Jenkins中的Unit Testing Express应用

Question

Ok, I'm searching a couple of hours for a solution to run my Mocha unit tests inside Jenkins, for my Express JS app.

Writing tests is quite easy, but connecting the tests with my app is a bit harder. An example of my current test:

/tests/backend/route.test.js

var should    = require('should'),
    assert    = require('assert'),
    request   = require('supertest'),
    express   = require('express');

describe('Routing', function() {

  var app = 'http://someurl.com';

  describe('Account', function() {
    it('should return error trying to save duplicate username', function(done) {
      var profile = {
        username: 'vgheri',
        password: 'test',
        firstName: 'Valerio',
        lastName: 'Gheri'
      };
    // once we have specified the info we want to send to the server via POST verb,
    // we need to actually perform the action on the resource, in this case we want to 
    // POST on /api/profiles and we want to send some info
    // We do this using the request object, requiring supertest!
    request(app)
    .post('/api/profiles')
    .send(profile)
    // end handles the response
    .end(function(err, res) {
          if (err) {
            throw err;
          }
          // this is should.js syntax, very clear
          res.should.have.status(400);
          done();
        });
    });
});

In above example I connect to a running app (see ```var app = ' http://someurl.com '``). Obviously this is not working inside Jenkins, except if I can tell Jenkins to first run the app and then check for a localhost url. But how to do this?

Now if I take a look at https://www.npmjs.org/package/supertest this should be enough to test my express app:

var request = require('supertest')
  , express = require('express');

var app = express();

But it's not. I receive 404 errors on all urls which I would like to test.

Anyone who knows how to test my app inside Jenkins?

Answer 1

Is the app you referenced at http://someurl.com the app you're trying to write this test for? If so...

Supertest should allow you to run tests without needing an external server running. The way you accomplish this is by separating out the server routing Express code from the code you'll run that actually starts the server, and use Supertest on the server routing code.

Here is an example:

Given this directory structure:

./package.json
./server/index.js
./app.js
./test/server-test.js

Here are my files:

./package.json

All of these dependencies aren't required for this example, I just pulled this from my package.json I'm using in my project.

{
  "name": "StackOverflowExample",
  "version": "1.0.0",
  "description": "Example for stackoverflow",
  "main": "app.js",
  "scripts": {
    "test": "mocha"
  },
  "author": "Mark",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.15.2",
    "ejs": "^2.5.2",
    "express": "^4.14.0",
    "express-validator": "^2.21.0",
  },
  "devDependencies": {
    "chai": "^3.5.0",
    "mocha": "^3.1.2",
    "supertest": "^2.0.1"
  }
}

./server/index.js

var express = require('express');
var app = express();
app.get('/', function(req, res) {
    res.send('Hello World');
});
module.exports = app;

./app.js

var app = require('./server');
var server = app.listen(8000, function() {
    console.log('Listening on port 8000');
});

./tests/server-test.js

var request = require('supertest');
var app = require('../server');

var assert = require('assert'); //mocha
var chai = require('chai');
var expect = null;

chai.should();
expect = chai.expect;

describe('GET /', function() {
    it('should return a 200', function(done) {
        request(app).get('/').expect(200, done);
    });
});

I'm using Mocha and Chai here (didn't have time to refactor and make the example simpler, sorry). The main point is that within the it statement you can run your tests.

Doing it this way does not require a separate server running. Supertest magically starts one up for you and runs it based on the express server you exported from the server module. I think this approach should allow you to run your tests seamlessly through Jenkins.

In ./server/index.js , an Express object is created. That object is exported, and imported via require in both ./app.js and ./test/server-test.js . In ./app.js it's used to start a server via listen() . In the test file, Supetest uses it to start a server for testing internally.

When you are running the server in this example, you would run it via ./app.js . That would set the port you choose (8000 in this example) and start listening for connections on that port.

Hope this helps! Good luck!