Object.defineProperty(window, "localStorage", {
  value: {
    getItem: jest.fn(),
    setItem: jest.fn(),
    removeItem: jest.fn(),
  },
});

or

jest.spyOn(Object.getPrototypeOf(localStorage), "getItem");
jest.spyOn(Object.getPrototypeOf(localStorage), "setItem");

或者你只是像这样使用一个模拟包:

https://www.npmjs.com/package/jest-localstorage-mock

它不仅处理存储功能，还允许您测试是否实际调用了存储。

对于Jest, React和TypeScript用户:

我创建了一个mockLocalStorage.ts

export const mockLocalStorage = () => {
  const setItemMock = jest.fn();
  const getItemMock = jest.fn();

  beforeEach(() => {
    Storage.prototype.setItem = setItemMock;
    Storage.prototype.getItem = getItemMock;
  });

  afterEach(() => {
    setItemMock.mockRestore();
    getItemMock.mockRestore();
  });

  return { setItemMock, getItemMock };
};

我的组件:

export const Component = () => {
    const foo = localStorage.getItem('foo')
    localStorage.setItem('bar', 'true')
    return <h1>{foo}</h1>
}

然后在我的测试中，我这样使用它:

import React from 'react';

import { mockLocalStorage } from '../../test-utils';
import { Component } from './Component';

const { getItemMock, setItemMock } = mockLocalStorage();

it('fetches something from localStorage', () => {
    getItemMock.mockReturnValue('bar');
    render(<Component />);
    expect(getItemMock).toHaveBeenCalled();
    expect(getByText(/bar/i)).toBeInTheDocument()
});

it('expects something to be set in localStorage' () => {
    const value = "true"
    const key = "bar"
    render(<Component />);
    expect(setItemMock).toHaveBeenCalledWith(key, value);
}

在这个网站的帮助下，我们找到了答案:https://groups.google.com/forum/#!主题/ jestjs / 9 ephunwvytg

设置一个包含以下内容的文件:

var localStorageMock = (function() {
  var store = {};
  return {
    getItem: function(key) {
      return store[key];
    },
    setItem: function(key, value) {
      store[key] = value.toString();
    },
    clear: function() {
      store = {};
    },
    removeItem: function(key) {
      delete store[key];
    }
  };
})();
Object.defineProperty(window, 'localStorage', { value: localStorageMock });

然后将以下行添加到包中。json在你的Jest配置

:“setupTestFrameworkScriptFile PATH_TO_YOUR_FILE”,

这对我很有效，

delete global.localStorage;
global.localStorage = {
getItem: () => 
 }

这对我来说是可行的，只需要一行代码

const setItem = jest.spyOn(Object.getPrototypeOf(localStorage)， 'setItem');