Question

I’m new to unit testing in general, but wanted to implement it in MVC pattern (using PHP). Now I’m not sure how to approach this.

Should unit testing be built into the framework, or we just create a new folder called tests and include all necessary classes and unit test each one ?

In short, if there is a model M, it also has some coupling with the framework itself. So to test the model, should I include some portions of the framework in the unit tests ?

Are there some good code examples on how to go about accomplishing this.

Answer 1

Should unit testing be built into the framework, or we just create a new folder called tests and include all necessary classes and unit test each one ?

You should definitely create a separate folder for it. Cluttering up production code with tests is generally not a good idea for performance and debugging reasons.

So to test the model, should I include some portions of the framework in the unit tests ?

The least the better. Unit tests should require little to no dependencies. If class A depends on B, you should mock B to ensure that if B fails, it doesn’t make A fail too.

The main advantage to unit tests (when done correctly) is that it allows you to easily pinpoint the problem. If A fails because of its B dependency, you will first look at A, then B. Again, if B depends on C and C fails, you will have to look into A, B and then C. This pretty much ruins one of the greatest advantage to unit testing. If all tests are done properly, a failure in C will not cause a failure anywhere else than in C, so you will have a single class to lookup to fix the problem.

To really make your code error-proof, you can use unit tests in conjunction with PHP assertions:

$return = $this->addOne($some_param);
assert('$return == $some_param + 1');

By the way, there is no difference between unit testing MVC as opposed to unit testing in general.