Posts Tagged bdd
I’ve just finished reading “The Rspec Book: Behaviour-Driven Development with RSpec, Cucumber, and Friends”, and I totally recommend it to anybody writing Ruby code. Being fairly new to Ruby, I had limited experience (still do) to RSpec and Cucumber, but despite plenty of literature available on the web, I was glad to find a book dedicated to this subject so I could absorb some structured information.
|The RSpec Book: Behaviour Driven Development with Rspec, Cucumber, and Friends (The Facets of Ruby Series)|
I like the way the book is organized and how it develops the idea of “outside-in” development; starting from writing features in Cucumber, writing “the code you wish you had”, and then going into RSpec to drive out the implementation of controllers and models.
The authors do a great job at explaining how RSpec works, and that was very useful as that had been kind of magical for me. I start to see more and more what people have been raving about regarding how Ruby is such an elegant language. The book also includes tips on how one can clean up tests by using built-in matcher, or creating custom matchers, and stuff like that.
I’m keeping this book handy so I can use it as a reference as I write my tests and look for ways to improve clarity.
Three years ago I blogged about my thoughts at time on the whole testing thing. I have stuck with the practices and really believe on it. I’ve tried different tools and approaches, and I keep trying different things as I go. Behavior-Driven Development (BDD) seemed like my next step, but it didn’t take me long to realize MS-Test didn’t give me what I needed in order to start to get into that practice. There wasn’t much I could do as I was stuck with it.
When C# 3.0 came out, I’ve learned how I could improve my tests using extension methods, building some sort of fluent DSL to test certain things. Eventually, I was able to migrate to xUnit, along with SubSpec, and then I was able to write tests a lot better, following the “given-when-then” style. Writing new features and certain components following that style has been great; I believe everything I wrote following that approach has a much better design and quality.
I had heard Rails developers gave a lot more importance to BDD and testability than .NET developers, so that was one of the driving factors that encouraged me to try Rails.
After getting a little more comfortable with Rails and Ruby, I started to devote more time to RSpec and Cucumber, without really understanding much what they were exactly. So far, I’m enjoying using both. I’m almost done reading the RSpec book (I’ll post a quick review once I’m done) and writing as many tests as I can, but I still have lots to learn; I’m still at that stage where I do know there must be a better way to write something, but I’m not to a point where I know how to do it.
I am writing lots of “features” formatted so that I can drop them into Cucumber .feature files, and then implementing them. I’m finally realizing some benefits of BDD that were apparent to me before. Up until recently, I was seeing BDD mostly as a way to write tests where the scenarios were described such as “given whatever, when something happens, then I should get x”. But those were described as strings surrounded by C# code, so the business value wasn’t immediately apparent.
Now, however, I’ve been sticking to this format (right off the official Cucumber site):
This format makes it a lot easier to see the business value out of an atomic feature. It shows a short title for the feature, the ultimate value out of it (“in order to…”), who’s getting benefit from it (“as a…”), and what the person wants (“I want to…”). Then, it describes the different scenarios that exist for the given feature. I like the fact that there’s no specific programming language clutter mixed in with the description of the feature.
If I’m the one writing those stories, as a developer, it forces me to be as clear and succinct with the English language as possible, so that it will make it easier for me to validate these with my clients and users; and as they get familiar with the format, they can start providing me the stories themselves.
Another advantage I’ve been noticing doing these is that by analyzing the number of steps within a given scenario I can identify whether the user experience is going to be good or not. The scenario unveils how hard it is for the user to access the feature (“user has to click this, select that, fill out the other, click this other thing, and only then get to what she needs…”), and how the user interacts with the system (what the user does, and how the application responds).
Breaking scenarios into small, concise units… doesn’t that sound similar to “breaking classes into smaller, concise classes, methods, etc.”? Putting some good thought into writing these stories can help out the developer later when actually implementing the feature.
And here’s another benefit of keeping scenarios small and concise: planning. When discussing the feature with the clients, I can get them a feel for the complexity on each scenario, and they can tell me which scenarios are must-to-have, and which ones could come at a later time. This way we can plan on which features and which specific scenarios are going to be implemented on a given iteration or release.
I’m also following the idea that “Cucumber tests cover the application’s behavior, and RSpec tests cover class’ behavior”. In other words, I write Cucumber tests to check a feature end-to-end, from the user’s point of view, and I use RSpec to test a class’ behavior.
Some people say one of the main advantages of Cucumber is that non-technical people can easily read, or even write, the tests, but some developers say “the non-technical people will never read anything anyways, so why bother?”. So far, I’m seeing the Cucumber tests as being very beneficial for myself, for the reasons listed above (like forcing me to think of the features in a cleaner and more concise way, etc.).
At the moment, I have the following workflow:
- Write the features and store it in Evernote (tagging everything so I can group features based on specific user roles and things like that);
- Review stories with the client, rewrite pieces, split features up, move scenarios around, etc;
- Once it feels like a given feature is a little more stable, I put it on the Kanban board in AgileZen;
- Pick features that are on the board, and plan them accordingly;
- Once I start working on a given feature, it’s just a matter of turning them into a Cucumber file, and go about implementing it.
This is not written in stone, and it’s just something I’m trying out. I have no idea whether that’d scale for large teams or whatever, but I’m being pragmatic and doing whatever it takes to be productive given what I have. It seems to be working. I’ll keep you posted.