Merge pull request #14151 from Automattic/vkarpov15/gh-14058

fix: avoid minimizing single nested subdocs if they are required

Author: vkarpov15

lib/helpers/clone.js

@@ -54,7 +54,7 @@ function clone(obj, options, isArrayChild) {
       ret = obj.toObject(options);
     }
 
-    if (options && options.minimize && isSingleNested && Object.keys(ret).length === 0) {
+    if (options && options.minimize && !obj.constructor.$__required && isSingleNested && Object.keys(ret).length === 0) {
       return undefined;
     }
 

lib/schema/SubdocumentPath.js

@@ -48,7 +48,7 @@ function SubdocumentPath(schema, path, options) {
 
   schema = handleIdOption(schema, options);
 
-  this.caster = _createConstructor(schema);
+  this.caster = _createConstructor(schema, null, options);
   this.caster.path = path;
   this.caster.prototype.$basePath = path;
   this.schema = schema;
@@ -69,7 +69,7 @@ SubdocumentPath.prototype.OptionsConstructor = SchemaSubdocumentOptions;
  * ignore
  */
 
-function _createConstructor(schema, baseClass) {
+function _createConstructor(schema, baseClass, options) {
   // lazy load
   Subdocument || (Subdocument = require('../types/subdocument'));
 
@@ -89,6 +89,7 @@ function _createConstructor(schema, baseClass) {
   _embedded.prototype = Object.create(proto);
   _embedded.prototype.$__setSchema(schema);
   _embedded.prototype.constructor = _embedded;
+  _embedded.$__required = options?.required;
   _embedded.base = schema.base;
   _embedded.schema = schema;
   _embedded.$isSingleNested = true;

test/document.test.js

@@ -793,6 +793,17 @@ describe('document', function() {
       assert.strictEqual(myModel.toObject().foo, void 0);
     });
 
+    it('does not minimize single nested subdocs if they are required (gh-14058) (gh-11247)', async function() {
+      const nestedSchema = Schema({ bar: String }, { _id: false });
+      const schema = Schema({ foo: { type: nestedSchema, required: true } });
+
+      const MyModel = db.model('Test', schema);
+
+      const myModel = await MyModel.create({ foo: {} });
+
+      assert.deepStrictEqual(myModel.toObject().foo, {});
+    });
+
     it('should propogate toObject to implicitly created schemas (gh-13599) (gh-13325)', async function() {
       const transformCalls = [];
       const userSchema = Schema({