This post and others like it still get a strange amount of traffic. It’s worth noting the details here are out of date and I won’t be keeping it up. Use at your own risk!
In my last post I wrote about two testing libraries for WordPress and briefly discussed the difference between integration tests and unit tests. I also mentioned a concept called test driven development (TDD) and breifly explained how it might help write better code from the start. This post will expand on that and show how to write a simple WordPress plugin from a test-first approach. Since we’re writing unit tests, we’re going to use WP-Mock to create a test double for us and we’ll use PHPunit for our test runner.
TDD starts with a problem you want to solve—the same problem your plugin wants to solve. In this case, let’s say we have a plugin that will add some metadata to a post with the title “Test”. Since that’s going to require us to mock some WordPress core functionality, make sure WP-Mock is configured in your working environment. We’ll start by writing a test that verifies the metadata was attached to the post.Continue reading “Writing Unit Tests for WordPress”