Re: any thoughts on self-testing classes?

Dmitri Snytkine wrote: > Just wondering what experienced developers think about self-testing classes, > - classes that include their own test() method inside the class which runs > test suite and tests all methods. > > This is one way to have access to private methods while running tests. > > Any of you using this approach in your development? Hi Dmitri, I would not consider this approach simply because it mixes purposes, and introduces all kinds of weird ways to screw up the intended normal operation of the class. I would also suggest that this is not the way to solve the problem of accessing private methods. After having used PPP for a couple of years in PHP now, I can report that the best solution is to avoid the word "private" unless you really mean "final" - as in the entire operation of the class would be jeopardized if any change is ever made to the operation of a method. In this case, slapping "private" in front of it is a very good idea. For most situations, once you switch "private" to "protected" you get the best of both worlds. It becomes impossible to call a method from outside the class hierarchy, but you can still extend the class and override the method, which allows testing to work simply via a mock. For instance: class MyMock extends Fancy_Class { public function whatever() { return parent::whatever(); } } This way, your test can simply instantiate MyMock and call whatever() directly to test it. There are other problems with including test() methods inside the class, one of which is that the memory usage of your class and load time increases even with an opcode cache, all with deadweight code that is never executed in normal operation. This is all another way of saying that if you design your code to be testable, then you won't need to do anything awkward in the code itself in order to test it. Greg