MAGETWO-83171: Fix json encoded attribute backend type when attribute value is null #11947

Author: ishakhsuvarov

app/code/Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php

@@ -58,7 +58,7 @@ public function afterLoad($object)
     {
         parent::afterLoad($object);
         $attrCode = $this->getAttribute()->getAttributeCode();
-        $object->setData($attrCode, $this->jsonSerializer->unserialize($object->getData($attrCode)));
+        $object->setData($attrCode, $this->jsonSerializer->unserialize($object->getData($attrCode) ?: '{}'));
         return $this;
     }
 }

app/code/Magento/Eav/Test/Unit/Model/Entity/Attribute/Backend/JsonEncodedTest.php

@@ -95,4 +95,18 @@ public function testAfterLoad()
         $this->model->afterLoad($product);
         $this->assertEquals([1, 2, 3], $product->getData('json_encoded'));
     }
+
+    /**
+     * Test after load handler with null attribute value
+     */
+    public function testAfterLoadWithNullAttributeValue()
+    {
+        $product = new \Magento\Framework\DataObject(
+            [
+                'json_encoded' => null
+            ]
+        );
+        $this->model->afterLoad($product);
+        $this->assertEquals([], $product->getData('json_encoded'));
+    }
 }