Implement the conversion of XPath to NodeElement in CoreDriver

The goal is to ease the development of Mink 2.0 by allowing drivers to
be compatible with both Mink 1.7 and 2.0 on a single code base. The only
change required for drivers is now handled at the level of the
CoreDriver shipped in Mink when drivers should to override
findElementXpaths rather than find.

Author: stof

src/Driver/CoreDriver.php

@@ -10,6 +10,7 @@
 
 namespace Behat\Mink\Driver;
 
+use Behat\Mink\Element\NodeElement;
 use Behat\Mink\Exception\UnsupportedDriverActionException;
 use Behat\Mink\Session;
 
@@ -21,12 +22,17 @@
  */
 abstract class CoreDriver implements DriverInterface
 {
+    /**
+     * @var Session
+     */
+    private $session;
+
     /**
      * {@inheritdoc}
      */
     public function setSession(Session $session)
     {
-        throw new UnsupportedDriverActionException('Setting the session is not supported by %s', $this);
+        $this->session = $session;
     }
 
     /**
@@ -89,6 +95,28 @@ public function getContent()
      * {@inheritdoc}
      */
     public function find($xpath)
+    {
+        $elements = array();
+
+        foreach ($this->findElementXpaths($xpath) as $xpath) {
+            $elements[] = new NodeElement($xpath, $this->session);
+        }
+
+        return $elements;
+    }
+
+    /**
+     * Finds elements with specified XPath query.
+     *
+     * @see find()
+     *
+     * @param string $xpath
+     *
+     * @return string[] The XPath of the matched elements
+     *
+     * @throws UnsupportedDriverActionException When operation not supported by the driver
+     */
+    protected function findElementXpaths($xpath)
     {
         throw new UnsupportedDriverActionException('Finding elements is not supported by %s', $this);
     }

tests/Driver/CoreDriverTest.php

@@ -2,6 +2,8 @@
 
 namespace Behat\Mink\Tests\Driver;
 
+use Behat\Mink\Element\NodeElement;
+
 class CoreDriverTest extends \PHPUnit_Framework_TestCase
 {
     public function testNoExtraMethods()
@@ -17,6 +19,34 @@ public function testNoExtraMethods()
         }
     }
 
+    public function testCreateNodeElements()
+    {
+        $driver = $this->getMockBuilder('Behat\Mink\Driver\CoreDriver')
+            ->setMethods(array('findElementXpaths'))
+            ->getMockForAbstractClass();
+
+        $session = $this->getMockBuilder('Behat\Mink\Session')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $driver->setSession($session);
+
+        $driver->expects($this->once())
+            ->method('findElementXpaths')
+            ->with('xpath')
+            ->willReturn(array('xpath1', 'xpath2'));
+
+        /** @var NodeElement[] $elements */
+        $elements = $driver->find('xpath');
+
+        $this->assertInternalType('array', $elements);
+        $this->assertCount(2, $elements);
+        $this->assertContainsOnlyInstancesOf('Behat\Mink\Element\NodeElement', $elements);
+
+        $this->assertSame('xpath1', $elements[0]->getXpath());
+        $this->assertSame('xpath2', $elements[1]->getXpath());
+    }
+
     /**
      * @dataProvider getDriverInterfaceMethods
      */
@@ -29,6 +59,10 @@ public function testInterfaceMethods(\ReflectionMethod $method)
             sprintf('CoreDriver should implement a dummy %s method', $method->getName())
         );
 
+        if ('setSession' === $method->getName()) {
+            return; // setSession is actually implemented, so we don't expect an exception here.
+        }
+
         $driver = $this->getMockForAbstractClass('Behat\Mink\Driver\CoreDriver');
 
         $this->setExpectedException('Behat\Mink\Exception\UnsupportedDriverActionException');