Defaulting missing alt-text for a product to use the product name.

app/code/Magento/Catalog/Block/Product/View/Gallery.php

@@ -116,7 +116,7 @@ public function getGalleryImagesJson()
                 'thumb' => $image->getData('small_image_url'),
                 'img' => $image->getData('medium_image_url'),
                 'full' => $image->getData('large_image_url'),
-                'caption' => $image->getLabel(),
+                'caption' => ($image->getLabel() ?: $this->getProduct()->getName()),
                 'position' => $image->getPosition(),
                 'isMain' => $this->isMainImage($image),
                 'type' => str_replace('external-', '', $image->getMediaType()),

app/code/Magento/Catalog/Test/Unit/Block/Product/View/GalleryTest.php

@@ -77,6 +77,85 @@ protected function mockContext()
             ->willReturn($this->registry);
     }
 
+    public function testGetGalleryImagesJsonWithLabel()
+    {
+        $this->prepareGetGalleryImagesJsonMocks();
+        $json = $this->model->getGalleryImagesJson();
+        $decodedJson = json_decode($json, true);
+        $this->assertEquals('product_page_image_small_url', $decodedJson[0]['thumb']);
+        $this->assertEquals('product_page_image_medium_url', $decodedJson[0]['img']);
+        $this->assertEquals('product_page_image_large_url', $decodedJson[0]['full']);
+        $this->assertEquals('test_label', $decodedJson[0]['caption']);
+        $this->assertEquals('2', $decodedJson[0]['position']);
+        $this->assertEquals(false, $decodedJson[0]['isMain']);
+        $this->assertEquals('test_media_type', $decodedJson[0]['type']);
+        $this->assertEquals('test_video_url', $decodedJson[0]['videoUrl']);
+    }
+
+    public function testGetGalleryImagesJsonWithoutLabel()
+    {
+        $this->prepareGetGalleryImagesJsonMocks(false);
+        $json = $this->model->getGalleryImagesJson();
+        $decodedJson = json_decode($json, true);
+        $this->assertEquals('test_product_name', $decodedJson[0]['caption']);
+    }
+
+    private function prepareGetGalleryImagesJsonMocks($hasLabel = true)
+    {
+        $storeMock = $this->getMockBuilder(\Magento\Store\Model\Store::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $productMock = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $productTypeMock = $this->getMockBuilder(\Magento\Catalog\Model\Product\Type\AbstractType::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $productTypeMock->expects($this->any())
+            ->method('getStoreFilter')
+            ->with($productMock)
+            ->willReturn($storeMock);
+
+        $productMock->expects($this->any())
+            ->method('getTypeInstance')
+            ->willReturn($productTypeMock);
+        $productMock->expects($this->any())
+            ->method('getMediaGalleryImages')
+            ->willReturn($this->getImagesCollectionWithPopulatedDataObject($hasLabel));
+        $productMock->expects($this->any())
+            ->method('getName')
+            ->willReturn('test_product_name');
+
+        $this->registry->expects($this->any())
+            ->method('registry')
+            ->with('product')
+            ->willReturn($productMock);
+
+        $this->imageHelper->expects($this->any())
+            ->method('init')
+            ->willReturnMap([
+                [$productMock, 'product_page_image_small', [], $this->imageHelper],
+                [$productMock, 'product_page_image_medium_no_frame', [], $this->imageHelper],
+                [$productMock, 'product_page_image_large_no_frame', [], $this->imageHelper],
+            ])
+            ->willReturnSelf();
+        $this->imageHelper->expects($this->any())
+            ->method('setImageFile')
+            ->with('test_file')
+            ->willReturnSelf();
+        $this->imageHelper->expects($this->at(2))
+            ->method('getUrl')
+            ->willReturn('product_page_image_small_url');
+        $this->imageHelper->expects($this->at(5))
+            ->method('getUrl')
+            ->willReturn('product_page_image_medium_url');
+        $this->imageHelper->expects($this->at(8))
+            ->method('getUrl')
+            ->willReturn('product_page_image_large_url');
+    }
+
     public function testGetGalleryImages()
     {
         $storeMock = $this->getMockBuilder(\Magento\Store\Model\Store::class)
@@ -154,4 +233,30 @@ private function getImagesCollection()
 
         return $collectionMock;
     }
+
+    /**
+     * @return \Magento\Framework\Data\Collection
+     */
+    private function getImagesCollectionWithPopulatedDataObject($hasLabel)
+    {
+        $collectionMock = $this->getMockBuilder(\Magento\Framework\Data\Collection::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $items = [
+            new \Magento\Framework\DataObject([
+                'file' => 'test_file',
+                'label' => ($hasLabel ? 'test_label' : ''),
+                'position' => '2',
+                'media_type' => 'external-test_media_type',
+                "video_url" => 'test_video_url'
+            ]),
+        ];
+
+        $collectionMock->expects($this->any())
+            ->method('getIterator')
+            ->willReturn(new \ArrayIterator($items));
+
+        return $collectionMock;
+    }
 }