A little while ago, Carl and I starting digging into Rails’ initializer. We already made a number of improvements, such as adding the ability to add a new initializer at any step in the process, and to make it possible to have multiple initializers in a single process. The second improvement is the first step toward running multiple Rails apps in a single process, which requires moving all global Rails state into instances of objects, so each application can have its own contained configuration in its own object. More on this in the next few weeks.

One of the things that has both pleasantly surprised and frustrated me over the past six months is the state of Rails’ internal tests. While the tests can sometimes cover the most obscure, important bugs, they can sometimes be heavily mock-based or very coupled to internal implementation.