• Stars
    star
    4,671
  • Rank 9,016 (Top 0.2 %)
  • Language
    TypeScript
  • License
    MIT License
  • Created almost 13 years ago
  • Updated 6 months ago

Reviews

There are no reviews yet. Be the first to send feedback to the community and the maintainers!

Repository Details

Diff & patch JavaScript objects

jsondiffpatch

Build Status Code Climate Test Coverage NPM version NPM dependencies

Diff & patch JavaScript objects


  • min+gzipped ~ 16KB
  • browser and server (ESM-only)
  • (optionally) uses google-diff-match-patch for long text diffs (diff at character level)
  • smart array diffing using LCS, IMPORTANT NOTE: to match objects inside an array you must provide an objectHash function (this is how objects are matched, otherwise a dumb match by position is used). For more details, check Array diff documentation
  • reverse a delta
  • unpatch (eg. revert object to its original state using a delta)
  • simplistic, pure JSON, low footprint delta format
  • multiple output formatters:
    • html (check it at the Live Demo)
    • annotated json (html), makes the JSON delta format self-explained
    • console (colored), try running ./node_modules/.bin/jsondiffpatch left.json right.json
    • JSON Patch format RFC 6902 support
    • write your own! check Formatters documentation
  • BONUS: jsondiffpatch.clone(obj) (deep clone)

Supported platforms

  • Any browser that supports ES6
  • Node.js 18, 20+

Usage

// sample data
const country = {
  name: 'Argentina',
  capital: 'Buenos Aires',
  independence: new Date(1816, 6, 9),
  unasur: true,
};

// clone country, using dateReviver for Date objects
const country2 = JSON.parse(JSON.stringify(country), jsondiffpatch.dateReviver);

// make some changes
country2.name = 'Republica Argentina';
country2.population = 41324992;
delete country2.capital;

const delta = jsondiffpatch.diff(country, country2);

assertSame(delta, {
  name: ['Argentina', 'Republica Argentina'], // old value, new value
  population: ['41324992'], // new value
  capital: ['Buenos Aires', 0, 0], // deleted
});

// patch original
jsondiffpatch.patch(country, delta);

// reverse diff
const reverseDelta = jsondiffpatch.reverse(delta);
// also country2 can be return to original value with: jsondiffpatch.unpatch(country2, delta);

const delta2 = jsondiffpatch.diff(country, country2);
assert(delta2 === undefined);
// undefined => no difference

Array diffing:

// sample data
const country = {
  name: 'Argentina',
  cities: [
    {
      name: 'Buenos Aires',
      population: 13028000,
    },
    {
      name: 'Cordoba',
      population: 1430023,
    },
    {
      name: 'Rosario',
      population: 1136286,
    },
    {
      name: 'Mendoza',
      population: 901126,
    },
    {
      name: 'San Miguel de Tucuman',
      population: 800000,
    },
  ],
};

// clone country
const country2 = JSON.parse(JSON.stringify(country));

// delete Cordoba
country.cities.splice(1, 1);

// add La Plata
country.cities.splice(4, 0, {
  name: 'La Plata',
});

// modify Rosario, and move it
const rosario = country.cities.splice(1, 1)[0];
rosario.population += 1234;
country.cities.push(rosario);

// create a configured instance, match objects by name
const diffpatcher = jsondiffpatch.create({
  objectHash: function (obj) {
    return obj.name;
  },
});

const delta = diffpatcher.diff(country, country2);

assertSame(delta, {
  cities: {
    _t: 'a', // indicates this node is an array (not an object)
    1: [
      // inserted at index 1
      {
        name: 'Cordoba',
        population: 1430023,
      },
    ],
    2: {
      // population modified at index 2 (Rosario)
      population: [1137520, 1136286],
    },
    _3: [
      // removed from index 3
      {
        name: 'La Plata',
      },
      0,
      0,
    ],
    _4: [
      // move from index 4 to index 2
      '',
      2,
      3,
    ],
  },
});

For more example cases (nested objects or arrays, long text diffs) check packages/jsondiffpatch/test/examples/

If you want to understand deltas, see delta format documentation

Installing

NPM

This works for node, or in browsers if you already do bundling on your app

npm install jsondiffpatch
import * as jsondiffpatch from 'jsondiffpatch';
const jsondiffpatchInstance = jsondiffpatch.create(options);

browser

In a browser, you can load a bundle using a tool like esm.sh or Skypack.

Options

import * as jsondiffpatch from 'jsondiffpatch';

// Only import if you want text diffs using diff-match-patch
import DiffMatchPatch from 'diff-match-patch';

const jsondiffpatchInstance = jsondiffpatch.create({
  // used to match objects when diffing arrays, by default only === operator is used
  objectHash: function (obj) {
    // this function is used only to when objects are not equal by ref
    return obj._id || obj.id;
  },
  arrays: {
    // default true, detect items moved inside the array (otherwise they will be registered as remove+add)
    detectMove: true,
    // default false, the value of items moved is not included in deltas
    includeValueOnMove: false,
  },
  textDiff: {
    // If using text diffs, it's required to pass in the diff-match-patch library in through this proprty.
    // Alternatively, you can import jsondiffpatch using `jsondiffpatch/with-text-diffs` to avoid having to pass in diff-match-patch through the options.
    diffMatchPatch: DiffMatchPatch,
    // default 60, minimum string length (left and right sides) to use text diff algorythm: google-diff-match-patch
    minLength: 60,
  },
  propertyFilter: function (name, context) {
    /*
       this optional function can be specified to ignore object properties (eg. volatile data)
        name: property name, present in either context.left or context.right objects
        context: the diff context (has context.left and context.right objects)
      */
    return name.slice(0, 1) !== '$';
  },
  cloneDiffValues: false /* default false. if true, values in the obtained delta will be cloned
      (using jsondiffpatch.clone by default), to ensure delta keeps no references to left or right objects. this becomes useful if you're diffing and patching the same objects multiple times without serializing deltas.
      instead of true, a function can be specified here to provide a custom clone(value)
      */,
});

Visual Diff

<!doctype html>
<html>
  <head>
    <link rel="stylesheet" href="./style.css" type="text/css" />
    <link
      rel="stylesheet"
      href="https://esm.sh/[email protected]/lib/formatters/styles/html.css"
      type="text/css"
    />
    <link
      rel="stylesheet"
      href="https://esm.sh/[email protected]/lib/formatters/styles/annotated.css"
      type="text/css"
    />
  </head>
  <body>
    <div id="visual"></div>
    <hr />
    <div id="annotated"></div>
    <script type="module">
      import * as jsondiffpatch from 'https://esm.sh/[email protected]';
      import * as annotatedFormatter from 'https://esm.sh/[email protected]/formatters/annotated';
      import * as htmlFormatter from 'https://esm.sh/[email protected]/formatters/html';

      const left = { a: 3, b: 4 };
      const right = { a: 5, c: 9 };
      const delta = jsondiffpatch.diff(left, right);

      // beautiful html diff
      document.getElementById('visual').innerHTML = htmlFormatter.format(
        delta,
        left,
      );

      // self-explained json
      document.getElementById('annotated').innerHTML =
        annotatedFormatter.format(delta, left);
    </script>
  </body>
</html>

To see formatters in action check the Live Demo.

For more details check Formatters documentation

Console

# diff two json files, colored output (using chalk lib)
./node_modules/.bin/jsondiffpatch ./docs/demo/left.json ./docs/demo/right.json

# or install globally
npm install -g jsondiffpatch

jsondiffpatch ./docs/demo/left.json ./docs/demo/right.json

console_demo!

Plugins

diff(), patch() and reverse() functions are implemented using Pipes & Filters pattern, making it extremely customizable by adding or replacing filters on a pipe.

Check Plugins documentation for details.

More Repositories

1

fetch-wrap

extend WHATWG fetch wrapping it with middlewares
JavaScript
23
star
2

gitdeployhub

Git-based deployment on IIS
C#
23
star
3

dialogo

Javascript Differential Synchronization
JavaScript
16
star
4

jLiveTime

jQuery plugin for live timestamps, countdowns, time-ago, and timers
JavaScript
16
star
5

tent

Tiny Entity Framework for Javascript
JavaScript
15
star
6

hubot-skype

Skype adapter for hubot
Python
14
star
7

FrameProxy

small script to proxy cross-domain ajax callbacks or other functions thru a hidden iframe
JavaScript
10
star
8

golem

run apps in automatically provisioned virtual machines or docker containers
JavaScript
9
star
9

markdown-diagram

generate diagrams from markdown documents
JavaScript
8
star
10

explain.sh

explainshell.com cli
Shell
8
star
11

mutagen

experiment with multiple variations of websites.
JavaScript
6
star
12

PiroPiro

Acceptance test framework for web apps
C#
5
star
13

AssemblyHasher

Hash tool for .Net assemblies
C#
4
star
14

scrumy-utils

Some utilities to use with scrumy.com scrumboards
JavaScript
3
star
15

frame-channels

pub/sub channels between browser [i]frames
JavaScript
3
star
16

phenotype

Trait based typing system for Javascript
JavaScript
3
star
17

CinchBot

Cinchcast's Hubot
CoffeeScript
3
star
18

ScrumyCLI

CLI for simple batch tasks on scrumy.com boards
JavaScript
3
star
19

CFT

.net config file transformations tool
C#
3
star
20

fiberglass

some material to scaffold javascript modules
JavaScript
3
star
21

pelpa

create simple, single-page, static-content sites, using markdown and node.js
JavaScript
2
star
22

ga-experiments-bundler

bundle multiple google analytics content experiments in 1 file
JavaScript
2
star
23

resource-shadow

keep a synchronized copy of a remote http resource
JavaScript
2
star
24

hubot-issues

hubot issue tracker
JavaScript
1
star
25

mongo-listener

mongodb oplog listener
JavaScript
1
star
26

highlight-cov

atom linter for lcov test coverage info
CoffeeScript
1
star
27

PageStopwatch

measure load times in real user browsers
JavaScript
1
star
28

apidoc-json-schema

generate json schema from apidoc.json
JavaScript
1
star
29

page-object-pattern

page object pattern implementation for javascript
JavaScript
1
star
30

ObjBind

change tracking (and custom events) for plain JavaScript objects and Arrays
JavaScript
1
star
31

touch-wheel

touch UI experimental wheel for selection with a finger drag
JavaScript
1
star