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: {}.

Solution 1

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

module.exports = server

Solution 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 ...', () => {

Solution 3

This may also help, and satisfies @dman point of changing application code to fit a test.

make your request to the localhost and port as needed chai.request('http://localhost:5000')

instead of

chai.request(server)

this fixed the same error message I had using Koa JS (v2) and ava js.

Solution 4

The answers above correctly address the issue: supertest wants an http.Server to work on. However, calling app.listen() to get a server will also start a listening server, this is bad practice and unnecessary.

You can get around by this by using http.createServer():

import * as http from 'http';
import * as supertest from 'supertest';
import * as test from 'tape';
import * as Koa from 'koa';

const app = new Koa();

# add some routes here

const apptest = supertest(http.createServer(app.callback()));

test('GET /healthcheck', (t) => {
    apptest.get('/healthcheck')
    .expect(200)
    .expect(res => {
      t.equal(res.text, 'Ok');
    })
    .end(t.end.bind(t));
});

Solution 5

Just in case, if someone uses Hapijs the issue still occurs, because it does not use Express.js, thus address() function does not exist.

TypeError: app.address is not a function
      at serverAddress (node_modules/chai-http/lib/request.js:282:18)

The workaround to make it work

// this makes the server to start up
let server = require('../../server')

// pass this instead of server to avoid error
const API = 'http://localhost:3000'

describe('/GET token ', () => {
    it('JWT token', (done) => {
       chai.request(API)
         .get('/api/token?....')
         .end((err, res) => {
          res.should.have.status(200)
          res.body.should.be.a('object')
          res.body.should.have.property('token')
          done()
      })
    })
  })

View more solutions

Comments

[dman]

the only issue I have with this is that the application code should never be changed to fit a test.

[Skyguard]

@chovy did you resolve this? I have an alternative below that worked for me.

[atom2ueki]

the potential problem is dealing with server which contains a async services, because chai-http don't know the logic of that, and it will run directly even before your server fully started

[Anita Mehta]

After doing this error is not coming, but in get data is coming null and statuscode 200 ok.

[GrumpyCrouton]

You should include in your answer why it's "important to export the http.Server object".

[Kim Kern]

@GrumpyCrouton I added the error you will get otherwise

[GrumpyCrouton]

Thank you Kim. I gave you a +1 because I think that does improve your answer. In the future, you should explain why. Imagine someone looking at this question and only has basic knowledge, a well thought out and explained answer will teach them a lot more.

[Garr Godfrey]

@Nabuska in this case server is probably already set with app.listen(...)

[Whyhankee]

For your tests you shoud not use app.listen() which starts an actual server, use http.createServer() instead

[Whyhankee]

For your tests you shoud not use app.listen() which starts an actual server, use http.createServer() instead

[Amirhosein Al]

Works for me but when I wrap it in an if(!process.env.prod) it doesn't

[1011 1110]

Honestly I think this should be the accepted answer, calling app.listen() in the app will make you run into issues later.

[Catfish]

The problem with this answer is that you create a separate app to run your tests, which doesn't include the actual code of your route handlers. How I've always solved this problem is simply have a function which accepts a param on whether to call app.listen or not and that function always returns the app object.

[an1waukoni]

Thanks for your answer and explanation. I've been debugging this for two days straight!