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

在我的组件，我需要访问window.location.search。这是我在Jest测试中所做的:

Object.defineProperty(global, "window", {
  value: {
    location: {
      search: "test"
    }
  }
});

如果窗口属性在不同的测试中必须不同，我们可以将窗口模拟放到函数中，并使其可写，以便在不同的测试中重写:

function mockWindow(search, pathname) {
  Object.defineProperty(global, "window", {
    value: {
      location: {
        search,
        pathname
      }
    },
    writable: true
  });
}

并在每次测试后重置:

afterEach(() => {
  delete global.window.location;
});

2020-06-29 17:33:39

其他回答

试一试:

let windowOpenSpy: jest.SpyInstance;
beforeEach(() => {
    windowOpenSpy = jest.spyOn(window, 'open');
});

it('should open window with dashboard url', () => {
    expect(windowOpenSpy).toBeCalledWith('your URL', '_blank');
});

2021-08-25 08:03:59

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

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

我直接将jest.fn()赋值给window.open。

window.open = jest.fn()
// ...code
expect(window.open).toHaveBeenCalledTimes(1)
expect(window.open).toHaveBeenCalledWith('/new-tab','_blank')

2020-09-04 07:22:22

使用global而不是window:

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

你也可以试试:

const open = jest.fn()
Object.defineProperty(window, 'open', open);

2017-01-27 07:19:39

我如何使用Jest模拟JavaScript的“窗口”对象?

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