我从github找到了这个解决方案

var localStorageMock = (function() {
  var store = {};

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

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

您可以在setupTests中插入这段代码，它应该可以正常工作。

我在一个使用typesctipt的项目中测试了它。

正如Niket Pathak在评论中提到的， 从jest@24 / jsdom@11.12.0及以上开始，localStorage将自动被模拟。

2021年,打印稿

class LocalStorageMock {
  store: { [k: string]: string };
  length: number;

  constructor() {
    this.store = {};
    this.length = 0;
  }

  /**
   * @see https://developer.mozilla.org/en-US/docs/Web/API/Storage/key
   * @returns
   */
  key = (idx: number): string => {
    const values = Object.values(this.store);
    return values[idx];
  };

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

  getItem(key: string) {
    return this.store[key] || null;
  }

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

  removeItem(key: string) {
    delete this.store[key];
  }
}

export default LocalStorageMock;

然后你可以用它

global.localStorage = new LocalStorageMock();

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");

首先，我创建了一个名为localStorage.ts(localStorage.js)的文件

class LocalStorageMock {
  store: Store;
  length: number;

  constructor() {
    this.store = {};
    this.length = 0;
  }

  key(n: number): any {
    if (typeof n === 'undefined') {
      throw new Error(
        "Uncaught TypeError: Failed to execute 'key' on 'Storage': 1 argument required, but only 0 present."
      );
    }

    if (n >= Object.keys(this.store).length) {
      return null;
    }

    return Object.keys(this.store)[n];
  }

  getItem(key: string): Store | null {
    if (!Object.keys(this.store).includes(key)) {
      return null;
    }

    return this.store[key];
  }

  setItem(key: string, value: any): undefined {
    if (typeof key === 'undefined' && typeof value === 'undefined') {
      throw new Error(
        "Uncaught TypeError: Failed to execute 'setItem' on 'Storage': 2 arguments required, but only 0 present."
      );
    }

    if (typeof value === 'undefined') {
      throw new Error(
        "Uncaught TypeError: Failed to execute 'setItem' on 'Storage': 2 arguments required, but only 1 present."
      );
    }

    if (!key) return undefined;

    this.store[key] = value.toString() || '';
    this.length = Object.keys(this.store).length;

    return undefined;
  }

  removeItem(key: string): undefined {
    if (typeof key === 'undefined') {
      throw new Error(
        "Uncaught TypeError: Failed to execute 'removeItem' on 'Storage': 1 argument required, but only 0 present."
      );
    }

    delete this.store[key];
    this.length = Object.keys(this.store).length;
    return undefined;
  }

  clear(): undefined {
    this.store = {};
    this.length = 0;

    return undefined;
  }
}

export const getLocalStorageMock = (): any => {
  return new LocalStorageMock();
};

global.localStorage = new LocalStorageMock();

然后创建名为session.test.ts的测试文件(session.test.js)

import { getLocalStorageMock } from '../localstorage';
describe('session storage', () => {
  let localStorage;
  beforeEach(() => {
    localStorage = getLocalStorageMock();
  });

  describe('getItem', () => {
    it('should return null if the item is undefined', () => {
      expect(localStorage.getItem('item')).toBeNull();
    });
    it("should return '' instead of null", () => {
      localStorage.setItem('item', '');
      expect(localStorage.getItem('item')).toBe('');
    });
    it('should return navid', () => {
      localStorage.setItem('item', 'navid');
      expect(localStorage.getItem('item')).toBe('navid');
    });

  });
});

这对我很有效，

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