Nested Object Diff
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
npm i --save nested-object-diffImporting
NodeJs / ES5:
var diff = require("nested-object-diff").diff;ES6 / Babel:
import { diff } from "nested-object-diff";Usage:
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
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
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' } }
]Function Arguments
-
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
-
Differences
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
