Jest mock localStorage #test #jest

localStorage.js

// ./__mocks__/localStorage.js
let mockStorage = {};

module.exports = window.localStorage = {
  setItem: (key, val) => Object.assign(mockStorage, {[key]: val}),
  getItem: (key) => mockStorage[key],
  clear: () => mockStorage = {}
};


// Then import it in the reducer test file 
import '../__mocks__/localStorage';

It worked! Thanks.

Hey, can you give me a little insight on the usage? Like in the .test.js file, do we have to initialize anything or code something?

@krey3ix line 11 has instructions. Just import it like import '../__mocks__/localStorage'; and it sets window.localStorage automatically. I guess you could do something like:

let mockStorage = {};

const localStorage = {
  setItem: (key, val) => Object.assign(mockStorage, {
    [key]: val
  }),
  getItem: (key) => mockStorage[key],
  clear: () => mockStorage = {}
};

export default localStorage;

Then

const localStorage = import '../__mocks__/localStorage';
global.localStorage = localStorage;