Why there’s no such thing as codeless automation

In today’s blog post – which, again, is really nothing more than a thinly veiled rant – I’d like to cover something that’s been covered before, just not by me: codeless test automation and why I think there isn’t and should not be such a thing.

I’ve seen numerous ‘solution’ vendors advertise their products as ‘codeless’, implying that everybody in the team will be able to create, run and maintain automated tests, without having to, well, write code. I’ve got a number of problems with selling test automation in this way.

It’s not codeless. It’s hiding code.
The first gripe I have with ‘codeless’ automation is a semantic one. These solutions aren’t codeless at all. They simply hide the code that runs the test from plain sight. There are no monkeys in the solution that magically execute the instructions that make up a test. No, those instructions are translated into actual code by the solution, then executed. As a user of such a solution, you’re still coding (i.e., writing instructions in a manner that can be interpreted by a machine), just in a different syntax. That’s not codeless.

While it might be empowering, it’s also limiting.
Sure, using codeless tools might potentially lead to more people contributing to writing automated tests (although from my experience, that’s hardly how it’s going to be in the end). The downside is: it’s also limiting the power of the automated tests. As I said above, the ‘codeless’ solution is usually nothing more than an abstraction layer on top of the test automation code. And with abstraction comes loss of detail. In this case, this might be loss of access to features of the underlying code. For example, if you’re using a codeless abstraction on top of Selenium, you might lose access to specific waiting, synchronization or error handling mechanisms (which are among the exact things that makes Selenium so powerful).

It might also be loss of access to logging, debugging or other types of root cause analysis tools, which in turn leads to shallower feedback in case something goes wrong. While the solution might show you that something has gone wrong, it loses detail on where things went wrong and what caused the failure. Not something I like.

Finally, it might also limit access to hooks in the application, or limit you to a specific type of automated tests. If such a solution makes it potentially easier to write automated tests on the user interface level, for example, there’s significant risk that all tests will be written at that level, even though that might not be the most efficient approach in the first place. If all you’ve got is a hammer…

It’s doing nothing for the hard problems in creating maintainable automation.
Let’s face it: while writing code might seem hard to people that haven’t done it before, it actually isn’t that difficult once you’ve had a couple of basic programming classes, or followed a course or two on Codecademy. What is hard is writing good, readable, maintainable code. Applying SOLID and DRY principles. Structuring your tests. Testing the right thing at the right level. Creating a solid test data and test environment strategy. Those things are hard. And codeless test automation does nothing for those problems. As I tried to make clear in the previous paragraphs, it’ll often make it even harder to solve those problems effectively.

I’m all for creating solutions that make it easier to write, run and maintain automation. I hate people selling solutions as something they’re not. Codeless test automation is not going to solve your test automation problems. People that know

  • how to decide what good automation is
  • how to write that automation, and
  • how to pick the tools that will help them achieve the goals of the team and organization

will.

Why I think unit testing is the basis of any solid automation strategy

In a recent blog post I talked about why and how I still use the test automation pyramid as a model to talk about different levels of test automation and how to combine them into an automation strategy that fits your needs. In this blog post I’d like to talk about the basis of the pyramid a little more: unit tests and unit testing. There’s a reason -or better, there are a number of reasons- why unit testing forms the basis of any solid automation strategy, and why it’s depicted as the broadest layer in the pyramid.

Unit tests are fast
Even though end-to-end testing using tools like Selenium is the first thing a lot of people think about when they hear the term ‘test automation’, Selenium tests are actually the hardest and most time-intensive to write, run and maintain. Unit tests, on the other hand, can be written fast, both in absolute time it takes to write unit test code as well as relative to the progress of the software development process. A very good example of the latter is the practice of Test Driven Development (TDD), where tests are written before the actual production code is created.

Unit tests are also fast to run. Their run time is typically in the milliseconds range, where integration and end-to-end tests take seconds or even minutes, depending on your test and their scope. This means that a solid set of unit tests will give you feedback on specific aspects of your application quality much faster than those other types of tests. I stressed ‘specific aspects’, because while unit tests can cover ground in relatively little time, there’s only so much they can do. As goes for automation as a whole.

Unit tests require (and enforce) code testability
Any developer can tell you that the better structured code is, the easier it is to isolate specific classes and methods and write unit tests for them, mocking away all dependencies that method or class requires. This is referred to as highly testable code. I’ve worked in projects where people were stuck with badly testable code and have seen the consequences. I’ve facilitated two day test automation hackathon where the end goal was to write a single unit test and integrate it into the Continuous Integration pipeline. Writing the test took ten minutes. Untangling the existing code so that the unit test could be written? Two days MINUS ten minutes.

This is where practices like TDD can help. When you’ve got your tests in place before the production code that lets the tests pass is written, the risk of that production code becoming untestable spaghetti code is far lower. And having testable code is a massive help with the next reason why unit testing should be the basis of your automation efforts.

Unit tests prevent outside in test automation (hopefully)
If you’re code is testable, it means that it’s far easier to write unit tests for it. Which in turn means that the likelihood that unit tests are actually written increases as well. And where unit tests are written consistently and visibly, the risk that everything and its mother it tested through the user interface (a phenomenon I’ve seen referred to as ‘outside-in test automation’) is far less high. Just writing lots of unit tests is not enough, though, their scope, intent and coverage should be clear to the team as well (so, testers, get involved!).

Unit tests are a safety net for code refactoring
Let’s face it: your production code isn’t going to live unchanged forever (although I’ve heard about lines of COBOL that are busy defying this). Changes to the application, renewed libraries or insights, all of these will in time be reason to refactor your existing code to improve effectivity, readability, maintainability or just to keep things running. This is where a decent set of unit tests helps a lot, since they can be used as a safety net that can give you feedback about the consequences of your refactoring efforts on overall application functionality. And even more importantly, they do this quickly. Developers are humans, and will move on to different tasks if they need to wait hours for feedback. With unit tests, that feedback arrives in seconds, keeping them and you both focused and on the right track.

In the end, unit tests can, will and need not replace integration and end-to-end tests, of course. There’s a reason all of them are featured in the test automation pyramid. But when you’re trying to create or improve your test automation strategy, I’d advise you to start with the basis and get your unit testing in place.

By the way, for those of you reading this on the publication date, I’d like to mention that I’ll be co-hosting a webinar with the folks at Testim, where I’ll be talking about the importance of unit testing, as well as much more with regards to test automation strategy. I hope to see you there! If you’re reading this at a later date, I’ll add a link to the recording as soon as it’s available.

Why and how I still use the test automation pyramid

Last week, while delivering part one of a two-evening API testing course, I found myself explaining the benefits of writing automated tests at the API level using the test automation pyramid. That in itself probably isn’t too noteworthy, but what immediately struck me as odd is that I found myself apologizing to the participants that I used a model that has received so many criticism as the pyramid.

Odd, because

  1. Half of the participants hadn’t even heard of the test automation pyramid before
  2. The pyramid, as a model, to me is still a very useful way for me to explain a number of concepts and good practices related to test automation.

#1 is a problem that should be tackled by better education around software testing and test automation, I think, but that’s not what I wanted to talk about in this blog post. No, what I would like to show is that, at least to me, the test automation pyramid is still a valuable model when explaining and teaching test automation, as long as it’s used in the right context.

The version of the test automation pyramid I tend to use in my talks

The basis of what makes the pyramid a useful concept to me is the following distinction:

It is a model, not a guideline.

A guideline is something that’s (claiming to be) correct, under certain circumstances. A model, as the statistician George Box said, is always wrong, but some models are useful. To me, this applies perfectly to the test automation pyramid:

There’s more to automation than meets the UI
The test automation pyramid, as a model, helps me explain to less experienced engineers that there’s more to test automation than end-to-end tests (those often driven through the user interface). I explain this often using examples from real life projects, where we chose to do a couple of end-to-end tests to verify that customers could complete a specific sequence of actions, combined with a more extensive set of API tests to verify business logic at a lower level, and why this was a much more effective approach than testing everything through the UI.

Unit testing is the foundation
The pyramid, as a model, perfectly supports my belief that a solid unit testing strategy is the basis for any successful, significantly-sized test automation effort. Anything that can be covered in unit tests should not have to be covered again in higher level tests, i.e., at the integration/API or even at the end-to-end level.

E2E and UI tests are two different concepts
The pyramid, as a model, helps me explain the difference between end-to-end tests, where the application as a whole is exercised from top (often the UI) to bottom (often a database), and user interface tests. The latter may be end-to-end tests, but unbeknownst to surprisingly many people you can write unit tests for your user interface just as well.There’s a reason the top layer of the pyramid that I use (together with many others) says ‘E2E’, not ‘UI’…

Don’t try to enforce ratios between test automation scope levels
The pyramid, when used as a guideline, can lead to less than optimal test automation decisions. This mainly applies to the ratio between the number of tests in each of the E2E, integration and unit categories. Even though well though through automation suites will naturally steer towards a ratio of more unit tests than integration tests and more integration tests than E2E tests, it should never be forced to do so. I’ve even seen some people, which unfortunately were the ones in charge, make decisions on what and how to automate based on ratios. Some even went as far as saying ‘X % of our automated tests HAVE TO be unit tests’. Personally, I’d rather go for the ratio that delivers in terms of effectiveness and time needed to write and maintain the tests instead.

Test automation is only part of the testing story
‘My’ version of the test automation pyramid (or at least the version I use in my presentations) prominently features what I call exploratory testing. This helps remind me to tell those that are listening that there’s more to testing than automation. I usually call this part of the testing story ‘exploratory testing’, because this is the part where humans explore and evaluate the application under test to inform themselves and others about aspects of its quality. This is what’s often referred to as ‘manual testing’, but I don’t like that term.

As you can see, to me, the test automation pyramid is still a very valuable model (and still a useless guideline) when it comes to me explaining my thoughts on automation, despite all the criticism it has received over the years. I hope I never find myself apologizing for using it again in the future..