Evan Henshaw-Plath (more commonly known as rabble) is in the process of writing a book for O'Reilly about testing and debugging Ruby on Rails applications, and has just launched a companion blog, Testing Rails. The subject of the blog is exactly what the title says, and rabble hopes to post at least one in-depth tutorial relating to Rails and testing each week. The first is Building Tests from Logs - Test Driven Debugging.