CODEWITHSUNDEEP
javascripttypescriptecmascript-6
Andrew C.
Andrew C.

Reputation: 461

Destructuring an undefined object

If response is undefined, it will fail when retrieving it's property status with the error:

TypeError: Cannot read property 'status' of undefined

const {
  response,
  response: { status },
  request,
  config,
} = error as AxiosError

Applying a default value to status does not change this error. It will still choke on response.

e.g.

response: { status = 420 },

How can this be safely destructured? Thanks.

Upvotes: 0

Views: 79

Answers (1)

zzzzBov
zzzzBov

Reputation: 179046

I'd recommend avoiding using destructuring for objects that have optional properties.

If your general case is covered by

const {
  response,
  request,
  config
} = error as AxiosError;

It's easier to follow it up with a new const declaration using optional chaining and null coalescing:

const status = response?.status ?? 420;

Otherwise your destructuring gets awkward by having to include multiple levels of default values:

const {
  response,
  response: {
    status = 420
  } = {}, // this could even be { status = ### } and differ from the other default value
  request,
  config
} = error as AxiosError;

Upvotes: 4

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