在Mocha测试中使用Superagent/Supertest和Express应用程序

Question

我正在尝试使用Mocha为我正在开发的REST API编写测试.我发现Superagent让我发出HTTP请求.我正在使用Express应用程序,我将其传递给Superagent,但是当我尝试使用以这种方式传递的Express应用程序运行这些测试时,我得到了关于Mongoose的奇怪错误.这是我的测试代码:

var
    // Node modules
    mongoose = require('mongoose')
  , async = require('async')
  , should = require('should')
  , request = require('superagent')

  , app = require('../../app_mocked')
  , Link = mongoose.model('Link')

request = request(app)

describe('Links resource', function () {

  var userId = '50dc81654dca01006b000005'
    , linkId
    , sampleLink = {
        'uri': 'http://test.com/',
        'meta': {
          'title': 'Test',
          'desc': 'Test link desc'
        },
        'shares': [{
          'uid': userId,
          'date': new Date(),
          'message': 'Test link message'
        }]
      }

  it('POST /api/users/:id/links', function (done) {
    request(app).post('/api/users/' + userId + '/links')
      .send(sampleLink)
      .end(function (err, res) {
        res.should.have.status(200)
        res.body.should.have.property('id')

        linkId = res.body.id

        done()
      })
  })

  it('GET /api/users/:id/links', function (done) {
    request(app).get('/api/users/50dc81654dca01006b000005/links')
      .end(function (err, res) {
        res.should.have.status(200)
        res.body.should.have.lengthOf(1)

        done()
      })
  })

})

我得到的错误是这样的:

1) Links resource POST /api/users/:id/links:
   TypeError: Cannot call method 'update' of null
    at MongoStore.MONGOSTORE.set (/Users/Oliver/Development/Personal/Reader/node_modules/connect-mongodb/lib/connect-mongodb.js:146:15)
    at Session.save (/Users/Oliver/Development/Personal/Reader/node_modules/express/node_modules/connect/lib/middleware/session/session.js:63:25)
    at ServerResponse.res.end (/Users/Oliver/Development/Personal/Reader/node_modules/express/node_modules/connect/lib/middleware/session.js:280:19)
    at ServerResponse.res.send (/Users/Oliver/Development/Personal/Reader/node_modules/express/lib/response.js:149:8)
    at ServerResponse.res.json (/Users/Oliver/Development/Personal/Reader/node_modules/express/lib/response.js:191:15)
    at ServerResponse.res.send (/Users/Oliver/Development/Personal/Reader/node_modules/express/lib/response.js:117:21)
    at Promise.exports.create (/Users/Oliver/Development/Personal/Reader/server/resources/links.js:29:9)

但是,此错误有时仅出现.1/5次,测试通过没有问题.这让我觉得测试有时会在app完全加载之前运行.

或者,如果我在一个单独的会话中运行应用程序并将URL传递给request,如下所示,那么它每次都有效:

request = request('http://localhost:3000')

这是为什么？如果是这样,我怎样才能app在完全加载后运行测试？

Answer 1

事实证明,before在运行测试之前,我必须指定一个等待MongoDB连接打开的测试.

before(function (done) {
  mongoose.connection.on('open', done)
})