Monday, January 30, 2012

Book Review: The Cucumber Book

One of the cool things about Pragmatic Publishing is the fact that they make it possible to get your hands on Beta books, meaning you get the chance to see a book as its actively being developed. The Cucumber Book was one of those books, and as such, I’ve had the benefit of looking at and reviewing this book for the past several months, and have watched it grow into the book that is today (and now available in print form).


Most people who have a passing understanding of Test Driven Development or Behavior Driven Development have likely heard of Cucumber. It’s a language that allows anyone who wants to define tests and requirements for applications the ability to do so in plain English (or fill in the blank language if supported). In truth, Cucumber isn’t really a programming language at all, but a symbolic phrase library that matches to various underlying commands and blocks of code (represented in Ruby in this book and referencing a variety of tools including Capybara, Rspec and others).


Matt Wynne and Aslak Hellesøy have put together a very readable and focused text that help the user get familiar with the basics of the language. The book also focuses the reader on understanding the underpinnings needed to create expressions that work with their respective technologies. Granted, if you are a tester and you want to take advantage of this framework, there is plenty in here to keep you busy. The Cucumber Book starts out by explaining what Cucumber is and the niche it is meant to fill (specifications based tests and requirements). If you are a developer, there is likewise plenty in here to keep you interested, too.


The process in the Cucumber book is heavy on examples and showing how the examples work. Yes, for those who want to know how to use the syntax and language specific details of Cucumber, that stuff is covered. What is also covered, and covered well, is the Behavioral Driven Development approach needed to effectively create tests and have them work effectively. Along with creating feature files and steps for those feature files, the underlying step definitions also have to be coded. Not only do they have to be coded, but they have to have assertions written that will effectively confirm if the step has passed, or if it fails, and why.


Since the book is primarily based on Cucumber, there is a large section that covers Cucumber fundamentals, including basic Gherkin (the underlying syntax that Cucumber uses), and the ability of using expressive options such as Scenario Outlines, Data tables, Doc Strings, tags, and dealing with some of the pain points seen in your tests (such as "flickering scenarios", where the tests pass some of the time but fail some times, too). More than just using Cucumber to define steps and have step definitions defined, the third part of the book deals with applying Cucumber to a number of different technologies; working with various databases, testing with RESTful web services, working with Rails, running tests and using capybara to simulate common browser actions and many other options that may come to play in your everyday testing life.


Bottom Line:


If you have ever been interested in looking at Cucumber and your testing environment is built around Ruby, then this will be an ideal book to use. If you are interested in deploying Cucumber in another type of environment, such as testing with Java or .NET, many of the ideas in this book will also carry over, but have a look at “The Secret Ninja Cucumber Scrolls” by David de Florinier and Gojko Adzic. It provides information about how to apply Cucumber to those environments. Regardless of your particular focus and environment needs, for a practical and effective book for learning and using Cucumber in a meaningful way, The Cucumber Book is an excellent addition to any tester or developer’s library.

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