进行异步调用的Mocha测试同步函数

Question

我正在尝试找出如何测试进行异步调用的同步方法。

我在下面有这个方法，我想简单地测试并断言res.status(HttpStatus.OK).send()返回200响应

'use strict'

const HttpStatus = require('http-status-codes')
let db = null

/**
 * Gets a resource by id
 * @param  {Object} req The request object
 * @param  {Object} res The response object
 * @return {Object}     An http response
 */
function getById (req, res) {
  const dockey = req.params.resourceType + '$' + req.params.id

  // The get by id query
  const query = ResourceTypesDao.getByIdQuery()

  db.transaction({
    write: ['auditevents', 'auditedges'],
    read: ['clindocs']
  },
  query,
  {
    key: dockey,
    id: req.params.id
  })
    .then(result => {
        return res.status(HttpStatus.OK).send()
    .catch(err => {
      console.log('err = ', err)
    })
}

module.exports = (database) => {
  db = database
  return getById
}

对应的spec文件

'use strict'

const expect = require('chai').expect

let db = {
  transaction: function(collections, query, params) {
    return new Promise((resolve, reject) => {
      return resolve({doc: {}})
    })
  }
}

const getById = require('../../../src/controllers/resource-types/getById')(db)

let req = {
  params: {
    id: 'foo'
  }
}

let res = {
  status: function() {

    let self = {}

    function send() {

    }

    self.send = send
    return self
  },
  send: function() {

  }
}

describe.only('#getById', () => {

  it('should pass', (done) => {

const result = getById(req, res)
    setTimeout(() => {

      console.log('result = ', result) <-- returning undefined so this aint right
      expect(result).to.be.instanceOf(Object)
      done()
    }, 1000)
  })
})

Answer 1

您需要从getById函数返回promise：

function getById (req, res) {
  ...
  return db.transaction({...}).then(...).catch(...);
}

然后，在您的测试中，等待它解决，然后再进行断言：

it('should pass', (done) => {
  getById(req, res)
    .then(result => {
      // make assertion here
      done()
    });
});