以下解决方案兼容更严格的TypeScript、ESLint、TSLint和Prettier配置测试:{"proseWrap": "always"， "semi": false， "singleQuote": true， "trailingComma": "es5"}:

class LocalStorageMock {
  public store: {
    [key: string]: string
  }
  constructor() {
    this.store = {}
  }

  public clear() {
    this.store = {}
  }

  public getItem(key: string) {
    return this.store[key] || undefined
  }

  public setItem(key: string, value: string) {
    this.store[key] = value.toString()
  }

  public removeItem(key: string) {
    delete this.store[key]
  }
}
/* tslint:disable-next-line:no-any */
;(global as any).localStorage = new LocalStorageMock()

HT/ https://stackoverflow.com/a/51583401/101290了解如何更新global.localStorage

在我的例子中，我需要在检查localStorage值之前设置它。

我所做的就是

const data = { .......}

const setLocalStorageValue = (name: string, value: any) => {
  localStorage.setItem(name, JSON.stringify(value))
}



 describe('Check X class', () => {
  setLocalStorageValue('Xname', data)
  const xClass= new XClass()

  console.log(xClass.initiate()) ; // it will work 

  
})

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。

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”,

2022年12月:Nx 14使用Angular 14 Jest。 我们有一个测试设置。Ts文件在每个app和libs文件夹。我们设置本地存储模拟全局。

import 'jest-preset-angular/setup-jest';

Storage.prototype.getItem = jest.fn();
Storage.prototype.setItem = jest.fn();
Storage.prototype.removeItem = jest.fn();

然后localStorage.service.spec.ts文件如下所示:

import { LocalStorageService } from './localstorage.service';

describe('LocalStorageService', () => {
    let localStorageService: LocalStorageService;

    beforeEach(() => {
        localStorageService = new LocalStorageService();
    });

    it('should set "identityKey" in localStorage', async () => {
        localStorageService.saveData('identityKey', '99');
        expect(window.localStorage.setItem).toHaveBeenCalled();
 expect(window.localStorage.setItem).toHaveBeenCalledWith('identityKey', '99');
        expect(window.localStorage.setItem).toHaveBeenCalledTimes(1);
});

it('should get "identityKey" from localStorage', async () => {
    localStorageService.getData('identityKey');
    expect(window.localStorage.getItem).toHaveBeenCalled();
    expect(window.localStorage.getItem).toHaveBeenCalledWith('identityKey');
    expect(window.localStorage.getItem).toHaveBeenCalledTimes(1);
});

it('should remove "identityKey" from localStorage', async () => {
    localStorageService.removeData('identityKey');
    expect(window.localStorage.removeItem).toHaveBeenCalled();
expect(window.localStorage.removeItem).toHaveBeenCalledWith('identityKey');
            expect(window.localStorage.removeItem).toHaveBeenCalledTimes(1);
        });
    });

注:不好意思，这个SatckOverflow窗口很糟糕。

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");