diffrence of two objects javascript

1import { transform, isEqual, isObject } from 'lodash';
2
3/**
4 * Deep diff between two object, using lodash
5 * @param  {Object} object Object compared
6 * @param  {Object} base   Object to compare with
7 * @return {Object}        Return a new object who represent the diff
8 */
9function difference(object, base) {
10	return transform(object, (result, value, key) => {
11		if (!isEqual(value, base[key])) {
12			result[key] = isObject(value) && isObject(base[key]) ? difference(value, base[key]) : value;
13		}
14	});
15}

1const { inspect } = require('util')
2const transform = require('lodash.transform')
3const isEqual = require('lodash.isequal')
4const isArray = require('lodash.isarray')
5const isObject = require('lodash.isobject')
6
7/**
8 * Find difference between two objects
9 * @param  {object} origObj - Source object to compare newObj against
10 * @param  {object} newObj  - New object with potential changes
11 * @return {object} differences
12 */
13function difference(origObj, newObj) {
14  function changes(newObj, origObj) {
15    let arrayIndexCounter = 0
16    return transform(newObj, function (result, value, key) {
17      if (!isEqual(value, origObj[key])) {
18        let resultKey = isArray(origObj) ? arrayIndexCounter++ : key
19        result[resultKey] = (isObject(value) && isObject(origObj[key])) ? changes(value, origObj[key]) : value
20      }
21    })
22  }
23  return changes(newObj, origObj)
24}
25
26/* Usage */
27
28const originalObject = {
29  foo: 'bar',
30  baz: 'fizz',
31  cool: true,
32  what: {
33    one: 'one',
34    two: 'two'
35  },
36  wow: {
37    deep: {
38      key: ['a', 'b', 'c'],
39      values: '123'
40    }
41  },
42  array: ['lol', 'hi', 'there']
43}
44
45const newObject = {
46  foo: 'bar',
47  baz: 'fizz',
48  cool: false, // <-- diff
49  what: {
50    one: 'one',
51    two: 'twox' // <-- diff
52  },
53  wow: {
54    deep: {
55      key: ['x', 'y', 'c'], // <-- diff
56      values: '098' // <-- diff
57    }
58  },
59  array: ['lol', 'hi', 'difference'] // <-- diff
60}
61
62// Get the Diff!
63const diff = difference(originalObject, newObject)
64
65console.log(inspect(diff, {showHidden: false, depth: null, colors: true}))
66/* result:
67{
68  cool: false,
69  what: { two: 'twox' },
70  wow: { deep: { key: [ 'x', 'y' ], values: '098' } },
71  array: [ 'difference' ]
72}
73*/
74
75if (diff.cool) {
76  console.log('Coolness changed to', diff.cool)
77}