Merge pull request #14395 from Automattic/vkarpov15/gh-14353

fix(document): make `$clone` avoid converting subdocs into POJOs

Author: vkarpov15

lib/document.js

@@ -4735,7 +4735,7 @@ Document.prototype.$clone = function() {
  const clonedDoc = new Model();
  clonedDoc.$isNew = this.$isNew;
  if (this._doc) {
- clonedDoc._doc = clone(this._doc);
+ clonedDoc._doc = clone(this._doc, { retainDocuments: true });
  }
  if (this.$__) {
  const Cache = this.$__.constructor;

lib/helpers/clone.js

@@ -36,10 +36,23 @@ function clone(obj, options, isArrayChild) {
  }
 
  if (isMongooseObject(obj)) {
- // Single nested subdocs should apply getters later in `applyGetters()`
- // when calling `toObject()`. See gh-7442, gh-8295
- if (options && options._skipSingleNestedGetters && obj.$isSingleNested) {
- options = Object.assign({}, options, { getters: false });
+ if (options) {
+ // Single nested subdocs should apply getters later in `applyGetters()`
+ // when calling `toObject()`. See gh-7442, gh-8295
+ if (options._skipSingleNestedGetters && obj.$isSingleNested) {
+ options = Object.assign({}, options, { getters: false });
+ }
+ if (options.retainDocuments && obj.$__ != null) {
+ const clonedDoc = obj.$clone();
+ if (obj.__index != null) {
+ clonedDoc.__index = obj.__index;
+ }
+ if (obj.__parentArray != null) {
+ clonedDoc.__parentArray = obj.__parentArray;
+ }
+ clonedDoc.$__parent = obj.$__parent;
+ return clonedDoc;
+ }
  }
  const isSingleNested = obj.$isSingleNested;
 

test/document.test.js

@@ -12070,6 +12070,27 @@ describe('document', function() {
  assert.strictEqual(clonedDoc.$session(), session);
  });
 
+ it('$clone() with single nested and doc array (gh-14353) (gh-11849)', async function() {
+ const schema = new mongoose.Schema({
+ subdocArray: [{
+ name: String
+ }],
+ subdoc: new mongoose.Schema({ name: String })
+ });
+ const Test = db.model('Test', schema);
+
+ const item = await Test.create({ subdocArray: [{ name: 'test 1' }], subdoc: { name: 'test 2' } });
+
+ const doc = await Test.findById(item._id);
+ const clonedDoc = doc.$clone();
+
+ assert.ok(clonedDoc.subdocArray[0].$__);
+ assert.ok(clonedDoc.subdoc.$__);
+
+ assert.deepEqual(doc.subdocArray[0], clonedDoc.subdocArray[0]);
+ assert.deepEqual(doc.subdoc, clonedDoc.subdoc);
+ });
+
  it('can create document with document array and top-level key named `schema` (gh-12480)', async function() {
  const AuthorSchema = new Schema({
  fullName: { type: 'String', required: true }