merge-deep

What is merge-deep?

The merge-deep npm package is a utility for deeply merging objects in JavaScript. It is useful for combining configurations, options, or states in a way that nested properties are not lost but instead merged together.

What are merge-deep's main functionalities?

Deep merging of objects

This feature allows you to deeply merge multiple objects into one. It recursively merges own and inherited enumerable properties of source objects into the destination object, skipping source properties that resolve to `undefined`.

{"const mergeDeep = require('merge-deep');\nconst object1 = { a: { b: 1 } };\nconst object2 = { a: { c: 2 }, d: 3 };\nconst result = mergeDeep(object1, object2);\nconsole.log(result); // Output: { a: { b: 1, c: 2 }, d: 3 }"}

Merging with array concatenation

Merge-deep can also merge arrays by concatenating them. This is useful when you want to combine arrays from different objects without losing any elements.

{"const mergeDeep = require('merge-deep');\nconst object1 = { a: [1, 2], b: 'one' };\nconst object2 = { a: [3, 4], b: 'two' };\nconst result = mergeDeep(object1, object2);\nconsole.log(result); // Output: { a: [1, 2, 3, 4], b: 'two' }"}

Customizing merge behavior

Users can define a custom merge function to control how merging is done. This is particularly useful when the default behavior of merge-deep does not suit the specific needs of your application.

{"const mergeDeep = require('merge-deep');\nfunction customMerge(a, b) {\n  return Array.isArray(a) ? a.concat(b) : undefined;\n}\nconst object1 = { a: [1], b: [2] };\nconst object2 = { a: [3], b: [4] };\nconst result = mergeDeep({ customMerge }, object1, object2);\nconsole.log(result); // Output: { a: [1, 3], b: [2, 4] }"}

Other packages similar to merge-deep

lodash.merge

Lodash's merge function is similar to merge-deep as it allows for deep merging of objects. Lodash is a larger utility library, and its merge function is one of many utilities it provides. It is well-tested and widely used in the JavaScript community.

deepmerge

Deepmerge is another npm package that provides deep merging capabilities. It is similar to merge-deep but offers additional options for customizing the merge behavior, such as whether to clone or not clone the source objects, and how to handle merging arrays.

extend

The extend package is a port of the jQuery extend method that can also perform deep merging of objects. It is less specialized than merge-deep and deepmerge, but it is still a viable option for users who prefer a jQuery-like API.

README

merge-deep

Recursively merge values in a javascript object.

Install

Install with npm:

$ npm install merge-deep --save

Based on mout's implementation of merge

Usage

var merge = require('merge-deep');

merge({a: {b: {c: 'c', d: 'd'}}}, {a: {b: {e: 'e', f: 'f'}}});
//=> { a: { b: { c: 'c', d: 'd', e: 'e', f: 'f' } } }

Related projects

You might also be interested in these projects:

• assign-deep: Deeply assign the enumerable properties and/or es6 Symbol properies of source objects to the target… more | homepage
• defaults-deep: Like extend but recursively copies only the missing properties/values to the target object. | homepage
• extend-shallow: Extend an object with the properties of additional objects. node.js/javascript util. | homepage
• merge-deep: Recursively merge values in a javascript object. | homepage
• mixin-deep: Deeply mix the properties of objects into the first object. Like merge-deep, but doesn't clone. | homepage
• omit-deep: Recursively omit the specified key or keys from an object. | homepage

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Building docs

Generate readme and API documentation with verb:

$ npm install verb && npm run docs

Or, if verb is installed globally:

$ verb

Running tests

Install dev dependencies:

$ npm install -d && npm test

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2016, Jon Schlinkert. Released under the MIT license.

---

This file was generated by verb, v0.9.0, on April 13, 2016.