如何用玩笑模拟多个 axios 调用？答案

【问题标题】：How to mock multiple axios call with jest?如何用玩笑模拟多个 axios 调用？
【发布时间】：2021-11-04 19:56:33
【问题描述】：

在我的 Typescript 处理程序中，我有多个 axios 调用，如下所示

export const handler = async (event: APIGatewayProxyEvent): Promise<APIGatewayProxyResult> => {
const options = {
   headers: {
      Accept: 'application/json',
     'Content-Type': 'application/json;charset=UTF-8',
     authorization: 'Token',
   },
 }; 
    const respData = await axios
    .all([
      axios.get('https://jsonplaceholder.typicode.com/todos?_limit=5', options),
      axios.get('https://jsonplaceholder.typicode.com/posts?_limit=5', options)
    ])
    .then(axios.spread((todos, posts) => {todos, posts}))
    .catch(err => console.error(err));

  return {
     statusCode: 200,
     body: JSON.stringify(respData),
  };

};

如何用 jest 模拟这些多个 API 调用？

【问题讨论】：

标签： typescript unit-testing aws-lambda axios jestjs

【解决方案1】：

您可以使用jest.spyOn(object, methodName) 和mockFn.mockImplementation(fn) 根据url 参数模拟具有不同解析值的axios.get() 方法。

此外，从文档 Concurrency (Deprecated) 中，我们知道 axios.all() 和 axios.spread() 方法已被弃用。使用Promise.all 替换它们。

main.ts:

import axios from 'axios';

interface APIGatewayProxyEvent {}
interface APIGatewayProxyResult {}

export const handler = async (event: APIGatewayProxyEvent): Promise<APIGatewayProxyResult> => {
  const options = {
    headers: {
      Accept: 'application/json',
      'Content-Type': 'application/json;charset=UTF-8',
      authorization: 'Token',
    },
  };
  const respData = await axios
    .all([
      axios.get('https://jsonplaceholder.typicode.com/todos?_limit=5', options),
      axios.get('https://jsonplaceholder.typicode.com/posts?_limit=5', options),
    ])
    .then(axios.spread((todos, posts) => ({ todos, posts })))
    .catch((err) => console.error(err));

  return { statusCode: 200, body: JSON.stringify(respData) };
};

main.test.ts:

import { handler } from './main';
import axios from 'axios';

describe('69096350', () => {
  test('should pass', async () => {
    const axiosGetSpy = jest.spyOn(axios, 'get').mockImplementation(async (url) => {
      if (url === 'https://jsonplaceholder.typicode.com/todos?_limit=5') {
        return [1, 2, 3, 4, 5];
      } else if (url === 'https://jsonplaceholder.typicode.com/posts?_limit=5') {
        return ['a', 'b', 'c', 'd', 'e'];
      }
    });
    const actual = await handler({});
    expect(actual).toEqual({
      statusCode: 200,
      body: JSON.stringify({ todos: [1, 2, 3, 4, 5], posts: ['a', 'b', 'c', 'd', 'e'] }),
    });
    expect(axiosGetSpy).toBeCalledWith('https://jsonplaceholder.typicode.com/todos?_limit=5', {
      headers: {
        Accept: 'application/json',
        'Content-Type': 'application/json;charset=UTF-8',
        authorization: 'Token',
      },
    });
    expect(axiosGetSpy).toBeCalledWith('https://jsonplaceholder.typicode.com/posts?_limit=5', {
      headers: {
        Accept: 'application/json',
        'Content-Type': 'application/json;charset=UTF-8',
        authorization: 'Token',
      },
    });
    axiosGetSpy.mockRestore();
  });
});

测试结果：

 PASS  examples/69096350/main.test.ts (7.535 s)
  69096350
    ✓ should pass (4 ms)

----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |   88.89 |      100 |      75 |   85.71 |                   
 main.ts  |   88.89 |      100 |      75 |   85.71 | 20                
----------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        8.035 s, estimated 9 s
Ran all test suites related to changed files.

【讨论】：