Cucumber is premised on reading feature files and matching strings to determine what to do, which is done by using regular expressions in step files. This means constant use of ruby regular expressions, and in polishing up on my regular expression skills, I have found rubular incredidly useful. I love the simple layout and the ‘Regex Quick Reference’ at the bottom, just where you need it. It’s very well done.
The other tool I have found incredibly useful is RubyMine. Up until now, I’ve never really bothered with an IDE for Watir stuff. I’ve mainly stuck to text editors before, but since I have started using Cucumber, I have found the RubyMine tool almost critical, as its support for Cucumber feature files and step definitions is superb. It features click through linking for feature files so you know exactly what step you’re calling, and the debugger is awesome; no more puts statements for me :)
So, if you’re thinking about implementing Cucumber, or using Cucumber but are annoyed with the lack of efficiency in managing a large suite of step definitions, I would thoroughly recommend these two tools. Rubular is free, and I believe RubyMine is about $99, but less if you need multiple licenses. There’s also an Early Access Program where you can use RubyMine for free as long as you’re happy to test it along the way.