[zendframework/zendframework#6] Test passing PHP config files to Factory

- Tested both using the Factory to get individual PHP files, as well as
  including PHP files in a mixed strategy
- Made factory Abstract to prevent instantiation

src/Factory.php

@@ -21,12 +21,14 @@
 namespace Zend\Config;
 
 /**
+ * Declared abstract to prevent instantiation
+ * 
  * @category  Zend
  * @package   Zend_Config
  * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
  * @license   http://framework.zend.com/license/new-bsd     New BSD License
  */
-class Factory
+abstract class Factory
 {
     /**
      * Readers used for config files.

test/FactoryTest.php

@@ -74,16 +74,30 @@ public function testFromXmlFiles()
         $this->assertEquals('baz', $config['test']['bar']);
     }
 
-    public function testFromIniAndXmlFiles()
+    public function testFromPhpFiles()
+    {
+        $files = array (
+            __DIR__ . '/TestAssets/Php/include-base.php',
+            __DIR__ . '/TestAssets/Php/include-base2.php'
+        );
+
+        $config = Factory::fromFiles($files);
+        $this->assertEquals('bar', $config['base']['foo']);
+        $this->assertEquals('baz', $config['test']['bar']);
+    }
+
+    public function testFromIniAndXmlAndPhpFiles()
     {
         $files = array (
             __DIR__ . '/TestAssets/Ini/include-base.ini',
-            __DIR__ . '/TestAssets/Xml/include-base2.xml'
+            __DIR__ . '/TestAssets/Xml/include-base2.xml',
+            __DIR__ . '/TestAssets/Php/include-base3.php',
         );
 
         $config = Factory::fromFiles($files);
         $this->assertEquals('bar', $config['base']['foo']);
         $this->assertEquals('baz', $config['test']['bar']);
+        $this->assertEquals('baz', $config['last']['bar']);
     }
 
     public function testNonExistentFileThrowsRuntimeException()

test/TestAssets/Php/include-base.php

@@ -0,0 +1,6 @@
+<?php
+return array(
+    'test' => array(
+        'bar' => 'baz',
+    ),
+);

test/TestAssets/Php/include-base2.php

@@ -0,0 +1,6 @@
+<?php
+return array(
+    'base' => array(
+        'foo' => 'bar',
+    ),
+);

test/TestAssets/Php/include-base3.php

@@ -0,0 +1,6 @@
+<?php
+return array(
+    'last' => array(
+        'bar' => 'baz',
+    ),
+);