我如何使用Jest模拟JavaScript的“窗口”对象?

我需要测试一个在浏览器中打开一个新选项卡的功能

openStatementsReport(contactIds) {
  window.open(`a_url_${contactIds}`);
}

我想模拟窗口的打开函数，这样我就可以验证正确的URL被传递给打开函数。

使用笑话，我不知道如何模拟窗口。我试着设置窗口。使用mock函数打开，但这种方式不起作用。下面是测试用例:

it('the correct URL is called', () => {
  window.open = jest.fn();
  statementService.openStatementsReport(111);
  expect(window.open).toBeCalled();
});

但是它给出了误差

expect(jest.fn())[.not].toBeCalled()

jest.fn() value must be a mock function or spy.
    Received:
      function: [Function anonymous]

我应该对测试用例做什么?

当前回答

我找到了一个简单的方法:删除和替换

describe('Test case', () => {
  const { open } = window;

  beforeAll(() => {
    // Delete the existing
    delete window.open;
    // Replace with the custom value
    window.open = jest.fn();
    // Works for `location` too, eg:
    // window.location = { origin: 'http://localhost:3100' };
  });

  afterAll(() => {
    // Restore original
    window.open = open;
  });

  it('correct url is called', () => {
    statementService.openStatementsReport(111);
    expect(window.open).toBeCalled(); // Happy happy, joy joy
  });
});

2020-03-13 05:15:14

其他回答

你可以试试这个:

import * as _Window from "jsdom/lib/jsdom/browser/Window";

window.open = jest.fn().mockImplementationOnce(() => {
    return new _Window({ parsingMode: "html" });
});

it("correct url is called", () => {
    statementService.openStatementsReport(111);
    expect(window.open).toHaveBeenCalled();
});

2018-03-01 12:00:51

下面的方法对我很有效。这种方法允许我测试一些在浏览器和Node.js中都可以工作的代码，因为它允许我将window设置为undefined。

这是笑话24.8(我相信):

let windowSpy;

beforeEach(() => {
  windowSpy = jest.spyOn(window, "window", "get");
});

afterEach(() => {
  windowSpy.mockRestore();
});

it('should return https://example.com', () => {
  windowSpy.mockImplementation(() => ({
    location: {
      origin: "https://example.com"
    }
  }));

  expect(window.location.origin).toEqual("https://example.com");
});

it('should be undefined.', () => {
  windowSpy.mockImplementation(() => undefined);

  expect(window).toBeUndefined();
});

2019-07-12 02:46:18

你可以测试它:

describe('TableItem Components', () => {
    let open_url = ""
    const { open } = window;
    beforeAll(() => {
        delete window.open;
        window.open = (url) => { open_url = url };
    });
    afterAll(() => {
        window.open = open;
    });
    test('string type', async () => {
        wrapper.vm.openNewTab('http://example.com')
        expect(open_url).toBe('http://example.com')
    })
})

2021-01-31 06:03:43

如果它类似于window.location.href中的窗口位置问题，则不能在测试中更改。#890，你可以尝试(调整):

delete global.window.open;
global.window = Object.create(window);
global.window.open = jest.fn();

2019-08-22 15:01:48

我有一个实用函数，它允许我模拟窗口上的任何方法，如下所示:

  function givenMockWindowMethods(methods: Partial<{ [key in keyof Window]: jest.Mock<any, any> }>): () => void {
    const mocks = Object.values(methods);

    Object.entries(methods).forEach(([key, value]) => {
      Object.defineProperty(window, key, { value });
    });

    return (): void => mocks.forEach((mock) => mock?.mockClear());
  }

因此，如果我需要模拟窗口上的open方法(或任何东西)，我可以这样做:

      const cleanupMocks = givenMockWindowMethods({ open: jest.fn() });
      // expect(...).toBe(...)

      //at the end of the test, clean it up
      cleanupMocks()

2021-09-14 00:14:43

我如何使用Jest模拟JavaScript的“窗口”对象?

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