@75lb/deep-merge

What is @75lb/deep-merge?

@75lb/deep-merge is an npm package designed to deeply merge multiple objects into one. It handles nested objects and arrays, providing a robust solution for combining complex data structures.

What are @75lb/deep-merge's main functionalities?

Basic Deep Merge

This feature allows you to merge two objects deeply, combining their properties. Nested objects are merged recursively.

const deepMerge = require('@75lb/deep-merge');
const obj1 = { a: 1, b: { c: 2 } };
const obj2 = { b: { d: 3 } };
const result = deepMerge(obj1, obj2);
console.log(result); // { a: 1, b: { c: 2, d: 3 } }

Merging Arrays

This feature demonstrates how arrays within objects are merged. The arrays are concatenated.

const deepMerge = require('@75lb/deep-merge');
const obj1 = { a: [1, 2, 3] };
const obj2 = { a: [4, 5] };
const result = deepMerge(obj1, obj2);
console.log(result); // { a: [1, 2, 3, 4, 5] }

Custom Merge Function

This feature allows you to provide a custom merge function to control how specific types of values are merged.

const deepMerge = require('@75lb/deep-merge');
const customMerge = (target, source) => Array.isArray(target) ? target.concat(source) : undefined;
const obj1 = { a: [1, 2], b: { c: 3 } };
const obj2 = { a: [3, 4], b: { d: 4 } };
const result = deepMerge(obj1, obj2, customMerge);
console.log(result); // { a: [1, 2, 3, 4], b: { c: 3, d: 4 } }

Other packages similar to @75lb/deep-merge

lodash.merge

Lodash's merge function is a popular utility for deep merging objects. It is part of the larger Lodash library, which provides a wide range of utility functions for JavaScript. Compared to @75lb/deep-merge, lodash.merge is more widely used and comes with the additional overhead of the entire Lodash library.

deepmerge

The deepmerge package is a standalone library specifically designed for deep merging objects. It is lightweight and focuses solely on merging, similar to @75lb/deep-merge. However, deepmerge has a larger user base and more frequent updates.

merge-deep

merge-deep is another package focused on deep merging objects. It offers similar functionality to @75lb/deep-merge but also includes options for customizing the merge behavior. It is a good alternative if you need more control over the merging process.

README

@75lb/deep-merge

Deep-merge the values of one object structure into another. Similar to Object.assign() except it processes the full depth of the object structure, not only the top level. Useful for merging config.

Synopsis

import deepMerge from '@75lb/deep-merge'

Simple

Typical example merging four objects. Input:

deepMerge(
  { port: 8000, data: { animal: 'cow' } },
  { stack: ['one'] },
  { stack: ['two'], help: true },
  { data: { animal: 'bat', metal: 'iron' } }
)

Result

{
  port: 8000,
  stack: ['two'],
  help: true,
  data: { animal: 'bat', metal: 'iron' }
}

Arrays

Empty arrays are ignored and not merged in. Input:

deepMerge(
  { stack: ['one'] },
  { stack: [] }
)

Result:

{ stack: ['one'] }

However, if the later array contains one or more values the later array will replace the original:

deepMerge(
  { stack: ['one'] },
  { stack: ['two'] }
)

Result:

{ stack: ['two'] }

Load anywhere

This library is compatible with Node.js, the Web and any style of module loader. It can be loaded anywhere, natively without transpilation.

Within a Node.js ECMAScript Module:

import deepMerge from '@75lb/deep-merge'

Within an modern browser ECMAScript Module:

import deepMerge from './node_modules/@75lb/deep-merge/dist/index.mjs'

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© 2018-24 Lloyd Brookes <[e-mail]>.

Tested by test-runner. Documented by jsdoc-to-markdown.