', req => {
       const { tenant, user, timestamp: time } = cds.context
@@ -16,6 +17,10 @@ module.exports = class AuditLogService extends OutboxService {
 
     // add self-explanatory api (await audit.log/logSync(event, data))
     this.log = this.emit
-    this.logSync = this.send
+    // NOTE: logSync is not a public API!
+    this.logSync = (...args) => {
+      if (outboxed) return this.immediate.send(...args)
+      return this.send(...args)
+    }
   }
 }

test/api/srv/api-service.js

@@ -1,12 +1,14 @@
 module.exports = async function () {
   const audit = await cds.connect.to('audit-log')
+  const outboxed = audit.immediate instanceof cds.Service
 
   this.on('testEmit', async function () {
     await audit.emit('foo', { bar: 'baz' })
   })
 
   this.on('testSend', async function () {
-    await audit.send('foo', { bar: 'baz' })
+    if (outboxed) await audit.immediate.send('foo', { bar: 'baz' })
+    else await audit.send('foo', { bar: 'baz' })
   })
 
   this.on('testLog', async function () {