用 Jest 抛出的异步测试答案

【问题标题】：Async test to throw with Jest用 Jest 抛出的异步测试
【发布时间】：2020-11-24 16:02:06
【问题描述】：

我是测试新手，我正在尝试找到一种使用异步函数引发错误的方法。

这是测试文件

import Yelp from './Yelp';
import axios from 'axios';

jest.mock('axios');

describe('testing searchRestaurantsInfo', () => {

  // Other tests

  test('returns error', async () => {
    await expect(
      Yelp.searchRestaurantsInfo('q_IoMdeM57U70GwqjXxGJw')
    ).rejects.toThrow('Error');
  });
});

我得到了错误

testing searchRestaurantsInfo › returns error

    expect(received).rejects.toThrow()

    Received promise resolved instead of rejected
    Resolved to value: "Error"

      102 | 
      103 |   test('returns error', async () => {
    > 104 |     await expect(
          |           ^
      105 |       Yelp.searchRestaurantsInfo('q_IoMdeM57U70GwqjXxGJw')
      106 |     ).rejects.toThrow(TypeError);
      107 |   });

这里是 Yelp.js

import axios from 'axios';

let YELP_API_KEY = process.env.REACT_APP_YELP_API_KEY;

const Yelp = {
  // Provides info about a single restaurant
  async searchRestaurantsInfo(id) {
    try {
      let response = await axios.get(
        `https://cors-anywhere.herokuapp.com/https://api.yelp.com/v3/businesses/${id}`,
        {
          headers: {
            Authorization: `Bearer ${YELP_API_KEY}`,
            'X-Requested-With': 'XMLHttpRequest',
            'Access-Control-Allow-Origin': '*',
          },
        }
      );

      let responseRew = await axios.get(
        `https://cors-anywhere.herokuapp.com/https://api.yelp.com/v3/businesses/${id}/reviews`,
        {
          headers: {
            Authorization: `Bearer ${YELP_API_KEY}`,
            'X-Requested-With': 'XMLHttpRequest',
            'Access-Control-Allow-Origin': '*',
          },
        }
      );

      const parameters = {
        name: response.data.name,
        address: response.data.location.display_address[0],
        coordinates: {
          lat: response.data.coordinates.latitude,
          lng: response.data.coordinates.longitude,
        },
        city: response.data.location.display_address[1],
        rating: response.data.rating,
        photos: response.data.photos,
        phone: response.data.phone,
        price: response.data.price,
        categories: response.data.categories[0].title,
        url: response.data.url,
        reviews: responseRew.data.reviews,
      };

      return parameters;
    } catch (e) {
      console.log(e);
      return 'Error';
    }
  },
}

我一直在寻找解决方案，实际上我想出的解决方案来自这里：Can you write async tests that expect toThrow? 但它对我不起作用，我不明白我做错了什么。

感谢您的帮助！

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标签： reactjs unit-testing testing jestjs try-catch

【解决方案1】：

假设您在测试中断言 Promise 拒绝之前模拟 axios.get 拒绝，那么在 catch 块中的 Yelp.js 中存在问题。你需要重新抛出错误：

catch (e) {
      console.log(e);
      throw e;
}

如果你还没有模拟 axios 抛出错误，请在调用函数之前添加：

axios.get.mockRejectedValue('error');

如果这对你有用，请告诉我。

【讨论】：