node-assign

Recursive Object.assign as a node module.

Usage

npm install node-assign

There are two functions included. The assign function (default) and the explicitly called merge function.

require('node-assign')(target, ...sources) 
//-> return target

require('node-assign').merge(target, ...sources) 
//-> return target

The only difference between the two is that assign will overwrite sub objects with supplied non-objects, whereas merge will preserve object depth in the target (or add to it). merge will never remove a target key hierarchy, whereas assign might drop entire sub objects if given non-object keys. See below for example.

Use assign

const assign = require('node-assign')

var objA = {foo: 1, bar: {a: 1, b: 2}, baz: {goo: 99}}
var objB = {bar: {c: 3}, baz: 3}

assign(objA, objB)

console.log(objA)
//-> {foo: 1, bar: {a: 1, b: 2, c: 3}, baz: 3}

Use merge

const merge = require('node-assign').merge

var objA = {foo: 1, bar: {a: 1, b: 2}, baz: {goo: 99}}
var objB = {bar: {c: 3}, baz: 3}

merge(objA, objB)

console.log(objA)
//-> {foo: 1, bar: {a: 1, b: 2, c: 3}, baz: {goo: 99}}

Globalize

You can also globalize it into Object, but I suggest you use a different name than assign, since the built-in function may be used in various libraries which require its specific functionality.

Object.rassign = require('node-assign') // recursive assign
Object.merge = Object.rassign.merge // deep merge

Caveats

Important version update 1.1

The current version of the function ALTERS the target object, similar to Object.assign. If you need the function to return a brand new object, use an empty object literal {} as the first argument.

Only objects

The original Object.assign can also accept primitives (which are then converted to objects). Our function does not accept primitives as arguments. It will throw a fit and report you to the authorities.