From df55110b9b6ec4e09117cfae2907e5be0599c271 Mon Sep 17 00:00:00 2001
From: Daniel <daniel.hutzel@sap.com>
Date: Wed, 28 Oct 2020 15:14:34 +0100
Subject: [PATCH] Updated to use srv-to-srv + declared events

---
 reviewed/server.js              |  3 +--
 reviews/srv/reviews-service.cds |  7 +++++++
 reviews/srv/reviews-service.js  | 11 +++++------
 test/messaging.test.js          |  8 ++------
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/reviewed/server.js b/reviewed/server.js
index 73ac1be3..1d59efb9 100644
--- a/reviewed/server.js
+++ b/reviewed/server.js
@@ -9,7 +9,6 @@ const cds = require ('@sap/cds')
 cds.once('served', async ({CatalogService}) => {
 
     const ReviewsService = await cds.connect.to('ReviewsService')
-    const messaging = await cds.connect.to('messaging')
 
     // reflect entity definitions used below...
     const { Books } = cds.entities('sap.capire.bookshop')
@@ -22,7 +21,7 @@ cds.once('served', async ({CatalogService}) => {
         return SELECT(columns).from(Reviews).limit(limit).where({subject:String(id)})
     }))
 
-    messaging.on ('reviewed', (msg) => {
+    ReviewsService.on ('reviewed', (msg) => {
         console.debug ('> received:', msg.event, msg.data)
         const { subject, rating } = msg.data
         return UPDATE(Books,subject).with({rating})
diff --git a/reviews/srv/reviews-service.cds b/reviews/srv/reviews-service.cds
index 8999e636..44fa83e2 100644
--- a/reviews/srv/reviews-service.cds
+++ b/reviews/srv/reviews-service.cds
@@ -2,10 +2,17 @@ using { sap.capire.reviews as my } from '../db/schema';
 
 service ReviewsService {
 
+  // Sync API
   entity Reviews as projection on my.Reviews excluding { likes }
   action like (review: type of Reviews:ID);
   action unlike (review: type of Reviews:ID);
 
+  // Async API
+   event reviewed : {
+     subject: type of Reviews:subject;
+     rating: Decimal(2,1)
+   }
+
   // Input validation
   annotate Reviews with {
     subject  @mandatory;
diff --git a/reviews/srv/reviews-service.js b/reviews/srv/reviews-service.js
index 0eec865f..10979994 100644
--- a/reviews/srv/reviews-service.js
+++ b/reviews/srv/reviews-service.js
@@ -4,27 +4,26 @@ module.exports = cds.service.impl (async function(){
   // Get the CSN definition for Reviews from the db schema for sub-sequent queries
   // ( Note: we explicitly specify the namespace to support embedded reuse )
   const { Reviews, Likes } = this.entities ('sap.capire.reviews')
-  const messaging = await cds.connect.to('messaging')
 
   this.before (['CREATE','UPDATE'], 'Reviews', req => {
     if (!req.data.rating) req.data.rating = Math.round(Math.random()*4)+1
   })
 
   // Emit an event to inform subscribers about new avg ratings for reviewed subjects
-  this.after (['CREATE','UPDATE','DELETE'], 'Reviews', async(_,req) => {
+  this.after (['CREATE','UPDATE','DELETE'], 'Reviews', async function(_,req) {
     const {subject} = req.data
-    const {rating} = await cds.transaction(req) .run (
+    const {rating} = await cds.tx(req) .run (
       SELECT.one (['round(avg(rating),2) as rating']) .from (Reviews) .where ({subject})
     )
     global.it || console.log ('< emitting:', 'reviewed', { subject, rating })
-    messaging.tx(req).emit ('reviewed', { subject, rating })
+    this.emit ('reviewed', { subject, rating })
   })
 
   // Increment counter for reviews considered helpful
   this.on ('like', (req) => {
     if (!req.user)  return req.reject(400, 'You must be identified to like a review')
     const {review} = req.data, {user} = req
-    const tx = cds.transaction(req)
+    const tx = cds.tx(req)
     return tx.run ([
       INSERT.into (Likes) .entries ({review_ID: review, user: user.id}),
       UPDATE (Reviews) .set({liked: {'+=': 1}}) .where({ID:review})
@@ -35,7 +34,7 @@ module.exports = cds.service.impl (async function(){
   this.on ('unlike', async (req) => {
     if (!req.user)  return req.reject(400, 'You must be identified to remove a former like of yours')
     const {review} = req.data, {user} = req
-    const tx = cds.transaction(req)
+    const tx = cds.tx(req)
     const affectedRows = await tx.run (DELETE.from (Likes) .where ({review_ID: review,user: user.id}))
     if (affectedRows === 1)  return tx.run (UPDATE (Reviews) .set ({liked: {'-=': 1}}) .where ({ID:review}))
   })
diff --git a/test/messaging.test.js b/test/messaging.test.js
index abc0d305..632b093f 100644
--- a/test/messaging.test.js
+++ b/test/messaging.test.js
@@ -1,14 +1,10 @@
 const cwd = process.cwd(); process.chdir (__dirname) //> only for internal CI/CD@SAP
 const cds = require ('./cds'), {expect} = cds.test
 const _model = '@capire/reviews'
-let messaging
 
 
 describe('Messaging', ()=>{
 
-    beforeAll(async () => {
-        messaging = await cds.connect.to('messaging')
-    })
     after(()=> process.chdir(cwd))
 
     it ('should bootstrap sqlite in-memory db', async()=>{
@@ -24,11 +20,11 @@ describe('Messaging', ()=>{
 
     let N=0, received=[], M=0
     it ('should add messaging event handlers', ()=>{
-        messaging.on('reviewed', (msg,next)=> { received.push(msg); return next() })
+        srv.on('reviewed', (msg,next)=> { received.push(msg); return next() })
     })
 
     it ('should add more messaging event handlers', ()=>{
-        messaging.on('reviewed', (_,next)=> { ++M; return next() })
+        srv.on('reviewed', (_,next)=> { ++M; return next() })
     })
 
     it ('should add review', async ()=>{