Fixes after review

CHANGELOG-3.1.md

@@ -33,3 +33,6 @@ https://github.com/FriendsOfSymfony/FOSElasticaBundle/compare/v3.0.4...v3.1.0
    that property while transforming. Combined with the above POST_TRANSFORM event
    developers can now create calculated dynamic properties on Elastica documents
    for indexing. #794
+ * Added a `SliceFetcher` abstraction for Doctrine providers that get more
+   information about the previous slice allowing for optimising queries during
+   population. #725

Doctrine/AbstractProvider.php

@@ -10,8 +10,15 @@ use FOS\ElasticaBundle\Provider\IndexableInterface;
 
 abstract class AbstractProvider extends BaseAbstractProvider
 {
+    /**
+     * @var SliceFetcherInterface
+     */
+    private $sliceFetcher;
+
+    /**
+     * @var ManagerRegistry
+     */
     protected $managerRegistry;
-    protected $sliceFetcher;
 
     /**
      * Constructor.

Tests/Doctrine/AbstractProviderTest.php

@@ -178,14 +178,14 @@ class AbstractProviderTest extends \PHPUnit_Framework_TestCase
         $nbObjects = 1;
         $objects = array(1);
 
-        $provider = $this->getMockAbstractProvider();
+        $provider = $this->getMockAbstractProvider(true);
 
         $provider->expects($this->any())
             ->method('countObjects')
             ->will($this->returnValue($nbObjects));
 
-        $provider->expects($this->any())
+        $this->sliceFetcher->expects($this->any())
-            ->method('fetchSlice')
+            ->method('fetch')
             ->will($this->returnValue($objects));
 
         $this->indexable->expects($this->any())