Testing

Testing UI changes in large web applications

Sannie Kwakman

When a web application starts to grow in terms of functionality, number of screens and amount of code, automated testing becomes a necessity. Not only will these tests prevent you from delivering bugs to your users but also help to maintain a high speed of development. This ensures that you'll be focusing on new and better features without having to fix bugs in the existing ones.

However even with all kinds of unit-, integration- and end-to-end tests in place,  you'll still end up with a huge blind spot: does your application still looks like it's supposed to?

Can we test for this as well? (hint: we can). Read more

Super fast unit test execution with WallabyJS

Frank van Wijk

Our current AngularJS project has been under development for about 2.5 years, so the number of unit tests has increased enormously. We tend to have a coverage percentage near 100%, which led to 4000+ unit tests. These include service specs and view specs. You may know that AngularJS - when abused a bit - is not suited for super large applications, but since we tamed the beast and have an application with more than 16,000 lines of high performing AngularJS code, we want to keep in charge about the total development process without any performance losses.

 Read more

5 Reasons why you should test your code

Frank van Wijk

It is just like in mathematics class when I had to make a proof for Thales’ theorem I wrote “Can’t you see that B has a right angle?! Q.E.D.”, but he still gave me an F grade.

You want to make things work, right? So you start programming until your feature is implemented. When it is implemented, it works, so you do not need any tests. You want to proceed and make more cool features.

Suddenly feature 1 breaks, because you did something weird in some service that is reused all over your application. Ok, let’s fix it, keep refreshing the page until everything is stable again. This is the point in time where you regret that you (or even better, your teammate) did not write tests.

In this article I give you 5 reasons why you should write them.

 Read more

Android: Custom ViewMatchers in Espresso

Steven Mulder

Somehow it seems that testing is still treated like an afterthought in mobile development. The introduction of the Espresso test framework in the Android Testing Support Library improved the situation a little bit, but the documentation is limited and it can be hard to debug problems. And you will run into problems, because testing is hard to learn when there are so few examples to learn from.

Anyway, I recently created my first custom ViewMatcher for Espresso and I figured I would like to share it here. I was building a simple form with some EditText views as input fields, and these fields should display an error message when the user entered an invalid input.

 Read more

ATDD with Lego Mindstorms EV3

Kishen Simbhoedatpanday

We have been building automated acceptance tests using web browsers, mobile devices and web services for several years now. Last week Erik Zeedijk and I came up with the (crazy) idea to implement features for a robot using ATDD. In this blog we will explain how we used ATDD while experimenting with Lego Mindstorms EV3.
 Read more

Testing Feature Branches Remotely with Grunt

Misja Alma

At my current job we are working on multiple features simultaneously, using git feature branches. We have a Jenkins build server which we use for integration testing of the master branch, which runs about 20 jobs simultaneously for Protractor and Fitnesse tests. An individual job typically takes around 10 minutes to complete.

Our policy is to keep the master branch production ready at all times. Therefore we have a review process in place that should assure that feature branches are only pushed to master when they can't break the application.
This all works very well as long as the feature which you are working on requires only one or two integration test suites to test its functionality. But every once in a while you're working on something that could have effects all over the application, and you would like to run a larger number of integration test suites. And of course before you merge your feature branch to master.
Running all the integration suites on your local machine would take too way much time. And Jenkins is configured to run all its suites against the master branch. So what to do?
 Read more

Ready, Test, Go!

Viktor Clerc

The full potential of many an agile organization is hardly ever reached. Many teams find themselves redefining user stories although they have been committed to as part of the sprint. The ‘ready phase’, meant to get user stories clear and sufficiently detailed so they can be implemented, is missed. How will each user story result in high quality features that deliver business value? The ‘Definition of Ready’ is lacking one important entry: “Automated tests are available.” Ensuring to have testable and hence automated acceptance criteria before committing to user stories in a sprint, allows you to retain focus during the sprint. We define this as: Ready, Test, Go!

 Read more

Mutation Testing: How Good are your Unit Tests?

Misja Alma

You write unit tests for every piece of code you deliver. Your test coverage is close to 100%. So when the point comes when you have to make some small changes to the existing code, you feel safe and confident that your test suite will protect you against possible mistakes.
You make your changes, and all your tests still pass. You should be fairly confident now that you can commit your new code without breaking anything, right?

Well, maybe not. Maybe your unit tests were fooling you. Sure they covered every line of your code, but they could have performed the wrong assertions.
In this post I will introduce mutation testing. Mutation testing can help you find omissions in your unit tests.
 Read more

Then When Given

Kishen Simbhoedatpanday

People who practice ATDD all know how frustrating it can be to write automated examples. Especially when you get stuck overthinking the preconditions of examples.

This post describes an alternative approach to writing acceptance tests: write them backwards!

 Read more

Fast and Easy integration testing with Docker and Overcast

Paul van der Ende

Challenges with integration testing

Suppose that you are writing a MongoDB driver for java. To verify if all the implemented functionality works correctly, you ideally want to test it against a REAL MongoDB server. This brings a couple of challenges:

  • Mongo is not written in java, so we can not embed it easily in our java application
  • We need to install and configure MongoDB somewhere, and maintain the installation, or write scripts to set it up as part of our test run.
  • Every test we run against the mongo server, will change the state, and tests might influence each other. We want to isolate our tests as much as possible.
  • We want to test our driver against multiple versions of MongoDB.
  • We want to run the tests as fast as possible. If we want to run tests in parallel, we need multiple servers. How do we manage them?

Let's try to address these challenges. Read more