Important: This documentation covers Yarn 1 (Classic).
For Yarn 2+ docs and migration guide, see yarnpkg.com.

Package detail

mergekit

jusimen1.4kMIT3.0.6TypeScript support: included

Uniquely flexible and light-weight utility for cloning and deep (recursive) merging of JavaScript objects. Supports descriptor values, accessor functions, and custom prototypes. Provides advanced options for customizing the clone/merge process.

deep, merge, assign, clone, copy, extend, object, recursive, immutable, filter, array, append, prepend, dedup, duplicates, sort, intersection, union, difference, get, getter, set, setter, accessor, descriptor, javascript, deepmerge, deep-merge, merge-deep

readme

MergeKit

Introductory Note

This repository is a fork of mergician with the goal of making it available on npm and updating with new features.
A huge thanks to John Hildenbiddle for creating such a great utility! 🎉

About

mergekit is a uniquely flexible and light-weight utility for cloning and deep (recursive) merging of JavaScript objects.

Unlike native methods and other utilities, mergekit faithfully clones and merges objects by properly handling descriptor values, accessor functions, and prototype properties while offering advanced options for customizing the clone/merge process.

Features

  • Deep (recursive) clone/merge JavaScript objects
  • Generates new object without modifying source object(s)
  • Clone/merge enumerable and non-enumerable properties
  • Clone/merge property descriptor values
  • Retain, skip, or convert accessor functions to static values
  • Inspect, filter, and modify properties
  • Merge, skip, or hoist prototype properties
  • Merge or skip key intersections, unions, and differences
  • Merge, sort, and remove duplicate array items
  • IntelliSense / code hinting support
  • TypeScript support
  • Lightweight (2k min+gzip) and dependency-free

Platform Support

Node 10+
Chrome 61+
Edge 16+
Firefox 60+
Safari 10.1+

Examples

Basic object cloning using default options:

// ES module shown. CommonJS module also available (see below).
import { mergekit } from 'mergekit';

const obj1 = { a: [1, 1], b: { c: 1, d: 1 } };
const clonedObj = mergekit({}, obj1);

// Results
console.log(clonedObj); // { a: [1, 1], b: { c: 1, d: 1 } }
console.log(clonedObj === obj1); // false
console.log(clonedObj.a === obj1.a); // false
console.log(clonedObj.b === obj1.b); // false

Advanced object merging using custom options:

// ES module shown. CommonJS module also available (see below).
import { mergekit } from 'mergekit';

const obj1 = { a: [1, 1], b: { c: 1, d: 1 } };
const obj2 = { a: [2, 2], b: { c: 2 } };
const obj3 = { e: 3 };

const mergedObj = mergekit({
  skipKeys: ['d'],
  appendArrays: true,
  dedupArrays: true,
  filter({ depth, key, srcObj, srcVal, targetObj, targetVal }) {
    if (key === 'e') {
      targetObj['hello'] = 'world';
      return false;
    }
  }
})(obj1, obj2, obj3);

// Result
console.log(mergedObj); // { a: [1, 2], b: { c: 2 }, hello: 'world' }

Installation

NPM

npm install mergekit
// ES module
import { mergekit } from 'mergekit';
// CommonJS module
const { mergekit } = require('mergekit');

CDN

Available on jsdelivr (below), unpkg, and other CDN services that auto-publish npm packages.

💡 Note the @ version lock in the URLs below. This prevents breaking changes in future releases from affecting your project and is therefore the safest method of loading dependencies from a CDN. When a new major version is released, you will need to manually update your CDN URLs by changing the version after the @ symbol.

// ES module @ latest v2.x.x
import { mergekit } from 'https://cdn.jsdelivr.net/npm/mergekit@2';

Usage & Options

See the documentation site for details.

Contact & Support

License

This project is licensed under the MIT license.

Copyright (c) Josue "Jusi" Monteiro (@jusimen)

changelog

Change Log

3.0.0

2024-11-15

  • ❗️ Breaking: Switch to TypeScript
  • ❗️ Breaking: Changed parameters

2.0.3

2024-11-12

  • ❗️ Breaking: Refactor to new package name MergeKit
  • Merge nested object arrays
  • Add onlyObjectWithKeyValues option

    Only merge properties that match the key/value pairs specified in the array, for example:

    const objs = [
      { action: 'read', domain: 'movies', id: '123' },
      {
        action: 'read',
        resource: { director: ['Christopher Nolan'] },
        domain: 'movies',
        id: '345'
      },
      {
        action: 'read',
        resource: { director: ['Quentin Tarantino'] },
        domain: 'movies',
        id: '7890'
      },
      {
        action: 'write',
        resource: { director: ['James Cameron'] },
        domain: 'movies',
        id: '9999'
      }
    ];
    
    mergekit({
      dedupArrays: true,
      appendArrays: true,
      onlyObjectWithKeyValues: [
        { key: 'domain', value: 'movies' },
        { key: 'action', value: 'read' }
      ]
    })(...objs);

    Output:

    {
      "action": "read",
      "domain": "movies",
      "resource": {
        "director": ["Christopher Nolan", "Quentin Tarantino"]
      }
    }

2.0.2

2024-05-05

  • Fix date object handling (#7)

2.0.1

2024-03-05

  • Export types in package.json

2.0.0

2024-01-18

  • ❗️ Breaking: Switch to named export
  • ❗️ Breaking: Clone/merge non-enumerable properties by default
  • ❗️ Breaking: Clone/merge custom prototype properties by default
  • ❗️ Breaking: Update hoistProto option to include non-enumerable custom prototype properties
  • ❗️ Breaking: Rename distributable .mjs files to .esm.js
  • ❗️ Breaking: Remove IIFE build
  • Add hoistEnumerable option
  • Add skipProto option
  • Add TypeScript type declarations
  • Update JSDoc comments / code hinting

1.1.0

2023-02-23

  • Add invokeGetters option
  • Add skipSetters option
  • Add hoistProto option
  • Add support for circular references
  • Add unminified IIFE distributable
  • Fix callback return values not replacing getter/setter properties
  • Fix internal object detection
  • Fix missing </script> tag in docs
  • Update dependencies

1.0.1 - 1.0.3

2022-07-28 - 2022-08-01

  • Update README.md

1.0.0

2022-07-14

  • Initial release