Testing static classes with PHPUnit

Question

Hi,

I've got a set of classes I'm trying to test. Class A depends on Class X. Class X contains functions which do random things and things with databases. I've created a mock version of Class X which returns exactly what I want it to in order to test Class A without dependencies.

So, my question is, how do I now test Class X as I've already included the mock version, which has the same name and filename. I get the "Cannot redeclare Class X" error.

I don't think I can use stubs as there's no way to pass the stubbed object into my class under test. The class under test (Class A) will ask for an instance of a static class (ClassA::getInstance();).

Is this going to be something to do with test suites or test cases as I can't un-include a the file which contains the mock version of Class X.

Thanks in advance for your help,

Mike

Answer 1

there's no way to pass the stubbed object into my class under test.

This means that your Class A strongly references Class X ? Personally I'd recommend to rename your Class X mockup to a real mockup (e.g. X_MockUp) put it in a test folder hierarchy and then pass it to the Class A that you want to test. It might be not possible at the moment, but then change your architecture! It will be more flexible and testable-friendly.

You get this error as you have the same class name in two files you are forced to differentiate them.

Answer 2

You can't uninclude files/classes in PHP, so the classes will either need to use different names or you will need to namespace them. As for using a stub class, two approaches you could use are. Use an instance/class variable that contains dependancies, so you can swap them out. Like

self::$_classes['classA']::methodCall();
$this->_classes['classA']::methodCall();

This will let you change the class dependancies at runtime if you really need statics. The other approach is to not use static classes and use a dependancy injection container like one found in symfony components. An injection container would let you inject mocks as needed as well.