Question

I’ve implemented the mockiterator solution from http://www.davegardner.me.uk/blog/2011/03/04/mocking-iterator-with-phpunit/ by creating classes that extend the Zend_Test_PHPUnit_DatabaseTestCase and Zend_Test_PHPUnit_ControllerTestCase and dropping in the the method to each child class.

However, I also ended up adding a few tweaks along the way, but it is a pain to have to make the same changes in each class to prevent divergent behaviour.

Both of the Zend classes inherit directly from the PHPUnit_Framework_TestCase is there a way of easily inserting a class between the PHPUnit and Zend classes which does not involve modifying the Zend library code directly? I guess I’m looking for an easy way to do something like this:

+-- PHPUnit_Framework_TestCase
 |
 +-- My_PHPUnit_Framework_TestCase 
  |
  +-- Zend_Test_PHPUnit_ControllerTestCase
  +-- Zend_Test_PHPUnit_DatabaseTestCase

I guess, as an alternative, I could replicate the two Zend classes in my library – but again, there could be problems whenever the Zend framework is uploaded, requiring my library to be rewritten from the new Zend testcase classes.

Answer 1

In PHP you have linear, single parent inheritance. Unfortunately, that means that you can’t insert a middle, proxy class without modifying the source of the Zend class.

If necessary (say, you have something which needs to be a child of two different DO classes, for example), there are ways to fake multiple inheritance, however.

Using, magic methods, for instance, you can create a multi-proxy:

class MultiProxy
{
    private $poxies;

    public function __construct( array $arr )
    {
        $this->proxies = $arr;
    }

    public function __get( $name )
    {
        foreach( $this->proxies as $proxy )
        {
            if( property_exists( $proxy, $name ) )
            {
                try
                {
                    return $proxy->$name
                }
                catch( Exception e )
                {
                    // swallow it.
                }
            }
        }
        trigger_error( "$name not found on $this" );
    }

    public function __set( $name, $val )
    {
        foreach( $this->proxies as $proxy )
        {
            if( property_exists( $proxy, $name ) )
            {
                try
                {
                    $proxy->$name = $val;
                }
                catch( Exception e )
                {
                    // swallow it.
                }
            }
        }
        trigger_error( "$name not found on $this" );
    }

    public function __call( $name, $args )
    {
        foreach( $this->proxies as $proxy )
        {
            $proxy = array( $proxy, $name );
            if( is_callable( $proxy ) )
            {
                try
                {
                    call_user_func_array( $proxy, $args );
                }
                catch( Exception e )
                {
                    // swallow it.
                }
            }
        }
        trigger_error( "$name not found on $this" );
    }

    public function __toString()
    {
        $ret = "[" . get_class( $this ) . '::{';
        foreach( $this->proxies as $proxy )
        {
            $ret .= get_class( $proxy ) . ',';
        }
        return substr( $ret, 0, -1 ) .'}]';
    }
}

// use:
class Foo{ public $a = 'FOO'; }
class Bar{ public function doSomething(){ echo 'YAY!'; } }
class Baz{ public $a = 'BAZ'; public function doSomething(){ echo 'BAAAZ!'; } }

$foo = new Foo();
$bar = new Bar(); // drink!
$baz = new Baz();

$multi = new MultiProxy( array( $foo, $bar, $baz ) );
$multi->a = 'MULTI!';
echo $multi->a == $foo->a? 1:0;
$multi->doSomething();// YAY!