@corex/deepmerge

---
title: '@corex/deepmerge'
custom_edit_url: 'https://github.com/iamvishnusankar/corex/edit/master/packages/deepmerge/README.md'
---

A zero dependency object merger with typescript support and built in common merge utilities. Support merging of n number of objects

Installation

``
yarn add @corex/deepmerge
`

Usage

`ts
import { merge } from '@corex/deepmerge'

merge([obj1, obj2, obj3], { options })
`

Merge Options

| property | default | description |
| -------------- | --------- | ---------------------------------------------------------------------------------------------------- |
| arrayMergeType | combine | Merge two array by concatenation and remove duplicates. Available options are combine, overwrite |
| arrayMerge | - | Custom merge function to handle array merging. |

Simple Object Merge

`ts
const obj1 = {
a: 1,
b: {
c: 2,
},
}

const obj2 = {
a: 2,
b: {
c: 4,
d: 5,
},
}

const result = merge([obj1, obj2])
console.log(result)

// {
// a: 2,
// b: {
// c: 4,
// d: 5,
// },
// }
`

Array Merge

`ts
const arr1 = {
a: [1, 2, 3],
}
const arr2 = {
a: [3, 4, 5],
}

const result = merge([arr1, arr2])
console.log(result)

// result = {
// a: [1, 2, 3, 4, 5],
// }
`

Complex Merge

`ts
const obj1 = {
a: 2,
b: (x: number, y: number) => x + y,
c: [1, 2, 4],
d: {
e: [4, 5, 7],
},
}

console.log(obj1.b(7, 5)) // ==> 12

const obj2 = {
a: 10,
b: (x: number, y: number) => x / y,
c: [20, 30],
d: {
e: [4, 7, 5],
f: {
g: 'another',
},
},
}

const obj3 = {
b: (x: number, y: number) => x * y,
c: [1, 2, 4],
d: {
e: [4, 7, 5],
},
}

const result = merge([obj1, obj2, obj3])

console.log(result.b(7, 5)) // ==> 35
`

Array merge types

By default @corex/deepmerge uses combine merge. However user can implement their own methods to perform merge or use the built in overwrite.

$3

`ts
const obj1 = {
a: [1, 2, 3],
b: ['c', 'd'],
c: {
d: [1, 2],
},
}

const obj2 = {
a: [1, 7, 6],
b: ['e', 'f'],
c: {
d: [9, 10],
},
}

const obj3 = {
a: [20, 40],
}

const result = merge([obj1, obj2, obj3], {
arrayMergeType: 'overwrite',
})
console.log(result)

// result = {
// a: [20, 40],
// b: ['e', 'f'],
// c: {
// d: [9, 10],
// },
// }
`

$3

`ts
const obj1 = {
a: ['1', '2'],
c: {
d: [1000, 500],
},
}

const obj2 = {
a: ['4', '5'],
c: {
d: [60, 80],
},
}

const customMergeFn = (_: any[], __: any[]) => 42

const result = merge([obj1, obj2], {
arrayMerge: customMergeFn,
})
console.log(result)

// {
// a: 42,
// c: {
// d: 42,
// },
// }
``