Autovivification of Javascript objects

Does this ever happen to you?

> cars = {}
{}
> cars.mercedes.sl600.color = 'blue'
TypeError: Cannot read property 'sl600' of undefined

Well now there's node-autovivify!

> Av = require('autovivify')
> cars = new Av()
{}
> cars.mercedes.sl600.color = 'blue'
'blue'

It also works with arrays!

Av = require('autovivify')
> cars = new Av()
> cars.mercedes.sl600.color = 'blue'
'blue'
> cars.carlist[0] = cars.mercedes
{ sl600: { color: 'blue' } }

Installation

npm install autovivify

Usage

const Av = require('autovivify')

const obj = new Av()

obj.subobj[4].subarray[2].myvalue = 'coolio'
assert(obj.subobj[4].subarray[2].myvalue === 'coolio')

Limitations

Symbols are not supported as properties.

You cannot use undefined checks with this structure as the very act of checking ensures that the structure is defined. Use membership or length checks to determine if something is empty.

Publishing a binary release

To make a new binary release:

• Edit package.json. Increment the version property.
• node-pre-gyp rebuild
• node-pre-gyp package
• node-pre-gyp-github publish
• npm publish

You will need a NODE_PRE_GYP_GITHUB_TOKEN with repo:status, repo_deployment and public_repo access to the target repo. You'll also need write access to the npm repo.