Thoughts about "UI Test Automation Tools are Snake Oil"
I just finished reading "UI Test Automation Tools are Snake Oil" by Michael Feathers. Although I agree with many of the ideas in the article, I also think it contains some hasty generalizations and misplaced blame.
Mr. Feathers points out that “selling UI test automation tools is irresponsible” and these tools are sold “with a dream, a very seductive and dangerous one.” The scenario that he refers to, to my understanding, is the one where tool vendors sell their (expensive) tools promising:
- “click and type,” quick test generation with a record/playback tool, no coding required
- test the whole application, including all different use case and data permutations, using this tool
This can be easily interpreted as “with my tool, you will have a comprehensive test suite in no time, and you can hire cheap monkeys to do all the testing.” It is indeed a very seductive promise: spend some money and get what you want fast and with minimal effort, just like “weight loss, without diet and exercise.”
I completely agree with Mr. Feathers that selling something based on a fallacy is irresponsible. At the same time, I also think this is the point where blame is misplaced. Instead of blaming the tool, blame should be shared between tool vendors and the people buying the tool, as long as the business transaction is based on the “seductive dream.” IMHO, this is a people problem: on one hand we have vendors taking advantage of the customers’ lack of knowledge and the customers, that did not do their proper homework on time and by now have a big, untestable mess.
Another good point that Mr. Feathers makes is that UI testing tools are brittle. Selling a UI testing tool promising that the generated test suite will never break is also careless. The fact is, when testing UIs there are many external elements that can introduce false failures. IMHO, it is impossible to fix all of them, but at least, the tool vendor should warn their customers about these limitations and offer ways to overcome them (more on that later.)
I also agree with Mr. Feathers that record/playback doesn’t work. I wish he went into more details to see if we agree based on the same premises. In my opinion, the major weakness of existing record/playback tools is expensive maintenance of the generated tests. Recorded scripts are often long and written in proprietary languages lacking object-oriented features. Modularization/refactoring is hard or impossible, resulting in duplicate test code. The common end result is that changes in the application requires re-recording all tests scenarios, a labor-intensive and error-prone task.
Not everything is black and white. UI test automation tools still have a place. Not every shop has the resources or time to rewrite an application, just to make it more testable. I’ve seen applications with massive code bases, that were not written with testability in mind. Extending or refactoring is scary due to the lack of the safety net that automated tests provide. The only way to test them is through the UI. UI testing can provide the initial safety net, which later on can be enhanced (or replaced) with API-based unit tests.
In his post, Mr. Feathers asks “Developing them open-source? Well, let your conscience be your guide.” I don’t sell a UI test automation tool per se. What I provide is an open source, API-based UI testing library, called FEST (you can find some testimonials here.) I think I’ve been pretty responsible by pointing out that UI testing is fragile and offering ways to overcome this limitation. What I’m missing, and I have to thank Mr. Feathers for it, is a guide on how to test the UI layer in isolation (which I will be doing soon.)
Like I mentioned in a previous post, I’m currently working on my spare time on a playback/recording tool. My intention is to create a tool that generates clean Java code, as if it was hand-crafted, to overcome to what I think are the problems with this technique. We’ll see if I can accomplish this ambitious goal :)
Overall, I liked and enjoyed Mr. Feathers article. It has pretty good points and observations. I wish he backed up his ideas with more details and examples, to sound less emotional and more objective. The problem is in the human factor, not in the tool. Ideally, vendors (in general) should set the right expectations about their products, and customers should have enough knowledge to avoid being taken advantage of. At least, some of us are trying to do the right thing :)
Feedback is always welcome :)