Test automation

The iterative approach in agile software development requires new approaches to testing. Test automation is necessary in order not to run into time constraints.

An indispensable part of agile development

Agile work promotes flexible, dynamic and uncomplicated work with as little bureaucracy as possible. The focus is on people and communication. Results mean more than documentation. Establishing a direct line to the customer and always reacting flexibly is more important than stubbornly sticking to a plan. Agile software development means constantly improving the end product in short iterations, together with colleagues and customers. In this article I would like to explain why automated tests are an integral part of software development. 

The importance of testing

Testing occupies an important position in software development. A high-quality product must go through different levels of testing, such as component tests, integration tests and functional tests. In Agile work, as mentioned above, the focus is on short development iterations, which also require short test iterations. In order to be able to carry out the various test stages without getting into a time crunch, it is necessary to execute various tests faster and with easy repeatability. The more complex the software, the greater the importance of test automation. Test automation alone can ensure that both test coverage and test depth are within a satisfactory range once the development reaches a certain complexity. 

The fallacy of automated tests

The pitfall of automated tests is that they can only take over the manual task part of a software tester. Behind clean and reliable tests, however, there is just as much creative intuitive thinking and clever action. Under no circumstances should test automation be seen as a rationalisation of a tester’s work, but rather as a tool for the tester that can hardly be imagined without. While he no longer has to spend hours working through new developments of his company through automated processes, he has more time for the intellectual part of software testing. He can test better and in a more concentrated way instead of getting lost in a huge amount of tests. Of course, test automation does not always make sense, such as with small transitional programmes. However, the longer-lived and more complex the software, the more costs and effort test automation saves in the long run. 

Selenium as a general-purpose tool

There are many tools for test automation. Selenium is probably one of the best known, especially in the area of websites and their user interface. Selenium offers various tools for projects of different sizes and requirements. 

Selenium as a browser plug-in

The Selenium IDE is a browser add-on that allows you to record clicks, keystrokes and movements on the website. Later, you can replay the recorded actions and thus obtain a test that can be executed as often as you like. However, since the recording is very time-consuming manually, the add-on is only available for the browsers Chrome and Firefox and there is no possibility to document the tests, the browser plug-in is only suitable for smaller projects or for beginners. 

Selenium WebDriver - When websites suddenly become self-sufficient

The Selenium WebDriver, on the other hand, acts as a programming interface for the browser, is compatible with the most common browsers and supports many different programming languages, including JavaScript, Python, Ruby, and many more. Tests can be programmed in any code editor, e.g. Visual Studio, and the browser is then addressed via the WebDriver. Each time the written test is called up, a new window opens in which the website runs itself through the test. A major advantage over the add-on is that the test can be parameterised. The test coverage can be increased much more quickly and easily. 

Cucumber, anything but a cucumber

Since this testing does not provide a clear documentation of the work done, there is a tool for various programming languages (Ruby, Java, C++, …) called Cucumber, which makes it very easy to write and read the test cases and also produces easily readable documentation when the tests are executed. In Cucumber, tests are written in the language Gherkin and then translated into the corresponding programming language. Gherkin essentially contains the commands Given, When and Then, through which the optimal functionality of the software is described by conditions (Given), executed actions (When) and desired result (Then). Since the desired behaviour of the software is directly formulated, Cucumber is a very good tool for Behaviour-Driven-Development. The documentation then contains the simple sentences of the Cucumber programming and is thereupon comprehensible for everyone. 

Selenium-Cucumber a reliable double pack

The Ruby extension Selenium-Cucumber takes over the translation of the Cucumber tests into the corresponding programming language. Instead of arbitrary sentences, as previously in Cucumber, there is now a defined set of commands that is independently “translated” into an executable test case. The writing effort on the part of Cucumber naturally becomes greater and more incomprehensible, but the programming elsewhere is omitted altogether. Through this interaction of Selenium-Cucumber it is possible to write automated test cases without in-depth programming knowledge. This way, product owners can pack the requirements for the end product itself into the test without any loss. 

Our first steps are done

The combination of Selenium WebDriver, Selenium-Cucumber and Ruby or others allows us to take the first steps towards test automation. Besides the easy writing of the tests and the good documentation in html format, the Selenium WebDriver also allows a wide test coverage in different browsers. 

What's next: test automation a must

Test automation is a must in an agile environment. The simpler the tests and the more frequently they have to be performed, the more important automation is. However, automation does not replace a tester but facilitates and improves his work, giving him more freedom for tests that cannot be automated (e.g. UX/UI tests). In the course of continuous improvement, every software company should use automated tests. This is the only way to succeed in meeting the high demands and time pressure of today’s world.

Sources: Buch: Seidl, Richard/Baumgartner, Manfred/Bucsics, Thomas (2011), Basiswissen Testautomatisierung (2. Auflage), Heidelberg, dpunkt.verlag

https://agilemanifesto.org/iso/de/manifesto.html https://de.slideshare.net/MaibornWolff/universum-der-testautomatisierung-von-sven-schirmer-maibornwolff