Merge pull request #14042 from meabed/fix-index-alias

Index: Fix index alias object key position

Author: vkarpov15

lib/schema.js

@@ -2037,11 +2037,9 @@ Schema.prototype.index = function(fields, options) {
   }
   for (const key in fields) {
     if (this.aliases[key]) {
-      fields[this.aliases[key]] = fields[key];
-      delete fields[key];
+      fields = utils.renameObjKey(fields, key, this.aliases[key]);
     }
   }
-
   for (const field of Object.keys(fields)) {
     if (fields[field] === 'ascending' || fields[field] === 'asc') {
       fields[field] = 1;

lib/utils.js

@@ -964,6 +964,29 @@ exports.each = function(arr, fn) {
   }
 };
 
+/**
+ * Rename an object key, while preserving its position in the object
+ *
+ * @param {Object} oldObj
+ * @param {String|Number} oldKey
+ * @param {String|Number} newKey
+ * @api private
+ */
+exports.renameObjKey = function(oldObj, oldKey, newKey) {
+  const keys = Object.keys(oldObj);
+  return keys.reduce(
+    (acc, val) => {
+      if (val === oldKey) {
+        acc[newKey] = oldObj[oldKey];
+      } else {
+        acc[val] = oldObj[val];
+      }
+      return acc;
+    },
+    {}
+  );
+};
+
 /*!
  * ignore
  */