From 56e7c17a207f5c6fca9686b9cdcbc2f1b156b79e Mon Sep 17 00:00:00 2001
From: Wenjun Zheng <wenjun.zheng@sap.com>
Date: Fri, 29 Aug 2025 17:49:23 +0800
Subject: [PATCH] fix: enhance change tracking logic to support parent entity
 checks

---
 lib/change-log.js | 78 +++++++++++++++++++++++++++++++----------------
 1 file changed, 51 insertions(+), 27 deletions(-)

diff --git a/lib/change-log.js b/lib/change-log.js
index 61a2429..96eeae0 100644
--- a/lib/change-log.js
+++ b/lib/change-log.js
@@ -16,7 +16,7 @@ const {
 } = require("./entity-helper")
 const { localizeLogFields } = require("./localization")
 const isRoot = "change-tracking-isRootEntity"
-
+const hasParent = "change-tracking-parentEntity"
 
 function formatDecimal(str, scale) {
   if (typeof str === "number" && !isNaN(str)) {
@@ -439,12 +439,12 @@ async function generatePathAndParams (req, entityKey) {
     hasComp: true
   };
 
-  if (hasParentAndForeignKey && parentEntity[isRoot]) {
+  if (hasParentAndForeignKey && isRootEntity(parentEntity)) {
     return compContext;
   }
 
   let parentAssoc = await processEntity(targetEntity, targetKey, compContext);
-  while (parentAssoc && !parentAssoc.entity[isRoot]) {
+  while (parentAssoc && !isRootEntity(parentAssoc.entity)) {
     parentAssoc = await processEntity(
       parentAssoc.entity,
       parentAssoc.ID,
@@ -454,36 +454,59 @@ async function generatePathAndParams (req, entityKey) {
   return compContext;
 }
 
-async function processEntity (entity, entityKey, compContext) {
+async function processEntity(entity, entityKey, compContext) {
+  if (!entity || !entityKey || !compContext) return;
+
   const { ID, foreignKey, parentEntity } = getAssociationDetails(entity);
 
-  if (foreignKey && parentEntity) {
-    const parentResult =
-      (await SELECT.one
-        .from(entity.name)
-        .where({ [ID]: entityKey })
-        .columns(foreignKey)) || {};
-    const hasForeignKey = parentResult[foreignKey];
-    if (!hasForeignKey) return;
-    compContext.path = `${parentEntity.name}/${compContext.path}`;
-    compContext.params.unshift({ [ID]: parentResult[foreignKey] });
-    return {
-      entity: parentEntity,
-      [ID]: hasForeignKey ? parentResult[foreignKey] : undefined
-    };
-  }
+  if (!foreignKey || !parentEntity) return;
+
+  const parentResult = await SELECT.one
+    .from(entity.name)
+    .where({ [ID]: entityKey })
+    .columns(foreignKey);
+
+  if (!parentResult || typeof parentResult !== 'object') return;
+
+  const hasForeignKey = parentResult[foreignKey];
+  if (!hasForeignKey) return;
+
+  compContext.path = `${parentEntity.name}/${compContext.path}`;
+  compContext.params.unshift({ [ID]: hasForeignKey });
+
+  return {
+    entity: parentEntity,
+    [ID]: hasForeignKey
+  };
 }
 
 function getAssociationDetails (entity) {
-  if (!entity) return {};
-  const assocName = entity['change-tracking-parentEntity']?.associationName;
-  const assoc = entity.elements[assocName];
-  const parentEntity = assoc?._target;
-  const foreignKey = assoc?.keys?.[0]?.$generatedFieldName;
-  const ID = assoc?.keys?.[0]?.ref[0] || 'ID';
+  if (!entity || typeof entity !== 'object') return {};
+
+  const { name } = entity;
+  if (!name || typeof name !== 'string') return {};
+
+  const definition = cds.model.definitions[name];
+  if (!definition) return {};
+
+  const assocName = entity[hasParent]?.associationName ?? definition[hasParent]?.associationName;
+  if (!assocName) return {};
+
+  const elements = entity.elements || {};
+  const assoc = elements[assocName];
+  if (!assoc) return {};
+
+  const parentEntity = assoc._target;
+  const foreignKey = assoc.keys?.[0]?.$generatedFieldName;
+  const ID = assoc.keys?.[0]?.ref?.[0] ?? 'ID';
+  
   return { ID, foreignKey, parentEntity };
 }
 
+function isRootEntity (entity) {
+  return entity[isRoot] || (cds.model.definitions[entity.name]?.[isRoot] || false);
+}
+
 function isEmpty(value) {
   return value === null || value === undefined || value === "";
 }
@@ -517,8 +540,9 @@ async function trackChangesForDiff(diff, req, that){
   let target = req.target
   let compContext = null;
   let entityKey = diff.ID
+  let isTopLevel = isRootEntity(target);
   const params = convertSubjectToParams(req.subject);
-  if (req.subject.ref.length === 1 && params.length === 1 && !target[isRoot]) {
+  if (req.subject.ref.length === 1 && params.length === 1 && !isTopLevel) {
     compContext = await generatePathAndParams(req, entityKey);
   }
   let isComposition = _isCompositionContextPath(
@@ -527,7 +551,7 @@ async function trackChangesForDiff(diff, req, that){
   );
   if (
     req.event === "DELETE" &&
-    target[isRoot] &&
+    isTopLevel &&
     !cds.env.requires["change-tracking"]?.preserveDeletes
   ) {
     await DELETE.from(`sap.changelog.ChangeLog`).where({ entityKey });