Throw exception when extension isn't loaded

Author: tersmitten

Model/Datasource/RedisSource.php

@@ -63,12 +63,13 @@ class RedisSource extends DataSource {
  *
  * @param array $config Array of configuration information for the Datasource
  * @return bool True if connecting to the DataSource succeeds, else false
+ * @throws RedisSourceException
  */
 	public function __construct($config = array()) {
 		parent::__construct($config);
 
 		if (!$this->enabled()) {
-			return false;
+			throw new RedisSourceException(__d('redis', 'Extension is not loaded.'));
 		}
 
 		$this->_connection = new Redis();

Test/Case/Model/Datasource/RedisSourceTest.php

@@ -91,6 +91,7 @@ public function tearDown() {
  *
  *  Tests that `connect` will never be called when redis extension is not loaded.
  *
+ * @expectedException RedisSourceException
  * @return void
  */
 	public function testConstructExtensionNotLoaded() {