prevent property undefined error in using desturcturing

Question

This is my original code

import Cookies from 'js-cookie'
const getUser = () => {
  const {user} = Cookies.getJSON('user')
  if (user) return user
}

I got user is undefined error because user cookie doesn't exist.

I have to change it to

const getUser = () => {
  const cookie = Cookies.getJSON('user')
  if (!cookie) return false

  if (cookie.user) return cookie.user
}

Is there any more elegant way to prevent undefined error when doing desturcturing?

Or, `const {user} = Cookies.getJSON('user') || {}` – palaѕн Feb 21 '20 at 15:55 — palaѕн, Feb 21 '20 at 15:55
`return Cookies.getJSON('user')?.user ?? false;` – Jonas Wilms Feb 21 '20 at 16:44 — Jonas Wilms, Feb 21 '20 at 16:44

score 0 · Answer 1 · answered Feb 21 '20 at 15:56

0

One way to prevent it is to use || :

const {user} = Cookies.getJSON('user') || {};

answered Feb 21 '20 at 15:56

Taki

but it's still subtle, should I do this every time I do desturcturing? – Mellisa Lee Feb 22 '20 at 00:20

score 0 · Answer 2 · answered Feb 21 '20 at 16:18

0

In case you like one line...

const getUser = () => (Cookies.getJSON('user') || {}).user

answered Feb 21 '20 at 16:18

NCM

2 Answers2