From 82fd5e4e5d576c2dd1d0d69bca9df02167943861 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 27 Feb 2023 12:22:55 -0500
Subject: [PATCH] BREAKING CHANGE: copy schema options when merging schemas
 using `new Schema()` or `Schema.prototype.add()`

---
 lib/helpers/schema/merge.js |  7 +++++++
 test/schema.test.js         | 16 ++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/lib/helpers/schema/merge.js b/lib/helpers/schema/merge.js
index 55ed82466f7..aeb8c453b00 100644
--- a/lib/helpers/schema/merge.js
+++ b/lib/helpers/schema/merge.js
@@ -15,6 +15,13 @@ module.exports = function merge(s1, s2, skipConflictingPaths) {
   s1.method(s2.methods);
   s1.static(s2.statics);
 
+  for (const [option, value] of Object.entries(s2._userProvidedOptions)) {
+    if (!(option in s1._userProvidedOptions)) {
+      s1._userProvidedOptions[option] = value;
+      s1.options[option] = value;
+    }
+  }
+
   for (const query in s2.query) {
     s1.query[query] = s2.query[query];
   }
diff --git a/test/schema.test.js b/test/schema.test.js
index 8ec9a32c5f0..cb334f0ce79 100644
--- a/test/schema.test.js
+++ b/test/schema.test.js
@@ -1391,8 +1391,24 @@ describe('schema', function() {
       assert.ok(s.path('created'));
       assert.ok(s.path('name'));
       assert.ok(!s.options.id);
+    });
+
+    it('copies options from array of schemas', function() {
+      const baseSchema = new Schema({ created: Date }, { id: true, toJSON: { virtuals: true } });
+      const s = new Schema([baseSchema, { name: String }]);
 
+      assert.ok(s.path('created'));
+      assert.ok(s.path('name'));
+      assert.ok(s.options.id);
+      assert.deepEqual(s.options.toJSON, { virtuals: true });
+      assert.strictEqual(s.options.toObject, undefined);
 
+      s.add(new Schema({}, { toObject: { getters: true } }));
+      assert.ok(s.path('created'));
+      assert.ok(s.path('name'));
+      assert.ok(s.options.id);
+      assert.deepEqual(s.options.toJSON, { virtuals: true });
+      assert.deepEqual(s.options.toObject, { getters: true });
     });
   });