MAGETWO-70391: Return URL in getThumbnailUrl instead of nothing #10106

Author: Oleksii Korshenko

app/code/Magento/Catalog/Helper/Product.php

@@ -251,12 +251,18 @@ public function getSmallImageUrl($product)
      * Retrieve thumbnail image url
      *
      * @param ModelProduct|\Magento\Framework\DataObject $product
-     * @return string
-     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     * @return string|bool
      */
     public function getThumbnailUrl($product)
     {
-        return '';
+        $url = false;
+        $attribute = $product->getResource()->getAttribute('thumbnail');
+        if (!$product->getThumbnail()) {
+            $url = $this->_assetRepo->getUrl('Magento_Catalog::images/product/placeholder/thumbnail.jpg');
+        } elseif ($attribute) {
+            $url = $attribute->getFrontend()->getUrl($product);
+        }
+        return $url;
     }
 
     /**

dev/tests/integration/testsuite/Magento/Catalog/Helper/ProductTest.php

@@ -90,13 +90,13 @@ public function testGetSmallImageUrl()
 
     public function testGetThumbnailUrl()
     {
-        $this->assertEmpty(
-            $this->helper->getThumbnailUrl(
-                \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create(
-                    \Magento\Catalog\Model\Product::class
-                )
-            )
+        /** @var $product \Magento\Catalog\Model\Product */
+        $product = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create(
+            \Magento\Catalog\Model\Product::class
         );
+        $this->assertStringEndsWith('placeholder/thumbnail.jpg', $this->helper->getThumbnailUrl($product));
+        $product->setThumbnail('test_image.png');
+        $this->assertStringEndsWith('/test_image.png', $this->helper->getThumbnailUrl($product));
     }
 
     public function testGetEmailToFriendUrl()