MockStorage.js

/* global jest */
export default class MockStorage {
  constructor(cache = {}) {
    this.storageCache = cache;
  }

  setItem = jest.fn((key, value) => {
    return new Promise((resolve, reject) => {
      return typeof key !== 'string' || typeof value !== 'string'
        ? reject(new Error('key and value must be string'))
        : resolve((this.storageCache[key] = value));
    });
  });

  getItem = jest.fn(key => {
    return new Promise(resolve => {
      return this.storageCache.hasOwnProperty(key) ? resolve(this.storageCache[key]) : resolve(null);
    });
  });

  removeItem = jest.fn(key => {
    return new Promise((resolve, reject) => {
      return this.storageCache.hasOwnProperty(key) ? resolve(delete this.storageCache[key]) : reject(new Error('No such key!'));
    });
  });

  clear = jest.fn(key => {
    return new Promise((resolve, reject) => resolve((this.storageCache = {})));
  });

  getAllKeys = jest.fn(key => {
    return new Promise((resolve, reject) => resolve(Object.keys(this.storageCache)));
  });
}