Update: I've edited the post according to Aaron's comment :)
Last monday I started reading the book Everyday Rails Testing with Rspec. The author (Aaron Sumner) provides a github repo with the source code but I find its structure to be confusing. Even though there's a branch that serves as a starting point, and after that, each chapter builds off of the previous chapter, the merges among the different branches and the commits in between (see example image below) make the repository intricate which plays against the correct visualization on how the app evolves along with the book.
Because of this I decided to create a rails 4 application from scratch and add the code from the example app included in the author's repository. This application is available at my github repository and should allow everyone reading the book to follow the exercises step by step. I also added tags to show milestones of how the code should look at the beginning and end of each chapter. So far I've uploaded up to chapter 4.