MAGETWO-63988: Remove usages of serialize/unserilize from Swatches module

Author: Mykola Palamar

app/code/Magento/Swatches/Test/Unit/Helper/DataTest.php

@@ -121,9 +121,19 @@ protected function setUp()
 
         $serializer = $this->getMock(
             \Magento\Framework\Serialize\Serializer\Json::class,
-            null
+            ['serialize', 'unserialize']
         );
 
+        $serializer->expects($this->any())
+            ->method('serialize')->willReturnCallback(function($parameter) {
+                return json_encode($parameter);
+            });
+
+        $serializer->expects($this->any())
+            ->method('unserialize')->willReturnCallback(function($parameter) {
+                return json_decode($parameter, true);
+            });
+
         $this->swatchHelperObject = $this->objectManager->getObject(
             \Magento\Swatches\Helper\Data::class,
             [

app/code/Magento/Swatches/Test/Unit/Model/Plugin/EavAttributeTest.php

@@ -80,9 +80,19 @@ protected function setUp()
 
         $serializer = $this->getMock(
             \Magento\Framework\Serialize\Serializer\Json::class,
-            null
+            ['serialize', 'unserialize']
         );
 
+        $serializer->expects($this->any())
+            ->method('serialize')->willReturnCallback(function($parameter) {
+                return json_encode($parameter);
+            });
+
+        $serializer->expects($this->any())
+            ->method('unserialize')->willReturnCallback(function($parameter) {
+                return json_decode($parameter, true);
+            });
+
         $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
         $this->eavAttribute = $objectManager->getObject(
             \Magento\Swatches\Model\Plugin\EavAttribute::class,