Question

I’m working on simple benchmark “framework” (reason: boredom and practice).
Now I’m trying to get my head around something.
First things first:

class DataManager {

    private $persistanceStrategy;

    public function __construct(IPersistence $persistenceStrategy) {
        $this->persistanceStrategy = $persistenceStrategy;
    }

    public function saveData() {
        $this->persistanceStrategy->saveData($params);
    }

    public function getData() {
        $this->persistanceStrategy->getData($params);
    }
}

interface IPersistence {
    public function saveData(array $params);
    public function getData(array $params);
}

class XMLPersistence implements IPersistence {

    // Params would contain something like path to the
    // xml file, and unique name of some tag
    public function saveData(array $params) {
         // write something to xml file
    }
    public function getData(array $params) {
       // get something from xml file
    }
}

class DBPersistence implements IPersistence {
 // $params would contain unique name of data that is needed
 // and data for db connection
  ...
}

class SessionPersistence implements IPersistence {
  ....
}

Questions:

1. Is there a better way of designing this part of code.

2. How would someone unit test DataManager class, and “strategy” classes?

Answer 1

1. Using the stragety pattern here makes sense to me, so I don’t have any improvement suggestions.

2. Here’s a blog with one way to test your DataManager class. Basically you give it a mock strategy class and make sure that the proper strategy methods are indeed called.

   Testing Your Mocks

   I think testing the persistence classes would straightforward, make sure the XMLPersistence makes expected xml data, DB puts data in expected database, and maybe Session is asserted against an expected serialization.