From 2e26e07f921575dbb10c049eaa7a864867e696c6 Mon Sep 17 00:00:00 2001
From: Mariusz Nowak <medyk@medikoo.com>
Date: Fri, 9 Oct 2020 12:19:01 +0200
Subject: [PATCH] fix: Ensure to preserve `undefined` valued propeties as
 `undefined`

---
 lib/classes/ConfigSchemaHandler/index.js | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/classes/ConfigSchemaHandler/index.js b/lib/classes/ConfigSchemaHandler/index.js
index 205ffaceca1..5046bd1b817 100644
--- a/lib/classes/ConfigSchemaHandler/index.js
+++ b/lib/classes/ConfigSchemaHandler/index.js
@@ -27,7 +27,7 @@ const normalizeSchemaObject = (object, instanceSchema) => {
 // normalizedObjectsMap allows to handle circular structures without issues
 const normalizeUserConfig = userConfig => {
   const normalizedObjectsSet = new WeakSet();
-  const nullPaths = [];
+  const removedValuesMap = [];
   const normalizeObject = (object, path) => {
     if (normalizedObjectsSet.has(object)) return;
     normalizedObjectsSet.add(object);
@@ -38,7 +38,7 @@ const normalizeUserConfig = userConfig => {
     } else {
       for (const [key, value] of Object.entries(object)) {
         if (value == null) {
-          nullPaths.push(path.concat(key));
+          removedValuesMap.push({ path: path.concat(key), value });
           delete object[key];
         } else if (_.isObject(value)) {
           normalizeObject(value, path.concat(key));
@@ -47,10 +47,12 @@ const normalizeUserConfig = userConfig => {
     }
   };
   normalizeObject(userConfig, []);
-  return { nullPaths };
+  return { removedValuesMap };
 };
-const denormalizeUserConfig = (userConfig, { nullPaths }) => {
-  for (const nullPath of nullPaths) _.set(userConfig, nullPath, null);
+const denormalizeUserConfig = (userConfig, { removedValuesMap }) => {
+  for (const removedValueData of removedValuesMap) {
+    _.set(userConfig, removedValueData.path, removedValueData.value);
+  }
 };
 
 class ConfigSchemaHandler {