Fix the issue where change tracking compilation errors occur when an association is used as a key. (#139)

Although we currently do not support the use of associations as keys, it
should not cause compilation errors in this case, leading to the project
being halted. Therefore, this fix is needed to ensure that the project
does not stop.

Author: Sv7enNowitzki

cds-plugin.js

@@ -156,17 +156,32 @@ cds.on('loaded', m => {
 
       // Determine entity keys
       const keys = [], { elements: elms } = entity
-      for (let e in elms) if (elms[e].key) keys.push(e)
+      for (let e in elms) {
+        if (elms[e].key) {
+          if (elms[e].type === 'cds.Association') {
+            keys.push({
+              e,
+              val: elms[e]
+            });
+          } else {
+            keys.push(e);
+          }
+        }
+      }
 
       // If no key attribute is defined for the entity, the logic to add association to ChangeView should be skipped.
       if(keys.length === 0) {
         continue;
       }
 
       // Add association to ChangeView...
-      const on = [...changes.on]; keys.forEach((k, i) => { i && on.push('||'); on.push({
-        ref: k === 'up_' ? [k,'ID'] : [k] // REVISIT: up_ handling is a dirty hack for now
-      })})
+      const on = [...changes.on];
+      keys.forEach((k, i) => {
+        i && on.push("||");
+        on.push({
+          ref: k?.val?.type === "cds.Association" ? [k.e, k.val.keys?.[0]?.ref?.[0]] : [k]
+        });
+      });
       const assoc = { ...changes, on }
       const query = entity.projection || entity.query?.SELECT
       if(!entity['@changelog.disable_assoc'])

tests/bookshop/db/schema.cds

@@ -261,3 +261,21 @@ entity City : cuid {
 entity Country : cuid {
   countryName : CountryName;
 }
+
+entity FirstEntity : managed, cuid {
+  name : String;
+  children : Association to one Children;
+}
+
+entity SecondEntity : managed, cuid {
+  name : String;
+  children : Association to one Children;
+}
+
+@changelog : [one_ID]
+entity Children : managed {
+  @changelog
+  key one : Association to one FirstEntity;
+  @changelog
+  key two : Association to one SecondEntity;
+}