MAGETWO-36908: Stock Items API service to return low stock information does not return the correct results

Author: Yaroslav Onischenko

app/code/Magento/CatalogInventory/Model/StockRegistry.php

@@ -172,7 +172,7 @@ public function getLowStockItems($websiteId, $qty, $currentPage = 1, $pageSize =
         $criteria = $this->criteriaFactory->create();
         $criteria->setLimit($currentPage, $pageSize);
         $criteria->setWebsiteFilter($websiteId);
-        $criteria->setQtyFilter('>=', $qty);
+        $criteria->setQtyFilter('<=', $qty);
         $criteria->addField('qty');
         return $this->stockItemRepository->getList($criteria);
     }

app/code/Magento/CatalogInventory/Test/Unit/Model/StockRegistryTest.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * Copyright © 2015 Magento. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\CatalogInventory\Test\Unit\Model;
+
+/**
+ * Class StockRegistryTest
+ */
+class StockRegistryTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var \Magento\CatalogInventory\Model\StockRegistry
+     */
+    protected $model;
+
+    /**
+     * @var \PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $criteria;
+
+    public function setUp()
+    {
+        $this->criteria = $this->getMockBuilder('Magento\CatalogInventory\Api\StockItemCriteriaInterface')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $criteriaFactory = $this->getMockBuilder('Magento\CatalogInventory\Api\StockItemCriteriaInterfaceFactory')
+            ->disableOriginalConstructor()
+            ->getMock();
+        $criteriaFactory->expects($this->once())->method('create')->willReturn($this->criteria);
+
+        $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $this->model = $objectManager->getObject(
+            'Magento\CatalogInventory\Model\StockRegistry',
+            [
+                'criteriaFactory' => $criteriaFactory
+            ]
+        );
+    }
+
+    public function testGetLowStockItems()
+    {
+        $this->criteria->expects($this->once())->method('setLimit')->with(1, 0);
+        $this->criteria->expects($this->once())->method('setWebsiteFilter')->with(1);
+        $this->criteria->expects($this->once())->method('setQtyFilter')->with('<=');
+        $this->criteria->expects($this->once())->method('addField')->with('qty');
+        $this->model->getLowStockItems(1, 100);
+    }
+}