react-native - 我如何用 throw e Jest 进行测试？

Question

我如何在 Jest 错误情况下进行测试？
这就是我所做的:
我不知道是否存在一种方法来测试这个。

it ('the fetch fails and throw an error', async () => {
      let response = {
        status: 400,
        body: 
        {
          base : "RON",
          date: "2019-08-01",
          rates: {"error": 'error'}
        }
      };
      fetch.mockReject(response)
      try {
        await fetchData();
      } catch (e) {
        expect(e).toEqual(response);
        expect(await fetchData()).rejects.toThrow(e);
      }
    });

这是代码:

 fetchData = async () => {
    try {
      const response = await fetch('https://api.exo/latest?base=RON');
      const data = await response.json();
      return data;
    } catch (e) {
      throw e;
    }
  };

Answer 1

您可以通过以下方式进行操作:

async function throws () {
  throw new Error('error')
}

test('promise throws', async () => {
  await expect(throws()).rejects.toThrow()
})

test('the fetch fails with an error', async () => {
  await expect(throws()).rejects.toThrow('error');
});

test('the fetch fails with an error', () => {
  return expect(throws()).rejects.toMatch('error');
});

阅读更多 docs .