saffy

Safest way to get and set properties in Javascript

Installation

$ npm i saffy

or

$ bower i saffy

Usage

Having the following object

var obj = {
  user: {
    id: 1234,
    city: 'Springfield',
    info: {
      name: {
        firstName: 'Homer'
      }
    } 
  }
};

You want to set obj.user.info.name.lastName = "Simpson". Easy right? But wait... this is Javascript, so, maybe you end having something like this :\

if (obj && obj.user && obj.user.info && obj.user.info.name) {
  obj.user.info.name.lastName = 'Simpson';
}

Ok, now let's see how looks using Saffy

import {set} from 'saffy';

set(obj, 'user.info.name.lastName', 'Simpson');

And same thing with get

import {get, set} from 'saffy';

get(obj, 'user.info.name.firstName');

Others goodies

Playing with Arrays

import {get} from 'saffy';

let obj = {
  cars: ['mercedes', 'bmw', 'audi'],
  food: [['paella', 'bravas'], ['pizza', 'spaghetti']]
}

get(obj, 'cars.firstObject') === 'mercedes';
get(obj, 'cars.lastObject') === 'audi';
get(obj, 'cars[1]') === 'bmw';
get(obj, 'food[1].lastObject') === 'spaghetti';
get(obj, 'food[0][1]') === 'bravas';
get(obj, 'food[0].length') === 2;

Playing with Functions

import {get} from 'saffy';

let obj = {
  foo: 'bar',
  getFoo: function() {
    return this.foo;
  },
  getHash: function() {
    return {
      a: this.foo
    };
  }
}

get(obj, 'getFoo()') === 'bar';
get(obj, 'getHash().a') === 'bar';

Motivation

Inspired by @sindresorhus words...

You make small focused modules for reusability and to make it possible to build larger more advanced things that are easier to reason about

Full Post https://github.com/sindresorhus/ama/issues/10#issuecomment-117766328