Recipe: Refactor public to private

FixtureTest.class.php

<?php
  uses('unittest.TestCase');

  abstract class FixtureTest extends TestCase {
    protected $fixture= NULL;
  
    protected abstract function newFixtureInstance();

    public function setUp() {
      $this->fixture= $this->newFixtureInstance();
    }
    
    #[@test]
    public function accessParams() {
      $this->assertEquals(array(), $this->fixture->params);
    }

    #[@test]
    public function modifyParams() {
      $value= array('a' => 'b');
      $this->fixture->params= $value;
      $this->assertEquals($value, $this->fixture->params);
    }

    #[@test]
    public function writeParam() {
      $this->fixture->params['a']= 'b';
      $this->assertEquals(array('a' => 'b'), $this->fixture->params);
    }

    #[@test]
    public function readParam() {
      $this->fixture->params= array('a' => 'b');
      $this->assertEquals('b', $this->fixture->params['a']);
    }
  }
?>

FixtureV1.class.php

<?php
  class FixtureV1 extends Object {
    public $params= array();
  }
?>

FixtureV1Test.class.php

<?php
  uses('FixtureTest', 'FixtureV1', 'FixtureV2');

  class FixtureV1Test extends FixtureTest {
  
    protected function newFixtureInstance() {
      return new FixtureV1();
    }

    #[@test]
    public function serializationRoundtrip() {
      $this->fixture->params= array('a' => 'b');
      $serialized= serialize($this->fixture);
      
      // Simulate system boundary
      $serialized= str_replace('"FixtureV1"', '"FixtureV2"', $serialized);
      var_dump($serialized);
      
      $v2= unserialize($serialized);
      $this->assertEquals($this->fixture->params, $v2->params);
    }
  }
?>

FixtureV2.class.php

<?php
  class FixtureV2 extends Object {
    protected $_params= array();
    protected $__serialization= FALSE;
    
    public function __set($name, $value) {
      if ('params' === $name) {
        if ($this->__serialization) {
          $this->{'params'}= $value;    // "Invent" property
        } else {
          $this->_params= $value;
        }
        return;
      }
      parent::__set($name, $value);
    }

    public function &__get($name) {
      if ('params' === $name) {
        return $this->_params;
      }
      return parent::__get($name);
    }
    
    public function __sleep() {
      $this->__serialization= TRUE;
      $this->params= $this->_params;
      $this->__serialization= FALSE;
      
      // The filter is to prevent public properties with leading "\0" 
      // being "invented". For performance, this could be omitted.
      return array_filter(array_keys((array)$this), function($key) {
        return "\0" !== $key{0};
      });
    }

    public function __wakeup() {
      $this->_params= $this->params;
      unset($this->params);
    }
  }
?>

FixtureV2Test.class.php

<?php
  uses('FixtureTest', 'FixtureV2');

  class FixtureV2Test extends FixtureTest {
  
    protected function newFixtureInstance() {
      return new FixtureV2();
    }

    #[@test]
    public function serializationRoundtrip() {
      $this->fixture->params= array('a' => 'b');
      $serialized= serialize($this->fixture);
      
      // Simulate system boundary
      $serialized= str_replace('"FixtureV2"', '"FixtureV1"', $serialized);
      var_dump($serialized);
      
      $v1= unserialize($serialized);
      $this->assertEquals($this->fixture->params, $v1->params);
    }
  }
?>