refactor: extract deepObjectClone into libs/utils.js

Move the deep clone logic (JSON.parse/JSON.stringify) out of
index.js and into a reusable deepObjectClone utility in
libs/utils.js alongside forEachObject.

Author: jkyberneees

index.js

@@ -8,6 +8,7 @@
 
 const requestRouter = require('./libs/request-router')
 const applySecurityHeaders = require('./libs/security-headers')
+const { deepObjectClone } = require('./libs/utils')
 const exts = {
   request: {},
   response: require('./libs/response-extensions')
@@ -82,7 +83,7 @@ module.exports = (options = {}) => {
         const val = copy[key]
         if (val && typeof val === 'object' && !Array.isArray(val) &&
             key !== 'server' && val.constructor === Object) {
-          copy[key] = deepFreezePlain(JSON.parse(JSON.stringify(val)))
+          copy[key] = deepFreezePlain(deepObjectClone(val))
         }
       }
       return Object.freeze(copy)

libs/utils.js

@@ -6,3 +6,15 @@ module.exports.forEachObject = (obj, cb) => {
     cb(obj[keys[i]], keys[i])
   }
 }
+
+/**
+ * Creates a deep clone of a serializable plain object.
+ * Uses JSON.parse/stringify for a clean, immutable copy.
+ * Skips non-serializable values (functions, symbols, undefined).
+ *
+ * @param {Object} obj
+ * @returns {Object}
+ */
+module.exports.deepObjectClone = (obj) => {
+  return JSON.parse(JSON.stringify(obj))
+}