Mocha API Testing: getting 'TypeError: app.address is not a function'

Question

My Issue

I've coded a very simple CRUD API and I've started recently coding also some tests using chai and chai-http but I'm having an issue when running my tests with $ mocha.

When I run the tests I get the following error on the shell:

TypeError: app.address is not a function

My Code

Here is a sample of one of my tests (/tests/server-test.js):

var chai = require('chai');
var mongoose = require('mongoose');
var chaiHttp = require('chai-http');
var server = require('../server/app'); // my express app
var should = chai.should();
var testUtils = require('./test-utils');

chai.use(chaiHttp);

describe('API Tests', function() {
  before(function() {
    mongoose.createConnection('mongodb://localhost/bot-test', myOptionsObj);
  });

  beforeEach(function(done) {
    // I do stuff like populating db
  });

  afterEach(function(done) {
    // I do stuff like deleting populated db
  });

  after(function() {
    mongoose.connection.close();
  });

  describe('Boxes', function() {

    it.only('should list ALL boxes on /boxes GET', function(done) {
      chai.request(server)
        .get('/api/boxes')
        .end(function(err, res){
          res.should.have.status(200);
          done();
        });
    });

    // the rest of the tests would continue here...

  });

});

And my express app files (/server/app.js):

var mongoose = require('mongoose');
var express = require('express');
var api = require('./routes/api.js');
var app = express();

mongoose.connect('mongodb://localhost/db-dev', myOptionsObj);

// application configuration
require('./config/express')(app);

// routing set up
app.use('/api', api);

var server = app.listen(3000, function () {
  var host = server.address().address;
  var port = server.address().port;

  console.log('App listening at http://%s:%s', host, port);
});

and (/server/routes/api.js):

var express = require('express');
var boxController = require('../modules/box/controller');
var thingController = require('../modules/thing/controller');
var router = express.Router();

// API routing
router.get('/boxes', boxController.getAll);
// etc.

module.exports = router;

Extra notes

I've tried logging out the server variable in the /tests/server-test.js file before running the tests:

...
var server = require('../server/app'); // my express app
...

console.log('server: ', server);
...

and I the result of that is an empty object: server: {}.

Answer 1

You don't export anything in your app module. Try adding this to your app.js file:

module.exports = server

Answer 2

It's important to export the http.Server object returned by app.listen(3000) instead of just the function app, otherwise you will get TypeError: app.address is not a function.

Example:

index.js

const koa = require('koa');
const app = new koa();
module.exports = app.listen(3000);

index.spec.js

const request = require('supertest');
const app = require('./index.js');

describe('User Registration', () => {
  const agent = request.agent(app);

  it('should ...', () => {