Cleaning up between tests

I am currently trying to get some good end-to-end (e2e with protractor,  which is a great tool!) tests running for my Angular app ‘Extreme Results’ (wrote a bit about the app here).

I very quickly found a big problem. How do I clean up my database between tests and test-runs?

The way I see it, there are two ways to solve this problem:

1. Let the e2e tests actually clean up the way a user would.
   In other words, clicking around and deleting thing “manually” with tests.
   Every test needs to manually clean up after themselves.
   This actually works pretty well. It makes for a well tested application, but errors propagate quickly through every test.
2. Calling the backend directly through REST between each test (or possibly between test “files”).
   This way, you can rely on tests being clean when you start with a new one.
   Feels a bit safer and cleaner (and less error-prone).

In my case, I was in no shape to even allow the user to delete stuff manually (not yet implemented in the app), so it made more sense to delete stuff through a REST call (also less work).

I use Parse as my back-end, so I created a Cloud Code function (which is just a REST call that fires some server-side code) that clears my entire database. Extremely dangerous code in other words. Do not deploy such code in production please!

If you want to see the Cloud Code, take a look on Github:
https://github.com/bjaanes/ExtremeResults-CloudCode/commit/e7452fce6701875fddfc5271d9083c31cc38e7fb

Performing a REST call from your protractor tests

I created a common module that I can use from every test class. It looks like this:

var http = require('https');

var Common = function () {

    this.clearDB = function () {
        var deferred = protractor.promise.defer();

        var options = {
            hostname: 'api.parse.com',
            path: '/1/functions/clearDB',
            method: 'POST',
            headers: {
                'X-Parse-Application-Id': 'PARSE-APPLICATION-ID',
                'X-Parse-REST-API-Key': 'PARSE-REST-API-KEY'
            }
        };

        var callback = function() {
            deferred.fulfill();
        };

        var req = http.request(options, callback);
        req.end();

        return deferred.promise;
    };

};

module.exports = Common;

It uses a node package called https.

I set up some options like host, path, method and headers.

And then I just perform the call with http.request() and req.end(). Simple and nice.

They way I actually use this is even simpler:

var OverviewPage = require('./overview.po.js');
var Common = require('../common/common.js');

describe('Overview Page', function () {

    var overviewPage = new OverviewPage();
    var common = new Common();

    beforeAll(function () {
       common.clearDB();
    });

    // Tests...

});

The important bits are:

var Common = require('../common/common.js');

var common = new Common();

Which both set up the required ‘common’ module.

But the real code is:

beforeAll(function () {
       common.clearDB();
 });

Which actually performs the database clear between every tests. Neat huh?