Aaron Sumner

Rails Test Prescriptions is going to be the best book on Rails testing

This week I went through Rails Test Prescriptions: Keeping Your Application Healthy by Noel Rappin, from Pragmatic Programmers. It’s still a beta book, and has only been out for a couple of weeks, but I think I’ve finally found a book that will help me write and maintain tests for my Rails app .

For starters, it may be helpful to me that I already understand the basic philosophies behind TDD. Outside-in design, red-green-refactor, I get all that. However, it always seemed to me that those approaches didn’t always reflect real-world development. At least, they didn’t reflect my real world of development. As much as I wanted to test my code, it didn’t happen at the rate I wanted–either because I got sick of helping Cucumber understand English, or working around Webrat’s finickiness, or waiting for The RSpec Book to get done. So I put together test suites as best as I could, using tools I understood, testing the things I knew how to test while fully acknowledging that there were other things that should be tested, but writing possibly flawed tests would be worse than writing no tests. That’s been my system for the past year.

Imagine my delight, then, when Rappin admits that while outside-in and red-green-refactor may be the gold standards, in real life they don’t always work out. As long as your feedback loop between test and code is relatively tight, you’re probably doing OK. I don’t know why, but seeing this in electronic print was a huge relief to me–not that I needed validation from other developers, but mainly for my own sanity as I continue to chip away at a couple of years’ worth of code that needs testing. I think I’m going to get this all figured out. The explanation of mocks versus stubs alone is worth the price of the e-book.

The book, by my estimation, is probably about half done, with chapters specific to RSpec, Shoulda, Selenium, Cucumber, and legacy testing still to be written. What’s in place now may not be for the reader who wants to follow along as the author codes—there are code samples, but it’s not structured in a set-and-app-up-from-scratch way like other computer texts are. I don’t know if the book will be in this same format once it’s out of beta, but as-is it lends itself more to a read-and-refresh than a tutorial or reference book. However, I’ve yet to see anything better for explaining Rails testing from a high level, and look forward to subsequent updates to the beta book.

. Questions or comments? Let me know what you think.