A lightweight javascript diff library for comparing two javascript object nested with supporting matching by value of the object's choosen key name in array.

Installation

``js
npm i --save nested-object-diff
`

Importing

NodeJs / ES5:

`js
var diff = require("nested-object-diff").diff;
`

ES6 / Babel:

`js
import { diff } from "nested-object-diff";
`

Usage:

`js
var diff = require("./dist/index").diff;

var lhs = {
shop: {
products: [
{ id: 1, name: "a" },
{ id: 2, name: "b" },
{ id: 3, name: "c" }
]
},
name: "foo"
};

var rhs = {
shop: {
products: [
{ id: 1, name: 'a' },
{ id: 4, name: 'd' },
{ id: 5, name: 'e' },
{ id: 3, name: 'cc' }
]
},
name: "baz"
};

var differences = diff(lhs, rhs);

//The code snippet above would result only added and deleted propery/element in the following structure describing the differences:
[
{ type: 'A', path: 'shop.products.3', rhs: { id: 3, name: 'cc' } },
{ type: 'E', path: 'shop.products.2.id', lhs: 3, rhs: 5 },
{ type: 'E', path: 'shop.products.2.name', lhs: 'c', rhs: 'e' },
{ type: 'E', path: 'shop.products.1.id', lhs: 2, rhs: 4 },
{ type: 'E', path: 'shop.products.1.name', lhs: 'b', rhs: 'd' },
{ type: 'E', path: 'name', lhs: 'foo', rhs: 'baz' }
]
`
With match options

`js
var differences = diff(lhs, rhs, { matchKey: 'id' });

//The code snippet above would result in the following structure describing the differences:
[
{ type: 'D', path: 'shop.products', lhs: { id: 2, name: 'b' } },
{ type: 'M', path: 'shop.products', item: { id: 3, name: 'c' }, lhsIndex: 2, rhsIndex: 3},
{ type: 'E', path: 'shop.products.3.name', lhs: 'c', rhs: 'cc' },
{ type: 'A', path: 'shop.products.1', rhs: { id: 4, name: 'd' } },
{ type: 'A', path: 'shop.products.2', rhs: { id: 5, name: 'e' } },
{ type: 'E', path: 'name', lhs: 'foo', rhs: 'baz' }
]
`

With types options

`js
var differences = diff(lhs, rhs, { matchKey: 'id', types:['A','D'] });

//The code snippet above would result only added and deleted propery/element in the following structure describing the differences:
[
{ type: 'D', path: 'shop.products', lhs: { id: 2, name: 'b' } },
{ type: 'A', path: 'shop.products.1', rhs: { id: 4, name: 'd' } },
{ type: 'A', path: 'shop.products.2', rhs: { id: 5, name: 'e' } }
]
`

$3

- lhs - the left-hand operand; the origin object.
- rhs - the right-hand operand; the object being compared structurally with the origin object.
- options - A configuration object that can have the following properties:
- matchKey: used to match objects when diffing arrays, by default only === operator is used; string
- types: calculates differences for given types; array

$3

Differences are reported as one or more change records. Change records have the following structure:

- type - indicates the kind of change; will be one of the following:
- A - indicates a newly added property/element
- D - indicates a property/element was deleted
- E - indicates a property/element was edited
- M - indicates a property/element was moved
- path - the property/element path
- item - when type === 'M', contains a nested change record indicating the change that occurred at the array index
- lhsIndex - when type === 'M', indicates the left-hand-side array index
- rhsIndex - when type === 'M', indicates the right-hand-side array index
- lhs - the value on the left-hand-side of the comparison (undefined if kind === 'A')
- rhs - the value on the right-hand-side of the comparison (undefined if kind === 'D')

Contributing

You discovered a bug or have an idea for a new feature? Great, why don't you send me a PR or open an issue so everyone can benefit from it?
If you decide to send PR please run the unit tests before submitting your PR: npm test`. Hopefully your PR includes additional unit tests to illustrate your changemodification!

License

MIT