dubl

A utility to deep copy any JavaScript object

Usage no npm install needed!

<script type="module">
  import dubl from 'https://cdn.skypack.dev/dubl';
</script>

README

Dubl

Build Status Coverage Status Maintainability

Dubl is a copy library to copy most of the main types of JavaScript objects.

Installation

To install the Dubl library run

npm install dubl

API

Functions

Dubl has only one function: *copy(obj, shouldDuplicate): copy takes a built-in JavaScript object to duplicate and creates a deep copy of it. In the case of potentially recursive objects, there is an optional shouldDuplicate function that can be passed in in case one wants to customize the deep copy logic. The parameter for shouldDuplicate is the current (sub-)object that is about to be deep copied. If shouldDuplicate returns true, that object will be deep copied; if false, it will be shallow copied.

Non-copiable objects

Some objects for various reasons cannot be copied (either because it is impossible to get the keys for that object, there is not enough access to information to be able to reconstruct it, or it makes no sense to make a copy). In this case, copy will return the original object.

The following cannot be copied:

  • Primitives (strings, numbers, booleans, null, undefined, symbols)
  • WeakMaps and WeakSets
  • The Math, JSON, and WebAssembly built-in objects
  • Generators

License

Dubl is licensed under the MIT license.