On the SitePoint PHP blog they've posted another article from author Christopher Pitt. This time he talks about snapshot testing and if it's a viable way to evaluate code in PHP applications.

Ah-ha moments are beautiful and rare in programming. Every so often, we’re fortunate enough to discover some trick or facet of a system that forever changes how we think of it. For me, that’s what snapshot testing is.

You probably write a lot of PHP code, but today I want to talk about something I learned in JavaScript. We’ll learn about what snapshot testing is and then see how it can help us write better PHP applications.

He starts with a brief introduction to the technology to be used (React in Javascript) and how it could be recreated in PHP. He then covers testing interfaces, evaluating the correct functionality of frontends via various testing tools. He includes some examples of this kind of testing and how it can help a developer mentally break up functionality into components. From there he switches over to the PHP side, introducing the spatie/phpunit-snapshot-assertions package and showing how to use it to check the make up of a snapshot and test several assertions that should exist.