MAGETWO-54283: ProductsList widget should implement IdentityInterface and return correct identities

Author: mslabko

app/code/Magento/CatalogWidget/Block/Product/ProductsList.php

@@ -81,9 +81,6 @@ class ProductsList extends \Magento\Catalog\Block\Product\AbstractProduct implem
      */
     protected $conditionsHelper;
 
-    /** @var array */
-    private $widgetIdentities;
-
     /**
      * @param \Magento\Catalog\Block\Product\Context $context
      * @param \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory
@@ -333,19 +330,16 @@ public function getPagerHtml()
      */
     public function getIdentities()
     {
-        if ($this->widgetIdentities === null) {
-            $collection = $this->productCollectionFactory->create();
-            $conditions = $this->getConditions();
-            $conditions->collectValidatedAttributes($collection);
-            $this->sqlBuilder->attachConditionToCollection($collection, $conditions);
-            $this->widgetIdentities = [];
-            foreach ($collection as $product) {
-                $this->widgetIdentities[] = \Magento\Catalog\Model\Product::CACHE_TAG . '_' . $product->getId();
+        $identities = [];
+        if ($this->getProductCollection()) {
+            foreach ($this->getProductCollection() as $product) {
+                if ($product instanceof IdentityInterface) {
+                    $identities = array_merge($identities, $product->getIdentities());
+                }
             }
-            $this->widgetIdentities = $this->widgetIdentities ?: [\Magento\Catalog\Model\Product::CACHE_TAG];
         }
 
-        return $this->widgetIdentities;
+        return $identities?: [\Magento\Catalog\Model\Product::CACHE_TAG];
     }
 
     /**

app/code/Magento/CatalogWidget/Test/Unit/Block/Product/ProductsListTest.php

@@ -329,18 +329,16 @@ public function testGetIdentities()
             ])->disableOriginalConstructor()
             ->getMock();
 
-        $this->collectionFactory->expects($this->once())->method('create')->willReturn($collection);
-        $this->productsList->setData('conditions_encoded', 'some_serialized_conditions');
-
-        $this->builder->expects($this->once())->method('attachConditionToCollection')
-            ->with($collection, $this->getConditionsForCollection($collection))
-            ->willReturnSelf();
-        $product = $this->getMock('Magento\Catalog\Api\ProductInterface', ['getId']);
-        $product->expects($this->once())->method('getId')->willReturn('product_id');
-        $collection->expects($this->once())->method('getIterator')->willReturn(new \ArrayIterator([$product]));
+        $product = $this->getMock('Magento\Framework\DataObject\IdentityInterface', ['getIdentities']);
+        $notProduct = $this->getMock('NotProduct', ['getIdentities']);
+        $product->expects($this->once())->method('getIdentities')->willReturn(['product_identity']);
+        $collection->expects($this->once())->method('getIterator')->willReturn(
+            new \ArrayIterator([$product, $notProduct])
+        );
+        $this->productsList->setData('product_collection', $collection);
 
         $this->assertEquals(
-            [\Magento\Catalog\Model\Product::CACHE_TAG . '_' . 'product_id'],
+            ['product_identity'],
             $this->productsList->getIdentities()
         );
     }