Skip to main content

Pick a card...

Take a pack of cards, shuffle them well, and place them on the desk in front of you. Could you accurately tell me what the order of the cards would be, without looking?
 
By Rosapicci - Own work, CC BY-SA 4.0
Now spend 2 weeks in a software development team, writing code & using services, and deploy that code to your cloud server environments.
Could you tell me where the bugs would be, before looking?

In both cases we have a rough idea of what’s in the product at the end. But the detail, how its actually going to play out? we have no realistic idea.

Skeptical?

Take the playing cards…

If we lay the cards out one card at a time. Then the order in which they are laid out, has probably never been seen before. Ever.The number of permutations of the well-known 52 playing card pack is 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000.

OK, now let’s get back to our code.

Even trivial apps, include dozens of code libraries, and are built on a myriad of operating systems calls. These in-turn process a huge number of potential inputs, and distribute them across an complicated series of devices each with own their configurations etc. You get the picture. There are many combinations of code, inputs and tools involved.

So, as with the playing cards, we might know at a high level what is coming... But we won't know for sure until we play it out.

If we play the cards out, one by one, we learn about their ordering. We know what 'works', and can better judge the nature of the unseen cards.

Remember that, next time someone asks you to write your tests before the app is developed.




Comments

Popular posts from this blog

A h̶i̶t̶c̶h̶h̶i̶k̶e̶r̶'s̶ software tester's guide to randomised testing - Part 1

Mostly Harmless, I've talked and written about randomisation as a technique in software testing several times over the last few years. It's great to see people's eyes light up when they grok the concept and its potential. 
The idea that they can create random test data on the fly and pour this into the app step back and see what happens is exciting to people looking to find new blockers on their apps path to reliability.
But it's not long before a cloud appears in their sunny demeanour and they start to conceive of the possible pitfalls. Here are a few tips on how to avert the common apparent blockers. (Part 1) Problem: I've created loads of random numbers as input data, but how will I know the answer the software returns, is correct? - Do I have to re-implement the whole app logic in my test code?
Do you remember going to the fun-fair as a kid? Or maybe you recall taking your kids now as an adult? If so then you no doubt are familiar with the height restriction -…

Betting in Testing

“I’ve completed my testing of this feature, and I think it's ready to ship”
“Are you willing to bet on that?”
No, Don't worry, I’m not going to list various ways you could test the feature better or things you might have forgotten.
Instead, I recommend you to ask yourself that question next time you believe you are finished. 
Why? It might cause you to analyse your belief more critically. We arrive at a decision usually by means of a mixture of emotion, convention and reason. Considering the question of whether the feature and the app are good enough as a bet is likely to make you use a more evidence-based approach.

Why do I think I am done here? Would I bet money/reputation on it? I have a checklist stuck to one of my screens, that I read and contemplate when I get to this point. When you have considered the options, you may decide to check some more things or ship the app. Either could be the right decision.
Then the app fails…
The next day you log on and find that the feature is b…

DevOps and Software Testing.

Most of my recent work has been with DevOps teams. While in one sense DevOps is another evolution in software development. It also introduces some new skill requirements and responsibilities into the daily routine of a tester.


I've created a short video to highlight some of these changes and the opportunities they bring. It's not an exhaustive view of DevOps but it gives a highlight of what you could be working with.


While DevOps isn't a panacea to our software development problems, I have found that empowering teams with the ability to build and use the tools they need, can rapidly improve team morale and productivity.