Unit Testing

[RubyStack]

Hi guys,
I have a question regarding Unit Testing. How can I test the LocalStorage in unit testing using the Jest library?

[ZikaZaki]

Hi @RubyStack,
In fact, the Jest library does not support calls to localStorage. It is not a browser and doesn't implement localStorage.

The solution is to mock your own fake localStorage support like below:

browserMocks.js

const localStorageMock = (function() {
  let store = {}

  return {
    getItem: function(key) {
      return store[key] || null
    },
    setItem: function(key, value) {
      store[key] = value.toString()
    },
    removeItem: function(key) {
      delete store[key]
    },
    clear: function() {
      store = {}
    }
  }
})()

Object.defineProperty(window, 'localStorage', {
  value: localStorageMock
})

[RubyStack]

Thanks a trillion @ZikaZaki.

[ZikaZaki]

Yo're welcome @RubyStack .