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Tuesday, October 2, 2007

Is Automated testing development?

I'm not talking about unit testing. I am talking about regression testing. There are a number of automation tools out there and for some applications you can just use the record and playback feature. WinRunner, SilkTest, RationalRobot, etc. all have a feature where you can turn on a recorder, manually walk through an application then save the script. Later you can play the script back; if nothing has changed the script should execute without error.

This is the theory. The reality is that most projects change and the scripts fail. You then have to take the time to re-record the script or edit the code so it matches the change in the application. Additionally, the scripts tend to make the application do things but the tester still needs to add code to the script to confirm the right things happen, e.g. assert statements or capture points.

So testers are creating, maintaining, enhancing and debugging source code. This sounds a lot like development work. Yet in most the places I've seen people doing automation and with most the people I've interviewed (and some I hired), very few have knowledge of software development.

Yesterday I was talking to someone using an automated script. The script worked fine for the person developing it but did not for the person I was talking to. It turns out that the script assumes relative paths to other things. If you don't run it from the right directory (not the directory the script is in) it fails to work. To fix this flaw the 'developer' added a command line option to the script. The logic was "If there is a $1 parameter, cd $1 else assume you are in the correct directory."

There was no comments in the script, they did not reassign the $1 variable to something more sensible and they checked for $1 deep in the script, i.e. not at the top.

The person I spoke with spent an hour trying to figure out what was wrong. She even spoke with the creator of the script and he couldn't figure out she was doing wrong.

A good development practice is a coding style guideline. Using appropriate comments, parsing input parameters near the beginning of the script and possibly writing it as a function. Developers working on a team have learned that a consistent style makes it easier for everyone to take over someone else's code. At first a new developer might want everyone to switch to their standard but once they come around everyone benefits.

Creators of automated regression tests never create a coding standard. In many cases they don't use source control. Additionally, they will pick automation tools that have poor or no debugging capabilities. Developers like Visual C++ or Java because the IDEs are so advanced. Once you get familiar with Eclipse or NetBeans, you could never imagine using Java from the command line again.

If developers are using powerful tools like Eclipse to develop their code, how is an automated tester going to keep up? Every time the developer makes a required change/enhancement to the application, the tester will have to maintain their scripts. If the developer can make the change in minutes but the tester takes hours, the cost of maintaining the automation will not be worth it.

I like the idea of pair programming where one person does the development and the other person codes the tests. Agile programmers are more thinking about unit testing when they describe this concept but why not have an integration or system level tester be a person with development skills?

I'm not saying that developers should start doing automation testing. Developers have a different mindset then a tester. I'm suggesting that testers should have some fundamental development training. If you hire QA or testing staff with development experience you will probably get better automation.

Additionally, if you are an automation tester, learn development techniques and apply them to your script development. Become more efficient. In many companies, they get automation tools but end up abandoning them because they become a maintenance nightmare. Maybe you will be the person who saves the tools and keeps the company using them.

Finally, automated testing is not WHAT you want to test. It is HOW you want to test. If I'm creating an application, I'll first come up with a list of requirements and design WHAT I want to create. If I decide I'm going to write the application in Java or C++, the language does not, for the most part, dictate WHAT I'm going to create. The automation tool you use comes at the implementation stage. You still need a test strategy, test plans and a list of test cases. Only then should you be looking at HOW you are going to automate the test cases.

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