开玩笑嘲笑 document.referrer

Question

我在反应应用程序服务中有以下方法，需要单元测试。

onDeclineCallback = () => {
    console.log("boom " + document.referrer);

    if (document.referrer === "") {
      console.log("redirect to our age policy page");
    } else {
      history.back();
    }
  };

我的单元测试目前看起来像：

onDeclineCallback = () => {
    console.log("boom " + document.referrer);

    if (document.referrer === "") {
      console.log("redirect to our age policy page");
    } else {
      history.back();
    }
  };

我正在尝试找到一种模拟方法，document.referrer以便为每种情况编写单元测试。谁能为此提供一种方法？

Answer 1

您可以使用Object.defineProperty方法来设置模拟值document.referrer。

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例如\nindex.ts：

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export class AgeVerification {\n  public onDeclineCallback = () => {\n    console.log(\'boom \' + document.referrer);\n\n    if (document.referrer === \'\') {\n      console.log(\'redirect to our age policy page\');\n    } else {\n      history.back();\n    }\n  };\n}\n

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index.spec.ts:

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import { AgeVerification } from \'./\';\n\ndescribe(\'age verifiction service test\', () => {\n  let ageVerification;\n  beforeEach(() => {\n    ageVerification = new AgeVerification();\n    history.back = jest.fn();\n  });\n  afterAll(() => {\n    jest.restoreAllMocks();\n    jest.resetAllMocks();\n  });\n  it(\'returns user to referrer if declined and referrer is available\', () => {\n    const originalReferrer = document.referrer;\n    Object.defineProperty(document, \'referrer\', { value: \'Refferer Test\', configurable: true });\n    ageVerification.onDeclineCallback();\n    expect(history.back).toHaveBeenCalledTimes(1);\n    Object.defineProperty(document, \'referrer\', { value: originalReferrer });\n  });\n\n  it(\'should print log\', () => {\n    const logSpy = jest.spyOn(console, \'log\');\n    ageVerification.onDeclineCallback();\n    expect(logSpy.mock.calls[0]).toEqual([\'boom \']);\n    expect(logSpy.mock.calls[1]).toEqual([\'redirect to our age policy page\']);\n  });\n});\n

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100%覆盖率的单元测试结果：

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 PASS  src/stackoverflow/59198002/index.test.ts (13.915s)\n  age verifiction service test\n    \xe2\x9c\x93 returns user to referrer if declined and referrer is available (17ms)\n    \xe2\x9c\x93 should print log (3ms)\n\n  console.log src/stackoverflow/59198002/index.ts:264\n    boom Refferer Test\n\n  console.log node_modules/jest-mock/build/index.js:860\n    boom \n\n  console.log node_modules/jest-mock/build/index.js:860\n    redirect to our age policy page\n\n----------|----------|----------|----------|----------|-------------------|\nFile      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |\n----------|----------|----------|----------|----------|-------------------|\nAll files |      100 |      100 |      100 |      100 |                   |\n index.ts |      100 |      100 |      100 |      100 |                   |\n----------|----------|----------|----------|----------|-------------------|\nTest Suites: 1 passed, 1 total\nTests:       2 passed, 2 total\nSnapshots:   0 total\nTime:        15.385s\n

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源代码：https ://github.com/mrdulin/jest-codelab/tree/master/src/stackoverflow/59198002

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