From cbe4589476d419553fa272c63779be0ed957fbed Mon Sep 17 00:00:00 2001
From: Timo Hocker <t-hocker@web.de>
Date: Tue, 10 Mar 2020 10:46:12 +0100
Subject: [PATCH] function to copy objects

---
 README.md     |  6 ++++++
 index.js      | 14 +++++++++++++-
 test/index.js |  8 ++++++++
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 672093b..b611d7b 100644
--- a/README.md
+++ b/README.md
@@ -11,4 +11,10 @@ util.truncate_decimal(12.345678, 2);
 
 // will return null instead of throwing on invalid json
 util.try_parse_json('{{foo');
+
+// copy an object to prevent modification of the original
+const obj = {foo:'bar'};
+const copy = util.copy_object(obj);
+copy.foo = 'baz';
+console.log(obj.foo); // bar
 ```
diff --git a/index.js b/index.js
index cff0c8f..74d5ef7 100644
--- a/index.js
+++ b/index.js
@@ -32,7 +32,19 @@ function try_parse_json (text) {
   return null;
 }
 
+
+/**
+ * copy an object to prevent modification to the original
+ *
+ * @param {object} obj object to copy
+ * @returns {object} copy
+ */
+function copy_object (obj) {
+  return JSON.parse (JSON.stringify (obj));
+}
+
 module.exports = {
   truncate_decimal,
-  try_parse_json
+  try_parse_json,
+  copy_object
 };
diff --git a/test/index.js b/test/index.js
index faca10e..92b2860 100644
--- a/test/index.js
+++ b/test/index.js
@@ -30,3 +30,11 @@ test ('try_parse_json should fail', (t) => {
     t.is (json, null);
   });
 });
+
+test ('copy object', (t) => {
+  const obj = {foo:'bar'};
+  const copy = util.copy_object(obj);
+  copy.foo = 'baz';
+  t.is(copy.foo, 'baz');
+  t.is(obj.foo, 'bar');
+});