ISSUE-29690: Fixing issue when the images's order was using ID instead of position.

Author: viniciusbordinhao-blueacorn

app/code/Magento/ConfigurableProduct/Block/Plugin/Product/Media/Gallery.php

@@ -59,7 +59,7 @@ public function afterGetOptionsMediaGalleryDataJson(
     private function getProductGallery($product)
     {
         $result = [];
-        $images = $product->getMediaGalleryImages();
+        $images = $this->getImagesOrderedByPosition($product);
         foreach ($images as $image) {
             $result[] = [
                 'mediaType' => $image->getMediaType(),
@@ -69,4 +69,18 @@ private function getProductGallery($product)
         }
         return $result;
     }
+
+    /**
+     * @param Product $product
+     * @return array
+     */
+    private function getImagesOrderedByPosition($product)
+    {
+        $imagesCollection = $product->getMediaGalleryImages();
+        $images = $imagesCollection->getItems();
+        usort($images, function ($el1, $el2) {
+            return $el1['position'] <=> $el2['position'];
+        });
+        return $images;
+    }
 }

app/code/Magento/ConfigurableProduct/Test/Unit/Block/Plugin/Product/Media/GalleryTest.php

@@ -11,6 +11,7 @@
 use Magento\ConfigurableProduct\Block\Plugin\Product\Media\Gallery;
 use Magento\ConfigurableProduct\Model\Product\Type\Configurable;
 use Magento\Framework\DataObject;
+use Magento\Framework\Data\Collection as DataCollection;
 use Magento\Framework\Serialize\Serializer\Json;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use PHPUnit\Framework\MockObject\MockObject;
@@ -41,13 +42,20 @@ public function testAfterGetOptions()
             ['media_type' => 'type', 'video_url' => 'url', 'file' => 'image.jpg']
         );
 
+        $dataCollection = $this->getMockBuilder(DataCollection::class)
+            ->disableOriginalConstructor()
+            ->onlyMethods(['getItems'])
+            ->getMock();
+
+
         $galleryMock->expects(($this->any()))->method('getProduct')->willReturn($productMock);
         $productMock->expects($this->once())->method('getTypeId')->willReturn('configurable');
         $productMock->expects($this->once())->method('getTypeInstance')->willReturn($configurableTypeMock);
         $configurableTypeMock->expects($this->once())->method('getUsedProducts')->with($productMock)
             ->willReturn([$variationProductMock]);
         $variationProductMock->expects($this->once())->method('getId')->willReturn($variationProductId);
-        $variationProductMock->expects($this->once())->method('getMediaGalleryImages')->willReturn([$image]);
+        $variationProductMock->expects($this->once())->method('getMediaGalleryImages')->willReturn($dataCollection);
+        $dataCollection->expects($this->once())->method('getItems')->willReturn([$image]);
         $variationProductMock->expects($this->once())->method('getImage')->willReturn('image.jpg');
         $jsonMock->expects($this->once())->method('serialize')->with($expectedGalleryJson)
             ->willReturn(json_encode($expectedGalleryJson));