From 98a96e1d48213e24fb8c878caa267e26cf843a90 Mon Sep 17 00:00:00 2001
From: egargan <edwgargan@gmail.com>
Date: Wed, 27 Oct 2021 15:35:41 +0100
Subject: [PATCH] add 'objectProto' option to create parsed objects as {}

This gives clients the ability to go back to the old behaviour
before c85a430, where any parsed object was created as {}.
---
 lib/parse.js              |  6 +++++-
 test/object-proto-test.js | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 test/object-proto-test.js

diff --git a/lib/parse.js b/lib/parse.js
index 84d142f..085880b 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -84,6 +84,7 @@ var json_parse = function (options) {
   var _options = {
     strict: false, // not being strict means do not generate syntax errors for "duplicate key"
     storeAsString: false, // toggles whether the values should be stored as BigNumber (default) or a string
+    objectProto: false, // toggles whether to parse objects as Objects (consistent with JSON.parse), or as null-prototype objects
     alwaysParseAsBig: false, // toggles whether all numbers should be Big
     useNativeBigInt: false, // toggles whether to use native BigInt instead of bignumber.js
     protoAction: 'error',
@@ -98,6 +99,9 @@ var json_parse = function (options) {
     if (options.storeAsString === true) {
       _options.storeAsString = true;
     }
+    if (options.objectProto === true) {
+      _options.objectProto = true;
+    }
     _options.alwaysParseAsBig =
       options.alwaysParseAsBig === true ? options.alwaysParseAsBig : false;
     _options.useNativeBigInt =
@@ -328,7 +332,7 @@ var json_parse = function (options) {
       // Parse an object value.
 
       var key,
-        object = Object.create(null);
+        object = _options.objectProto ? {} : Object.create(null);
 
       if (ch === '{') {
         next('{');
diff --git a/test/object-proto-test.js b/test/object-proto-test.js
new file mode 100644
index 0000000..04a0ae1
--- /dev/null
+++ b/test/object-proto-test.js
@@ -0,0 +1,22 @@
+const makeJSON = require('../index.js');
+const expect = require('chai').expect;
+
+describe('objectProto option', function(){
+    it("should parse objects as Object instances if 'objectProto' set to true", function(done){
+        const JSONbigObjectProto = makeJSON({ objectProto: true });
+        var json_with_object = '{ "foo": { "bar": "baz" }}';
+        var result = JSONbigObjectProto.parse(json_with_object);
+        expect(result instanceof Object).to.be.true;
+        expect(result['foo'] instanceof Object).to.be.true;
+        done();
+    });
+
+    it("should parse objects as null-prototype objects if 'objectProto' set to false", function(done){
+        const JSONbigNullProto = makeJSON({ objectProto: false });
+        var json_with_object = '{ "foo": { "bar": "baz" }}';
+        var result = JSONbigNullProto.parse(json_with_object);
+        expect(result.__proto__).to.be.undefined;
+        expect(result['foo'].__proto__).to.be.undefined;
+        done();
+    });
+});