From a23b1924668920f3c92fec0566b57091d0e8aae8 Mon Sep 17 00:00:00 2001
From: Rahul Lanjewar <63550998+RahulLanjewar93@users.noreply.github.com>
Date: Sun, 14 Dec 2025 21:09:17 +0530
Subject: [PATCH] feat: Log more debug info when failing to set duplicate value
 for field with unique values (#9919)

---
 spec/schemas.spec.js                              | 7 +++++++
 src/Adapters/Storage/Mongo/MongoStorageAdapter.js | 3 ++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/spec/schemas.spec.js b/spec/schemas.spec.js
index 5d92ef36..f9f29c73 100644
--- a/spec/schemas.spec.js
+++ b/spec/schemas.spec.js
@@ -3842,6 +3842,7 @@ describe('schemas', () => {
     });
 
     it_id('cbd5d897-b938-43a4-8f5a-5d02dd2be9be')(it_exclude_dbs(['postgres']))('cannot update to duplicate value on unique index', done => {
+      loggerErrorSpy.calls.reset();
       const index = {
         code: 1,
       };
@@ -3868,6 +3869,12 @@ describe('schemas', () => {
         .then(done.fail)
         .catch(error => {
           expect(error.code).toEqual(Parse.Error.DUPLICATE_VALUE);
+          // Client should only see generic message (no schema info exposed)
+          expect(error.message).toEqual('A duplicate value for a field with unique values was provided');
+          // Server logs should contain full MongoDB error message with detailed information
+          expect(loggerErrorSpy).toHaveBeenCalledWith('Duplicate key error:', jasmine.stringContaining('E11000 duplicate key error'));
+          expect(loggerErrorSpy).toHaveBeenCalledWith('Duplicate key error:', jasmine.stringContaining('test_UniqueIndexClass'));
+          expect(loggerErrorSpy).toHaveBeenCalledWith('Duplicate key error:', jasmine.stringContaining('code_1'));
           done();
         });
     });
diff --git a/src/Adapters/Storage/Mongo/MongoStorageAdapter.js b/src/Adapters/Storage/Mongo/MongoStorageAdapter.js
index 50fd3488..24b206ae 100644
--- a/src/Adapters/Storage/Mongo/MongoStorageAdapter.js
+++ b/src/Adapters/Storage/Mongo/MongoStorageAdapter.js
@@ -519,7 +519,7 @@ export class MongoStorageAdapter implements StorageAdapter {
       .then(() => ({ ops: [mongoObject] }))
       .catch(error => {
         if (error.code === 11000) {
-          // Duplicate value
+          logger.error('Duplicate key error:', error.message);
           const err = new Parse.Error(
             Parse.Error.DUPLICATE_VALUE,
             'A duplicate value for a field with unique values was provided'
@@ -605,6 +605,7 @@ export class MongoStorageAdapter implements StorageAdapter {
       .then(result => mongoObjectToParseObject(className, result, schema))
       .catch(error => {
         if (error.code === 11000) {
+          logger.error('Duplicate key error:', error.message);
           throw new Parse.Error(
             Parse.Error.DUPLICATE_VALUE,
             'A duplicate value for a field with unique values was provided'