aihornmac / mobx-localstorage Goto Github PK

import localStorageMobx from "mobx-localstorage"

console.log(localStorageMobx.getItem("foo") // null -- incorrect
console.log(localStorage.getItem("foo") // bar -- correct

For some reason, all values returned by mobx-localstorage are null but using the normal localstorage returns the correct value. Seems to have broken in v1.1.1, because it doesn't work in 1.1.1 or 1.1.2, but does work in 1.1.0.

Function: getItem
Expected: null result for a key that doesn't exist
Actual result: got underfined for a key that doesn't exist

https://html.spec.whatwg.org/multipage/webstorage.html

The getItem(key) method must return the current value associated with the given key. If the given key does not exist in the list associated with the object then this method must return null.

Is there any reason why strings saved into localstorage are in quotes "string"?

The issue is that when MobX is configured to always enforce actions, this library does not respect the pattern that all observable properties can only be modified with a function decorated as an action.

The main issue is in the constructor in the call super.set() and super.delete():

constructor() {
    super(undefined, referenceEnhancer, 'LocalStorage')
    const len = localStorage.length
    for (let i = 0; i < len; i++) {
      const key = localStorage.key(i)!
      const value = parseValue(localStorage.getItem(key))
      super.set(key, value)
    }
    localStorage.on('change', (key, value) => {
      if (typeof value === 'string') {
        super.set(key, parseValue(value))
      } else {
        super.delete(key)
      }
    })
  }

Also, the class functions for setting / removing keys should probably also be decorated as actions to be safe.