Jest Axios测试在不应该通过的情况下通过了

Question

我正在编写一个脚本（请参阅下文），以确保axios函数在收到特定状态代码时会引发错误。但是我发现，即使我使该测试失败，Jest仍然说该测试通过了，即使它在控制台中返回了错误（请参阅下文）。为什么开玩笑说这个测试实际上失败了就通过了？它是否与我期望发生错误有关，所以即使测试失败，但仍会收到一个错误（测试失败）并认为这意味着我达到了我的预期？谢谢。

foo.test.js：

import axios from 'axios';

jest.mock('axios', () => ({
  get: jest.fn(() => Promise.resolve({ data: 'payload' })),
}));

const getData = async (url) => {
  const response = await axios.get(url);
  if (response.status !== 200) {
    return response.text().then((error) => {
      throw new Error(error.message);
    });
  } else {
    return response.data;
  }
};

test('testing that an error is thrown', async () => {
  axios.get.mockImplementation(() =>
    Promise.resolve({
      data: {data: 'payload'},
      status: 400,
      text: () => Promise.resolve(JSON.stringify({message: 'This is an error.'})),
    })
  );

  const expectedError = async () => {
    await getData('sampleUrl');
  };

  // The error should return 'This is an error.' and instead
  // is expecting 'foo', so this test should fail.
  expect(expectedError()).rejects.toThrowError('foo');
});

Answer 1

您需要进行两项更改才能使测试按预期失败。

• 不要对text中的解析值进行字符串化处理
• await使用rejects的expect

这是更新的版本，按预期失败：

import axios from 'axios';

jest.mock('axios', () => ({
  get: jest.fn(() => Promise.resolve({ data: 'payload' })),
}));

const getData = async (url) => {
  const response = await axios.get(url);
  if (response.status !== 200) {
    return response.text().then((error) => {
      throw new Error(error.message);
    });
  } else {
    return response.data;
  }
};

test('testing that an error is thrown', async () => {
  axios.get.mockImplementation(() =>
    Promise.resolve({
      data: {data: 'payload'},
      status: 400,
      text: () => Promise.resolve({message: 'This is an error.'}),  // <= don't stringify
    })
  );

  const expectedError = async () => {
    await getData('sampleUrl');
  };

  await expect(expectedError()).rejects.toThrowError('foo');  // <= await
});