I've seen it way too many times. As your application grows, so does your sloppy, untested codebase. Before long, you begin to drown, as your ability to manually test the application becomes unrealistic, or even impossible! It's at these specific times, when you begin to realize the down-right necessity for testing. Sure, you might have read a TDD book in the past, but, like many things in life, we require real-life experience, before we suddenly - in a wonderful, blissful "aha moment" - get it.
The only problem is that testing can be a tricky thing. In fact, it's quite possible that your codebase, as it currently stands, is untestable! What you may not realize is that, while, yes, testing does help to ensure that your code works as expected, following this pattern will also make you a better developer. That messy, untestable spaghetti code that you might have snuck into your project in the past will never happen again. Trust me: as soon as you bring the phrase "how could I test this" to the forefront of every new piece of code, you'll, with a smile on your face, look back to your former self, and laugh at your crazy, cowboy ways. Welcome to modern software development.
While the principles of testing (and TDD) are language-agnostic, when it comes to execution, there are a variety of tools and techniques at your finger tips. This book is as much an introduction to TDD as it is a deep analysis of the Laravel way of testing applications. Updates will be free for life.