When Symfony2 was created I first learned about the functional test, which is an interesting type of test where everything about your application is as real as possible. Just like with an integration or end-to-end test. One big difference: the test runner exercises the application's front controller programmatically, instead of through a web server. This means that the input for the test is a Request object, not an actual HTTP message.

It's very easy not to write a book.

Mostly since it's such an awful lot of work. You'll first need to figure out what you're going to write about, and find an angle that makes it interesting enough for potential readers to buy the book and spend the time to finish it. The writing itself is hard work as well, and may take several years. Along the way you'll be telling yourself things that will keep you from finishing the task: I'm not doing anything original here. Nobody will be interested. Somebody else wrote a better book about this than I could ever do. If I don't cover topic B as well, it's not going to be a useful book at all.

During a recent run of my Advanced Web Application Architecture training, we discussed the distinction between infrastructure code and non-infrastructure code, which I usually call core code. One of the participants summarized the difference between the two as: "everything in your vendor directory is infrastructure code". I don't agree with that, and I will explain why in this article.