Joe Moore's blog
At Pivotal, we are passionate about test driven development, keeping things DRY, and writing readable and understandable code. Satisfying all of these desires can be challenging, especially when writing test code. In particular, ActiveRecord extensions present several challenges: which models using an extension should we test? How do we both test our extension in isolation while also testing all model's usage of that extension? Is it even worth it?
The answer is yes, it is worth it, and it's also fairly easy, readable, understandable, and DRY. I will present both a common problem and a solution, using a cumulation of technologies and techniques from multiple Pivotal projects, in particular using acts_as_fu to create laser-targeted, isolated, and disposable ActiveRecord models for testing extensions and RSpec shared behaviors to minimize the amount of duplicated test code.