Question

当然，我不想在测试中调用任何真实的端点。但是我不知道如何模拟.on()的{{1}}函数。

我不确定什么是正确的，但是我尝试了https.get()

https.get.on.mockResolvedValue({})

我可以模拟https .get('https://jsonplaceholder.typicode.com/todos/1', apiRes => { console.log('statusCode:', apiRes.statusCode); console.log('headers:', apiRes.headers); apiRes.on('data', d => { process.stdout.write(d); res.status(200).json({ message: 'message' }); }); }) .on('error', e => { console.error(e); res.status(500).json({ error: 'error' }); });。但是就算我开玩笑测试，我也会得到https.get()。如果删除https.get(...).on is not a function件，我的测试将可以继续。

Answer 1

这是解决方案：

index.ts：

import https from 'https';

const response = {
  status(code: number) {
    console.log('status code: ', code);
    return response;
  },
  json(data: any) {
    console.log(JSON.stringify(data));
    return response;
  }
};

function getTodo(res = response) {
  https
    .get('https://jsonplaceholder.typicode.com/todos/1', apiRes => {
      console.log('statusCode:', apiRes.statusCode);
      console.log('headers:', apiRes.headers);

      apiRes.on('data', d => {
        process.stdout.write(d);
        res.status(200).json({ message: 'message' });
      });
    })
    .on('error', e => {
      console.error(e);
      res.status(500).json({ error: 'error' });
    });
}

export { getTodo };

index.spec.ts：

import { getTodo } from './';
import https from 'https';
import { EventEmitter } from 'events';

describe('test', () => {
  const emitter = new EventEmitter();
  const httpIncomingMessage = {
    on: jest.fn(),
    statusCode: 'mock status code',
    headers: {
      authorization: 'Bearer mocked token'
    }
  };
  https.get = jest.fn().mockImplementation((uri, callback?) => {
    if (callback) {
      callback(httpIncomingMessage);
    }
    return emitter;
  });
  it('should get todo correctly', () => {
    getTodo();
  });

  it.only('should trigger error event handler correctly', done => {
    getTodo();
    emitter.emit('error', 'error message');
    process.nextTick(() => {
      done();
    });
  });
});

单元测试结果：

 PASS  src/stackoverflow/57283122/index.spec.ts
  test
    ✓ should get todo correctly (10ms)
    ✓ should trigger error event handler correctly (14ms)

  console.log src/stackoverflow/57283122/index.ts:17
    statusCode: mock status code

  console.log src/stackoverflow/57283122/index.ts:18
    headers: { authorization: 'Bearer mocked token' }

  console.log src/stackoverflow/57283122/index.ts:17
    statusCode: mock status code

  console.log src/stackoverflow/57283122/index.ts:18
    headers: { authorization: 'Bearer mocked token' }

  console.error src/stackoverflow/57283122/index.ts:26
    error message

  console.log src/stackoverflow/57283122/index.ts:5
    status code:  500

  console.log src/stackoverflow/57283122/index.ts:9
    {"error":"error"}

  console.error src/stackoverflow/57283122/index.ts:26
    error message

  console.log src/stackoverflow/57283122/index.ts:5
    status code:  500

  console.log src/stackoverflow/57283122/index.ts:9
    {"error":"error"}

Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        1.104s, estimated 3s

如何嘲笑https的'on'功能？

1 个答案: