We might write perfect code but, unfortunately, our users are mere mortals and thus are prone to giving us cruddy data by mistake. If you recall, in Chapter 1, Getting Started with Luminus, we used the Luminus template to generate the hipstr application, which includes the lib-noir library for us. One of the helper namespaces provided by lib-noir is a noir.validation namespace.
The noir.validation namespace provides methods to validate data in a variety of ways. It includes functions to check whether or not an input is nil, is an e-mail, is of a certain minimum length, and so on. This is excellent because I hate writing validation code, and I'm sure you do, too.
However, while noir.validation has a lot of functions that can be used to validate data, its actual validation framework makes some unfortunate assumptions as to how it will be used. It is also stateful, which makes it difficult to test and, frankly, is pretty unnecessary for a...