cleaned up code

suppliers/srv/mashup.js

@@ -12,7 +12,7 @@ module.exports = async()=>{ // called by server.js
   const db = await cds.connect.to('db')                         //> our primary database
 
   // Reflect CDS definition of the Suppliers entity
-  const Suppliers  = db.entities.Suppliers;
+  const { Suppliers }  = db.entities
 
   admin.prepend (()=>{ //> to ensure our .on handlers below go before the default ones
 
@@ -23,19 +23,19 @@ module.exports = async()=>{ // called by server.js
     })
 
     // Replicate Supplier data when edited Books have suppliers
-    admin.on (['CREATE','UPDATE'], 'Books', async ({data:{supplier_ID: supplierId}}, next) => {
-      // Using Promise.all(...) to parallelize local write, i.e. next(), and replication
-
-      const replicateIfNotExists = async()=>{
-        let replicated = await db.exists (Suppliers, supplierId);
-        if (!replicated) await replicate (supplierId, 'initial');
-      };
-
-      if (supplierId) {
-        const [result, _] = await Promise.all([next(), replicateIfNotExists()]);
-        return result;
-      } else
-        return next(); //> don't forget to pass down the interceptor stack
+    admin.on (['CREATE','UPDATE'], 'Books', async ({data:{supplier_ID:ID}}, next) => {
+      if (ID) {
+        // Using Promise.all(...) to parallelize local write, i.e. next(), and replication
+        const [result] = await Promise.all([ next(), (async()=>{
+          let replicated = await db.exists (Suppliers,ID)
+          if (!replicated) { // initially replicate Supplier info
+            let supplier = await S4bupa.read (Suppliers,ID)
+            await INSERT(supplier) .into (Suppliers)
+          }
+        })()])
+        return result
+      }
+      else return next() //> don't forget to pass down the interceptor stack
     })
 
   })
@@ -44,18 +44,11 @@ module.exports = async()=>{ // called by server.js
   S4bupa.on ('BusinessPartner.Changed', async msg => { //> would be great if we had batch events from S/4
     console.log(">>", msg.event, msg.data)
     const ID = msg.data.BusinessPartner;
-    let replica = await SELECT.one('ID').from(Suppliers).where({ID});
-    if (replica) await replicate(ID);
+    let replicated = await db.exists (Suppliers,ID)
+    if (replicated) { // update replicated Supplier info
+      let supplier = await S4bupa.read (Suppliers,ID)
+      await UPDATE(Suppliers,ID) .with (supplier)
+    }
   })
 
-  /**
-   * Helper function to replicate Suppliers data.
-   * @param {string} ID a single ID
-   * @param {truthy|falsy} _initial indicates whether an insert or an update is required
-   */
-  async function replicate (ID,_initial) {
-    let supplier = await S4bupa.run(SELECT.one(Suppliers).where({ID}));
-    if (_initial) return db.insert(supplier).into(Suppliers);
-    else return db.update(Suppliers).with(supplier).where({ID});
-  }
 }