Disabled localStorage will immediately throw error

[yumauri]

This line will immediately fail if localStorage is disabled

effector-storage/src/local/index.ts

Line 45 in 3587df8

typeof localStorage !== 'undefined'

In Chrome:

In Safari on iOS:

Same applies to sessionStorage as well.

[yumauri]

Actually, I'm not sure what correct behaviour should be in that case:

1. Leave this as it is now — runtime error when calling persist function.
2. Ignore error and behave like local/session storage doesn't exist at all (like in node environment).
3. Trigger fail event once, when calling persist function. In that case, if fail event will be participant in any logic after calling persist function — this logic will not work, because connections with fail event are not created yet.
4. Trigger fail event every read/write attempt.

Any item, except 1 — is breaking change, because some code may already depends on runtime error throwing.

[yumauri]

Maybe extend adapters with optional function supports (or smth like that)

import { persist, supports } from 'effector-storage/local'

const reason = supports()
if (reason != null) {
  console.log('localStorage is not supported:', reason)
}

And persist will behave like item 2↑ in case adapter is not supported in this particular environment.

[zerobias]

Is this will work in that way?

function isLSDefined() {
  try {
    return typeof localStorage !== 'undefined'
  } catch (err) {
    return false
  }
}

Any item, except 1 — is breaking change, because some code may already depends on runtime error throwing.

Usually you might imagine code which rely on any throwable case and you'll unable to add even new properties

try {
  persist().anyProperty.toString()
} catch {
  // business logic goes here
  return 'ok'
}
return 'damn effector-storage 😠'

[yumauri]

Yes, it is possible to catch this error, and go by 2 way — behave like there is no localStorage at all.

I thought about smth like this, maybe:

function supports() {
  try {
    if (typeof localStorage === 'undefined') {
      return new Error('localStorage is undefined')
    }
  } catch (error) {
    return error
  }
}

Function, which could get the reason, without throwing error.
Inside persist I can use it and ignore all errors (use nil adapter with no-op behaviour) and user could call supports manually, if it is needed.

[yumauri]

Fixed in version 4.4.0