The npm package 'just-diff-apply' is a utility that allows users to apply differences between objects or arrays. It is typically used in scenarios where changes need to be tracked and applied, such as in state management or data synchronization.

What are just-diff-apply's main functionalities?

Applying differences to objects

This feature allows you to apply a set of differences to an object. In the provided code, a difference is applied to change the value of 'a' from 3 to 4.

const diffApply = require('just-diff-apply');
const obj = {a: 3, b: 5};
const diff = [{op: 'replace', path: ['a'], value: 4}];
diffApply(obj, diff);
console.log(obj); // {a: 4, b: 5}

Applying differences to arrays

This feature enables the application of differences to arrays. In the example, an element with value 5 is added at index 1.

const diffApply = require('just-diff-apply');
const arr = [1, 2, 3];
const diff = [{op: 'add', path: [1], value: 5}];
diffApply(arr, diff);
console.log(arr); // [1, 5, 2, 3]

Other packages similar to just-diff-apply

Readme

Source

just-diff-apply

Part of a library of zero-dependency npm modules that do just do one thing. Guilt-free utilities for every occasion.

🍦 Try it

npm install just-diff-apply

yarn add just-diff-apply

Apply a diff object to an object. Pass converter to apply a http://jsonpatch.com standard patch

  import diffApply from 'just-diff-apply';

  const obj1 = {a: 3, b: 5};
  diffApply(obj1,
    [
      { "op": "remove", "path": ['b'] },
      { "op": "replace", "path": ['a'], "value": 4 },
      { "op": "add", "path": ['c'], "value": 5 }
    ]
  );
  obj1; // {a: 4, c: 5}

  // using converter to apply jsPatch standard paths
  // see http://jsonpatch.com
  import {diffApply, jsonPatchPathConverter} from 'just-diff-apply'
  const obj2 = {a: 3, b: 5};
  diffApply(obj2, [
    { "op": "remove", "path": '/b' },
    { "op": "replace", "path": '/a', "value": 4 }
    { "op": "add", "path": '/c', "value": 5 }
  ], jsonPatchPathConverter);
  obj2; // {a: 4, c: 5}

  // arrays (array key can be string or numeric)
  const obj3 = {a: 4, b: [1, 2, 3]};
  diffApply(obj3, [
    { "op": "replace", "path": ['a'], "value": 3 }
    { "op": "replace", "path": ['b', 2], "value": 4 }
    { "op": "add", "path": ['b', 3], "value": 9 }
  ]);
  obj3; // {a: 3, b: [1, 2, 4, 9]}

  // nested paths
  const obj4 = {a: 4, b: {c: 3}};
  diffApply(obj4, [
    { "op": "replace", "path": ['a'], "value": 5 }
    { "op": "remove", "path": ['b', 'c']}
    { "op": "add", "path": ['b', 'd'], "value": 4 }
  ]);
  obj4; // {a: 5, b: {d: 4}}

Keywords

FAQs

What is just-diff-apply?

Is just-diff-apply well maintained?

Last updated on 09 Jan 2022

Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install