From 316c54bd7dc52a130e274b08a2d8a742ec0cbd08 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Sun, 11 Sep 2022 19:53:17 -0400
Subject: [PATCH] fix(array): apply fix for #12294 to nested paths

---
 lib/types/array/methods/index.js | 39 +++++++++++++++++++++++++++++++-
 test/types.array.test.js         |  3 +++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/lib/types/array/methods/index.js b/lib/types/array/methods/index.js
index 61f7b10d7d7..12c2f611d1c 100644
--- a/lib/types/array/methods/index.js
+++ b/lib/types/array/methods/index.js
@@ -5,6 +5,7 @@ const ArraySubdocument = require('../../ArraySubdocument');
 const MongooseError = require('../../../error/mongooseError');
 const cleanModifiedSubpaths = require('../../../helpers/document/cleanModifiedSubpaths');
 const internalToObjectOptions = require('../../../options').internalToObjectOptions;
+const mpath = require('mpath');
 const utils = require('../../../utils');
 const isBsonType = require('../../../helpers/isBsonType');
 
@@ -349,7 +350,9 @@ const methods = {
               }
 
               Object.keys(v.$__.activePaths.getStatePaths('default')).forEach(path => {
-                delete ret[path];
+                mpath.unset(path, ret);
+
+                _minimizePath(ret, path);
               });
 
               return ret;
@@ -937,6 +940,40 @@ function _isAllSubdocs(docs, ref) {
   return true;
 }
 
+/*!
+ * Minimize _just_ empty objects along the path chain specified
+ * by `parts`, ignoring all other paths. Useful in cases where
+ * you want to minimize after unsetting a path.
+ *
+ * #### Example:
+ *
+ *     const obj = { foo: { bar: { baz: {} } }, a: {} };
+ *     _minimizePath(obj, 'foo.bar.baz');
+ *     obj; // { a: {} }
+ */
+
+function _minimizePath(obj, parts, i) {
+  if (typeof parts === 'string') {
+    if (parts.indexOf('.') === -1) {
+      return;
+    }
+
+    parts = mpath.stringToParts(parts);
+  }
+  i = i || 0;
+  if (i >= parts.length) {
+    return;
+  }
+  if (obj == null || typeof obj !== 'object') {
+    return;
+  }
+
+  _minimizePath(obj[parts[0]], parts, i + 1);
+  if (obj[parts[0]] != null && typeof obj[parts[0]] === 'object' && Object.keys(obj[parts[0]]).length === 0) {
+    delete obj[parts[0]];
+  }
+}
+
 /*!
  * ignore
  */
diff --git a/test/types.array.test.js b/test/types.array.test.js
index 8aef5ed7043..19b337c36b1 100644
--- a/test/types.array.test.js
+++ b/test/types.array.test.js
@@ -829,6 +829,9 @@ describe('types array', function() {
         colors: [{
           _id: false,
           hex: { type: String, default: '#ffffff' },
+          properties: {
+            hue: { type: Number, default: 0 }
+          },
           name: String
         }]
       });