MAGETWO-62134: Create data converter that can process nested serialized data

Resolving code review feedback

app/code/Magento/Tax/Model/Quote/GrandTotalDetailsPlugin.php

@@ -14,27 +14,27 @@ class GrandTotalDetailsPlugin
     /**
      * @var \Magento\Tax\Api\Data\GrandTotalDetailsInterfaceFactory
      */
-    protected $detailsFactory;
+    private $detailsFactory;
 
     /**
      * @var \Magento\Tax\Api\Data\GrandTotalRatesInterfaceFactory
      */
-    protected $ratesFactory;
+    private $ratesFactory;
 
     /**
      * @var TotalSegmentExtensionFactory
      */
-    protected $totalSegmentExtensionFactory;
+    private $totalSegmentExtensionFactory;
 
     /**
      * @var \Magento\Tax\Model\Config
      */
-    protected $taxConfig;
+    private $taxConfig;
 
     /**
      * @var string
      */
-    protected $code;
+    private $code;
 
     /**
      * @var Json
@@ -42,6 +42,8 @@ class GrandTotalDetailsPlugin
     private $serializer;
 
     /**
+     * Constructor
+     *
      * @param \Magento\Tax\Api\Data\GrandTotalDetailsInterfaceFactory $detailsFactory
      * @param \Magento\Tax\Api\Data\GrandTotalRatesInterfaceFactory $ratesFactory
      * @param TotalSegmentExtensionFactory $totalSegmentExtensionFactory
@@ -53,14 +55,14 @@ class GrandTotalDetailsPlugin
         \Magento\Tax\Api\Data\GrandTotalRatesInterfaceFactory $ratesFactory,
         TotalSegmentExtensionFactory $totalSegmentExtensionFactory,
         \Magento\Tax\Model\Config $taxConfig,
-        Json $serializer = null
+        Json $serializer
     ) {
         $this->detailsFactory = $detailsFactory;
         $this->ratesFactory = $ratesFactory;
         $this->totalSegmentExtensionFactory = $totalSegmentExtensionFactory;
         $this->taxConfig = $taxConfig;
+        $this->serializer = $serializer;
         $this->code = 'tax';
-        $this->serializer = $serializer ?: ObjectManager::getInstance()->get(Json::class);
     }
 
     /**
@@ -83,7 +85,6 @@ class GrandTotalDetailsPlugin
      * @param \Magento\Quote\Model\Cart\TotalsConverter $subject
      * @param \Magento\Quote\Api\Data\TotalSegmentInterface[] $totalSegments
      * @param \Magento\Quote\Model\Quote\Address\Total[] $addressTotals
-     *
      * @return \Magento\Quote\Api\Data\TotalSegmentInterface[]
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)

dev/tests/integration/testsuite/Magento/GroupedProduct/Model/Product/Type/GroupedTest.php

@@ -82,10 +82,9 @@ class GroupedTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
+     * @magentoDataFixture Magento/GroupedProduct/_files/product_grouped.php
      * @magentoAppIsolation enabled
      * @magentoDbIsolation disabled
-     * @covers \Magento\GroupedProduct\Model\Product\Type\Grouped::_prepareProduct()
-     * @magentoDataFixture Magento/GroupedProduct/_files/product_grouped.php
      */
     public function testPrepareProduct()
     {

dev/tests/integration/testsuite/Magento/Sales/Model/AdminOrder/CreateTest.php

@@ -508,9 +508,9 @@ class CreateTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
-     * @magentoAppIsolation enabled
      * @magentoDataFixture Magento/Sales/_files/quote.php
      * @magentoDataFixture Magento/Customer/_files/customer.php
+     * @magentoAppIsolation enabled
      */
     public function testGetCustomerCartExistingCart()
     {
@@ -535,10 +535,9 @@ class CreateTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
-     * @covers \Magento\Sales\Model\AdminOrder\Create::moveQuoteItem()
-     * @magentoAppIsolation enabled
      * @magentoDataFixture Magento/Sales/_files/quote.php
      * @magentoDataFixture Magento/Customer/_files/customer.php
+     * @magentoAppIsolation enabled
      */
     public function testMoveQuoteItemToCart()
     {

dev/tests/integration/testsuite/Magento/Sales/Model/Order/ItemTest.php

@@ -12,10 +12,9 @@ namespace Magento\Sales\Model\Order;
 class ItemTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @covers \Magento\Sales\Model\Order\Item::getProductOptions
-     * @dataProvider getProductOptionsDataProvider
      * @param string $options
      * @param array $expectedData
+     * @dataProvider getProductOptionsDataProvider
      */
     public function testGetProductOptions($options, $expectedData)
     {

dev/tests/integration/testsuite/Magento/Wishlist/Model/ItemTest.php

@@ -31,11 +31,9 @@ class ItemTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
+     * @magentoDataFixture Magento/Catalog/_files/product_simple.php
      * @magentoAppIsolation enabled
      * @magentoDbIsolation enabled
-     * @magentoDataFixture Magento/Catalog/_files/product_simple.php
-     * @covers \Magento\Wishlist\Model\Item::getBuyRequest()
-     * @covers \Magento\Wishlist\Model\Item::mergeBuyRequest()
      */
     public function testBuyRequest()
     {
@@ -64,9 +62,6 @@ class ItemTest extends \PHPUnit_Framework_TestCase
         );
     }
 
-    /**
-     * @covers \Magento\Wishlist\Model\Item::setBuyRequest()
-     */
     public function testSetBuyRequest()
     {
         $buyRequest = $this->objectManager->create(