From 47c3b469c26635e7c8e9bbe652ccfcf7c0a4e346 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Sun, 6 Oct 2024 14:06:58 -0400
Subject: [PATCH 1/4] fix: set flattenObjectIds to false when calling
 toObject() for internal purposes

Fix #14935
---
 lib/model.js          |  3 +--
 lib/options.js        |  3 ++-
 test/document.test.js | 26 ++++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/lib/model.js b/lib/model.js
index 1c361bcb495..e2c4d68c7fa 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -75,8 +75,7 @@ const subclassedSymbol = Symbol('mongoose#Model#subclassed');
 const { VERSION_INC, VERSION_WHERE, VERSION_ALL } = Document;
 
 const saveToObjectOptions = Object.assign({}, internalToObjectOptions, {
-  bson: true,
-  flattenObjectIds: false
+  bson: true
 });
 
 /**
diff --git a/lib/options.js b/lib/options.js
index 3bae58e1200..bbdcda8b97e 100644
--- a/lib/options.js
+++ b/lib/options.js
@@ -12,5 +12,6 @@ exports.internalToObjectOptions = {
   depopulate: true,
   flattenDecimals: false,
   useProjection: false,
-  versionKey: true
+  versionKey: true,
+  flattenObjectIds: false
 };
diff --git a/test/document.test.js b/test/document.test.js
index 7150ffe64b4..84f0a73ebf0 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -13926,6 +13926,32 @@ describe('document', function() {
     cur.subdocs[0] = { test: 'updated' };
     await savedDoc.save();
   });
+
+  it('avoids flattening objectids on insertMany (gh-14935)', async function() {
+    const TestSchema = new Schema(
+      {
+        professionalId: {
+          type: Schema.Types.ObjectId
+        },
+        firstName: {
+          type: String
+        },
+        nested: {
+          test: String
+        }
+      },
+      {
+        toObject: { flattenObjectIds: true }
+      }
+    );
+    const Test = db.model('Test', TestSchema);
+
+    const professionalId = new mongoose.Types.ObjectId();
+    await Test.insertMany([{ professionalId, name: 'test' }]);
+
+    const doc = await Test.findOne({ professionalId }).lean().orFail();
+    assert.ok(doc.professionalId instanceof mongoose.Types.ObjectId);
+  });
 });
 
 describe('Check if instance function that is supplied in schema option is available', function() {

From 80441c00f5bb8e192fe1f16c49c5c3dca1826e4a Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 8 Oct 2024 12:54:54 -0400
Subject: [PATCH 2/4] style: fix lint

---
 test/document.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/document.test.js b/test/document.test.js
index b08abad27ee..6aa5e98413d 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -13952,7 +13952,7 @@ describe('document', function() {
     const doc = await Test.findOne({ professionalId }).lean().orFail();
     assert.ok(doc.professionalId instanceof mongoose.Types.ObjectId);
   });
-    
+
   it('handles buffers stored as EJSON POJO (gh-14911)', async function() {
     const pdfSchema = new mongoose.Schema({
       pdfSettings: {

From 8068c6a61d3ad7e1b748cc7101147d136bae0cdd Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 9 Oct 2024 11:22:50 -0400
Subject: [PATCH 3/4] Update test/document.test.js

Co-authored-by: hasezoey <hasezoey@gmail.com>
---
 test/document.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/document.test.js b/test/document.test.js
index 6aa5e98413d..b12f19ea686 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -13947,7 +13947,7 @@ describe('document', function() {
     const Test = db.model('Test', TestSchema);
 
     const professionalId = new mongoose.Types.ObjectId();
-    await Test.insertMany([{ professionalId, name: 'test' }]);
+    await Test.insertMany([{ professionalId, firstName: 'test' }]);
 
     const doc = await Test.findOne({ professionalId }).lean().orFail();
     assert.ok(doc.professionalId instanceof mongoose.Types.ObjectId);

From 6aecc016e84904d9dfce278b5458c7edc35b83da Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 9 Oct 2024 11:22:56 -0400
Subject: [PATCH 4/4] Update test/document.test.js

Co-authored-by: hasezoey <hasezoey@gmail.com>
---
 test/document.test.js | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/test/document.test.js b/test/document.test.js
index b12f19ea686..f3869b8e58c 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -13935,9 +13935,6 @@ describe('document', function() {
         },
         firstName: {
           type: String
-        },
-        nested: {
-          test: String
         }
       },
       {