On our development team, we decided to give Unit Testing a try. We use Simpletest. However, it’s been a tough road. After a week, I only have created 1 unit test that tests a certain helper file. That’s it. The rest (controllers, models, views, libraries) don’t have unit tests yet. And I plan to not test a majority of them. Views, for example, are too trivial to test, so I pass up on testing that. Next, the controllers. I plan my controllers to not do complex stuff, so that it only does passing of information between the models and the views. I’d move those more complex stuff to libraries or helpers.
Now for my questions:
1) Am I doing it wrong? So far, there’s nothing more that I can see that can be erroneous so it would need a unit test. Most of the stuff (right now) are just CRUD.
2) Do we really need to unit test controllers? Since a controller’s job is just minor processing of data passed between View and Model, I find very little initiative in unit testing it.
3) If I use WebTestCase to test for controllers, would that be still considered a Unit Test? Or is it already an integration test?
4) Suppose you got me to test my controller, how would I test it? As far as I know, CI follows the Front Controller pattern through index.php, so how would I handle (mock?) that?
Are you doing something wrong? I don’t think so.
Do we really need to unit test controllers? I don’t. Maybe I should. Seems like a lot of work, though.
If I use WebTestCase to test for controllers, would that be still considered a Unit Test? Or is it already an integration test? WebTestCase would be an interesting approach to testing controllers if some meaningful output could be detected; for example, detecting that no error has occurred when calling /some/specific/path.
Suppose you got me to test my controller, how would I test it? That’s a tough one. You would presumably need to initialize part of the application environment in order to do anything worthwhile.
Most articles/books tell you to define your tests before you start coding. Maybe I’ve tried that, but I’m usually too impatient. It seems to get in the way of quick prototyping, but maybe defining the unit tests is a way of quick prototyping.
I’ve found that deciding what to test with PHP is a challenge. I think you have to pick your battles. If it’s critical that a method return a value of specific type, then test for that. If a lot of things happen automatically when instantiating an object, you could test for that too.
In general, what I do — right or wrong — is get everything working, then create some basic tests and then add tests as needed based on any problems I encounter. The idea is to never have a repeat problem and each test will insure that the application behaves the same through its life-cycle.
As for specifics, I’m using Zend Framework, but it will be similar in CodeIgniter. I also use SimpleTest (but with my own class wrapper). I may or may not unit test models and I have never implemented tests for controllers or views; it’s seems like too much work and too little benefit. Most frameworks “fail early” and so issues are typically obvious. But any common library code make for easier targets and bugs here — especially logic bugs — are harder to detect. Set up your tests to make sure things work as expected so that your framework-specific code encounters few problems.